Merge pull request #62 from HueByte/dev_logs_room

Dev logs room

.env.example

@@ -6,8 +6,17 @@
 Server__Name=My EchoHub Server
 Server__Description=A self-hosted EchoHub chat server
 Server__PublicServer=false
-# Server__PublicHost=echohub.example.com
+# Registration mode: open (default), invite (codes via /invite, Admin+), or closed.
+# Server__Registration=open
+# Hostnames advertised to the EchoHubSpace directory. Index per entry.
+# Server__PublicHosts__0=echohub.example.com
+# Server__PublicHosts__1=alias.example.com
+# Topic tags surfaced in the EchoHubSpace browser. Index per entry.
+# Server__Tags__0=community
+# Server__Tags__1=gaming
 # Server__Admins__0=adminUsername
+# Override where the EchoHubSpace claim token file is stored (defaults next to the DB).
+# Server__DirectoryClaimPath=
 
 # ── JWT ──────────────────────────────────────────────────────────────
 # Auto-generated on first run if left empty. Only set if you need a stable secret across containers.
@@ -22,9 +31,32 @@ Server__PublicServer=false
 
 # ── Storage ──────────────────────────────────────────────────────────
 # Defaults are set in the Dockerfile to use /app/data for persistence.
+# Storage__Path=
 # Storage__CleanupIntervalHours=1
 # Storage__RetentionDays=30
 
+# ── Uploads ──────────────────────────────────────────────────────────
+# Uploads__MaxFileSizeMB=100
+# Uploads__MaxImageSizeMB=10
+# Uploads__MaxAudioSizeMB=10
+# Uploads__MaxAvatarSizeMB=2
+# Uploads__MaxAttachmentsPerMessage=10
+
+# ── Spam protection ──────────────────────────────────────────────────
+# Per-user flood/duplicate limits with auto-mute escalation; Mods and above are exempt.
+# Spam__Enabled=true
+# Spam__MaxMessagesPerWindow=8
+# Spam__WindowSeconds=5
+# Spam__MaxDuplicateMessages=3
+# Spam__AutoMuteMinutes=5
+# Spam__ViolationThreshold=5
+# Spam__ViolationWindowMinutes=5
+# Only first-time channel joins count — keep this above your public channel count.
+# Spam__MaxJoinsPerWindow=25
+# Spam__JoinWindowSeconds=30
+# Spam__MaxChannelCreatesPerWindow=3
+# Spam__ChannelCreateWindowMinutes=10
+
 # ── IRC Gateway ──────────────────────────────────────────────────────
 Irc__Enabled=false
 # Irc__Port=6667
@@ -34,6 +66,12 @@ Irc__Enabled=false
 # Irc__TlsCertPassword=
 # Irc__ServerName=echohub
 # Irc__Motd=Welcome to EchoHub IRC Gateway!
+# Public base URL used to make attachment links absolute for IRC clients.
+# Irc__PublicBaseUrl=https://chat.example.com
+
+# ── CORS ─────────────────────────────────────────────────────────────
+# Leave unset to allow all origins. Index per entry to whitelist.
+# Cors__AllowedOrigins__0=https://chat.example.com
 
 # ── Logging ──────────────────────────────────────────────────────────
 # Serilog__MinimumLevel__Default=Information

.github/workflows/ci.yml

@@ -14,6 +14,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          cache: npm
+
+      - name: Install pinned linter
+        run: npm ci
+
       - name: Run markdownlint
         run: bash scripts/lint-markdown.sh
 
@@ -33,6 +42,8 @@ jobs:
 
   build-and-test:
     name: Build & Test
+    # Run the cheap, fast checks first; only spend build/test compute if they pass.
+    needs: [format-check, lint-markdown]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4

.github/workflows/docker.yml

@@ -1,7 +1,11 @@
 name: Docker
 
+# Runs only after the CI workflow completes, so an image is never pushed for a commit
+# whose formatting, lint, build, or tests failed.
 on:
-  push:
+  workflow_run:
+    workflows: ["CI"]
+    types: [completed]
     branches: [master]
   workflow_dispatch:
 
@@ -15,23 +19,29 @@ env:
 jobs:
   docker:
     name: Build & Push Docker Image
+    # Proceed only for a successful CI run on a master push, or a manual dispatch.
+    if: >-
+      github.event_name == 'workflow_dispatch' ||
+      (github.event.workflow_run.conclusion == 'success' &&
+       github.event.workflow_run.event == 'push' &&
+       github.event.workflow_run.head_branch == 'master')
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
+          # The exact commit CI tested (workflow_run), or the current tip (manual dispatch).
+          ref: ${{ github.event.workflow_run.head_sha || github.sha }}
 
       - name: Check for src/ changes
         id: changes
-        env:
-          BEFORE: ${{ github.event.before }}
         run: |
-          if [ -z "$BEFORE" ] || [ "$BEFORE" = "0000000000000000000000000000000000000000" ]; then
+          if git rev-parse HEAD~1 >/dev/null 2>&1; then
-            echo "src_changed=true" >> "$GITHUB_OUTPUT"
+            CHANGED=$(git diff --name-only HEAD~1 HEAD -- 'src/' | wc -l)
           else
-            CHANGED=$(git diff --name-only "$BEFORE" HEAD -- 'src/' | wc -l)
+            CHANGED=1
-            [ "$CHANGED" -gt 0 ] && echo "src_changed=true" >> "$GITHUB_OUTPUT" || echo "src_changed=false" >> "$GITHUB_OUTPUT"
           fi
+          [ "$CHANGED" -gt 0 ] && echo "src_changed=true" >> "$GITHUB_OUTPUT" || echo "src_changed=false" >> "$GITHUB_OUTPUT"
 
       - name: Read version
         if: steps.changes.outputs.src_changed == 'true'

.github/workflows/release-checklist.yml

@@ -0,0 +1,60 @@
+name: Release Checklist
+
+on:
+  pull_request:
+    branches: [master]
+  workflow_dispatch:
+
+jobs:
+  release-checklist:
+    name: Release Checklist
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Extract version
+        id: version
+        run: |
+          VERSION=$(grep -oP '(?<=<Version>)[^<]+' src/Directory.Build.props)
+          if [ -z "$VERSION" ]; then
+            echo "::error file=src/Directory.Build.props::Could not read version from Directory.Build.props"
+            exit 1
+          fi
+          echo "version=$VERSION" >> "$GITHUB_OUTPUT"
+          echo "Version: $VERSION"
+
+      - name: Check version was bumped from master
+        run: |
+          BRANCH_VERSION="${{ steps.version.outputs.version }}"
+          git fetch origin master --depth=1
+          MASTER_VERSION=$(git show origin/master:src/Directory.Build.props | grep -oP '(?<=<Version>)[^<]+')
+          echo "Branch: $BRANCH_VERSION | Master: $MASTER_VERSION"
+          if [ "$BRANCH_VERSION" = "$MASTER_VERSION" ]; then
+            echo "::error file=src/Directory.Build.props::Version $BRANCH_VERSION was not bumped from master. Update <Version> in src/Directory.Build.props."
+            exit 1
+          fi
+
+      - name: Check changelog file exists
+        run: |
+          VERSION="${{ steps.version.outputs.version }}"
+          FILE="docs/changelog/v${VERSION}.md"
+          if [ ! -f "$FILE" ]; then
+            echo "::error::Missing changelog file: $FILE"
+            exit 1
+          fi
+          echo "Found: $FILE"
+
+      - name: Check changelog TOC
+        run: |
+          VERSION="${{ steps.version.outputs.version }}"
+          if ! grep -q "v${VERSION}.md" docs/changelog/toc.yml; then
+            echo "::error file=docs/changelog/toc.yml::v${VERSION} not found in changelog TOC. Add it to docs/changelog/toc.yml."
+            exit 1
+          fi
+          if ! grep -q "v${VERSION}" docs/changelog/index.md; then
+            echo "::error file=docs/changelog/index.md::v${VERSION} not found in changelog index. Add it to docs/changelog/index.md."
+            exit 1
+          fi
+          echo "toc.yml and index.md: OK"

.github/workflows/release.yml

@@ -1,7 +1,11 @@
 name: Release
 
+# Runs only after the CI workflow completes, so a release is never published on a commit
+# whose formatting, lint, build, or tests failed.
 on:
-  push:
+  workflow_run:
+    workflows: ["CI"]
+    types: [completed]
     branches: [master]
   workflow_dispatch:
 
@@ -11,6 +15,12 @@ permissions:
 jobs:
   release:
     name: Create Release
+    # Proceed only for a successful CI run on a master push, or a manual dispatch.
+    if: >-
+      github.event_name == 'workflow_dispatch' ||
+      (github.event.workflow_run.conclusion == 'success' &&
+       github.event.workflow_run.event == 'push' &&
+       github.event.workflow_run.head_branch == 'master')
     runs-on: ubuntu-latest
     outputs:
       should_release: ${{ steps.changes.outputs.src_changed == 'true' && steps.check_release.outputs.exists == 'false' }}
@@ -21,18 +31,18 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
+          # The exact commit CI tested (workflow_run), or the current tip (manual dispatch).
+          ref: ${{ github.event.workflow_run.head_sha || github.sha }}
 
       - name: Check for src/ changes
         id: changes
-        env:
-          BEFORE: ${{ github.event.before }}
         run: |
-          if [ -z "$BEFORE" ] || [ "$BEFORE" = "0000000000000000000000000000000000000000" ]; then
+          if git rev-parse HEAD~1 >/dev/null 2>&1; then
-            echo "src_changed=true" >> "$GITHUB_OUTPUT"
+            CHANGED=$(git diff --name-only HEAD~1 HEAD -- 'src/' | wc -l)
           else
-            CHANGED=$(git diff --name-only "$BEFORE" HEAD -- 'src/' | wc -l)
+            CHANGED=1
-            [ "$CHANGED" -gt 0 ] && echo "src_changed=true" >> "$GITHUB_OUTPUT" || echo "src_changed=false" >> "$GITHUB_OUTPUT"
           fi
+          [ "$CHANGED" -gt 0 ] && echo "src_changed=true" >> "$GITHUB_OUTPUT" || echo "src_changed=false" >> "$GITHUB_OUTPUT"
 
       - name: Read version
         id: version

README.md

@@ -84,10 +84,12 @@ graph TD
 - **JWT auth** with short-lived access tokens and 30-day refresh tokens
 - **Channels** — create, set topics, delete (no 47-step permission wizard required)
 - **Moderation** — ban, mute (timed or permanent), kick, role assignment
+- **Registration control** — open, invite-code-gated (`/invite`), or closed; codes live in your own database
 - **File & image uploads** with actual validation (magic bytes, not just trusting the extension)
 - **Image-to-ASCII** — because images in a terminal is objectively cool
 - **Presence tracking** — online/away/DND/invisible with custom status messages
 - **Rate limiting** — in case someone gets too excited
+- **Spam protection** — per-user flood/duplicate limits with auto-mute escalation, covering TUI and IRC alike; configurable under `Spam`, Mods exempt
 - **Auto-restart** on crash with exponential backoff — it picks itself back up
 - **Serilog logging** — console + rolling file, because `Console.WriteLine` isn't a logging strategy
 - **Zero config first run** — generates its own JWT secret and config on launch
@@ -95,11 +97,14 @@ graph TD
 ### Client
 
 - **Runs in your terminal** — no browser, no Electron, no 500MB of bundled Chromium
-- **13 built-in themes** — including `hacker` for when you want to feel like you're in a movie
+- **14 built-in themes** — including `hacker` for when you want to feel like you're in a movie
 - **Slash commands** — `/join`, `/send`, `/status`, `/theme`, etc.
 - **Colored nicknames** — pick your hex color, express yourself
 - **Clickable everything** — usernames, @mentions, #channels — just press Enter
-- **File/image sharing** — local files or URLs
+- **File/image sharing** — local files or URLs; drag & drop a file onto the terminal to send it; save the original behind any ASCII-art image
+- **End-to-end encrypted rooms** — password-protected channels are encrypted with a passphrase-derived key that never reaches the server, so not even the server owner can read messages or files (they can still see counts and storage size)
+- **Replies** — quote a message, jump back to the original; being replied to pings like a mention
+- **Your data is yours** — `/export` everything the server holds about you; `/deleteaccount` removes it
 - **Multi-server** — save and switch between servers
 - **Auto-reconnect** — drops happen, it rejoins your channels automatically
 - **Auto-updater** — updates in-place with automatic rollback if something goes wrong
@@ -197,6 +202,8 @@ Auth works via `PASS`/`NICK`/`USER` or SASL PLAIN. New usernames are auto-regist
 | Feature | How it maps to IRC |
 | ------- | ------------------ |
 | Text messages | Standard `PRIVMSG` (long messages split at ~400 byte chunks) |
+| `/me` actions | Native CTCP ACTION in both directions |
+| Replies | TUI replies arrive as `> nick: snippet \| text` |
 | Images | `[Image: filename]` + download URL + ASCII art line-by-line |
 | File uploads | `[File: filename] /api/files/{id}` |
 | Channels | `JOIN`, `PART`, `NAMES`, `TOPIC`, `LIST` |
@@ -224,21 +231,31 @@ For direct TLS without a reverse proxy, the IRC gateway can terminate TLS itself
 
 | Command | Description |
 | ------- | ----------- |
-| `/join <channel>` | Join a channel |
+| `/join <channel> [password]` | Join a channel (passphrase for encrypted channels) |
+| `/me <action>` | Action message — `* nick waves` (native CTCP ACTION over IRC) |
+| `/banner <text>` | Render short text as a big ASCII banner |
+| `/passwd <old> <new>` | Change the current encrypted channel's passphrase (creator only) |
+| `/size [s\|m\|l]` | ASCII-art size for attached images (no arg = picker) |
+| `/downloadpath [path]` | Set the download folder (no path = native folder picker) |
 | `/leave` | Leave current channel |
 | `/topic <text>` | Set channel topic (creator only) |
 | `/send <file or URL>` | Upload a file or image |
 | `/status <online\|away\|dnd\|invisible>` | Set your status |
-| `/status <message>` | Set a status message |
+| `/status msg <text>` | Set a status message (keeps your status; empty text clears it) |
 | `/nick <name>` | Set display name |
 | `/color <#hex>` | Set nickname color |
 | `/theme <name>` | Switch theme |
 | `/profile` | Open profile editor |
 | `/users` | List online users in channel |
 | `/servers` | Manage saved servers |
+| `/invite [uses] [hours]` | Create a registration invite code (Admin+); also `list` / `revoke <code>` |
+| `/export` | Download everything the server stores about you as JSON |
+| `/deleteaccount` | Permanently delete your account (password re-confirmed) |
 | `/help` | Show help |
 | `/quit` | Exit |
 
+**Message actions:** **right-click a message** for a context menu — reply (quotes the message; Esc cancels a pending reply), delete, save/download/play its attachment, mention the sender, view their profile, or copy the text. (Keyboard alternative: press <kbd>F6</kbd> to focus the message list, select with the arrow keys, and press <kbd>Delete</kbd>; <kbd>F6</kbd> again returns to the input.) You can always delete your own messages; moderators and above can delete others' messages, but only from users below their own role.
+
 ## Themes
 
 `/theme <name>` to switch:
@@ -247,6 +264,7 @@ For direct TLS without a reverse proxy, the IRC gateway can terminate TLS itself
 | ----- | ---- |
 | `default` | Gray on black — clean and quiet |
 | `transparent` | White on black — for fancy transparent terminals |
+| `transparentlight` | Black on transparent — dark characters for light transparent terminals |
 | `classic` | White on blue — IRC nostalgia |
 | `light` | Black on white — for the brave |
 | `hacker` | Green on black — *I'm in* |
@@ -270,6 +288,7 @@ For direct TLS without a reverse proxy, the IRC gateway can terminate TLS itself
 | `Jwt:Secret` | *(auto-generated)* | JWT signing key |
 | `Server:Name` | `My EchoHub Server` | Server display name |
 | `Server:Description` | `A self-hosted EchoHub chat server` | Server description |
+| `Server:Registration` | `open` | `open`, `invite` (codes via `/invite`, Admin+), or `closed` |
 | `Server:PublicServer` | `false` | List on the [public directory](https://echohub.voidcube.cloud/servers) |
 | `Server:PublicHost` | *(empty)* | Public hostname for directory listing |
 | `Irc:Enabled` | `false` | Enable the IRC gateway |

docs/articles/architecture.md

@@ -52,7 +52,7 @@ Terminal.Gui v2 TUI application:
 
 - **UI**: Main window, dialogs, chat renderer with ANSI color support
 - **Services**: API client with automatic token refresh, SignalR connection wrapper, audio playback (NetCoreAudio), automatic update checker (AlwaysUpToDate)
-- **Themes**: 13 built-in color themes (including transparent theme with true terminal transparency)
+- **Themes**: 14 built-in color themes (including transparent dark/light themes with true terminal transparency)
 - **Config**: Client configuration management with session persistence ("Remember Me" refresh tokens)
 
 ## Communication

docs/articles/configuration.md

@@ -98,8 +98,48 @@ Access tokens expire after 15 minutes, refresh tokens after 30 days with rotatio
 | `Server:Name` | `My EchoHub Server` | Display name shown to clients |
 | `Server:Description` | `A self-hosted EchoHub chat server` | Server description |
 | `Server:PublicServer` | `false` | Register on the [public directory](https://echohub.voidcube.cloud/servers) |
-| `Server:PublicHost` | *(empty)* | Public hostname for the directory listing (e.g. `chat.example.com:5000`) |
+| `Server:PublicHosts` | `[]` | Hostnames advertised to the directory (array, e.g. `["chat.example.com"]`). Required when `PublicServer` is `true` |
+| `Server:Tags` | `[]` | Topic tags surfaced in the directory browser (array, e.g. `["community", "gaming"]`) |
 | `Server:Admins` | `[]` | Array of admin usernames (e.g. `["alice", "bob"]`) |
+| `Server:Registration` | `open` | Registration mode: `open`, `invite` (codes via `/invite`, Admin+), or `closed` |
+| `Server:DirectoryClaimPath` | *(empty)* | Overrides where the directory claim token file is stored. Empty = `directory-claim.json` next to the SQLite database. Treat it as a secret and back it up with the database |
+
+### Uploads
+
+Per-attachment size limits by kind (in megabytes) and the per-message attachment cap. An
+absent or partial `Uploads` section keeps the built-in defaults. See
+[Messages & Attachments](messages-and-attachments.md) for how kinds are detected.
+
+| Key | Default | Description |
+| --- | --- | --- |
+| `Uploads:MaxImageSizeMB` | `10` | Max size for one image attachment |
+| `Uploads:MaxAudioSizeMB` | `10` | Max size for one audio attachment |
+| `Uploads:MaxFileSizeMB` | `100` | Max size for any other attachment |
+| `Uploads:MaxAvatarSizeMB` | `2` | Max avatar upload size |
+| `Uploads:MaxAttachmentsPerMessage` | `10` | Attachments allowed on a single message |
+
+The server sizes its request-body limits from these values, so raising a limit here is all
+that's needed — no separate Kestrel tuning.
+
+### Spam Protection
+
+Per-user flood, duplicate, join, and channel-create limits with auto-mute escalation. Mods and
+above are always exempt, and the defaults are lenient enough that a fast typist never trips them.
+An absent or partial `Spam` section keeps these defaults.
+
+| Key | Default | Description |
+| --- | --- | --- |
+| `Spam:Enabled` | `true` | Master switch for all spam protection |
+| `Spam:MaxMessagesPerWindow` | `8` | Max messages per `WindowSeconds` before a send is rejected |
+| `Spam:WindowSeconds` | `5` | Sliding window (seconds) for the message-rate check |
+| `Spam:MaxDuplicateMessages` | `3` | Identical messages in a row tolerated before rejection (E2E rooms are exempt — ciphertext differs each time) |
+| `Spam:AutoMuteMinutes` | `5` | Auto-mute duration once a user hits the violation threshold. `0` disables auto-mute (rejections still apply) |
+| `Spam:ViolationThreshold` | `5` | Rejected sends within `ViolationWindowMinutes` that trigger an auto-mute |
+| `Spam:ViolationWindowMinutes` | `5` | Window (minutes) over which violations accumulate |
+| `Spam:MaxJoinsPerWindow` | `25` | Max first-time channel joins per `JoinWindowSeconds` — keep this above your public channel count |
+| `Spam:JoinWindowSeconds` | `30` | Sliding window (seconds) for the join-rate check |
+| `Spam:MaxChannelCreatesPerWindow` | `3` | Max channel creations per `ChannelCreateWindowMinutes` |
+| `Spam:ChannelCreateWindowMinutes` | `10` | Window (minutes) for the channel-create check |
 
 ### Encryption
 
@@ -112,6 +152,7 @@ Access tokens expire after 15 minutes, refresh tokens after 30 days with rotatio
 
 | Key | Default | Description |
 | --- | --- | --- |
+| `Storage:Path` | *(empty)* | Directory for uploaded file blobs (attachments, avatars). Empty = `uploads/` in the app directory; the Docker image sets it to `/app/data/uploads` on the persistent volume |
 | `Storage:CleanupIntervalHours` | `1` | How often the cleanup job runs (hours) |
 | `Storage:RetentionDays` | `30` | Days to keep uploaded files before cleanup |
 
@@ -128,6 +169,23 @@ Access tokens expire after 15 minutes, refresh tokens after 30 days with rotatio
 | `Irc:ServerName` | `echohub` | IRC server name in protocol messages |
 | `Irc:Motd` | `Welcome to EchoHub IRC Gateway!` | Message of the day |
 
+### Server Logs Room
+
+When enabled, EchoHub auto-creates a read-only system channel and streams log events to it live,
+so operators can watch the server from inside the app. Log lines are **never stored as messages** —
+the rolling Serilog files remain the only persistence, and the room replays recent lines from those
+files when someone opens it.
+
+| Key | Default | Description |
+| --- | --- | --- |
+| `ServerLogs:Enabled` | `true` | Master switch for the live log room |
+| `ServerLogs:RoomName` | `server-logs` | Name of the auto-created channel (reserved — users can't create a channel with this name) |
+| `ServerLogs:MinRole` | `Mod` | Minimum server role that can see and join the room (`Member`, `Mod`, `Admin`, `Owner`) |
+| `ServerLogs:MinLevel` | `Information` | Minimum log level streamed to the room (`Verbose`, `Debug`, `Information`, `Warning`, `Error`, `Fatal`) — affects only the room, not the file/console sinks |
+| `ServerLogs:BacklogLines` | `100` | Recent log lines replayed from file when someone opens the room |
+| `ServerLogs:LogDirectory` | `logs` | Directory holding the rolling log files (must match the Serilog file sink path below) |
+| `ServerLogs:LogFilePattern` | `echohub-server-*.log` | Filename glob for the rolling log files inside `LogDirectory` |
+
 ### Logging
 
 EchoHub uses [Serilog](https://serilog.net/) for structured logging — console output + daily rolling files with 14-day retention by default.

docs/articles/encrypted-rooms.md

@@ -0,0 +1,160 @@
+# Encrypted Rooms (Password-Protected Channels)
+
+An **encrypted room** is a channel whose entire content — every message and every file — is
+end-to-end encrypted with a key derived from a shared passphrase. Only people who know the
+passphrase can read the room. **Not even the server owner can read the content**, yet the server
+can still gate who joins, and it can count and measure what's stored (message count, file sizes,
+timestamps) without ever seeing the plaintext.
+
+This is a stronger guarantee than the [transport and at-rest encryption](encryption.md) described
+elsewhere, where the server decrypts every message to process it. Here the server is treated as
+*untrusted* for content: it holds only ciphertext and wrapped keys.
+
+> **The passphrase is the only key.** There is no recovery. If everyone who knows a room's
+> passphrase forgets it, that room's history is permanently unreadable — by design.
+
+## What the server can and cannot see
+
+| The server **can** see | The server **cannot** see |
+| --- | --- |
+| That the channel is encrypted | Message text |
+| Message count and timestamps | File contents |
+| Who sent each message (sender identity) | Image previews (ASCII art) |
+| Each attachment's **file name** and byte size | The passphrase, the room key, or the key-encryption key |
+| The estimated total size (via `/meta`) | Anything that would let it decrypt the above |
+
+File **names are stored in plaintext** so the file list stays usable — treat a file name itself as
+non-secret. Everything *inside* the file is encrypted.
+
+## Key hierarchy
+
+Three keys are derived from one passphrase. The passphrase, the key-encryption key, and the room
+content key **never leave the client**.
+
+```mermaid
+flowchart TD
+    P[Passphrase] -->|PBKDF2-SHA256, 210k iterations, per-room salt| OKM[64-byte output]
+    OKM --> AK["Auth key (first 32 bytes)"]
+    OKM --> KEK["Key-encryption key / KEK (last 32 bytes)"]
+    AK -->|sent as lowercase hex| SRV1["Server: BCrypt-hash as the join gate"]
+    RCK["Room Content Key (random 256-bit)"] -->|encrypts all content| CONTENT[Messages + files + previews]
+    RCK -->|AES-256-GCM wrap under KEK| WRAP["Wrapped room key"]
+    WRAP -->|stored| SRV2["Server: stores wrapped key + salt only"]
+```
+
+- **Auth key** — the join credential. Derived from the passphrase, sent to the server as hex, and
+  stored only as a **BCrypt hash**. Proving knowledge of it is what lets you join; it reveals
+  nothing about the content key.
+- **Key-encryption key (KEK)** — never sent. Used locally to *wrap* (encrypt) and *unwrap* the room
+  content key.
+- **Room Content Key (RCK)** — a random 256-bit key generated once, at room creation. It encrypts
+  every message and file. The server stores it only in wrapped form, so it can hand the wrapped key
+  to a joiner but can never unwrap it itself.
+
+All content encryption is **AES-256-GCM** with a random 12-byte nonce and a 16-byte authentication
+tag per item, so identical inputs never produce identical ciphertext, and any tampering is detected.
+
+Room-encrypted text carries a self-describing prefix so clients and the server can tell it apart
+from plaintext:
+
+```text
+$RC1$base64(nonce || tag || ciphertext)
+```
+
+## Creating a room
+
+The client does all the cryptography locally, then hands the server only what it needs to gate joins
+and store (but not read) the content.
+
+```mermaid
+sequenceDiagram
+    participant Client
+    participant Server
+
+    Client->>Client: generate salt + random Room Content Key (RCK)
+    Client->>Client: DeriveKeys(passphrase, salt) → auth key + KEK
+    Client->>Client: wrap RCK under KEK
+    Client->>Server: create channel { authKey(hex), salt, wrappedRoomKey }
+    Server->>Server: BCrypt-hash auth key, store salt + wrapped key
+    Note over Server: Server never receives passphrase, KEK, or RCK
+```
+
+## Joining a room
+
+```mermaid
+sequenceDiagram
+    participant Client
+    participant Server
+
+    Client->>Server: GET /crypto → { isEncrypted, salt }
+    Client->>Client: DeriveKeys(passphrase, salt) → auth key + KEK
+    Client->>Server: join { authKey(hex) }
+    Server->>Server: BCrypt-verify against stored hash
+    alt correct passphrase
+        Server->>Client: history (ciphertext) + wrapped room key
+        Client->>Client: unwrap RCK with KEK, then decrypt everything locally
+    else wrong passphrase
+        Server->>Client: rejected (join gate fails)
+    end
+```
+
+A wrong passphrase fails the BCrypt gate, so the server never even hands out the wrapped key. Even if
+it did, an attacker without the KEK cannot unwrap it.
+
+## What gets encrypted
+
+When you send a message or attach files to an encrypted room, the client encrypts each part with the
+room content key **before** uploading:
+
+- **Message text** → `$RC1$…` ciphertext.
+- **Files** (any kind) → the whole blob is AES-256-GCM encrypted client-side; the server stores an
+  opaque ciphertext blob.
+- **Image ASCII previews** → rendered on the client, then room-encrypted. The server never sees the
+  rendered art.
+
+The server records each attachment's **kind**, **file name**, and **byte size** (of the ciphertext
+blob) as metadata, and broadcasts the ciphertext to other members, who decrypt locally.
+
+## Changing the passphrase
+
+`/passwd <old> <new>` rotates the passphrase. Because only the *wrapping* of the room content key
+changes — not the RCK itself — **all existing history stays readable**:
+
+1. The client proves knowledge of the old passphrase (old auth key).
+2. It unwraps the RCK with the old KEK, then re-wraps it under the new KEK (new salt).
+3. It uploads the new auth key + salt + re-wrapped key. The content is never re-encrypted.
+
+## Inspecting a room
+
+Use `/meta` in any channel to see what the server knows about it, including encrypted rooms:
+
+```text
+Room info for #private-room:
+  Room ID       3f2a…-…-…
+  Created       7/16/2026 2:31 PM
+  Messages      128
+  Unique users  4
+  Est. size     42.5 MB
+  Protection    end-to-end encrypted
+```
+
+`Est. size` is the sum of stored attachment blob sizes plus message text length — an estimate of the
+room's footprint, computed entirely from metadata the server holds without reading any content.
+
+## Limitations & security notes
+
+- **No recovery.** A lost passphrase means unrecoverable history. Keep it safe; there is no reset.
+- **File names are plaintext.** They stay readable so the file list works — don't put secrets in a
+  file name.
+- **IRC is disabled for encrypted rooms.** The IRC gateway forwards plaintext and cannot participate
+  in the room's key scheme, so encrypted channels are not bridged to IRC.
+- **Metadata is visible.** Message counts, timestamps, sender identities, file names, and sizes are
+  intentionally readable so the server can moderate at the metadata level and report `/meta`.
+- **Endpoint trust.** End-to-end encryption protects content from the server and the network, not
+  from a compromised client device that already holds the passphrase.
+
+## Related
+
+- [Message Encryption](encryption.md) — transport (`$ENC$v1$`) and optional at-rest database
+  encryption, where the server *does* decrypt content for processing. Encrypted rooms are a separate,
+  stronger layer that sits on top.

docs/articles/encryption.md

@@ -118,7 +118,7 @@ If you need to recover old encrypted messages, restore the original key from a b
 ### Limitations
 
 - **TLS-inspecting proxies** — if a corporate proxy terminates TLS with a trusted root CA, it can intercept the key exchange (`GET /api/server/encryption-key`) and read all traffic. A future upgrade to ECDH key exchange would address this.
-- **Server has full access** — the server decrypts all messages for processing. This is not end-to-end encryption between users; it's transport encryption between client and server.
+- **Server has full access** — the server decrypts all messages for processing. This is not end-to-end encryption between users; it's transport encryption between client and server. For true end-to-end encryption where the server cannot read content, use [encrypted rooms](encrypted-rooms.md).
 - **IRC clients receive plaintext** — IRC is an open protocol and third-party clients cannot participate in the encryption scheme.
 
 ## Troubleshooting

docs/articles/getting-started.md

@@ -17,7 +17,7 @@ curl -sSfL https://raw.githubusercontent.com/HueByte/EchoHub/master/scripts/inst
 To install a specific version or to a custom directory:
 
 ```bash
-curl -sSfL .../install.sh | sh -s -- --version 0.2.10
+curl -sSfL .../install.sh | sh -s -- --version 0.2.14
 curl -sSfL .../install.sh | sh -s -- --install-dir /opt/echohub
 ```
 
@@ -76,11 +76,11 @@ Then connect with any standard IRC client:
 irssi -c localhost -p 6667 -w <password> -n <username>
 ```
 
-IRC users must have an existing EchoHub account. Authentication works via `PASS`/`NICK`/`USER` or SASL PLAIN. Messages flow bidirectionally between IRC and TUI clients.
+Your nick is your EchoHub username and the server password is your account password (`PASS`/`NICK`/`USER` or SASL PLAIN). Connecting with a new username registers the account. Messages flow bidirectionally between IRC and TUI clients.
 
 For TLS, set `TlsEnabled: true`, `TlsPort: 6697`, and provide a PKCS#12 certificate path.
 
-See the [Architecture](architecture.md) page for details on how the IRC gateway integrates with the chat service.
+See the [IRC Gateway guide](irc-gateway.md) for command mapping, attachment rendering, and limitations, or [Architecture](architecture.md) for how the gateway integrates with the chat service.
 
 ## Configuration
 

docs/articles/irc-gateway.md

@@ -0,0 +1,103 @@
+# IRC Gateway
+
+Every EchoHub server can expose a second door: a built-in **IRC gateway** that speaks the
+classic IRC protocol on port 6667. Any standard IRC client — irssi, WeeChat, HexChat,
+Halloy — can join the same channels as TUI users, see the same messages, and chat with the
+same accounts. Under the hood both protocols call the same chat service, so a message sent
+from IRC appears instantly in the TUI and vice versa (see [Architecture](architecture.md)).
+
+## Enabling the gateway
+
+The gateway is off by default. Enable it in `appsettings.json` (or `Irc__Enabled=true` as an
+environment variable):
+
+```json
+{
+  "Irc": {
+    "Enabled": true,
+    "Port": 6667,
+    "TlsEnabled": false,
+    "TlsPort": 6697,
+    "TlsCertPath": "",
+    "ServerName": "echohub",
+    "Motd": "Welcome to EchoHub IRC Gateway!"
+  }
+}
+```
+
+The plaintext listener always starts on `Port`. The TLS listener on `TlsPort` starts only
+when `TlsEnabled` is `true` **and** `TlsCertPath` points to a PKCS#12 (`.pfx`) certificate.
+See the [configuration reference](configuration.md#irc-gateway) for every option.
+
+## Connecting & authentication
+
+Your IRC **nick is your EchoHub username** and your server password is your **account
+password**. Two flows are supported:
+
+```bash
+# classic PASS/NICK/USER — most clients call this the "server password"
+irssi -c chat.example.com -p 6667 -w <password> -n <username>
+```
+
+or **SASL PLAIN** (advertised via `CAP LS`), where the SASL username/password are the account
+credentials.
+
+A few things worth knowing:
+
+- **Connecting auto-registers.** If the username doesn't exist yet, the gateway creates the
+  account with that password (usernames: 3–50 chars of `a-z 0-9 _ -`; passwords: 6+ chars).
+  The very first account ever created on a server becomes the **Owner**.
+- Because of that, a typo'd password for an *existing* account fails with
+  `Username is already taken` — the gateway tried to log in, couldn't, then tried to register
+  the name. If you see that error, re-check your password.
+- Connecting without a password is rejected: `Password required. Use PASS command or SASL PLAIN.`
+
+## What maps to what
+
+| IRC | EchoHub |
+| --- | --- |
+| `JOIN #room` | Join a channel (history is replayed on join) |
+| `JOIN #room <key>` | Join a password-protected (`+k`) channel |
+| `PART` / `QUIT` | Leave channel / disconnect |
+| `LIST` | Public channels only (password-protected ones show a `[+k]` hint) |
+| `TOPIC` | Read or set the channel topic (permission-checked) |
+| `NAMES` / `WHO` | Online users in the channel |
+| `WHOIS` | Profile: display name, channels, idle time, away status |
+| `AWAY [message]` | Sets your EchoHub status to Away / back to Online |
+| `MODE #room +k <key>` / `-k` | Set / clear the channel password |
+
+Private (unlisted) channels don't appear in `LIST`, but members who know the exact name can
+still `JOIN` them. Channels are not auto-created from IRC — create them from the TUI first.
+
+## How messages look
+
+- **Attachments** arrive as labeled link lines — `[Image: photo.png] https://…`,
+  `♪ [Audio: song.mp3] https://…`, `[File: report.pdf] https://…` — and image attachments
+  additionally render their **ASCII-art preview** using truecolor ANSI escapes, so a modern
+  terminal IRC client shows actual picture previews.
+- **Link embeds** are appended as `│`-prefixed text lines.
+- Long messages are split at word boundaries into IRC-safe lines (~400 bytes each);
+  incoming messages may be up to 2,000 characters like any EchoHub message.
+- Your own messages aren't echoed back (standard IRC convention).
+- Moderation actions surface natively: kicks arrive as `KICK`, bans and channel nukes as
+  server `NOTICE`s.
+
+## Limitations
+
+The gateway bridges what IRC can express — and deliberately refuses what it can't:
+
+- **No end-to-end encrypted rooms.** Joining an [encrypted room](encrypted-rooms.md) fails
+  with *"Cannot join channel — end-to-end encrypted, use the EchoHub client."* Bridging one
+  would require the server to hold the room key, breaking the zero-knowledge design.
+- **No private messages.** `PRIVMSG` to a nick is rejected; EchoHub is channel-based.
+- **Usernames, not display names.** Messages are attributed to the account username;
+  a user's display name is visible via `WHOIS`/`WHO` (realname field).
+- **No client features.** Uploading attachments, profiles, themes, and reactions to status
+  changes are TUI-client features. Other users' status changes aren't pushed to IRC —
+  discover them with `WHOIS`/`WHO`.
+
+## How IRC users appear to TUI users
+
+Users connected *only* through the gateway are tagged `[irc]` in the users panel — a hint
+that they can't receive encrypted content or use client-side features. Someone connected
+with both an IRC client and the TUI shows untagged.

docs/articles/messages-and-attachments.md

@@ -0,0 +1,109 @@
+# Messages & Attachments
+
+An EchoHub message is **text content plus up to 10 attachments**, Discord-style. A plain chat
+line is just a message with no attachments; a photo dump is one message with several files and
+an optional caption. This page explains how to attach files, what happens to them on the way to
+the server, and how other clients receive them.
+
+## Message basics
+
+| Limit | Value |
+| --- | --- |
+| Max message length | 2,000 characters |
+| Max newlines per message | 30 (no blank-line runs) |
+| Max attachments per message | 10 |
+| Link embeds per message | first 3 URLs |
+
+Multiline messages are written with `Ctrl+N` for a newline; `Enter` sends. URLs in a message
+get link embeds (title, description, theme color) fetched by the server.
+
+## Attaching files
+
+All of these end up in the same place — the **staging tray** — and are sent together as one
+message the next time you press `Enter`, with whatever you've typed as the caption:
+
+- **Paste a copied file** — copy one *or several* files in your file manager and press
+  `Ctrl+V` in the input. All of them are staged at once.
+- **Paste an image from the clipboard** — copy an image in a browser (right-click → *Copy
+  image*), take a screenshot (`Win+Shift+S`), or copy from an image editor, then `Ctrl+V`.
+  The image is attached directly as a PNG named `image.png` — no saving to disk first.
+  On Linux this uses `wl-paste` or `xclip`; on macOS it requires
+  [`pngpaste`](https://github.com/jcsalterego/pngpaste) (`brew install pngpaste`).
+- **Drag & drop** — drop a file onto the terminal window; the client recognizes the dropped
+  path and stages the file.
+- **`/send <filepath>`** — stage a file by path (quote paths containing spaces).
+
+The input frame's title shows what's currently staged. `/clear` drops all staged attachments
+without sending. Sending with an empty input is fine — the message is just the attachments.
+
+```text
+┌ Message (2 attached: report.pdf, image.png) ──────────────┐
+│ here's the summary and a screenshot_                      │
+└────────────────────────────────────────────────────────────┘
+```
+
+**URL sends are different:** `/send <https://…>` sends an image URL immediately as its own
+message — nothing is staged, and it isn't available in end-to-end encrypted rooms (the server
+would have to fetch the image, which would defeat the encryption).
+
+## Attachment kinds
+
+The kind is detected per attachment, not per message:
+
+| Kind | Detected by | Renders as | Default size limit |
+| --- | --- | --- | --- |
+| **Image** | Magic bytes: JPEG, PNG, GIF, WebP | ASCII-art preview in chat | 10 MB |
+| **Audio** | Extension: `.mp3` `.wav` `.ogg` `.flac` `.aac` `.m4a` `.wma` | Playable row (▶) | 10 MB |
+| **File** | Everything else | Downloadable row | 100 MB |
+
+Limits are per file and server-configurable — see the `Uploads` section in the
+[configuration guide](configuration.md) (`MaxImageSizeMB`, `MaxAudioSizeMB`, `MaxFileSizeMB`,
+`MaxAttachmentsPerMessage`).
+
+## Image previews (ASCII art)
+
+Images are rendered in chat as half-block ASCII art. You pick the rendering size:
+
+| Flag | Size | Feel |
+| --- | --- | --- |
+| `-s` / `/size s` | 40 × 40 | compact |
+| `-m` / `/size m` | 80 × 80 | default |
+| `-l` / `/size l` | 120 × 120 | detailed |
+
+`/size` with no argument opens a picker; the choice persists as your default. A one-off
+`-s|-m|-l` flag on `/send` applies to that message.
+
+## Receiving attachments
+
+Right-click a message (or press `F6` to select one with the arrow keys) for actions:
+
+- **Images** → save to disk
+- **Audio** → play (in-client playback)
+- **Files** → download
+
+Downloads go to your configured download folder — set it with `/downloadpath` (no argument
+opens a native folder picker, or pass a path directly).
+
+## Attachments in encrypted rooms
+
+In an [end-to-end encrypted room](encrypted-rooms.md) every attachment is encrypted
+client-side **before** upload:
+
+```mermaid
+flowchart LR
+    F[File bytes] -->|AES-256-GCM with room key| B[Ciphertext blob]
+    F -->|if image: render ASCII locally| A[ASCII preview]
+    A -->|room-encrypt| AP["$RC1$… preview"]
+    B --> S[Server stores blob + name + size]
+    AP --> S
+```
+
+The server never sees the file contents or the rendered preview — it stores an opaque blob and
+broadcasts it to members, who decrypt locally. File **names and sizes remain visible** to the
+server so the file list stays usable; don't put secrets in a file name. Pasted clipboard
+images go through exactly the same pipeline.
+
+## Deleting messages with attachments
+
+Deleting a message also removes its uploaded attachment files from the server. You can always
+delete your own messages; moderators can delete others' — see [Moderation & Roles](moderation.md).

docs/articles/moderation.md

@@ -0,0 +1,71 @@
+# Moderation & Roles
+
+Every EchoHub server has a four-tier role hierarchy. Moderation is **strictly hierarchical**:
+acting on another user requires outranking them — equal rank is never enough — and a few
+invariants protect the server owner from lockouts.
+
+## Roles
+
+| Role | Rank | Users panel glyph | How it's granted |
+| --- | --- | --- | --- |
+| **Owner** | 3 | ★ | The first account ever registered on the server |
+| **Admin** | 2 | ♦ | Assigned by the Owner |
+| **Mod** | 1 | ❀ | Assigned by an Admin or the Owner |
+| **Member** | 0 | — | Everyone else |
+
+Assign roles with `/role <user> <admin|mod|member>`. Two rules apply:
+
+- You can only assign roles **strictly below your own** — an Admin can promote to Mod but
+  cannot create another Admin; only the Owner can.
+- **Owner is not assignable and not demotable.** There is exactly one Owner (the first
+  account), nobody can be promoted to it, and the Owner's role can't be changed.
+
+## Actions
+
+| Command | Minimum role | Effect |
+| --- | --- | --- |
+| `/kick <user> [reason]` | Mod | Disconnects the user. Not persistent — they can reconnect immediately. |
+| `/ban <user> [reason]` | Admin | Persistent: flags the account banned and disconnects it. Banned accounts are rejected at login. |
+| `/unban <user>` | Admin | Lifts a ban. |
+| `/mute <user> [minutes]` | Mod | Blocks the user from sending messages or uploading files. Without a duration the mute is **indefinite**; with one it auto-expires (checked every ~15 seconds). |
+| `/unmute <user>` | Mod | Lifts a mute early. |
+| `/role <user> <role>` | Admin | Assign a role (see rules above). |
+| `/nuke` | Mod | Deletes the **entire history of the current channel**, including all attachment files on disk. Channel-wide — no per-user check. |
+
+Kick, ban, and mute all enforce the hierarchy: the target's role must be **strictly lower**
+than yours. A Mod cannot kick another Mod; nobody can kick, ban, mute, or demote the Owner.
+
+## Deleting messages
+
+Deletion has its own, slightly different rule set:
+
+- **Your own messages** — always deletable, whatever your role. Right-click a message →
+  *Delete message*, or press `F6`, pick the message, and hit `Delete`.
+- **Someone else's messages** — requires **Mod or higher** *and* strictly outranking the
+  author. A Mod can delete a Member's message, but not another Mod's.
+
+Deleting a message also purges its uploaded attachment blobs from the server's disk, and the
+removal is broadcast live — the message disappears from everyone's chat immediately.
+
+## How actions surface
+
+Everyone in the channel sees moderation happen:
+
+- **TUI clients** show system messages — *"alice was kicked (reason)"*, *"bob was banned"*,
+  *"Channel history has been cleared by a moderator."* The kicked or banned user themselves
+  gets a dialog with the reason, then the client disconnects.
+- **IRC clients** get native protocol events: kicks arrive as a real `KICK` command, bans as
+  a server `NOTICE`. (See the [IRC Gateway guide](irc-gateway.md).)
+
+Muted users aren't announced; they simply receive *"You are muted and cannot send messages."*
+when they try to speak.
+
+## Design notes
+
+- All checks run server-side in the moderation API — the client commands are conveniences,
+  and the same rules bind IRC users and any direct API caller.
+- Bans are account-level, not IP-level. A banned person can register a fresh account; pair
+  bans with registration hygiene on public servers.
+- In [end-to-end encrypted rooms](encrypted-rooms.md) moderation still works at the metadata
+  level — messages can be deleted and users muted/kicked by identity — but no moderator can
+  *read* the content, including the Owner.

docs/articles/toc.yml

@@ -2,6 +2,14 @@
   items:
     - name: Getting Started
       href: getting-started.md
+    - name: TUI Guide
+      href: tui-guide.md
+    - name: Messages & Attachments
+      href: messages-and-attachments.md
+    - name: Moderation & Roles
+      href: moderation.md
+    - name: IRC Gateway
+      href: irc-gateway.md
     - name: Docker
       href: docker.md
     - name: Architecture
@@ -10,6 +18,8 @@
       href: configuration.md
     - name: Encryption
       href: encryption.md
+    - name: Encrypted Rooms
+      href: encrypted-rooms.md
     - name: Notification Sounds
       href: notification-sounds.md
 - name: Flows

docs/articles/tui-guide.md

@@ -0,0 +1,116 @@
+# TUI Guide
+
+Everything you can do in the EchoHub terminal client: keyboard shortcuts, mouse actions,
+slash commands, themes, and the everyday behaviors (unread markers, auto-join, scrollback)
+that make it feel like a proper IRC-era client with modern comforts.
+
+## Layout
+
+```text
+┌ Menu bar ──────────────────────────────────────────────────┐
+│ ┌ Channels ─┐ ┌ Messages ────────────────────┐ ┌ Users ──┐ │
+│ │ #general 3│ │ 12:01 <alice> hi             │ │ ★ alice │ │
+│ │ #dev      │ │ ── new messages ──           │ │ ❀ bob   │ │
+│ │ #random*~ │ │ 12:04 <bob> anyone around?   │ │ carol   │ │
+│ └───────────┘ └──────────────────────────────┘ │ d [irc] │ │
+│ ┌ Message │ Enter=send │ Tab=complete │ … ────┐ └─────────┘ │
+│ │ _                                           │             │
+│ └─────────────────────────────────────────────┘             │
+│ Status: Connected │ v0.2.14 │ alice │ Act: #dev             │
+└─────────────────────────────────────────────────────────────┘
+```
+
+Channel list markers: `*` = password-protected, `~` = private (unlisted), plus unread counts
+(orange when you were @mentioned). Users panel glyphs: `★` Owner, `♦` Admin, `❀` Mod,
+`[irc]` for IRC-gateway-only users; status icons `●`/`○`/`◐`/`◌` for online/offline/away/dnd.
+
+## Keyboard shortcuts
+
+### In the message input
+
+| Key | Action |
+| --- | --- |
+| `Enter` | Send the message (also sends staged attachments with the text as caption) |
+| `Ctrl+N` | Insert a newline (multiline message) |
+| `Tab` | Autocomplete a slash command (`/th` → `/theme`) |
+| `Ctrl+V` (or `Ctrl+Y`) | Paste — copied files and images become attachments, text pastes normally ([details](messages-and-attachments.md)) |
+| `Ctrl+C` / `Ctrl+X` | Copy / cut in the input |
+| `Ctrl+W` | Delete the word left of the cursor |
+| `Ctrl+K` | Open the search palette |
+| `F6` | Move focus into the message list |
+
+### In the message list (after `F6`)
+
+| Key | Action |
+| --- | --- |
+| `↑` / `↓` | Select a message |
+| `Enter` | Activate: play/download/save an attachment, open an `@mention`'s profile, join a `#channel`, or open the sender's profile |
+| `Delete` / `Backspace` | Delete the selected message (with confirmation; [permission rules](moderation.md)) |
+| `F6` | Return focus to the input |
+
+### Anywhere
+
+| Key | Action |
+| --- | --- |
+| `F2` | Toggle the users panel |
+| `Ctrl+K` | Search palette |
+| `Alt+Q` | Quit |
+
+## The search palette (`Ctrl+K`)
+
+A command-palette that searches **channels and app actions** — type to filter, `↓` to
+navigate, `Enter` to jump. Actions include Connect, Disconnect, Logout, My Profile,
+Set Status, Create/Delete Channel, Saved Servers, Toggle Users Panel, Check for Updates,
+and Quit. `Ctrl+K` again closes it.
+
+## Mouse
+
+- **Right-click a message** for the context menu: save image / play audio / download file
+  (depending on the attachment), *Mention @user*, *View profile*, *Copy text*,
+  *Copy message ID*, *Delete message*.
+- **Left-click a message** does the most useful thing for that line: attachments
+  play/download/save, `@mentions` and the sender open profiles, `#channel` references join
+  that channel.
+- **Click a user** in the users panel to open their profile; **click a channel** to switch.
+
+## Slash commands
+
+Type `/help` in any channel for the full list. The highlights:
+
+| Command | What it does |
+| --- | --- |
+| `/status <online\|away\|dnd\|invisible>` or `/status <message>` | Presence / status message |
+| `/nick <name>`, `/color <#hex>`, `/avatar <url or path>` | Display name, nick color, avatar |
+| `/theme <name>` | Switch theme |
+| `/send`, `/clear`, `/size`, `/downloadpath` | Attachments — see [Messages & Attachments](messages-and-attachments.md) |
+| `/join <channel> [password]`, `/leave`, `/topic <text>` | Channel membership and topic |
+| `/passwd <old> <new>` | Rotate an encrypted room's passphrase |
+| `/profile [user]`, `/users`, `/meta` | Profiles, online users, room info |
+| `/kick`, `/ban`, `/mute`, `/role`, `/nuke`, … | [Moderation](moderation.md) |
+| `/servers`, `/quit` | Saved servers, exit |
+
+Emoji shortcodes (`:smile:` style) are replaced live as you type.
+
+## Themes
+
+14 built-in themes: **Default, Transparent, TransparentLight, Classic, Light, Hacker,
+Solarized, Dracula, Monokai, Nord, Gruvbox, Ocean, HighContrast, RosePine** — switch from
+the User menu or `/theme <name>`. The two *Transparent* themes use no background color at
+all, so your terminal's own background (and any blur/acrylic) shows through.
+
+You can add your own: drop a theme JSON into `~/.echohub/themes/` and it appears in the list
+(names that collide with a built-in are skipped).
+
+## Everyday behaviors
+
+- **Unread markers** — a `── new messages ──` rule marks where you left off in each channel,
+  irssi-style. Read positions are **persisted per server**, so the marker survives
+  reconnects and restarts. The status bar's `Act:` segment lists channels with activity
+  (orange when you were @mentioned), and day boundaries draw a date rule.
+- **Auto-join** — connecting joins `#general` plus every channel you're a member of, so
+  unread counts and mentions accumulate everywhere. Channels you `/leave` stay left, and
+  password-protected or [encrypted rooms](encrypted-rooms.md) are never auto-prompted —
+  join those explicitly. `#general` is the home channel and can't be left or deleted.
+- **Scrollback** — history loads 100 messages at a time; scrolling to the top of a channel
+  fetches the next page and keeps your position (no jump).
+- **Drag & drop** — dropping a file onto the window stages it as an attachment.

docs/auriondocs/index.html

@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>AurionDocs</title>
+  <style>
+    body { font-family: system-ui, sans-serif; display: grid; place-items: center; min-height: 100vh; margin: 0; background: #1a1a1e; color: #ddd; }
+    main { text-align: center; }
+    a { color: #7aa2f7; }
+  </style>
+</head>
+<body>
+  <main>
+    <h1>AurionDocs</h1>
+    <p>Supplementary documentation for EchoHub.</p>
+    <p><a href="../index.html">&larr; Back to EchoHub documentation</a></p>
+  </main>
+</body>
+</html>

docs/changelog/index.md

@@ -4,6 +4,11 @@ Release history for EchoHub.
 
 ## Releases
 
+- [v0.2.15](v0.2.15.md) - Invite Codes, Data Export & Deletion, /me, /banner, Replies, Open Images In Browser & IRC Image Links
+- [v0.2.14](v0.2.14.md) - Clipboard Image & Multi-File Paste, E2E Room Unlock Fixes, Encrypted Key Cache & IRC Gateway Polish
+- [v0.2.13](v0.2.13.md) - Chat Visual Overhaul, Auto-Join All Channels & Persistent Read Positions
+- [v0.2.12](v0.2.12.md) - End-to-End Encrypted Channels, IRC Channel Keys, Image Save & Ctrl+W Crash Fix
+- [v0.2.11](v0.2.11.md) - EchoHubSpace Auth, Live Directory Updates & Server Browser Metadata
 - [v0.2.10](v0.2.10.md) - Command Palette, Infinite History Scroll & Auto-Updater Fixes
 - [v0.2.9](v0.2.9.md) - Install Script & Chocolatey Fixes
 - [v0.2.8](v0.2.8.md) - Docker Support, IRC Account Creation & BOM Fix

docs/changelog/toc.yml

@@ -1,5 +1,15 @@
 - name: Overview
   href: index.md
+- name: v0.2.15
+  href: v0.2.15.md
+- name: v0.2.14
+  href: v0.2.14.md
+- name: v0.2.13
+  href: v0.2.13.md
+- name: v0.2.12
+  href: v0.2.12.md
+- name: v0.2.11
+  href: v0.2.11.md
 - name: v0.2.10
   href: v0.2.10.md
 - name: v0.2.9

docs/changelog/v0.2.11.md

@@ -0,0 +1,23 @@
+# v0.2.11
+
+EchoHubSpace directory protocol overhaul: authenticated server registration with persistent claim tokens, near-real-time user-count updates, and richer server metadata (tags, multi-host, version). Coordinated cutover with the EchoHubSpace directory deploy.
+
+## New Features
+
+- EchoHubSpace claim-token authentication — the directory issues a per-server claim token on first registration, persisted atomically alongside the SQLite database (chmod 0600 on Unix). Subsequent reconnects authenticate with the token instead of relying on raw hostname-squatting protection. Token survives both client and directory restarts; lost tokens require an admin-side `DELETE /api/servers/{id}` on the directory to recover
+- Server tags — public servers can advertise topic tags via the new `Server:Tags` config array, surfacing as filter facets in the EchoHubSpace browser
+- Multi-host advertisement — a single server can register multiple hostnames (e.g. apex domain, IPv6, alias domains) by listing them in `Server:PublicHosts`. All hosts route to the same directory row
+- Server version sent to directory — the EchoHubSpace browser shows what version each public server is running, pulled from the server's assembly informational version
+- Operator-facing `GET /api/server/directory` endpoint (Admin role required) — returns `ServerId`, `IsRegistered`, `LastRegisteredAt`, `LastError`, and any `ConflictingHosts` for support tickets. Never exposes the claim token itself, only a `HasClaimToken` boolean
+
+## Refactoring
+
+- Replace 30s polling with event-driven directory updates — `PresenceTracker` now raises `UserCountChanged` only when the distinct user count actually changes (multi-tab/multi-connection users no longer trigger). `ServerDirectoryService` consumes via a single-slot `Channel<int>` (latest-wins coalesces bursts) with a 1-second min-interval throttle. Directory reflects user-count changes within ~1s instead of up to 30s stale
+- Wrap directory hub responses in a `Response<T>` envelope with `IsSuccess`/`Data`/`Errors`/`Version` shape — protocol version is pinned client-side (currently `1.0`); mismatches trigger a permanent-failure stop with operator-facing log
+- Stop attempting re-registration after permanent failures (`HostAlreadyClaimed`, `InvalidToken`, `HostConflict`, `InvalidInput`) — the directory no longer terminates the connection on these errors, so the client suppresses re-register on `Reconnected` to avoid tight retry loops. Operator must restart the server after fixing config
+
+## Configuration
+
+- **Breaking**: `Server:PublicHost` (string) renamed to `Server:PublicHosts` (string array). Public servers must update `appsettings.json` — single-host deployments use a one-element array
+- New `Server:Tags` (string array) — defaults to empty
+- New optional `Server:DirectoryClaimPath` — overrides the path of the persisted claim file. Defaults to a `directory-claim.json` next to the SQLite database. Treat the file as a secret; back it up alongside the database

docs/changelog/v0.2.12.md

@@ -0,0 +1,56 @@
+# v0.2.12
+
+Private channels are now genuinely private: password-protected channels are end-to-end encrypted, so the server (and its operators) can gate joins and measure storage but cannot read message or file contents. The IRC gateway grows real MODE/TOPIC support and channel keys, and the client gets image "save original", a transparent-light theme, drag-and-drop file sending, Ctrl+V paste, and a fix for the intermittent Ctrl+W crash.
+
+## New Features
+
+- **End-to-end encrypted channels** — creating a channel with a password now provisions a zero-knowledge room:
+  - The passphrase never leaves the client. It derives (PBKDF2-SHA256, 210k iterations) two keys: an *auth key* sent to the server as the join credential, and a *key-encryption key* that never leaves the machine.
+  - A random room content key encrypts every message and file with AES-256-GCM. The server only ever stores the room key *wrapped* under the passphrase, so it can gate joins and report a channel's message count, storage size, and attachments — but cannot decrypt any of it. Even the server owner cannot read a private room's contents.
+  - Members' clients cache the derived room key locally (in the per-server config, like saved sessions) so the passphrase isn't retyped every launch; joining on a new device prompts for it once.
+  - Change the passphrase with `/passwd <old> <new>` (channel creator only). The room key is re-wrapped, not rotated, so **existing history stays readable** and members who join later with the new passphrase can still read older messages.
+  - Files and images are encrypted client-side before upload; for images the ASCII-art preview is rendered on the client and stored room-encrypted too. Sending images by URL is disabled in encrypted channels (the server can't fetch-and-render without the key).
+  - End-to-end encrypted channels cannot be joined over the IRC gateway (that would require the server to hold the room key) — IRC `JOIN` returns `475` directing users to the EchoHub client.
+- Password-protected channels — set an optional password when creating a channel (masked field in the Create Channel dialog, `password` on `POST /api/channels`). Passwords are BCrypt-hashed server-side; the join gate applies on first join only (existing members and the creator are unaffected). Protected channels show a `*` marker in the channel list and `+k` in the status bar
+- Save original images — image messages now show a clickable "[↓ save original]" line under the ASCII-art preview that downloads the full-resolution original to your Downloads folder (decrypting locally in encrypted channels)
+- **Messages with attachments (Discord-style)** — a message is now text **plus** a list of attachments instead of being either text or a single file. One message can carry a caption and several files (images, audio, docs) together:
+  - Compose with a **staging tray**: `/send <file>` or dropping files onto the terminal stages them (shown on the input bar); the next Enter sends your typed caption and all staged files as one message. `/clear` drops staged files. `/send <URL>` still posts an image immediately.
+  - Each image attachment renders its own ASCII preview with its own "save original" action; audio/file attachments each get their own play/download line.
+  - In encrypted channels every attachment is encrypted individually (blob + ASCII preview), and the caption is room-encrypted — the server still stores only ciphertext and can report count/size but not contents.
+  - Up to 10 attachments per message.
+- **Right-click message menu** — right-click any message for a context menu: save/download/play its attachment, mention the sender, view their profile, copy the text, copy the message ID (for linking or command arguments), or delete the message. (Keyboard: F6 focuses the message list for arrow-key selection + Delete.) The selected message is now highlighted while the list is focused.
+- **Message deletion** — press Delete on a selected message to remove it. You can always delete your own messages; moderators and above can delete others' messages, but only from users **below their own role** (a mod can't delete an admin's or owner's message). Deleting a message also removes its attachment blobs from server storage.
+- **Customizable download folder** — `/downloadpath` opens your OS-native folder picker (Windows Explorer / macOS Finder / Linux GTK or KDE) to choose where downloaded attachments and saved images go; `/downloadpath <path>` sets it directly (the fallback when no native picker is available). Downloaded files now land in that folder (with automatic `(n)` de-duplication) instead of a temp directory.
+- `/join <channel> [password]` — join protected channels inline, or let the client prompt: joining a protected channel without a password opens a masked prompt that re-prompts on a wrong password
+- IRC channel keys — `JOIN #room <key>` works against room passwords (RFC 1459 comma-paired key lists supported); keyless or wrong-key joins get `475 ERR_BADCHANNELKEY`
+- IRC `MODE` implemented — `MODE #chan` reports `+k`/`+`, `MODE #chan +k <key>` sets and `-k` clears the room password (channel creator or admin only), ban-list probes get a clean empty reply, and `CHANMODES` is advertised in ISUPPORT
+- IRC `TOPIC` set support — the channel creator can change the topic from IRC; the change broadcasts to connected TUI clients (previously topic changes were rejected with a stub error)
+- Attach a file by drag & drop or by pasting — drop a file onto the terminal, or **copy a file in your file manager and press Ctrl+V**, to stage it as an attachment (the next Enter sends it with your caption). Multiple files at once are supported. Ctrl+V still pastes text when the clipboard holds text; Ctrl+Y is a paste alias. On Windows the copied-file paste reads the clipboard's file list directly (Windows Terminal never pastes copied files as text), with `xclip`/`wl-paste` used on Linux
+- Pick ASCII-art size for attached images — `/size` opens a Small/Medium/Large picker (40×40 / 80×80 / 120×120) with descriptions, `/size <s|m|l>` sets it directly, and `/send <file> -l` sets it for that message. The choice is a saved preference and applies to copy-paste/drag-drop images (which have no per-file flag); the current size is shown in the staging tray
+- New `TransparentLight` theme — dark characters on a transparent background, for light terminal color schemes (`/theme transparentlight`)
+- **`/meta` command** — shows a summary of the current room: room id, created date, message count, unique participant count, estimated storage size, and protection level (open / password-protected / end-to-end encrypted). Works for encrypted rooms too, since these are all metadata the server tracks without reading content. (`/info` is an alias.)
+- **Configurable upload limits** — a new `Uploads` section in the server settings sets the maximum size per file, image, audio clip, and avatar, plus the maximum attachments per message. Absent values fall back to the previous built-in limits, so existing servers are unaffected until they opt in.
+- **Updater progress bar** — the self-updater now draws a real progress bar on the console (`Downloading [████████░░] 62%`) for each step, replacing the plain status lines, so a large download shows visible progress.
+- Timestamps in messages are culture-aware and now **always include the date**: today's messages show a compact date + short time, and older messages show the general short date/time.
+
+## Bug Fixes
+
+- Transparent themes no longer draw an opaque box behind the message input. The input `TextView` renders with the `Editable` visual role, which Terminal.Gui derives as an opaque color when a theme leaves it unset; the themes now pin `Editable`/`ReadOnly` to their base colors so the input matches its (transparent) background.
+- Attachments whose files have been pruned (retention cleanup deletes blobs older than `Storage:RetentionDays` but left the message rows) no longer render a dead download/preview. When channel history loads, the server checks which attachment blobs still exist: missing ones are dropped from the message, and an attachment-only message whose files are all gone is removed from the database.
+- Fixed intermittent crash on Ctrl+W — Terminal.Gui binds Ctrl+W to clipboard-cut, and Windows clipboard contention (another app holding the clipboard) threw an unhandled `Win32Exception` that took the app down. Ctrl+W now deletes the previous word (readline behavior, no clipboard), and all clipboard shortcuts (Ctrl+X/C/V/Y) are guarded so transient clipboard failures log a warning instead of crashing
+- Fixed emoji shortcode replacement permanently disabling itself if a cursor update threw mid-replacement
+- Fixed new messages showing no date — today's messages rendered time-only, and the "is it today?" check compared the server's UTC date against the local date, so the classification could also be wrong near midnight. Timestamps are now converted to local time first and always include the date.
+- Fixed the self-updater hanging at "extracting" — the update ran while the Terminal.Gui main loop still owned the console, so the old and new processes deadlocked over it. The update now runs after the TUI shuts down, on a clean console
+- IRC `LIST` no longer leaks private channels; protected channels are marked `[+k]`
+
+## API Changes
+
+- `ChannelDto` gains `isProtected` and `isEncrypted`; `CreateChannelRequest` gains optional `password`, `encryptionSalt`, and `wrappedRoomKey`; SignalR `JoinChannel` takes an optional second `password` argument and `JoinChannelResult` gains `passwordRequired`, `encryptionSalt`, and `wrappedRoomKey` (older clients must update to join over SignalR)
+- New endpoints: `GET /api/channels/{channel}/crypto` (public crypto metadata — salt only, never the wrapped key) and `POST /api/channels/{channel}/rekey` (creator-only passphrase change)
+- New endpoint `GET /api/channels/{channel}/meta` returns a `ChannelMetaDto` (room id, name, topic, encrypted/protected flags, message count, unique user count, estimated size, created date) backing the `/meta` command
+- New server `Uploads` configuration section (`MaxFileSizeMB`, `MaxImageSizeMB`, `MaxAudioSizeMB`, `MaxAvatarSizeMB`, `MaxAttachmentsPerMessage`); the message-upload endpoint's request-body ceiling is now derived from these values at runtime rather than from compile-time constants
+- The upload endpoint accepts `type` and `content` form fields for encrypted channels, where the client supplies the declared message type and room-encrypted content
+- `ImageToAsciiService` and `FileValidationHelper` moved from `EchoHub.Server` to `EchoHub.Core` so the client can render ASCII art and detect file types for encrypted uploads
+- **Message shape change**: `MessageDto` drops `Type`/`AttachmentUrl`/`AttachmentFileName`/`AttachmentFileSize` and gains `Attachments` (a list of `AttachmentDto { Kind, Url, FileName, FileSize, AsciiPreview }`, null/empty for plain text). New `Attachment` entity + table with a cascade FK to `Message`
+- New endpoint `POST /api/channels/{channel}/messages` (multipart: `content` + N `files`, plus `kind`/`preview` per file for encrypted channels) replaces the single-file `upload` endpoint; `DELETE /api/moderation/messages/{id}` now enforces the own-or-higher-role rule
+- New EF migrations `AddChannelPasswordHash`, `AddChannelEncryptionEnvelope`, and `AddMessageAttachments` (applied automatically on server start); a one-time startup data migration folds legacy single-attachment messages into the new model

docs/changelog/v0.2.13.md

@@ -0,0 +1,26 @@
+# v0.2.13
+
+A visual overhaul of the chat client — WeeChat-style column layout, per-user nick colors, date rules, unread markers, an activity status segment, and an ASCII welcome banner — plus reliable cross-channel notifications: the client now joins all your channels at connect so unread counts and @mentions light up everywhere, and read positions persist across restarts so activity that happened while you were offline still shows. Modern polish, old IRC soul.
+
+## New Features
+
+- **Aligned message layout (WeeChat-style)** — every message renders as `HH:mm  nickname │ text`: a dim timestamp, the nick right-aligned in a fixed 12-column gutter, and a dim `│` rail separating names from content. Word-wrapped continuation lines, multi-line messages, attachments, ASCII-art image previews, and link embeds all align under the text column and extend the rail, so conversations read as a clean two-column grid. Over-long nicks are truncated with `…` in the gutter only — profiles, mentions, and the users panel always use the full name. System and status lines (`joined`, `is now Away`, …) show `--` in the nick column, replacing the old `**` prefix.
+- **Deterministic nickname colors** — users who haven't picked a `/color` now get an automatic, stable color derived from their nick (12-entry palette chosen to stay readable on dark and light backgrounds). The same user is the same color in message headers and the online-users panel, on every client, every session. An explicitly chosen nickname color still takes priority.
+- **Date separator rules** — a full-width `── Wed, Jul 16 2026 ─────` rule is inserted whenever the calendar day changes (live, in loaded history, and when scrolling back through older messages). Timestamps are now a compact `HH:mm` — the date lives in the rules instead of being repeated on every line.
+- **"New messages" marker** — the first message that arrives in a channel you're not viewing gets an orange `── new messages ──` rule above it (irssi-style). Switch to the channel and the marker shows exactly where you left off; it survives the history reload on channel switch and is consumed when you move away again.
+- **Status bar activity segment** — channels with unread messages appear in the status bar as `│ Act: #dev,#random` (up to 4, `+n` overflow). Channels where you were @mentioned show in orange, others in cyan.
+- **Connecting spinner** — transitional connection states (Connecting, Reconnecting, Authenticating…) now animate a braille spinner in the status bar instead of sitting on static text.
+- **Mention-aware channel list** — a channel where you were @mentioned turns orange in the channel list (name and unread badge), escalating above the cyan plain-unread highlight. The highlight clears when you view the channel.
+- **Welcome banner** — with no channel selected (fresh start, or after disconnecting) the chat pane shows a gold-gradient ASCII "ECHOHUB" logo with the version and key hints, instead of an empty box. Narrow panes get a compact variant.
+- **Rounded frame borders** — the channels, chat, input, and users panels draw with rounded corners.
+- **Auto-join all channels at connect** — the client now joins every channel it lists for you (public channels and prior memberships) as part of connecting, so message events flow for all of them: unread badges, @mention highlights, and the status-bar activity segment work without having to open each channel first. Protected channels you've never entered are skipped silently (joining them stays a prompted, manual action), and channels you `/leave` are remembered and excluded until you join them again.
+- **Read positions survive restarts** — the client persists the last message you read per channel (locally, per server). On the next connect it compares that against fetched history, so messages that arrived while you were offline still produce unread counts, mention highlights, and a correctly placed "new messages" marker.
+- **Theme-tinted frame borders** — themes can now color the window frame borders independently of text via a new optional `border` section (hex values supported). The Transparent and TransparentLight themes use it to draw dim gray borders instead of stark white ones, for a subtler, glassier look. Custom theme JSON files without a `border` section keep their base colors.
+
+## Bug Fixes
+
+- The @mention highlight no longer drops off the second and later lines of a long mention message — wrapped continuation lines now inherit the highlight.
+- The unread-position marker is re-anchored after a channel switch reloads history, instead of being wiped by the reload before you could see it.
+- Cached room keys for end-to-end encrypted channels no longer disappear from the config on reconnect. Saving the server entry after a successful connect replaced it wholesale, wiping the cached keys (and forcing a passphrase re-entry on the next launch); the entry is now updated in place.
+- A failed channel rejoin after a reconnect (e.g. a channel deleted while you were away) no longer aborts rejoining the remaining channels.
+- Client config file access is now serialized across threads (token refresh, room-key cache, and read-position checkpoints all write it), preventing rare config corruption.

docs/changelog/v0.2.14.md

@@ -0,0 +1,22 @@
+# v0.2.14
+
+A reliability and security pass over end-to-end encrypted rooms: locked channels now offer the passphrase prompt instead of dead-ending on the "rejoin to unlock" placeholder, the client can no longer be tricked into sending plaintext into an encrypted room, and cached room keys are encrypted at rest instead of sitting in the config as base64. Ctrl+V grows up too — images copied from a browser or screenshot tool paste straight into the chat as attachments, and copying several files pastes them all into one message. Plus a set of IRC gateway fixes — decrypted image previews, display-name plumbing, and user/channel indicators.
+
+## New Features
+
+- **Paste images straight from the clipboard** — copy an image from a browser, a screenshot tool (Win+Shift+S), or an image editor and Ctrl+V it into the input: it's attached as a PNG (`image.png`), no saving to disk first, Discord-style. Transparency is preserved when the source provides PNG data; plain clipboard bitmaps are converted automatically. On Linux this uses `wl-paste`/`xclip`; on macOS it requires `pngpaste`. In end-to-end encrypted rooms pasted images go through the same client-side encryption as any other attachment.
+- **Multi-file paste** — copying several files in your file manager and pasting attaches them all to a single message (up to the 10-attachment cap), staged as one batch alongside anything you type as the caption. Previously each pasted file was routed through its own `/send`, which could misbehave on large batches.
+- **Room keys encrypted at rest** — the per-channel room keys cached so you don't retype a passphrase every launch are no longer stored as plain base64 in `config.json`. On Windows they're protected with DPAPI (current-user scope); on Linux/macOS with AES-GCM under a per-user key file created with `0600` permissions next to the config. Existing plain entries migrate to the encrypted format automatically on first load. The passphrase itself is never stored in any form.
+- **`[irc]` tag in the users panel** — users online only through the IRC gateway are tagged `[irc]`, useful context since IRC clients lack encryption, attachments, and profiles. Someone also running the TUI shows untagged.
+- **`~` marker for private channels** — the channel list now marks private (unlisted) channels with a trailing `~`, alongside the existing `*` for password-protected ones (`#room*~` when both apply).
+
+## Bug Fixes
+
+- **Locked encrypted channels now prompt for the passphrase.** Auto-joining your channels at connect silently entered end-to-end encrypted rooms you're a member of without running the unlock flow — on a new device (or after a cancelled prompt) the room showed only `[encrypted — rejoin this channel with its passphrase to unlock]` placeholders, and only a manual `/join` recovered it. Selecting the channel now offers the passphrase prompt; entering it unlocks history and live messages in place. Cancelling is remembered for the session so reselecting the channel doesn't nag — `/join` or trying to send always re-offers the prompt.
+- **A stale cached room key no longer beats a fresh one.** If an encrypted channel was deleted and recreated under the same name, a client that still had the old key cached kept encrypting messages nobody else could read. Typing the passphrase on join now always adopts the key from the server's current envelope, replacing the stale cache.
+- **IRC clients no longer get flooded with ciphertext for image messages.** The gateway forwarded image ASCII previews without stripping transport encryption, spamming IRC clients with one enormous `$ENC$v1$…` line per image. Previews are now decrypted before formatting, and any that still can't be read (e.g. end-to-end room ciphertext the server cannot decrypt) are skipped in favor of the plain `[Image: name] url` line.
+- **Display names now show on chat messages.** Messages only carried the sender's username, so a configured display name appeared in the user list but not on the messages themselves. Live messages, history, and attachment messages now all carry it; mention and profile lookups stay keyed to the username.
+
+## Security
+
+- **No plaintext can leak into an encrypted room.** Previously, a client without the room key silently sent unencrypted text into an end-to-end encrypted channel (and other members saw it as a normal message, none the wiser it went over the wire readable by the server). All send paths — typed messages, staged file attachments, and URL sends — are now blocked while a room is locked: the client offers the unlock prompt, keeps staged files in the tray, and refuses to transmit until the key is present, with a hard guard at the connection layer as backstop.

docs/changelog/v0.2.15.md

@@ -0,0 +1,78 @@
+# v0.2.15
+
+A big one. Server owners can gate registration behind invite codes, users can export or delete
+everything the server holds about them, and chat gets three classics — `/me` actions that
+interop natively with IRC, `/banner` ASCII text, and message replies with quote rendering and
+jump-to-original. Images become properly shareable: every image gets an **[open]** action that
+views it in your browser (or, in end-to-end encrypted rooms, decrypts and opens it locally).
+The IRC gateway stops painting ANSI art nobody asked for and posts plain image links any IRC
+client can open or auto-preview. And a long-standing dual-session annoyance is fixed: messages
+you send from the TUI now reach your own connected IRC client instantly.
+
+## New Features
+
+- **Invite-gated registration** — set `Server:Registration` to `"invite"` (or `"closed"`) in
+  `appsettings.json` and new accounts require a valid invite code; the default `"open"` keeps
+  today's behavior. Admins mint codes with `/invite [uses] [hours]` (single-use, never-expiring
+  by default), list them with `/invite list`, and revoke with `/invite revoke <code>`. Codes are
+  unguessable (`K7QM-3XPF` style), stored only in your server's own database, and consumed
+  atomically so a code's last use can't be taken twice. The IRC gateway respects the gate too:
+  unknown nicknames connecting to an invite-only server get a clear error instead of a silent
+  auto-registered account. The very first account (server owner bootstrap) is always allowed.
+- **Data export** — `/export` downloads everything the server stores about you (profile, your
+  messages, attachment metadata) as JSON into your download folder. Content from end-to-end
+  encrypted rooms appears as ciphertext, because the server never had the plaintext — "you own
+  the data", demonstrably.
+- **Account deletion** — `/deleteaccount` permanently removes your account after a typed
+  confirmation and password re-check: profile, sessions, and every file you uploaded are
+  deleted. Your messages remain (deleting them would gut other people's conversations) but are
+  re-attributed to a reserved `deleted-user` name. The last remaining Owner can't self-delete.
+- **`/me` actions** — `/me waves` renders as `* nick waves`. On the wire it's a real CTCP
+  ACTION, so irssi/WeeChat users see a native action line, and their `/me` renders properly in
+  the TUI. Works in encrypted rooms (the marker encrypts with the text).
+- **`/banner <text>`** — renders short text (up to 20 characters) as a 5-row block-letter
+  banner. Rendered locally with a built-in font — no network, no dependencies — and sent as
+  plain message content, so it works over IRC and in encrypted rooms.
+- **Message replies** — right-click a message (or F6-select) and pick **Reply**: the input
+  shows a "Replying to" strip (Esc cancels), and the sent message renders with a dim
+  `┌ nick: snippet` quote line. Activating the quote line jumps to the original message.
+  Being replied to lights up the channel like an @mention. IRC clients see the familiar
+  `> nick: snippet | text` convention. In encrypted rooms the quoted snippet is decrypted
+  client-side with the room key — the server still never reads room content.
+- **`[open]` images without saving them** — every image attachment now shows `[open] [↓ save original]` beneath its preview. Open views the image in your default browser straight from the server; in end-to-end encrypted rooms (where a browser would only see ciphertext) the client downloads, decrypts with the room key, and opens the image in your OS viewer from a temp file instead. Both actions are individually clickable, Enter on the line opens, and the right-click menu carries both.
+- **Attachment links work in a browser** — `GET /api/files/{id}` is now a capability URL: the unguessable GUID in the link is the access token (Discord-CDN style), so attachment links can be opened directly in a browser or shared to IRC without a login token. Images and audio are served inline so the browser displays them instead of forcing a download. Blobs from encrypted rooms remain ciphertext, so their links reveal nothing.
+- **IRC gets image links instead of terminal art** — the gateway no longer floods IRC clients with truecolor-ANSI ASCII art for images. Each attachment is now a single line — `[Image: photo.png] https://your-server/api/files/…` — the convention every IRC client understands, and ones like TheLounge or IRCCloud auto-preview. Set the new `Irc:PublicBaseUrl` option (e.g. `"https://chat.example.com"`) so those links come out absolute; unset, they fall back to relative paths as before.
+- **Spam protection** — per-user message flood and duplicate-message limits, join and
+  channel-creation throttles, and automatic escalation: enough rejected sends in a few minutes
+  earns a timed auto-mute through the normal mute system (moderators see it, and it expires on
+  its own). One guard covers every ingress — TUI and IRC clients hit the same limits. Mods and
+  above are exempt, everything is configurable under the new `Spam` section
+  (`Spam:Enabled` master switch, lenient defaults a fast typist won't trip), and the guard only
+  ever sees stored content — encrypted-room messages stay ciphertext.
+
+## Improvements
+
+- **Strict `/status`** — `/status garbage` is now an error instead of silently becoming your
+  status message (and resetting you to Online). Status messages moved to `/status msg <text>`,
+  which preserves your current status; `/status msg` with no text clears it. The server also
+  rejects out-of-range status values sent by misbehaving clients.
+- **Registration dialog** — gained Invite Code support, and the Display Name field you could
+  already type into is now actually sent with registration.
+
+## Bug Fixes
+
+- **Messages sent from the TUI now reach your own IRC session.** With the same account online via both the TUI and an IRC client, messages sent from the TUI never appeared in the IRC client until it reconnected (which replayed history). The gateway suppressed the sender's echo by *nickname*, which swallowed the message for every IRC connection on that account — it now excludes only the exact connection a message originated from, so all your other sessions (a second IRC client included) receive it immediately.
+- **Channel deleted event** — when a channel is deleted, all connected clients are now immediately notified via the new `ChannelDeleted` SignalR event. The channel is removed from the channel list. Previously only the deleting client was able to delete the channel. Other clients would see the channel linger until the next manual refresh.
+- **Deleted accounts don't break history** — channel history now left-joins users, so messages
+  from deleted accounts render (as `deleted-user`) instead of silently disappearing.
+
+## Notes for server operators
+
+- New config key: `Server:Registration` — `"open"` (default), `"invite"`, or `"closed"`.
+- New config section: `Spam` — flood/duplicate/join/create thresholds and auto-mute duration;
+  see `appsettings.example.json`. On by default with lenient limits; `Spam:Enabled: false`
+  turns it all off. Note `Spam:MaxJoinsPerWindow` counts only *first-time* channel joins —
+  keep it above your public channel count so a new member's first connect isn't throttled.
+- New REST endpoints: `POST/GET/DELETE /api/invites` (Admin+), `GET /api/users/me/export`,
+  `DELETE /api/users/me`.
+- One new database migration (`AddInvitesAndReplies`) applies automatically on startup.

docs/docfx.json

@@ -46,7 +46,7 @@
     "content": [
       {
         "files": ["**/*.{md,yml}"],
-        "exclude": ["_site/**", "_api_meta/**"]
+        "exclude": ["_site/**", "_api_meta/**", "auriondocs/**"]
       },
       {
         "src": "_api_meta/core",
@@ -75,7 +75,7 @@
     ],
     "resource": [
       {
-        "files": ["images/**"]
+        "files": ["images/**", "auriondocs/**"]
       }
     ],
     "output": "_site",

docs/index.md

@@ -11,6 +11,10 @@ Welcome to the EchoHub documentation. EchoHub is a decentralized, IRC-style chat
 ## Quick Links
 
 - [Getting Started](articles/getting-started.md) - Set up and run EchoHub
+- [TUI Guide](articles/tui-guide.md) - Keyboard shortcuts, slash commands, and everyday usage
+- [Messages & Attachments](articles/messages-and-attachments.md) - Attaching, pasting, and receiving files
+- [Encrypted Rooms](articles/encrypted-rooms.md) - End-to-end encrypted channels
+- [IRC Gateway](articles/irc-gateway.md) - Connect with any IRC client
 - [Architecture](articles/architecture.md) - System design and IRC gateway
 - [API Reference](api/index.md) - Generated C# API documentation
 - [Changelog](changelog/index.md) - Release history

docs/toc.yml

@@ -7,3 +7,5 @@
 - name: API
   href: api/
   homepage: api/index.md
+- name: AurionDocs
+  href: auriondocs/index.html

docs/todo.md

@@ -3,7 +3,7 @@
 - [ ] fix the chat trailing; when user scrolls up, and somebody sends a message – the chat instantly "teleports" to the very bottom
 - [x] disable the autorun of files (maybe keep for mp4? gotta do some sec research on it)
 - [x] when user creates a new channel, he gets moved to that channel; but the userlist does not refresh the state on that – it refreshes when user re-enters the channel again
-- [ ] password protected rooms
+- [x] password protected rooms (end-to-end encrypted — server cannot read contents)
 - [ ] better audio lib, current one (NetCoreAudio) does not support seek or other audio actions
 - [ ] Use options pattern for both client & server
   - ref: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/configuration/options?view=aspnetcore-10.0

package.json

@@ -0,0 +1,12 @@
+{
+  "name": "echohub",
+  "private": true,
+  "description": "Repo tooling — markdown linting. Not an npm package.",
+  "scripts": {
+    "lint:md": "markdownlint-cli2",
+    "lint:md:fix": "markdownlint-cli2 --fix"
+  },
+  "devDependencies": {
+    "markdownlint-cli2": "^0.23.0"
+  }
+}

packaging/choco/echohub.nuspec

@@ -4,11 +4,11 @@
     <id>echohub</id>
     <version>__VERSION__</version>
     <title>EchoHub</title>
-    <authors>HueByte</authors>
+    <authors>HueByte, StoneRed</authors>
     <owners>HueByte</owners>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <licenseUrl>https://github.com/HueByte/EchoHub/blob/master/LICENSE</licenseUrl>
-    <projectUrl>https://github.com/HueByte/EchoHub</projectUrl>
+    <projectUrl>https://echohub.voidcube.cloud/</projectUrl>
     <projectSourceUrl>https://github.com/HueByte/EchoHub</projectSourceUrl>
     <docsUrl>https://huebyte.github.io/EchoHub</docsUrl>
     <bugTrackerUrl>https://github.com/HueByte/EchoHub/issues</bugTrackerUrl>

packaging/choco/tools/LICENSE.txt

@@ -1,21 +0,0 @@
-MIT License
-
-Copyright (c) 2026 Hue
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.

packaging/choco/tools/VERIFICATION.txt

@@ -1,17 +0,0 @@
-VERIFICATION
-
-To verify the package contents:
-
-1. Download the official release from:
-   https://github.com/HueByte/EchoHub/releases
-
-2. Download: EchoHub-Client-win-x64.zip
-
-3. Calculate the SHA256 checksum:
-   - PowerShell: Get-FileHash EchoHub-Client-win-x64.zip -Algorithm SHA256
-   - Linux/macOS: sha256sum EchoHub-Client-win-x64.zip
-
-4. Compare with the checksum in chocolateyInstall.ps1 (checksum64 value).
-
-LICENSE: MIT License - see LICENSE.txt in this directory or
-https://github.com/HueByte/EchoHub/blob/master/LICENSE

scripts/install.sh

@@ -30,7 +30,7 @@ while [ $# -gt 0 ]; do
             sed -n '2,8p' "$0" 2>/dev/null || true
             echo ""
             echo "  curl -sSfL https://raw.githubusercontent.com/$REPO/master/scripts/install.sh | sh"
-            echo "  curl ... | sh -s -- --version 0.2.10"
+            echo "  curl ... | sh -s -- --version 0.2.11"
             echo "  curl ... | sh -s -- --install-dir /opt/echohub"
             exit 0
             ;;

scripts/lint-markdown.ps1

@@ -0,0 +1,61 @@
+# EchoHub - Markdown Lint
+#
+# Runs markdownlint-cli2 over the repo. Rules, globs, and ignores all live in
+# .markdownlint-cli2.jsonc; the linter version is pinned in package.json.
+#
+# Usage:
+#   .\scripts\lint-markdown.ps1            # lint-only, exits non-zero on violations
+#   .\scripts\lint-markdown.ps1 -Fix       # auto-fix what markdownlint can
+#
+# Requires: Node + npx on PATH. Prefers the locally installed linter
+# (`npm install` once); otherwise npx fetches the same pinned version.
+
+param(
+    [switch]$Fix
+)
+
+$ErrorActionPreference = "Stop"
+
+if (-not (Get-Command npx -ErrorAction SilentlyContinue)) {
+    Write-Host "  ERROR: npx not found on PATH. Install Node.js (https://nodejs.org) and retry." -ForegroundColor Red
+    exit 1
+}
+
+$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
+$RootDir   = Split-Path -Parent $ScriptDir
+
+Push-Location $RootDir
+try {
+    # Local install is version-pinned via package.json/package-lock.json; the
+    # npx fallback pins the same version so CI and local can never drift.
+    if (Test-Path "node_modules/.bin/markdownlint-cli2") {
+        $npxArgs = @('--no-install', 'markdownlint-cli2')
+    } else {
+        $npxArgs = @('--yes', '[email protected]')
+    }
+
+    if ($Fix) {
+        Write-Host "  Auto-fix mode (--fix): markdownlint will rewrite files in place." -ForegroundColor Yellow
+        $npxArgs += '--fix'
+    }
+
+    Write-Host "  > npx $($npxArgs -join ' ')" -ForegroundColor Gray
+    & npx @npxArgs
+    $exit = $LASTEXITCODE
+
+    if ($exit -eq 0) {
+        Write-Host "  Markdown lint clean." -ForegroundColor Green
+    } elseif ($Fix) {
+        Write-Host ""
+        Write-Host "  Some issues could not be auto-fixed. Review the output above and fix manually." -ForegroundColor Yellow
+    } else {
+        Write-Host ""
+        Write-Host "  Markdown lint failed. Re-run with -Fix to auto-correct the fixable rules:" -ForegroundColor Red
+        Write-Host "    .\scripts\lint-markdown.ps1 -Fix" -ForegroundColor Yellow
+    }
+
+    exit $exit
+}
+finally {
+    Pop-Location
+}

scripts/lint-markdown.sh

@@ -2,6 +2,8 @@
 #
 # Lint all Markdown files in the repository.
 # Config, globs, and ignores are defined in .markdownlint-cli2.jsonc.
+# The linter version is pinned in package.json — run `npm install` once,
+# or just use `npm run lint:md` / `npm run lint:md:fix` directly.
 #
 # Usage:
 #   ./scripts/lint-markdown.sh          # check
@@ -12,11 +14,12 @@ set -euo pipefail
 REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
 cd "$REPO_ROOT"
 
-# Resolve markdownlint-cli2 binary
+# Prefer the locally installed (version-pinned) linter; fall back to a one-off
-if command -v markdownlint-cli2 &>/dev/null; then
+# npx install of the same version pinned in package.json.
-    LINT_CMD="markdownlint-cli2"
+if [ -x "node_modules/.bin/markdownlint-cli2" ]; then
+    LINT_CMD="npx --no-install markdownlint-cli2"
 else
-    LINT_CMD="npx --yes markdownlint-cli2"
+    LINT_CMD="npx --yes markdownlint-cli2@0.23.0"
 fi
 
 echo "Linting Markdown files..."

src/.dockerignore

@@ -0,0 +1,2 @@
+**/obj/
+**/bin/

src/Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>0.2.10</Version>
+    <Version>0.2.15</Version>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
   </PropertyGroup>

src/EchoHub.Client/Commands/CommandHandler.cs

@@ -6,17 +6,34 @@ public record CommandResult(bool Handled, string? Message = null, bool IsError =
 
 public class CommandHandler
 {
-    public event Func<UserStatus, string?, Task>? OnSetStatus;
+    /// <summary>
+    /// Status update. A null status means "keep the current status"; a null message means
+    /// "keep the current message" and an empty message means "clear it". The orchestrator
+    /// resolves both against the session state.
+    /// </summary>
+    public event Func<UserStatus?, string?, Task>? OnSetStatus;
+    public event Func<string, Task>? OnSendAction;
+    public event Func<string, Task>? OnSendBanner;
+    public event Func<int?, int?, Task>? OnCreateInvite;
+    public event Func<Task>? OnListInvites;
+    public event Func<string, Task>? OnRevokeInvite;
+    public event Func<Task>? OnExportData;
+    public event Func<Task>? OnDeleteAccount;
     public event Func<string, Task>? OnSetNick;
     public event Func<string, Task>? OnSetColor;
     public event Func<string, Task>? OnSetTheme;
     public event Func<string, string?, Task>? OnSendFile;
     public event Func<string?, Task>? OnOpenProfile;
     public event Func<Task>? OnOpenServers;
-    public event Func<string, Task>? OnJoinChannel;
+    public event Func<string, string?, Task>? OnJoinChannel;
+    public event Func<string, string, Task>? OnChangeRoomPassword;
+    public event Func<Task>? OnClearAttachments;
+    public event Func<string, Task>? OnSetDownloadPath;
+    public event Func<string, Task>? OnSetAsciiSize;
     public event Func<Task>? OnLeaveChannel;
     public event Func<string, Task>? OnSetTopic;
     public event Func<Task>? OnListUsers;
+    public event Func<Task>? OnRoomInfo;
     public event Func<string, Task>? OnSetAvatar;
     public event Func<string, string?, Task>? OnKickUser;
     public event Func<string, string?, Task>? OnBanUser;
@@ -43,17 +60,27 @@ public class CommandHandler
         return command switch
         {
             "status" => await HandleStatus(args),
+            "me" => await HandleMe(args),
+            "banner" => await HandleBanner(args),
+            "invite" => await HandleInvite(args),
+            "export" => await HandleExport(),
+            "deleteaccount" => await HandleDeleteAccount(),
             "nick" => await HandleNick(args),
             "color" => await HandleColor(args),
             "theme" => await HandleTheme(args),
             "send" => await HandleSend(args),
+            "clear" => await HandleClear(),
+            "size" or "asciisize" => await HandleAsciiSize(args),
+            "downloadpath" or "downloads" => await HandleDownloadPath(args),
             "profile" => await HandleProfile(args),
             "avatar" => await HandleAvatar(args),
             "servers" => await HandleServers(),
             "join" => await HandleJoin(args),
+            "passwd" => await HandlePasswd(args),
             "leave" => await HandleLeave(),
             "topic" => await HandleTopic(args),
             "users" => await HandleUsers(),
+            "meta" or "info" => await HandleMeta(),
             "kick" => await HandleKick(args),
             "ban" => await HandleBan(args),
             "unban" => await HandleUnban(args),
@@ -68,12 +95,28 @@ public class CommandHandler
         };
     }
 
+    private const string StatusUsage =
+        "Usage: /status <online|away|dnd|invisible> or /status msg <text> (empty text clears it)";
+
     private async Task<CommandResult> HandleStatus(string args)
     {
         if (string.IsNullOrWhiteSpace(args))
-            return new CommandResult(true, "Usage: /status <online|away|dnd|invisible> or /status <message>", IsError: true);
+            return new CommandResult(true, StatusUsage, IsError: true);
+
+        var parts = args.Trim().Split(' ', 2, StringSplitOptions.TrimEntries);
+        var statusArg = parts[0].ToLowerInvariant();
+
+        // /status msg <text> — set/clear the message, keep the current status
+        if (statusArg is "msg" or "message")
+        {
+            var message = parts.Length > 1 ? parts[1] : string.Empty;
+            if (OnSetStatus is not null)
+                await OnSetStatus(null, message);
+            return new CommandResult(true, message.Length > 0
+                ? $"Status message set: {message}"
+                : "Status message cleared.");
+        }
 
-        var statusArg = args.ToLowerInvariant().Trim();
         UserStatus? status = statusArg switch
         {
             "online" => UserStatus.Online,
@@ -83,17 +126,92 @@ public class CommandHandler
             _ => null,
         };
 
-        if (status.HasValue)
+        // Strict: anything else is an error — no silent "it became your status message"
+        if (!status.HasValue)
+            return new CommandResult(true, $"Unknown status '{parts[0]}'. {StatusUsage}", IsError: true);
+
+        if (parts.Length > 1)
+            return new CommandResult(true, StatusUsage, IsError: true);
+
+        if (OnSetStatus is not null)
+            await OnSetStatus(status.Value, null);
+        return new CommandResult(true, $"Status set to {status.Value}");
+    }
+
+    private async Task<CommandResult> HandleMe(string args)
+    {
+        if (string.IsNullOrWhiteSpace(args))
+            return new CommandResult(true, "Usage: /me <action> (e.g. /me waves)", IsError: true);
+
+        if (OnSendAction is not null)
+            await OnSendAction(args.Trim());
+        return new CommandResult(true);
+    }
+
+    private async Task<CommandResult> HandleBanner(string args)
+    {
+        if (string.IsNullOrWhiteSpace(args))
+            return new CommandResult(true, "Usage: /banner <text> (letters, digits, basic punctuation)", IsError: true);
+
+        if (OnSendBanner is not null)
+            await OnSendBanner(args.Trim());
+        return new CommandResult(true);
+    }
+
+    private async Task<CommandResult> HandleInvite(string args)
+    {
+        var parts = args.Split(' ', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+
+        // /invite list
+        if (parts.Length > 0 && parts[0].Equals("list", StringComparison.OrdinalIgnoreCase))
         {
-            if (OnSetStatus is not null)
+            if (OnListInvites is not null)
-                await OnSetStatus(status.Value, null);
+                await OnListInvites();
-            return new CommandResult(true, $"Status set to {status.Value}");
+            return new CommandResult(true);
         }
 
-        // Treat as custom status message (keep current status)
+        // /invite revoke <code>
-        if (OnSetStatus is not null)
+        if (parts.Length > 0 && parts[0].Equals("revoke", StringComparison.OrdinalIgnoreCase))
-            await OnSetStatus(UserStatus.Online, args);
+        {
-        return new CommandResult(true, $"Status message set: {args}");
+            if (parts.Length < 2)
+                return new CommandResult(true, "Usage: /invite revoke <code>", IsError: true);
+            if (OnRevokeInvite is not null)
+                await OnRevokeInvite(parts[1]);
+            return new CommandResult(true);
+        }
+
+        // /invite [maxUses] [expiresHours] — defaults to a single-use, never-expiring code
+        int? maxUses = null, expiresHours = null;
+        if (parts.Length > 0)
+        {
+            if (!int.TryParse(parts[0], out var uses) || uses < 1)
+                return new CommandResult(true, "Usage: /invite [maxUses] [expiresHours] | /invite list | /invite revoke <code>", IsError: true);
+            maxUses = uses;
+        }
+        if (parts.Length > 1)
+        {
+            if (!int.TryParse(parts[1], out var hours) || hours < 1)
+                return new CommandResult(true, "Usage: /invite [maxUses] [expiresHours]", IsError: true);
+            expiresHours = hours;
+        }
+
+        if (OnCreateInvite is not null)
+            await OnCreateInvite(maxUses, expiresHours);
+        return new CommandResult(true);
+    }
+
+    private async Task<CommandResult> HandleExport()
+    {
+        if (OnExportData is not null)
+            await OnExportData();
+        return new CommandResult(true);
+    }
+
+    private async Task<CommandResult> HandleDeleteAccount()
+    {
+        if (OnDeleteAccount is not null)
+            await OnDeleteAccount();
+        return new CommandResult(true);
     }
 
     private async Task<CommandResult> HandleNick(string args)
@@ -126,7 +244,7 @@ public class CommandHandler
     private async Task<CommandResult> HandleTheme(string args)
     {
         if (string.IsNullOrWhiteSpace(args))
-            return new CommandResult(true, "Usage: /theme <name> (Default, Dark, Light, Hacker, Solarized)", IsError: true);
+            return new CommandResult(true, "Usage: /theme <name> — pick one from the User menu's theme list (e.g. Default, Transparent, TransparentLight, Hacker)", IsError: true);
 
         if (OnSetTheme is not null)
             await OnSetTheme(args.Trim());
@@ -163,6 +281,29 @@ public class CommandHandler
         return new CommandResult(true, $"Uploading: {Path.GetFileName(target)}...");
     }
 
+    private async Task<CommandResult> HandleClear()
+    {
+        if (OnClearAttachments is not null)
+            await OnClearAttachments();
+        return new CommandResult(true, "Cleared staged attachments.");
+    }
+
+    private async Task<CommandResult> HandleAsciiSize(string args)
+    {
+        // No argument → open the size picker; an argument (s/m/l or small/medium/large) sets it.
+        if (OnSetAsciiSize is not null)
+            await OnSetAsciiSize(args.Trim());
+        return new CommandResult(true);
+    }
+
+    private async Task<CommandResult> HandleDownloadPath(string args)
+    {
+        // No argument → open the native folder picker; an argument sets the path directly.
+        if (OnSetDownloadPath is not null)
+            await OnSetDownloadPath(args.Trim());
+        return new CommandResult(true);
+    }
+
     private async Task<CommandResult> HandleProfile(string args)
     {
         var username = string.IsNullOrWhiteSpace(args) ? null : args.Trim();
@@ -193,11 +334,28 @@ public class CommandHandler
     private async Task<CommandResult> HandleJoin(string args)
     {
         if (string.IsNullOrWhiteSpace(args))
-            return new CommandResult(true, "Usage: /join <channel>", IsError: true);
+            return new CommandResult(true, "Usage: /join <channel> [password]", IsError: true);
+
+        var parts = args.Trim().Split(' ', 2, StringSplitOptions.TrimEntries);
+        var channel = parts[0].TrimStart('#');
+        var password = parts.Length > 1 && !string.IsNullOrWhiteSpace(parts[1]) ? parts[1] : null;
 
-        var channel = args.Trim().TrimStart('#');
         if (OnJoinChannel is not null)
-            await OnJoinChannel(channel);
+            await OnJoinChannel(channel, password);
+        return new CommandResult(true);
+    }
+
+    private async Task<CommandResult> HandlePasswd(string args)
+    {
+        var parts = args.Split(' ', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+        if (parts.Length != 2)
+            return new CommandResult(true, "Usage: /passwd <old passphrase> <new passphrase> — changes the current encrypted channel's passphrase", IsError: true);
+
+        if (parts[1].Length < 3)
+            return new CommandResult(true, "New passphrase must be at least 3 characters.", IsError: true);
+
+        if (OnChangeRoomPassword is not null)
+            await OnChangeRoomPassword(parts[0], parts[1]);
         return new CommandResult(true);
     }
 
@@ -225,6 +383,13 @@ public class CommandHandler
         return new CommandResult(true);
     }
 
+    private async Task<CommandResult> HandleMeta()
+    {
+        if (OnRoomInfo is not null)
+            await OnRoomInfo();
+        return new CommandResult(true);
+    }
+
     private async Task<CommandResult> HandleQuit()
     {
         if (OnQuit is not null)
@@ -335,18 +500,32 @@ public class CommandHandler
         return new CommandResult(true, """
             Available commands:
               /status <online|away|dnd|invisible>  - Set your status
-              /status <message>                    - Set status message
+              /status msg <text>                   - Set status message (empty = clear)
+              /me <action>                         - Action message (* nick waves)
+              /banner <text>                       - Send text as an ASCII banner
               /nick <name>                         - Set display name
               /color <#hex>                        - Set nickname color
               /theme <name>                        - Switch theme
-              /send <filepath or URL> [-s|-m|-l]      - Send file/image/audio (size flag for images)
+              /send <filepath> [-s|-m|-l]          - Stage a file to attach (Enter sends with your text)
+              /send <URL> [-s|-m|-l]               - Send an image URL immediately
+              /clear                               - Drop all staged attachments
+              /size [s|m|l]                        - ASCII art size for attached images (no arg = picker)
+            (Tip: copy a file and press Ctrl+V, or drag a file onto the window, to attach it.)
+            (Tip: right-click a message for actions — delete, save/download/play attachment,
+                  mention, view profile, copy. Or press F6 to pick a message, then Delete.)
+              /downloadpath [path]                 - Set download folder (no path = native folder picker)
               /avatar <URL or filepath>             - Set your avatar
               /profile [username]                   - View a profile
               /servers                             - Open saved servers
-              /join <channel>                      - Join a channel
+              /join <channel> [password]           - Join a channel (password if protected)
+              /passwd <old> <new>                  - Change current encrypted channel's passphrase
               /leave                               - Leave current channel
               /topic <text>                        - Set channel topic
               /users                               - List online users
+              /meta                                - Show room info (size, messages, users, created, id)
+              /export                              - Download everything the server stores about you
+              /deleteaccount                       - Permanently delete your account
+            (Tip: right-click a message and pick Reply to quote it; Esc cancels a pending reply.)
             Moderation:
               /kick <user> [reason]                - Kick a user (Mod+)
               /ban <user> [reason]                 - Ban a user (Admin+)
@@ -354,6 +533,8 @@ public class CommandHandler
               /mute <user> [minutes]               - Mute a user (Mod+)
               /unmute <user>                       - Unmute a user (Mod+)
               /role <user> <admin|mod|member>      - Assign role (Admin+)
+              /invite [uses] [hours]               - Create a registration invite code (Admin+)
+              /invite list | revoke <code>         - Manage invite codes (Admin+)
               /nuke                                - Clear channel history (Mod+)
               /test-sound                          - Play notification sound
               /quit                                - Exit the app

src/EchoHub.Client/Config/ClientConfig.cs

@@ -6,6 +6,18 @@ public class ClientConfig
     public AccountPreset DefaultPreset { get; set; } = new();
     public string ActiveTheme { get; set; } = "Default";
     public NotificationConfig Notifications { get; set; } = new();
+
+    /// <summary>
+    /// Folder where downloaded attachments and saved images are written. When null, the
+    /// OS Downloads folder is used. Set via the native folder picker or <c>/downloadpath</c>.
+    /// </summary>
+    public string? DownloadPath { get; set; }
+
+    /// <summary>
+    /// ASCII-art rendering size for images you attach: "s" (40×40), "m" (80×80), or "l" (120×120).
+    /// Applies to copy-paste/drag-drop attachments, which have no per-file size flag.
+    /// </summary>
+    public string DefaultAsciiSize { get; set; } = "m";
 }
 
 public class NotificationConfig
@@ -23,6 +35,26 @@ public class SavedServer
     public string? RefreshToken { get; set; }
     public bool RememberMe { get; set; }
     public DateTimeOffset LastConnected { get; set; }
+
+    /// <summary>
+    /// Cached room content keys for end-to-end encrypted channels on this server,
+    /// keyed by channel name and encrypted at rest (see RoomKeyProtector; legacy
+    /// entries were plain base64). Like RefreshToken, these live only on the
+    /// user's machine — the server never sees them.
+    /// </summary>
+    public Dictionary<string, string> ChannelKeys { get; set; } = [];
+
+    /// <summary>
+    /// Channels the user explicitly left with /leave. Excluded from the automatic
+    /// join-all-channels pass at connect until the user joins them again.
+    /// </summary>
+    public List<string> LeftChannels { get; set; } = [];
+
+    /// <summary>
+    /// Last message the user has read per channel (message id as string), persisted so
+    /// unread counts, @mention highlights, and the "new messages" marker survive restarts.
+    /// </summary>
+    public Dictionary<string, string> LastReadMessages { get; set; } = [];
 }
 
 public class AccountPreset

src/EchoHub.Client/Config/ConfigManager.cs

@@ -9,6 +9,13 @@ public static class ConfigManager
 
     private static readonly string ConfigPath = Path.Combine(ConfigDir, "config.json");
 
+    /// <summary>Directory holding the client config and local key material.</summary>
+    public static string ConfigDirectory => ConfigDir;
+
+    // Load-mutate-save cycles run from both the UI thread and background tasks
+    // (token refresh, room keys, last-read checkpoints) — serialize file access.
+    private static readonly Lock FileLock = new();
+
     private static readonly JsonSerializerOptions JsonOptions = new()
     {
         WriteIndented = true,
@@ -17,54 +24,66 @@ public static class ConfigManager
 
     public static ClientConfig Load()
     {
-        try
+        lock (FileLock)
         {
-            if (!File.Exists(ConfigPath))
+            try
-                return new ClientConfig();
+            {
+                if (!File.Exists(ConfigPath))
+                    return new ClientConfig();
 
-            var json = File.ReadAllText(ConfigPath);
+                var json = File.ReadAllText(ConfigPath);
-            return JsonSerializer.Deserialize<ClientConfig>(json, JsonOptions) ?? new ClientConfig();
+                return JsonSerializer.Deserialize<ClientConfig>(json, JsonOptions) ?? new ClientConfig();
-        }
+            }
-        catch
+            catch
-        {
+            {
-            return new ClientConfig();
+                return new ClientConfig();
+            }
         }
     }
 
     public static void Save(ClientConfig config)
     {
-        try
+        lock (FileLock)
         {
-            Directory.CreateDirectory(ConfigDir);
+            try
-            var json = JsonSerializer.Serialize(config, JsonOptions);
+            {
-            File.WriteAllText(ConfigPath, json);
+                Directory.CreateDirectory(ConfigDir);
-        }
+                var json = JsonSerializer.Serialize(config, JsonOptions);
-        catch
+                File.WriteAllText(ConfigPath, json);
-        {
+            }
-            // Silently fail — config save is best-effort
+            catch
+            {
+                // Silently fail — config save is best-effort
+            }
         }
     }
 
     public static void SaveServer(SavedServer server)
     {
-        var config = Load();
+        lock (FileLock)
-        var existing = config.SavedServers.FindIndex(s =>
+        {
-            string.Equals(s.Url, server.Url, StringComparison.OrdinalIgnoreCase));
+            var config = Load();
+            var existing = config.SavedServers.FindIndex(s =>
+                string.Equals(s.Url, server.Url, StringComparison.OrdinalIgnoreCase));
 
-        if (existing >= 0)
+            if (existing >= 0)
-            config.SavedServers[existing] = server;
+                config.SavedServers[existing] = server;
-        else
+            else
-            config.SavedServers.Add(server);
+                config.SavedServers.Add(server);
 
-        Save(config);
+            Save(config);
+        }
     }
 
     public static void RemoveServer(string url)
     {
-        var config = Load();
+        lock (FileLock)
-        config.SavedServers.RemoveAll(s =>
+        {
-            string.Equals(s.Url, url, StringComparison.OrdinalIgnoreCase));
+            var config = Load();
+            config.SavedServers.RemoveAll(s =>
+                string.Equals(s.Url, url, StringComparison.OrdinalIgnoreCase));
 
-        Save(config);
+            Save(config);
+        }
     }
 }

src/EchoHub.Client/EchoHub.Client.csproj

@@ -12,6 +12,7 @@
     <PackageReference Include="Serilog" Version="4.3.1" />
     <PackageReference Include="Serilog.Settings.Configuration" Version="10.0.0" />
     <PackageReference Include="Serilog.Sinks.File" Version="7.0.0" />
+    <PackageReference Include="System.Security.Cryptography.ProtectedData" Version="10.0.3" />
     <PackageReference Include="Terminal.Gui" Version="2.0.0-develop.5043" />
   </ItemGroup>
 

src/EchoHub.Client/Program.cs

@@ -126,10 +126,24 @@ try
     var theme = ThemeManager.GetTheme(config.ActiveTheme);
     ThemeManager.ApplyTheme(theme);
 
-    using var orchestrator = new AppOrchestrator(app, config);
+    var orchestrator = new AppOrchestrator(app, config);
 
     app.Run(orchestrator.MainWindow);
+
+    // Capture any confirmed update before tearing anything down, then restore the console.
+    var pendingUpdate = orchestrator.PendingUpdate;
     app.Dispose();
+
+    // Apply the update on a clean console: the TUI has released it, so the updater can extract
+    // and restart the process without deadlocking against the alternate-screen buffer. This call
+    // ends by starting the new version and calling Environment.Exit, so it does not return.
+    if (pendingUpdate is not null)
+    {
+        Log.Information("Applying confirmed update after shutdown");
+        await pendingUpdate();
+    }
+
+    orchestrator.Dispose();
 }
 catch (Exception ex)
 {

src/EchoHub.Client/Services/ApiClient.cs

@@ -29,9 +29,9 @@ public sealed class ApiClient : IDisposable
         };
     }
 
-    public async Task<LoginResponse> RegisterAsync(string username, string password, string? displayName = null)
+    public async Task<LoginResponse> RegisterAsync(string username, string password, string? displayName = null, string? inviteCode = null)
     {
-        var request = new RegisterRequest(username, password, displayName);
+        var request = new RegisterRequest(username, password, displayName, inviteCode);
         using var response = await _http.PostAsJsonAsync("/api/auth/register", request);
         await EnsureSuccessAsync(response);
 
@@ -185,17 +185,35 @@ public sealed class ApiClient : IDisposable
         return result?.AvatarAscii;
     }
 
-    public async Task<MessageDto?> UploadFileAsync(string channelName, Stream fileStream, string fileName, string? size = null)
+    /// <summary>
+    /// Sends one message with optional text and one or more file attachments.
+    /// For end-to-end encrypted channels each attachment carries a declared kind and a
+    /// room-encrypted preview (empty when none); the caption is likewise room-encrypted.
+    /// </summary>
+    public async Task<MessageDto?> SendMessageWithAttachmentsAsync(
+        string channelName, string content, IReadOnlyList<OutgoingAttachment> attachments, string? size = null)
     {
         EnsureAuthenticated();
-        using var content = new MultipartFormDataContent();
+        using var form = new MultipartFormDataContent { { new StringContent(content), "content" } };
-        using var streamContent = new StreamContent(fileStream);
+
-        streamContent.Headers.ContentType = new MediaTypeHeaderValue(GetContentType(fileName));
+        foreach (var att in attachments)
-        content.Add(streamContent, "file", fileName);
+        {
+            var streamContent = new StreamContent(att.Stream);
+            streamContent.Headers.ContentType = new MediaTypeHeaderValue(GetContentType(att.FileName));
+            form.Add(streamContent, "file", att.FileName);
+
+            // Encrypted channels: one kind + preview per file, in the same order, to keep
+            // the server's index alignment (empty preview string for non-images).
+            if (att.DeclaredKind is not null)
+            {
+                form.Add(new StringContent(att.DeclaredKind), "kind");
+                form.Add(new StringContent(att.EncryptedPreview ?? string.Empty), "preview");
+            }
+        }
 
         var sizeQuery = size is not null ? $"?size={size}" : "";
         using var response = await AuthenticatedRequestAsync(() =>
-            _http.PostAsync($"/api/channels/{Uri.EscapeDataString(channelName)}/upload{sizeQuery}", content));
+            _http.PostAsync($"/api/channels/{Uri.EscapeDataString(channelName)}/messages{sizeQuery}", form));
         await EnsureSuccessAsync(response);
         return await response.Content.ReadFromJsonAsync<MessageDto>();
     }
@@ -228,16 +246,54 @@ public sealed class ApiClient : IDisposable
         return tempPath;
     }
 
-    public async Task<ChannelDto?> CreateChannelAsync(string name, string? topic = null, bool isPublic = true)
+    public async Task<ChannelDto?> CreateChannelAsync(string name, string? topic = null, bool isPublic = true,
+        string? password = null, string? encryptionSalt = null, string? wrappedRoomKey = null)
     {
         EnsureAuthenticated();
-        var request = new CreateChannelRequest(name, topic, isPublic);
+        var request = new CreateChannelRequest(name, topic, isPublic, password, encryptionSalt, wrappedRoomKey);
         using var response = await AuthenticatedRequestAsync(() =>
             _http.PostAsJsonAsync("/api/channels", request));
         await EnsureSuccessAsync(response);
         return await response.Content.ReadFromJsonAsync<ChannelDto>();
     }
 
+    /// <summary>
+    /// Fetches a channel's public crypto metadata (whether it's E2E-encrypted and its
+    /// key-derivation salt). Returns null when the channel doesn't exist.
+    /// </summary>
+    public async Task<ChannelCryptoDto?> GetChannelCryptoAsync(string channelName)
+    {
+        EnsureAuthenticated();
+        using var response = await AuthenticatedGetAsync($"/api/channels/{Uri.EscapeDataString(channelName)}/crypto");
+        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
+            return null;
+        await EnsureSuccessAsync(response);
+        return await response.Content.ReadFromJsonAsync<ChannelCryptoDto>();
+    }
+
+    /// <summary>
+    /// Fetches a channel's human-facing metadata (message count, unique posters, estimated
+    /// size, created date, room id) for the <c>/meta</c> command. Returns null if it doesn't exist.
+    /// </summary>
+    public async Task<ChannelMetaDto?> GetChannelMetaAsync(string channelName)
+    {
+        EnsureAuthenticated();
+        using var response = await AuthenticatedGetAsync($"/api/channels/{Uri.EscapeDataString(channelName)}/meta");
+        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
+            return null;
+        await EnsureSuccessAsync(response);
+        return await response.Content.ReadFromJsonAsync<ChannelMetaDto>();
+    }
+
+    public async Task<ChannelDto?> RekeyChannelAsync(string channelName, RekeyChannelRequest request)
+    {
+        EnsureAuthenticated();
+        using var response = await AuthenticatedRequestAsync(() =>
+            _http.PostAsJsonAsync($"/api/channels/{Uri.EscapeDataString(channelName)}/rekey", request));
+        await EnsureSuccessAsync(response);
+        return await response.Content.ReadFromJsonAsync<ChannelDto>();
+    }
+
     public async Task<ChannelDto?> UpdateChannelTopicAsync(string channelName, string? topic)
     {
         EnsureAuthenticated();
@@ -256,6 +312,54 @@ public sealed class ApiClient : IDisposable
         await EnsureSuccessAsync(response);
     }
 
+    // ── Invites / Account ─────────────────────────────────────────────────
+
+    public async Task<InviteDto?> CreateInviteAsync(int? maxUses = null, int? expiresInHours = null)
+    {
+        EnsureAuthenticated();
+        using var response = await AuthenticatedRequestAsync(() =>
+            _http.PostAsJsonAsync("/api/invites", new CreateInviteRequest(maxUses, expiresInHours)));
+        await EnsureSuccessAsync(response);
+        return await response.Content.ReadFromJsonAsync<InviteDto>();
+    }
+
+    public async Task<List<InviteDto>> GetInvitesAsync()
+    {
+        EnsureAuthenticated();
+        using var response = await AuthenticatedGetAsync("/api/invites");
+        await EnsureSuccessAsync(response);
+        return await response.Content.ReadFromJsonAsync<List<InviteDto>>() ?? [];
+    }
+
+    public async Task RevokeInviteAsync(string code)
+    {
+        EnsureAuthenticated();
+        using var response = await AuthenticatedRequestAsync(() =>
+            _http.DeleteAsync($"/api/invites/{Uri.EscapeDataString(code)}"));
+        await EnsureSuccessAsync(response);
+    }
+
+    /// <summary>Downloads the caller's full data export as raw JSON text.</summary>
+    public async Task<string> ExportMyDataAsync()
+    {
+        EnsureAuthenticated();
+        using var response = await AuthenticatedGetAsync("/api/users/me/export");
+        await EnsureSuccessAsync(response);
+        return await response.Content.ReadAsStringAsync();
+    }
+
+    /// <summary>Deletes the caller's account. The password re-confirms intent.</summary>
+    public async Task DeleteMyAccountAsync(string password)
+    {
+        EnsureAuthenticated();
+        using var response = await AuthenticatedRequestAsync(() =>
+            _http.SendAsync(new HttpRequestMessage(HttpMethod.Delete, "/api/users/me")
+            {
+                Content = JsonContent.Create(new DeleteAccountRequest(password)),
+            }));
+        await EnsureSuccessAsync(response);
+    }
+
     // ── Moderation ────────────────────────────────────────────────────────
 
     public async Task AssignRoleAsync(string username, ServerRole role)

src/EchoHub.Client/Services/ClipboardFiles.cs

@@ -0,0 +1,154 @@
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using System.Text;
+using Serilog;
+
+namespace EchoHub.Client.Services;
+
+/// <summary>
+/// Reads file paths that live on the OS clipboard as a *file list* (e.g. after copying a file in
+/// Explorer/Finder/Nautilus), which terminals do not paste as text. Lets Ctrl+V attach a copied
+/// file directly instead of requiring the user to paste a raw path.
+/// </summary>
+public static class ClipboardFiles
+{
+    public static bool TryGetFiles(out List<string> files)
+    {
+        files = [];
+        try
+        {
+            if (OperatingSystem.IsWindows())
+                return TryGetWindows(out files);
+            if (OperatingSystem.IsLinux())
+                return TryGetLinux(out files);
+        }
+        catch (Exception ex)
+        {
+            Log.Warning(ex, "Reading files from the clipboard failed");
+        }
+
+        // macOS and everything else: no file-list clipboard support (text paste still works).
+        return false;
+    }
+
+    // ── Windows: CF_HDROP via the Win32 clipboard ────────────────────────────
+
+    private const uint CfHdrop = 15;
+
+    [SupportedOSPlatform("windows")]
+    private static bool TryGetWindows(out List<string> files)
+    {
+        files = [];
+        if (!IsClipboardFormatAvailable(CfHdrop))
+            return false;
+
+        // The clipboard may briefly be held by another process; a few quick retries cover that.
+        var opened = false;
+        for (var attempt = 0; attempt < 5 && !opened; attempt++)
+            opened = OpenClipboard(IntPtr.Zero);
+        if (!opened)
+            return false;
+
+        try
+        {
+            var hDrop = GetClipboardData(CfHdrop);
+            if (hDrop == IntPtr.Zero)
+                return false;
+
+            var count = DragQueryFileW(hDrop, 0xFFFFFFFF, null, 0);
+            for (uint i = 0; i < count; i++)
+            {
+                var len = DragQueryFileW(hDrop, i, null, 0);
+                if (len == 0)
+                    continue;
+
+                var sb = new StringBuilder((int)len + 1);
+                DragQueryFileW(hDrop, i, sb, (uint)sb.Capacity);
+                var path = sb.ToString();
+                if (File.Exists(path))
+                    files.Add(path);
+            }
+
+            return files.Count > 0;
+        }
+        finally
+        {
+            CloseClipboard();
+        }
+    }
+
+    [DllImport("user32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool OpenClipboard(IntPtr hWndNewOwner);
+
+    [DllImport("user32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool CloseClipboard();
+
+    [DllImport("user32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool IsClipboardFormatAvailable(uint format);
+
+    [DllImport("user32.dll", SetLastError = true)]
+    private static extern IntPtr GetClipboardData(uint uFormat);
+
+    [DllImport("shell32.dll", CharSet = CharSet.Unicode)]
+    private static extern uint DragQueryFileW(IntPtr hDrop, uint iFile, StringBuilder? lpszFile, uint cch);
+
+    // ── Linux: text/uri-list from the clipboard via xclip or wl-paste ─────────
+
+    [SupportedOSPlatform("linux")]
+    private static bool TryGetLinux(out List<string> files)
+    {
+        files = [];
+
+        var output = RunForOutput("wl-paste", ["--type", "text/uri-list", "--no-newline"])
+            ?? RunForOutput("xclip", ["-selection", "clipboard", "-t", "text/uri-list", "-o"]);
+        if (string.IsNullOrWhiteSpace(output))
+            return false;
+
+        foreach (var line in output.Split('\n', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries))
+        {
+            if (!line.StartsWith("file://", StringComparison.Ordinal))
+                continue;
+            try
+            {
+                var path = new Uri(line).LocalPath;
+                if (File.Exists(path))
+                    files.Add(path);
+            }
+            catch (UriFormatException) { /* skip malformed entry */ }
+        }
+
+        return files.Count > 0;
+    }
+
+    private static string? RunForOutput(string fileName, IEnumerable<string> args)
+    {
+        var psi = new ProcessStartInfo(fileName)
+        {
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+            CreateNoWindow = true,
+        };
+        foreach (var arg in args)
+            psi.ArgumentList.Add(arg);
+
+        try
+        {
+            using var process = Process.Start(psi);
+            if (process is null)
+                return null;
+
+            var output = process.StandardOutput.ReadToEnd();
+            process.WaitForExit(2000);
+            return process.ExitCode == 0 ? output : null;
+        }
+        catch (Exception ex) when (ex is System.ComponentModel.Win32Exception or FileNotFoundException)
+        {
+            return null; // tool not installed
+        }
+    }
+}

src/EchoHub.Client/Services/ClipboardImage.cs

@@ -0,0 +1,257 @@
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using Serilog;
+using SixLabors.ImageSharp;
+
+namespace EchoHub.Client.Services;
+
+/// <summary>
+/// Reads raw image data from the OS clipboard (e.g. an image copied from a browser, or a
+/// Win+Shift+S screenshot), which terminals cannot paste as text. Always returns PNG bytes:
+/// clipboard PNG data is passed through, clipboard bitmaps (CF_DIB) are re-encoded.
+/// </summary>
+public static class ClipboardImage
+{
+    private static readonly byte[] PngMagic = [0x89, 0x50, 0x4E, 0x47];
+
+    public static bool TryGetPng(out byte[] png)
+    {
+        png = [];
+        try
+        {
+            if (OperatingSystem.IsWindows())
+                return TryGetWindows(out png);
+            if (OperatingSystem.IsLinux())
+                return TryGetLinux(out png);
+            if (OperatingSystem.IsMacOS())
+                return TryGetMacOS(out png);
+        }
+        catch (Exception ex)
+        {
+            Log.Warning(ex, "Reading an image from the clipboard failed");
+        }
+
+        return false;
+    }
+
+    private static bool IsPng(byte[] data) =>
+        data.Length > PngMagic.Length && data.AsSpan(0, PngMagic.Length).SequenceEqual(PngMagic);
+
+    /// <summary>
+    /// Converts clipboard DIB bytes (a BITMAPINFOHEADER/V4/V5 + optional palette/masks + pixel
+    /// data, i.e. a .bmp file without its 14-byte file header) to PNG. Returns null when the
+    /// data is malformed or not decodable as a bitmap.
+    /// </summary>
+    public static byte[]? DibToPng(byte[] dib)
+    {
+        if (dib.Length < 40)
+            return null;
+
+        var headerSize = BitConverter.ToInt32(dib, 0);
+        if (headerSize < 40 || headerSize > dib.Length)
+            return null;
+
+        var bitCount = BitConverter.ToUInt16(dib, 14);
+        var compression = BitConverter.ToUInt32(dib, 16);
+        var clrUsed = BitConverter.ToUInt32(dib, 32);
+
+        // Pixel data offset: file header + info header + color masks + palette.
+        // BI_BITFIELDS masks follow a plain 40-byte header; larger headers embed them.
+        var maskBytes = headerSize == 40 && compression == 3 ? 12
+                      : headerSize == 40 && compression == 6 ? 16
+                      : 0;
+        var paletteEntries = clrUsed != 0 ? clrUsed
+                           : bitCount <= 8 ? 1u << bitCount
+                           : 0u;
+        var pixelOffset = (uint)(14 + headerSize + maskBytes) + paletteEntries * 4;
+
+        var bmp = new byte[14 + dib.Length];
+        bmp[0] = (byte)'B';
+        bmp[1] = (byte)'M';
+        BitConverter.TryWriteBytes(bmp.AsSpan(2), (uint)bmp.Length);
+        BitConverter.TryWriteBytes(bmp.AsSpan(10), pixelOffset);
+        dib.CopyTo(bmp, 14);
+
+        try
+        {
+            using var image = Image.Load(bmp);
+            using var ms = new MemoryStream();
+            image.SaveAsPng(ms);
+            return ms.ToArray();
+        }
+        catch (Exception ex) when (ex is ImageFormatException or InvalidOperationException)
+        {
+            Log.Warning(ex, "Clipboard DIB could not be decoded as a bitmap");
+            return null;
+        }
+    }
+
+    // ── Windows: "PNG" / "image/png" registered formats, then CF_DIB ─────────
+
+    private const uint CfDib = 8;
+
+    [SupportedOSPlatform("windows")]
+    private static bool TryGetWindows(out byte[] png)
+    {
+        png = [];
+
+        // Browsers register a "PNG" (Chromium) or "image/png" (some apps) clipboard format
+        // preserving transparency; CF_DIB is synthesized by Windows for everything else
+        // (screenshots, image editors), so together these cover all image sources.
+        var pngFormat = RegisterClipboardFormatW("PNG");
+        var mimeFormat = RegisterClipboardFormatW("image/png");
+
+        var hasAny = (pngFormat != 0 && IsClipboardFormatAvailable(pngFormat))
+                  || (mimeFormat != 0 && IsClipboardFormatAvailable(mimeFormat))
+                  || IsClipboardFormatAvailable(CfDib);
+        if (!hasAny)
+            return false;
+
+        var opened = false;
+        for (var attempt = 0; attempt < 5 && !opened; attempt++)
+            opened = OpenClipboard(IntPtr.Zero);
+        if (!opened)
+            return false;
+
+        try
+        {
+            foreach (var format in new[] { pngFormat, mimeFormat })
+            {
+                if (format == 0 || !IsClipboardFormatAvailable(format))
+                    continue;
+                var data = ReadHGlobal(GetClipboardData(format));
+                if (data is not null && IsPng(data))
+                {
+                    png = data;
+                    return true;
+                }
+            }
+
+            if (IsClipboardFormatAvailable(CfDib)
+                && ReadHGlobal(GetClipboardData(CfDib)) is { } dib
+                && DibToPng(dib) is { } converted)
+            {
+                png = converted;
+                return true;
+            }
+
+            return false;
+        }
+        finally
+        {
+            CloseClipboard();
+        }
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static byte[]? ReadHGlobal(IntPtr handle)
+    {
+        if (handle == IntPtr.Zero)
+            return null;
+
+        var ptr = GlobalLock(handle);
+        if (ptr == IntPtr.Zero)
+            return null;
+
+        try
+        {
+            var size = (int)GlobalSize(handle);
+            if (size <= 0)
+                return null;
+            var data = new byte[size];
+            Marshal.Copy(ptr, data, 0, size);
+            return data;
+        }
+        finally
+        {
+            GlobalUnlock(handle);
+        }
+    }
+
+    [DllImport("user32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool OpenClipboard(IntPtr hWndNewOwner);
+
+    [DllImport("user32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool CloseClipboard();
+
+    [DllImport("user32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool IsClipboardFormatAvailable(uint format);
+
+    [DllImport("user32.dll", SetLastError = true)]
+    private static extern IntPtr GetClipboardData(uint uFormat);
+
+    [DllImport("user32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
+    private static extern uint RegisterClipboardFormatW(string lpszFormat);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    private static extern IntPtr GlobalLock(IntPtr hMem);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool GlobalUnlock(IntPtr hMem);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    private static extern nuint GlobalSize(IntPtr hMem);
+
+    // ── Linux: image/png via wl-paste or xclip ────────────────────────────────
+
+    [SupportedOSPlatform("linux")]
+    private static bool TryGetLinux(out byte[] png)
+    {
+        png = [];
+        var data = RunForBytes("wl-paste", ["--type", "image/png"])
+                ?? RunForBytes("xclip", ["-selection", "clipboard", "-t", "image/png", "-o"]);
+        if (data is null || !IsPng(data))
+            return false;
+
+        png = data;
+        return true;
+    }
+
+    // ── macOS: pngpaste (brew install pngpaste), when present ────────────────
+
+    [SupportedOSPlatform("macos")]
+    private static bool TryGetMacOS(out byte[] png)
+    {
+        png = [];
+        var data = RunForBytes("pngpaste", ["-"]);
+        if (data is null || !IsPng(data))
+            return false;
+
+        png = data;
+        return true;
+    }
+
+    private static byte[]? RunForBytes(string fileName, IEnumerable<string> args)
+    {
+        var psi = new ProcessStartInfo(fileName)
+        {
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+            CreateNoWindow = true,
+        };
+        foreach (var arg in args)
+            psi.ArgumentList.Add(arg);
+
+        try
+        {
+            using var process = Process.Start(psi);
+            if (process is null)
+                return null;
+
+            using var ms = new MemoryStream();
+            process.StandardOutput.BaseStream.CopyTo(ms);
+            process.WaitForExit(2000);
+            return process.ExitCode == 0 && ms.Length > 0 ? ms.ToArray() : null;
+        }
+        catch (Exception ex) when (ex is System.ComponentModel.Win32Exception or FileNotFoundException)
+        {
+            return null; // tool not installed
+        }
+    }
+}

src/EchoHub.Client/Services/ConnectionManager.cs

@@ -9,11 +9,13 @@ namespace EchoHub.Client.Services;
 
 /// <summary>
 /// Result of a successful connection, returned to AppOrchestrator for UI updates.
+/// <paramref name="Histories"/> holds the initial history of every auto-joined channel
+/// (keyed by channel name, always including the default channel).
 /// </summary>
 internal record ConnectResult(
     LoginResponse Login,
     List<ChannelDto> Channels,
-    List<MessageDto> DefaultHistory);
+    Dictionary<string, List<MessageDto>> Histories);
 
 /// <summary>
 /// Owns connection lifecycle, authentication, SignalR event wiring, and channel tracking.
@@ -24,6 +26,7 @@ internal sealed class ConnectionManager : IAsyncDisposable
     private EchoHubConnection? _connection;
     private ApiClient? _apiClient;
     private readonly ClientEncryptionService _encryption = new();
+    private readonly RoomKeyStore _roomKeys = new();
     private readonly HashSet<string> _joinedChannels = [];
 
     // ── Properties ────────────────────────────────────────────────────────
@@ -31,6 +34,7 @@ internal sealed class ConnectionManager : IAsyncDisposable
     public bool IsConnected => _connection?.IsConnected == true;
     public bool IsAuthenticated => _apiClient is not null;
     public ApiClient? Api => _apiClient;
+    public RoomKeyStore RoomKeys => _roomKeys;
 
     // ── Events (forwarded from SignalR) ───────────────────────────────────
 
@@ -42,6 +46,7 @@ internal sealed class ConnectionManager : IAsyncDisposable
     public event Action<string, string?>? UserBanned;
     public event Action<string>? ForceDisconnected;
     public event Action<string, Guid>? MessageDeleted;
+    public event Action<string>? ChannelDeleted;
     public event Action<string>? ChannelNuked;
     public event Action<ChannelDto>? ChannelUpdated;
     public event Action<string>? Error;
@@ -73,7 +78,8 @@ internal sealed class ConnectionManager : IAsyncDisposable
             }
             else if (info.IsRegister)
             {
-                loginResponse = await _apiClient.RegisterAsync(info.Username, info.Password);
+                loginResponse = await _apiClient.RegisterAsync(
+                    info.Username, info.Password, info.DisplayName, info.InviteCode);
             }
             else
             {
@@ -101,29 +107,65 @@ internal sealed class ConnectionManager : IAsyncDisposable
             if (_connection is not null)
                 await _connection.DisposeAsync();
 
-            _connection = new EchoHubConnection(info.ServerUrl, _apiClient, _encryption);
+            _roomKeys.LoadForServer(info.ServerUrl);
+            _connection = new EchoHubConnection(info.ServerUrl, _apiClient, _encryption, _roomKeys);
             WireConnectionEvents(_connection);
             await _connection.ConnectAsync();
 
             var channels = await _apiClient.GetChannelsAsync();
-            onStatus("Connected");
+
+            // Known E2E channels — senders consult this so a client without the room
+            // key never emits plaintext into an encrypted room
+            foreach (var channel in channels)
+                _roomKeys.MarkChannelEncrypted(channel.Name, channel.IsEncrypted);
 
             // Join default channel + fetch history
+            onStatus("Joining channels...");
             _joinedChannels.Clear();
             _joinedChannels.Add(HubConstants.DefaultChannel);
             await _connection.JoinChannelAsync(HubConstants.DefaultChannel);
 
-            List<MessageDto> history = [];
+            var histories = new Dictionary<string, List<MessageDto>>(StringComparer.OrdinalIgnoreCase);
             try
             {
-                history = await _connection.GetHistoryAsync(HubConstants.DefaultChannel);
+                histories[HubConstants.DefaultChannel] = await _connection.GetHistoryAsync(HubConstants.DefaultChannel);
             }
             catch
             {
                 // History might not be available
             }
 
-            return new ConnectResult(loginResponse, channels, history);
+            // Auto-join every other channel the server lists for this user (public +
+            // prior memberships) so message events — unread counts, @mentions — flow for
+            // all of them, not just channels opened this session. Channels the user left
+            // with /leave stay out until rejoined; protected channels we can't enter
+            // silently (no cached membership) are skipped, never prompted for.
+            var leftChannels = FindServer(ConfigManager.Load(), info.ServerUrl)?.LeftChannels ?? [];
+            foreach (var channel in channels)
+            {
+                if (channel.Name.Equals(HubConstants.DefaultChannel, StringComparison.OrdinalIgnoreCase))
+                    continue;
+                if (leftChannels.Contains(channel.Name, StringComparer.OrdinalIgnoreCase))
+                    continue;
+
+                try
+                {
+                    var outcome = await _connection.JoinChannelAsync(channel.Name);
+                    _joinedChannels.Add(channel.Name);
+                    histories[channel.Name] = outcome.History;
+                }
+                catch (ChannelPasswordRequiredException)
+                {
+                    // First-time protected channel — joining stays a manual, prompted action
+                }
+                catch (Exception ex)
+                {
+                    Log.Warning(ex, "Auto-join failed for #{Channel}", channel.Name);
+                }
+            }
+
+            onStatus("Connected");
+            return new ConnectResult(loginResponse, channels, histories);
         }
         catch
         {
@@ -156,6 +198,7 @@ internal sealed class ConnectionManager : IAsyncDisposable
         _apiClient?.Dispose();
         _apiClient = null;
         _joinedChannels.Clear();
+        _roomKeys.Clear();
     }
 
     /// <summary>
@@ -169,11 +212,21 @@ internal sealed class ConnectionManager : IAsyncDisposable
 
     // ── Channel Operations ────────────────────────────────────────────────
 
-    public async Task<List<MessageDto>> JoinChannelAsync(string channelName)
+    public async Task<JoinOutcome> JoinChannelAsync(string channelName, string? password = null)
     {
         if (_connection is null) throw new InvalidOperationException("Not connected");
-        _joinedChannels.Add(channelName);
+        try
-        return await _connection.JoinChannelAsync(channelName);
+        {
+            var outcome = await _connection.JoinChannelAsync(channelName, password);
+            _joinedChannels.Add(channelName);
+            return outcome;
+        }
+        catch (ChannelPasswordRequiredException)
+        {
+            // Not actually joined — don't track, or reconnects would retry a doomed join
+            _joinedChannels.Remove(channelName);
+            throw;
+        }
     }
 
     public async Task LeaveChannelAsync(string channelName)
@@ -192,8 +245,8 @@ internal sealed class ConnectionManager : IAsyncDisposable
 
     // ── Delegate Operations ───────────────────────────────────────────────
 
-    public Task SendMessageAsync(string channel, string content) =>
+    public Task SendMessageAsync(string channel, string content, Guid? replyToMessageId = null) =>
-        _connection?.SendMessageAsync(channel, content)
+        _connection?.SendMessageAsync(channel, content, replyToMessageId)
         ?? throw new InvalidOperationException("Not connected");
 
     public Task<List<MessageDto>> GetHistoryAsync(string channel, int count = HubConstants.DefaultHistoryCount, int offset = 0) =>
@@ -222,11 +275,19 @@ internal sealed class ConnectionManager : IAsyncDisposable
 
         foreach (var channel in channels)
         {
-            _joinedChannels.Add(channel);
+            // One channel gone bad (deleted, membership revoked) must not stop the rest
-            await _connection.JoinChannelAsync(channel);
+            try
+            {
+                await _connection.JoinChannelAsync(channel);
+                _joinedChannels.Add(channel);
+            }
+            catch (Exception ex)
+            {
+                Log.Warning(ex, "Rejoin failed for #{Channel}", channel);
+            }
         }
 
-        Log.Information("Rejoined {Count} channel(s) after reconnect", channels.Count);
+        Log.Information("Rejoined {Count} channel(s) after reconnect", _joinedChannels.Count);
     }
 
     // ── SignalR Event Wiring ──────────────────────────────────────────────
@@ -241,8 +302,13 @@ internal sealed class ConnectionManager : IAsyncDisposable
         connection.OnUserBanned += (user, reason) => UserBanned?.Invoke(user, reason);
         connection.OnForceDisconnect += reason => ForceDisconnected?.Invoke(reason);
         connection.OnMessageDeleted += (ch, id) => MessageDeleted?.Invoke(ch, id);
+        connection.OnChannelDeleted += ch => ChannelDeleted?.Invoke(ch);
         connection.OnChannelNuked += ch => ChannelNuked?.Invoke(ch);
-        connection.OnChannelUpdated += ch => ChannelUpdated?.Invoke(ch);
+        connection.OnChannelUpdated += ch =>
+        {
+            _roomKeys.MarkChannelEncrypted(ch.Name, ch.IsEncrypted);
+            ChannelUpdated?.Invoke(ch);
+        };
         connection.OnError += msg => Error?.Invoke(msg);
         connection.OnConnectionStateChanged += status => ConnectionStatusChanged?.Invoke(status);
         connection.OnReconnected += () => Reconnected?.Invoke();
@@ -254,8 +320,7 @@ internal sealed class ConnectionManager : IAsyncDisposable
     {
         if (_apiClient?.RefreshToken is null) return;
         var config = ConfigManager.Load();
-        var server = config.SavedServers.FirstOrDefault(s =>
+        var server = FindServer(config, _apiClient.BaseUrl);
-            string.Equals(s.Url, _apiClient.BaseUrl, StringComparison.OrdinalIgnoreCase));
         if (server is not null && server.RememberMe)
         {
             server.RefreshToken = _apiClient.RefreshToken;
@@ -263,6 +328,10 @@ internal sealed class ConnectionManager : IAsyncDisposable
         }
     }
 
+    private static SavedServer? FindServer(ClientConfig config, string url) =>
+        config.SavedServers.FirstOrDefault(s =>
+            string.Equals(s.Url, url, StringComparison.OrdinalIgnoreCase));
+
     // ── Dispose ───────────────────────────────────────────────────────────
 
     public async ValueTask DisposeAsync()

src/EchoHub.Client/Services/EchoHubConnection.cs

@@ -1,14 +1,54 @@
 using EchoHub.Core.Constants;
 using EchoHub.Core.DTOs;
 using EchoHub.Core.Models;
+using EchoHub.Core.Security;
 using Microsoft.AspNetCore.SignalR.Client;
 
 namespace EchoHub.Client.Services;
 
+/// <summary>
+/// Result of joining a channel: decrypted history plus, for end-to-end encrypted
+/// channels, the key envelope needed to unlock the room content key.
+/// </summary>
+public sealed record JoinOutcome(List<MessageDto> History, string? EncryptionSalt, string? WrappedRoomKey);
+
+/// <summary>
+/// Thrown when joining a channel fails because a password is required or incorrect.
+/// The UI catches this to prompt the user and retry.
+/// </summary>
+public sealed class ChannelPasswordRequiredException : Exception
+{
+    public string ChannelName { get; }
+
+    public ChannelPasswordRequiredException(string channelName, string message) : base(message)
+    {
+        ChannelName = channelName;
+    }
+}
+
+/// <summary>
+/// Thrown when sending into an end-to-end encrypted channel whose room key isn't cached:
+/// without the key the message would leave the client as plaintext, which must never happen.
+/// </summary>
+public sealed class RoomLockedException : Exception
+{
+    public string ChannelName { get; }
+
+    public RoomLockedException(string channelName)
+        : base($"#{channelName} is end-to-end encrypted and locked — enter its passphrase to unlock it before sending.")
+    {
+        ChannelName = channelName;
+    }
+}
+
 public sealed class EchoHubConnection : IAsyncDisposable
 {
+    public const string LockedMessagePlaceholder =
+        "[encrypted — rejoin this channel with its passphrase to unlock]";
+
     private readonly HubConnection _connection;
     private readonly ClientEncryptionService _encryption;
+    private readonly RoomKeyStore _roomKeys;
 
     public event Action<MessageDto>? OnMessageReceived;
     public event Action<string, string, UserPresenceDto?>? OnUserJoined;
@@ -18,6 +58,7 @@ public sealed class EchoHubConnection : IAsyncDisposable
     public event Action<string, string, string?>? OnUserKicked;
     public event Action<string, string?>? OnUserBanned;
     public event Action<string, Guid>? OnMessageDeleted;
+    public event Action<string>? OnChannelDeleted;
     public event Action<string>? OnChannelNuked;
     public event Action<string>? OnForceDisconnect;
     public event Action<string>? OnError;
@@ -26,9 +67,10 @@ public sealed class EchoHubConnection : IAsyncDisposable
 
     public bool IsConnected => _connection.State == HubConnectionState.Connected;
 
-    public EchoHubConnection(string serverUrl, ApiClient apiClient, ClientEncryptionService encryption)
+    public EchoHubConnection(string serverUrl, ApiClient apiClient, ClientEncryptionService encryption, RoomKeyStore roomKeys)
     {
         _encryption = encryption;
+        _roomKeys = roomKeys;
         var hubUrl = serverUrl.TrimEnd('/') + HubConstants.ChatHubPath;
 
         _connection = new HubConnectionBuilder()
@@ -65,9 +107,7 @@ public sealed class EchoHubConnection : IAsyncDisposable
     {
         _connection.On<MessageDto>(nameof(Core.Contracts.IEchoHubClient.ReceiveMessage), message =>
         {
-            // Decrypt message content received from server
+            OnMessageReceived?.Invoke(DecryptMessage(message));
-            var decrypted = message with { Content = _encryption.Decrypt(message.Content) };
-            OnMessageReceived?.Invoke(decrypted);
         });
 
         _connection.On<string, string, UserPresenceDto?>(nameof(Core.Contracts.IEchoHubClient.UserJoined), (channelName, username, presence) =>
@@ -105,6 +145,11 @@ public sealed class EchoHubConnection : IAsyncDisposable
             OnMessageDeleted?.Invoke(channelName, messageId);
         });
 
+        _connection.On<string>(nameof(Core.Contracts.IEchoHubClient.ChannelDeleted), channelName =>
+        {
+            OnChannelDeleted?.Invoke(channelName);
+        });
+
         _connection.On<string>(nameof(Core.Contracts.IEchoHubClient.ChannelNuked), channelName =>
         {
             OnChannelNuked?.Invoke(channelName);
@@ -134,12 +179,18 @@ public sealed class EchoHubConnection : IAsyncDisposable
         OnConnectionStateChanged?.Invoke("Disconnected");
     }
 
-    public async Task<List<MessageDto>> JoinChannelAsync(string channelName)
+    public async Task<JoinOutcome> JoinChannelAsync(string channelName, string? password = null)
     {
-        var result = await _connection.InvokeAsync<JoinChannelResult>("JoinChannel", channelName);
+        var result = await _connection.InvokeAsync<JoinChannelResult>("JoinChannel", channelName, password);
         if (!result.Success)
+        {
+            if (result.PasswordRequired)
+                throw new ChannelPasswordRequiredException(channelName, result.Error ?? "Channel is password protected.");
             throw new InvalidOperationException(result.Error ?? "Failed to join channel.");
-        return DecryptMessages(result.History);
+        }
+        if (result.WrappedRoomKey is not null)
+            _roomKeys.MarkChannelEncrypted(channelName, true);
+        return new JoinOutcome(DecryptMessages(result.History), result.EncryptionSalt, result.WrappedRoomKey);
     }
 
     public async Task LeaveChannelAsync(string channelName)
@@ -147,11 +198,16 @@ public sealed class EchoHubConnection : IAsyncDisposable
         await _connection.InvokeAsync("LeaveChannel", channelName);
     }
 
-    public async Task SendMessageAsync(string channelName, string content)
+    public async Task SendMessageAsync(string channelName, string content, Guid? replyToMessageId = null)
     {
-        // Encrypt content before sending to server
+        // Room layer first (end-to-end, server can't read), then transport encryption
+        if (_roomKeys.TryGetKey(channelName, out var roomKey))
+            content = RoomCrypto.EncryptText(content, roomKey);
+        else if (_roomKeys.IsChannelEncrypted(channelName))
+            throw new RoomLockedException(channelName); // never fall through to plaintext
+
         var encrypted = _encryption.Encrypt(content);
-        await _connection.InvokeAsync("SendMessage", channelName, encrypted);
+        await _connection.InvokeAsync("SendMessage", channelName, encrypted, replyToMessageId);
     }
 
     public async Task<List<MessageDto>> GetHistoryAsync(string channelName, int count = HubConstants.DefaultHistoryCount, int offset = 0)
@@ -172,7 +228,50 @@ public sealed class EchoHubConnection : IAsyncDisposable
 
     private List<MessageDto> DecryptMessages(List<MessageDto> messages)
     {
-        return messages.Select(m => m with { Content = _encryption.Decrypt(m.Content) }).ToList();
+        return messages.Select(DecryptMessage).ToList();
+    }
+
+    /// <summary>
+    /// Strips the transport encryption, then the room layer for E2E channels, from the
+    /// message content and every attachment preview. Without the room key the content is
+    /// replaced by a locked placeholder — re-fetch history after unlocking to render it.
+    /// </summary>
+    private MessageDto DecryptMessage(MessageDto message)
+    {
+        _roomKeys.TryGetKey(message.ChannelName, out var roomKey);
+
+        var content = DecryptField(message.Content, roomKey) ?? LockedMessagePlaceholder;
+
+        List<AttachmentDto>? attachments = null;
+        if (message.Attachments is { Count: > 0 })
+        {
+            attachments = message.Attachments
+                .Select(a => a with { AsciiPreview = a.AsciiPreview is null ? null : DecryptField(a.AsciiPreview, roomKey) })
+                .ToList();
+        }
+
+        // Reply snippets are encrypted exactly like message content
+        var replyTo = message.ReplyTo is { } reply
+            ? reply with { Content = DecryptField(reply.Content, roomKey) ?? LockedMessagePlaceholder }
+            : null;
+
+        return message with { Content = content, Attachments = attachments, ReplyTo = replyTo };
+    }
+
+    /// <summary>
+    /// Decrypts one field: strips transport encryption, then the room layer if it is room
+    /// ciphertext. Returns null when it is room ciphertext but the room key is missing/wrong.
+    /// </summary>
+    private string? DecryptField(string value, byte[]? roomKey)
+    {
+        var plain = _encryption.Decrypt(value);
+        if (!RoomCrypto.IsRoomCiphertext(plain))
+            return plain;
+
+        if (roomKey is not null && RoomCrypto.TryDecryptText(plain, roomKey, out var decrypted))
+            return decrypted;
+
+        return null;
     }
 
     public async ValueTask DisposeAsync()

src/EchoHub.Client/Services/NativeFolderPicker.cs

@@ -0,0 +1,141 @@
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using System.Text;
+using Serilog;
+
+namespace EchoHub.Client.Services;
+
+public enum PickerOutcome
+{
+    /// <summary>The user picked a folder (<see cref="FolderPickResult.Path"/> is set).</summary>
+    Chosen,
+
+    /// <summary>The native dialog ran but the user cancelled it.</summary>
+    Cancelled,
+
+    /// <summary>No native picker is available on this machine (headless, missing tool, etc.).</summary>
+    Unavailable,
+}
+
+public sealed record FolderPickResult(PickerOutcome Outcome, string? Path);
+
+/// <summary>
+/// Opens the OS-native folder chooser (Windows Explorer, macOS Finder, Linux GTK/KDE) by shelling
+/// out, so the TUI doesn't need a GUI toolkit reference. Returns <see cref="PickerOutcome.Unavailable"/>
+/// when no native dialog can run, so callers can fall back to a configured path.
+/// </summary>
+public static class NativeFolderPicker
+{
+    private const string Title = "Choose your EchoHub download folder";
+
+    public static async Task<FolderPickResult> PickFolderAsync(string? initialDir)
+    {
+        try
+        {
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+                return await PickWindowsAsync(initialDir);
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+                return await PickMacAsync();
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+                return await PickLinuxAsync(initialDir);
+        }
+        catch (Exception ex)
+        {
+            Log.Warning(ex, "Native folder picker failed");
+        }
+
+        return new FolderPickResult(PickerOutcome.Unavailable, null);
+    }
+
+    private static async Task<FolderPickResult> PickWindowsAsync(string? initialDir)
+    {
+        var safeInit = (initialDir ?? string.Empty).Replace("'", "''");
+        var script = $$"""
+            Add-Type -AssemblyName System.Windows.Forms
+            $d = New-Object System.Windows.Forms.FolderBrowserDialog
+            $d.Description = '{{Title}}'
+            $d.ShowNewFolderButton = $true
+            $d.SelectedPath = '{{safeInit}}'
+            if ($d.ShowDialog() -eq [System.Windows.Forms.DialogResult]::OK) { [Console]::Out.Write($d.SelectedPath) }
+            """;
+
+        // -EncodedCommand avoids all quoting issues; FolderBrowserDialog needs an STA thread.
+        var encoded = Convert.ToBase64String(Encoding.Unicode.GetBytes(script));
+        var (started, _, stdout) = await RunAsync("powershell.exe",
+            ["-STA", "-NoProfile", "-NonInteractive", "-EncodedCommand", encoded]);
+
+        if (!started)
+            return new FolderPickResult(PickerOutcome.Unavailable, null);
+        return string.IsNullOrWhiteSpace(stdout)
+            ? new FolderPickResult(PickerOutcome.Cancelled, null)
+            : new FolderPickResult(PickerOutcome.Chosen, stdout);
+    }
+
+    private static async Task<FolderPickResult> PickMacAsync()
+    {
+        var (started, exit, stdout) = await RunAsync("osascript",
+            ["-e", $"POSIX path of (choose folder with prompt \"{Title}\")"]);
+
+        if (!started)
+            return new FolderPickResult(PickerOutcome.Unavailable, null);
+        return exit == 0 && !string.IsNullOrWhiteSpace(stdout)
+            ? new FolderPickResult(PickerOutcome.Chosen, stdout)
+            : new FolderPickResult(PickerOutcome.Cancelled, null);
+    }
+
+    private static async Task<FolderPickResult> PickLinuxAsync(string? initialDir)
+    {
+        // No graphical session → no native picker.
+        if (string.IsNullOrEmpty(Environment.GetEnvironmentVariable("DISPLAY"))
+            && string.IsNullOrEmpty(Environment.GetEnvironmentVariable("WAYLAND_DISPLAY")))
+            return new FolderPickResult(PickerOutcome.Unavailable, null);
+
+        var zenityArgs = new List<string> { "--file-selection", "--directory", $"--title={Title}" };
+        if (!string.IsNullOrWhiteSpace(initialDir))
+            zenityArgs.Add($"--filename={initialDir!.TrimEnd('/')}/");
+
+        var (zStarted, zExit, zOut) = await RunAsync("zenity", zenityArgs);
+        if (zStarted)
+            return zExit == 0 && !string.IsNullOrWhiteSpace(zOut)
+                ? new FolderPickResult(PickerOutcome.Chosen, zOut)
+                : new FolderPickResult(PickerOutcome.Cancelled, null);
+
+        var (kStarted, kExit, kOut) = await RunAsync("kdialog",
+            ["--getexistingdirectory", string.IsNullOrWhiteSpace(initialDir) ? "." : initialDir!]);
+        if (kStarted)
+            return kExit == 0 && !string.IsNullOrWhiteSpace(kOut)
+                ? new FolderPickResult(PickerOutcome.Chosen, kOut)
+                : new FolderPickResult(PickerOutcome.Cancelled, null);
+
+        return new FolderPickResult(PickerOutcome.Unavailable, null);
+    }
+
+    private static async Task<(bool Started, int ExitCode, string StdOut)> RunAsync(string fileName, IEnumerable<string> args)
+    {
+        var psi = new ProcessStartInfo(fileName)
+        {
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+            CreateNoWindow = true,
+        };
+        foreach (var arg in args)
+            psi.ArgumentList.Add(arg);
+
+        try
+        {
+            using var process = Process.Start(psi);
+            if (process is null)
+                return (false, -1, string.Empty);
+
+            var stdout = await process.StandardOutput.ReadToEndAsync();
+            await process.WaitForExitAsync();
+            return (true, process.ExitCode, stdout.Trim());
+        }
+        catch (Exception ex) when (ex is System.ComponentModel.Win32Exception or FileNotFoundException)
+        {
+            // Executable not found on PATH → treat as "no native picker".
+            return (false, -1, string.Empty);
+        }
+    }
+}

src/EchoHub.Client/Services/OutgoingAttachment.cs

@@ -0,0 +1,13 @@
+namespace EchoHub.Client.Services;
+
+/// <summary>
+/// One file to upload as part of a message. For end-to-end encrypted channels the stream
+/// is already ciphertext, <see cref="DeclaredKind"/> is set (image/audio/file), and
+/// <see cref="EncryptedPreview"/> holds the room-encrypted ASCII art for images.
+/// For normal channels only <see cref="Stream"/> and <see cref="FileName"/> are set.
+/// </summary>
+public sealed record OutgoingAttachment(
+    Stream Stream,
+    string FileName,
+    string? DeclaredKind = null,
+    string? EncryptedPreview = null);

src/EchoHub.Client/Services/RoomKeyProtector.cs

@@ -0,0 +1,120 @@
+using System.Security.Cryptography;
+using EchoHub.Core.Security;
+using Serilog;
+
+namespace EchoHub.Client.Services;
+
+/// <summary>
+/// Encrypts cached room content keys at rest so the client config never holds them as
+/// plain base64. Windows uses DPAPI (current-user scope, format prefix "dp1:"). On other
+/// platforms the keys are AES-GCM encrypted with a per-user master key file stored next
+/// to the config with 0600 permissions (prefix "k1:") — without an OS keychain that is
+/// file-permission-level protection, not zero-knowledge: anyone who can read both the
+/// config and the key file can recover the room keys. Values with no recognized prefix
+/// are legacy plain-base64 keys from older clients; they load once and are re-encrypted.
+/// The room passphrase itself is never stored in any form.
+/// </summary>
+public sealed class RoomKeyProtector
+{
+    public const string DpapiPrefix = "dp1:";
+    public const string KeyFilePrefix = "k1:";
+
+    private const string KeyFileName = "roomkeys.key";
+    private const int MasterKeySizeBytes = 32;
+    private const int RoomKeySizeBytes = 32;
+
+    private readonly string _keyFilePath;
+    private readonly bool _useDpapi;
+    private readonly Lock _lock = new();
+    private byte[]? _masterKey;
+
+    /// <param name="keyDirectory">Directory holding the master key file (the client config dir).</param>
+    /// <param name="useDpapi">Overrides the platform default (DPAPI on Windows) — for tests.</param>
+    public RoomKeyProtector(string keyDirectory, bool? useDpapi = null)
+    {
+        _keyFilePath = Path.Combine(keyDirectory, KeyFileName);
+        _useDpapi = useDpapi ?? OperatingSystem.IsWindows();
+    }
+
+    /// <summary>Encrypts a room key for storage in the config file.</summary>
+    public string Protect(byte[] roomKey)
+    {
+        if (_useDpapi && OperatingSystem.IsWindows())
+            return DpapiPrefix + Convert.ToBase64String(
+                ProtectedData.Protect(roomKey, null, DataProtectionScope.CurrentUser));
+
+        return KeyFilePrefix + Convert.ToBase64String(RoomCrypto.EncryptBytes(roomKey, GetMasterKey()));
+    }
+
+    /// <summary>
+    /// Decrypts a stored value back into a room key. <paramref name="wasLegacy"/> is true when
+    /// the value was an unencrypted legacy entry that should be re-persisted via
+    /// <see cref="Protect"/>. Returns false for unreadable values (wrong user/machine, missing
+    /// or regenerated key file, malformed data) — the caller drops the entry and the user can
+    /// recover it by re-entering the passphrase.
+    /// </summary>
+    public bool TryUnprotect(string stored, out byte[] roomKey, out bool wasLegacy)
+    {
+        roomKey = [];
+        wasLegacy = false;
+
+        try
+        {
+            if (stored.StartsWith(DpapiPrefix, StringComparison.Ordinal))
+            {
+                if (!OperatingSystem.IsWindows())
+                    return false; // config copied from a Windows machine
+
+                roomKey = ProtectedData.Unprotect(
+                    Convert.FromBase64String(stored[DpapiPrefix.Length..]), null, DataProtectionScope.CurrentUser);
+                return roomKey.Length > 0;
+            }
+
+            if (stored.StartsWith(KeyFilePrefix, StringComparison.Ordinal))
+            {
+                if (!File.Exists(_keyFilePath))
+                    return false;
+
+                roomKey = RoomCrypto.DecryptBytes(
+                    Convert.FromBase64String(stored[KeyFilePrefix.Length..]), GetMasterKey());
+                return roomKey.Length > 0;
+            }
+
+            // No recognized prefix — legacy plain-base64 room key from a pre-encryption client
+            roomKey = Convert.FromBase64String(stored);
+            wasLegacy = true;
+            return roomKey.Length == RoomKeySizeBytes;
+        }
+        catch (Exception ex) when (ex is FormatException or CryptographicException
+            or IOException or UnauthorizedAccessException)
+        {
+            return false;
+        }
+    }
+
+    private byte[] GetMasterKey()
+    {
+        lock (_lock)
+        {
+            if (_masterKey is not null)
+                return _masterKey;
+
+            if (File.Exists(_keyFilePath))
+            {
+                var existing = File.ReadAllBytes(_keyFilePath);
+                if (existing.Length == MasterKeySizeBytes)
+                    return _masterKey = existing;
+
+                Log.Warning("Room-key master key file has unexpected size — regenerating (previously cached keys become unreadable)");
+            }
+
+            var key = RandomNumberGenerator.GetBytes(MasterKeySizeBytes);
+            Directory.CreateDirectory(Path.GetDirectoryName(_keyFilePath)!);
+            File.WriteAllBytes(_keyFilePath, key);
+            if (!OperatingSystem.IsWindows())
+                File.SetUnixFileMode(_keyFilePath, UnixFileMode.UserRead | UnixFileMode.UserWrite);
+
+            return _masterKey = key;
+        }
+    }
+}

src/EchoHub.Client/Services/RoomKeyStore.cs

@@ -0,0 +1,178 @@
+using EchoHub.Client.Config;
+using EchoHub.Core.Security;
+using Serilog;
+
+namespace EchoHub.Client.Services;
+
+/// <summary>
+/// Holds room content keys for end-to-end encrypted channels: in-memory for the
+/// active session, persisted per-server in the client config (like saved sessions)
+/// so users don't retype the passphrase every launch. Keys never leave this machine
+/// and are encrypted at rest by <see cref="RoomKeyProtector"/>. Also tracks which
+/// channels are known to be end-to-end encrypted, so senders can refuse to emit
+/// plaintext into a room whose key isn't cached yet.
+/// </summary>
+public sealed class RoomKeyStore
+{
+    private readonly Dictionary<string, byte[]> _keys = new(StringComparer.OrdinalIgnoreCase);
+    private readonly HashSet<string> _encryptedChannels = new(StringComparer.OrdinalIgnoreCase);
+    private readonly RoomKeyProtector _protector;
+    private readonly Lock _lock = new();
+    private string? _serverUrl;
+
+    public RoomKeyStore() : this(new RoomKeyProtector(ConfigManager.ConfigDirectory))
+    {
+    }
+
+    public RoomKeyStore(RoomKeyProtector protector)
+    {
+        _protector = protector;
+    }
+
+    /// <summary>Binds the store to a server and loads that server's cached keys from config.</summary>
+    public void LoadForServer(string serverUrl)
+    {
+        lock (_lock)
+        {
+            _serverUrl = serverUrl;
+            _keys.Clear();
+            _encryptedChannels.Clear();
+
+            var server = FindServer(ConfigManager.Load(), serverUrl);
+            if (server is null) return;
+
+            var legacyFound = false;
+            foreach (var (channel, stored) in server.ChannelKeys)
+            {
+                if (_protector.TryUnprotect(stored, out var key, out var wasLegacy))
+                {
+                    _keys[channel] = key;
+                    legacyFound |= wasLegacy;
+                }
+                else
+                {
+                    Log.Warning("Ignoring unreadable cached room key for #{Channel}", channel);
+                }
+            }
+
+            // One-way upgrade: legacy plain-base64 entries get re-persisted encrypted
+            // (unreadable entries drop out — the unlock prompt recovers those rooms).
+            if (legacyFound)
+                Persist(s =>
+                {
+                    s.ChannelKeys.Clear();
+                    foreach (var (channel, key) in _keys)
+                        s.ChannelKeys[channel] = _protector.Protect(key);
+                });
+        }
+    }
+
+    public bool TryGetKey(string channelName, out byte[] key)
+    {
+        lock (_lock)
+        {
+            if (_keys.TryGetValue(channelName, out var k))
+            {
+                key = k;
+                return true;
+            }
+        }
+
+        key = [];
+        return false;
+    }
+
+    public bool HasKey(string channelName) => TryGetKey(channelName, out _);
+
+    /// <summary>Stores a key for the session and persists it to the server's config entry.</summary>
+    public void StoreKey(string channelName, byte[] key)
+    {
+        lock (_lock)
+        {
+            _keys[channelName] = key;
+            _encryptedChannels.Add(channelName);
+            Persist(server => server.ChannelKeys[channelName] = _protector.Protect(key));
+        }
+    }
+
+    /// <summary>
+    /// Unwraps a fresh key envelope and caches the key, overwriting any stale cached key
+    /// (e.g. the channel was deleted and recreated under the same name, so the old key
+    /// would encrypt messages nobody else can read). Returns false when the KEK doesn't
+    /// open the envelope — the cache is left untouched.
+    /// </summary>
+    public bool TryStoreFromEnvelope(string channelName, string wrappedRoomKey, byte[] kek)
+    {
+        if (!RoomCrypto.TryUnwrapRoomKey(wrappedRoomKey, kek, out var roomKey))
+            return false;
+
+        StoreKey(channelName, roomKey);
+        return true;
+    }
+
+    public void RemoveKey(string channelName)
+    {
+        lock (_lock)
+        {
+            _keys.Remove(channelName);
+            Persist(server => server.ChannelKeys.Remove(channelName));
+        }
+    }
+
+    /// <summary>
+    /// Records whether a channel is end-to-end encrypted (from channel listings, crypto
+    /// metadata, or join outcomes). Senders consult this to block plaintext into rooms
+    /// whose key isn't cached.
+    /// </summary>
+    public void MarkChannelEncrypted(string channelName, bool isEncrypted)
+    {
+        lock (_lock)
+        {
+            if (isEncrypted)
+                _encryptedChannels.Add(channelName);
+            else
+                _encryptedChannels.Remove(channelName);
+        }
+    }
+
+    public bool IsChannelEncrypted(string channelName)
+    {
+        lock (_lock)
+        {
+            return _encryptedChannels.Contains(channelName);
+        }
+    }
+
+    public void Clear()
+    {
+        lock (_lock)
+        {
+            _keys.Clear();
+            _encryptedChannels.Clear();
+            _serverUrl = null;
+        }
+    }
+
+    private void Persist(Action<SavedServer> mutate)
+    {
+        if (_serverUrl is null) return;
+
+        try
+        {
+            var config = ConfigManager.Load();
+            var server = FindServer(config, _serverUrl);
+            if (server is null) return; // server not saved yet — key stays in-memory only
+
+            mutate(server);
+            ConfigManager.Save(config);
+        }
+        catch (Exception ex)
+        {
+            Log.Warning(ex, "Failed to persist room key cache");
+        }
+    }
+
+    private static SavedServer? FindServer(ClientConfig config, string url) =>
+        config.SavedServers.FirstOrDefault(s =>
+            string.Equals(s.Url, url, StringComparison.OrdinalIgnoreCase));
+}

src/EchoHub.Client/Services/UpdateChecker.cs

@@ -1,3 +1,5 @@
+using System.Text;
+
 using AlwaysUpToDate;
 
 using EchoHub.Client.UI.Dialogs;
@@ -15,9 +17,17 @@ public sealed class UpdateChecker : IDisposable
 
     private readonly Updater _updater;
     private readonly IApplication _app;
-    private UpdateProgressDialog? _progressDialog;
+    private string? _pendingVersion;
+    private bool _applying;
+    private UpdateStep _lastStep = (UpdateStep)(-1);
     private bool _manualCheck;
 
+    /// <summary>
+    /// Set when the user confirms an update. The host runs this <b>after</b> the Terminal.Gui
+    /// main loop has exited and the console is restored, so the library's in-place restart doesn't
+    /// deadlock against a TUI that still owns the console.
+    /// </summary>
+    public Func<Task>? PendingUpdate { get; private set; }
 
     public static string CurrentVersion => typeof(UpdateChecker).Assembly.GetName().Version?.ToString(3) ?? "0.0.0";
 
@@ -40,7 +50,6 @@ public sealed class UpdateChecker : IDisposable
 #endif
     }
 
-
     public async Task CheckNowAsync()
     {
         _manualCheck = true;
@@ -54,67 +63,98 @@ public sealed class UpdateChecker : IDisposable
         }
     }
 
-    private async void OnUpdateAvailable(string version, string changelogUrl)
+    private void OnUpdateAvailable(string version, string changelogUrl)
     {
         Log.Information("Update available: v{Version}", version);
 
         _app.Invoke(() =>
         {
             var confirmed = UpdateConfirmDialog.Show(_app, CurrentVersion, version);
+            if (!confirmed)
+                return;
 
-            if (confirmed)
+            // Defer the actual download/extract/restart to after the TUI is torn down.
-            {
+            // Running it under the live main loop lets the library restart the process while
-                _progressDialog = new UpdateProgressDialog(_app, version);
+            // this one still holds the console in raw/alternate-screen mode — the two processes
-
+            // then deadlock over the console (the "stuck at N/N extracting" hang).
-                _ = Task.Run(async () =>
+            _pendingVersion = version;
-                {
+            PendingUpdate = ApplyUpdateAsync;
-                    // Create backup before the update starts
+            _app.RequestStop();
-                    try
-                    {
-                        _progressDialog?.UpdateProgress(0f, "Creating backup...");
-                        UpdateBackupService.CreateBackup();
-                    }
-                    catch (Exception ex)
-                    {
-                        Log.Error(ex, "Failed to create pre-update backup");
-
-                        var proceed = false;
-                        proceed = MessageBox.Query(
-                            _app,
-                            "Backup Warning",
-                            $"Could not create backup: {ex.Message}\n\nContinue update without backup?",
-                            "Continue", "Cancel") == 0;
-
-                        if (!proceed)
-                        {
-                            _progressDialog?.Close();
-                            _progressDialog = null;
-                            return;
-                        }
-                    }
-
-                    _progressDialog?.UpdateProgress(0f, "Downloading update...");
-                    await _updater.UpdateAsync();
-                });
-
-                _progressDialog.Show();
-            }
         });
     }
 
-    private void OnProgressChanged(UpdateStep step, long itemsProcessed, long? totalItems, double? progressPercentage)
+    /// <summary>
+    /// Runs the update on a plain console (invoked by the host after the main loop exits).
+    /// Ends by restarting the app and exiting the process, or restoring the backup on failure.
+    /// </summary>
+    private async Task ApplyUpdateAsync()
     {
-        var fraction = progressPercentage.HasValue ? (float)(progressPercentage.Value / 100.0) : 0f;
+        _applying = true;
-        var statusText = $"{step}: {itemsProcessed}/{totalItems ?? 0} ({progressPercentage ?? 0:F0}%)";
 
-        if (!progressPercentage.HasValue)
+        // The TUI restored the console on shutdown; make sure the block-glyph bar renders.
+        try { Console.OutputEncoding = Encoding.UTF8; } catch { /* redirected/non-interactive */ }
+
+        Console.WriteLine();
+        Console.WriteLine($"Updating EchoHub to v{_pendingVersion}...");
+
+        try
         {
-            statusText = $"{step}...";
+            Console.WriteLine("Creating backup...");
+            UpdateBackupService.CreateBackup();
+        }
+        catch (Exception ex)
+        {
+            Log.Error(ex, "Failed to create pre-update backup");
+            Console.WriteLine($"Warning: could not create a backup ({ex.Message}). Continuing without one.");
         }
 
-        _progressDialog?.UpdateProgress(fraction, statusText);
+        Console.WriteLine("Downloading update...");
+        await _updater.UpdateAsync(); // download → extract → restart → Environment.Exit(0)
     }
 
+    private const int BarWidth = 28;
+
+    private void OnProgressChanged(UpdateStep step, long itemsProcessed, long? totalItems, double? progressPercentage)
+    {
+        // Before the TUI is torn down (i.e. during a check) there is no progress surface; the
+        // real work happens headless after shutdown, so draw a progress bar on the console.
+        if (!_applying)
+            return;
+
+        // Finish the previous step's line so each step keeps its completed bar.
+        if (step != _lastStep)
+        {
+            if (_lastStep != (UpdateStep)(-1))
+                Console.WriteLine();
+            _lastStep = step;
+        }
+
+        var label = Humanize(step);
+
+        if (progressPercentage is { } percent)
+        {
+            var pct = (int)Math.Clamp(Math.Round(percent), 0, 100);
+            var filled = pct * BarWidth / 100;
+            var bar = new string('█', filled) + new string('░', BarWidth - filled); // █ / ░
+            Console.Write($"\r  {label,-13} [{bar}] {pct,3}%   ");
+        }
+        else
+        {
+            // Steps with no measurable total (verifying, restarting): show an indeterminate marker.
+            Console.Write($"\r  {label,-13} working...   ");
+        }
+    }
+
+    private static string Humanize(UpdateStep step) => step switch
+    {
+        UpdateStep.Downloading => "Downloading",
+        UpdateStep.VerifyingChecksum => "Verifying",
+        UpdateStep.Extracting => "Extracting",
+        UpdateStep.CleaningUp => "Cleaning up",
+        UpdateStep.Restarting => "Restarting",
+        _ => step.ToString(),
+    };
+
     private void OnUpdateStarted(string version)
     {
         Log.Information("Update started: v{Version}", version);
@@ -135,40 +175,40 @@ public sealed class UpdateChecker : IDisposable
     private void OnException(Exception exception)
     {
         Log.Error(exception, "Update failed");
-        _app.Invoke(() =>
+
+        // Headless failure (post-shutdown): report and offer rollback on the console.
+        if (_applying)
         {
-            _progressDialog?.Close();
+            Console.Error.WriteLine();
-            _progressDialog = null;
+            Console.Error.WriteLine($"Update failed: {exception.Message}");
 
             if (UpdateBackupService.BackupExists())
             {
-                var restore = MessageBox.Query(
+                Console.WriteLine("Restoring the previous version...");
-                    _app,
+                try
-                    "Update Failed",
-                    $"The update failed: {exception.Message}\n\n"
-                    + "A backup of the previous version is available.\nRestore now? (The app will restart.)",
-                    "Restore", "Cancel");
-
-                if (restore == 0)
                 {
-                    try
+                    UpdateBackupService.RestoreBackup(); // calls Environment.Exit(0)
-                    {
+                }
-                        UpdateBackupService.RestoreBackup();
+                catch (Exception restoreEx)
-                        // RestoreBackup calls Environment.Exit(0)
+                {
-                    }
+                    Log.Error(restoreEx, "Backup restoration failed");
-                    catch (Exception restoreEx)
+                    Console.Error.WriteLine($"Restore failed: {restoreEx.Message}. Re-download EchoHub to recover.");
-                    {
+                    Environment.Exit(1);
-                        Log.Error(restoreEx, "Backup restoration failed");
-                        MessageBox.ErrorQuery(_app, "Restore Failed",
-                            $"Could not restore backup: {restoreEx.Message}\n\nYou may need to re-download the application.", "OK");
-                    }
                 }
             }
             else
             {
-                MessageBox.ErrorQuery(_app, "Update Failed",
+                Console.Error.WriteLine("No backup available. Re-download EchoHub if it no longer starts.");
-                    $"The update failed: {exception.Message}\n\nYou may need to re-download the application.", "OK");
+                Environment.Exit(1);
             }
+            return;
+        }
+
+        // Failure during a check while the TUI is still running.
+        _app.Invoke(() =>
+        {
+            MessageBox.ErrorQuery(_app, "Update Check Failed",
+                $"Could not check for updates: {exception.Message}", "OK");
         });
     }
 
@@ -179,5 +219,6 @@ public sealed class UpdateChecker : IDisposable
         _updater.UpdateStarted -= OnUpdateStarted;
         _updater.NoUpdateAvailable -= OnNoUpdateAvailable;
         _updater.OnException -= OnException;
+        _updater.Dispose();
     }
 }

src/EchoHub.Client/Themes/Theme.cs

@@ -7,6 +7,14 @@ public class Theme
     public ThemeColors Menu { get; set; } = new();
     public ThemeColors Dialog { get; set; } = new();
     public ThemeColors Status { get; set; } = new();
+
+    /// <summary>
+    /// Colors for the main-window frame borders (and their titles). Null falls back
+    /// to <see cref="Base"/>. Lets themes tone borders down independently of text —
+    /// e.g. the transparent themes use a dim gray for a subtler, glassy look.
+    /// Supports hex values ("#6E6E6E") as well as named colors.
+    /// </summary>
+    public ThemeColors? Border { get; set; }
 }
 
 public class ThemeColors

src/EchoHub.Client/Themes/ThemeManager.cs

@@ -442,6 +442,55 @@ public static class ThemeManager
             Background = "None",
             FocusForeground = "Gray",
             FocusBackground = "None"
+        },
+        // Dim, grayish borders — bright white frames fight the glassy transparent look
+        Border = new ThemeColors
+        {
+            Foreground = "#6E6E6E",
+            Background = "None",
+            FocusForeground = "#8A8A8A",
+            FocusBackground = "None"
+        }
+    };
+
+    private static readonly Theme TransparentLightTheme = new()
+    {
+        Name = "TransparentLight",
+        Base = new ThemeColors
+        {
+            Foreground = "Black",
+            Background = "None",
+            FocusForeground = "Blue",
+            FocusBackground = "None"
+        },
+        Menu = new ThemeColors
+        {
+            Foreground = "Black",
+            Background = "None",
+            FocusForeground = "Blue",
+            FocusBackground = "None"
+        },
+        Dialog = new ThemeColors
+        {
+            Foreground = "Black",
+            Background = "Gray",
+            FocusForeground = "Blue",
+            FocusBackground = "White"
+        },
+        Status = new ThemeColors
+        {
+            Foreground = "DarkGray",
+            Background = "None",
+            FocusForeground = "DarkGray",
+            FocusBackground = "None"
+        },
+        // Softer gray borders against light terminal backgrounds
+        Border = new ThemeColors
+        {
+            Foreground = "#8F8F8F",
+            Background = "None",
+            FocusForeground = "#6E6E6E",
+            FocusBackground = "None"
         }
     };
 
@@ -449,6 +498,7 @@ public static class ThemeManager
     [
         DefaultTheme,
         TransparentTheme,
+        TransparentLightTheme,
         ClassicTheme,
         LightTheme,
         HackerTheme,
@@ -512,6 +562,8 @@ public static class ThemeManager
         SchemeManager.AddScheme("Base", BuildColorScheme(theme.Base));
         SchemeManager.AddScheme("Menu", BuildColorScheme(theme.Menu));
         SchemeManager.AddScheme("Dialog", BuildColorScheme(theme.Dialog));
+        // Frame borders/titles; themes without an explicit Border section keep Base
+        SchemeManager.AddScheme("Border", BuildColorScheme(theme.Border ?? theme.Base));
     }
 
     public static void SaveTheme(Theme theme)
@@ -541,7 +593,14 @@ public static class ThemeManager
             Focus = focus,
             HotNormal = normal,
             HotFocus = focus,
-            Disabled = normal
+            Disabled = normal,
+
+            // TextView/TextField draw their editable area with the Editable/ReadOnly roles. If
+            // left unset, Terminal.Gui derives an opaque background from Normal — which renders
+            // as a solid box behind the input under transparent themes. Pin them to the theme's
+            // own colors so the input matches its background (transparent stays transparent).
+            Editable = normal,
+            ReadOnly = normal
         };
     }
 

src/EchoHub.Client/UI/Chat/ChatColors.cs

@@ -21,6 +21,15 @@ public static partial class ChatColors
     public static readonly Attribute AudioAttr = new(new Color(180, 100, 255), Color.None);
     public static readonly Attribute FileAttr = new(new Color(100, 180, 255), Color.None);
 
+    /// <summary>The dim vertical rail (│) separating the nick column from message text.</summary>
+    public static readonly Attribute RailAttr = new(new Color(95, 95, 95), Color.None);
+
+    /// <summary>Horizontal date-separator rules (── Wed, Jul 16 ──…).</summary>
+    public static readonly Attribute DateRuleAttr = new(new Color(120, 120, 120), Color.None);
+
+    /// <summary>The irssi-style "new messages" unread marker rule.</summary>
+    public static readonly Attribute UnreadMarkerAttr = new(new Color(230, 140, 60), Color.None);
+
     /// <summary>
     /// Split text around @mentions and #channels, giving each the appropriate accent color.
     /// Non-special text uses the provided default color.

src/EchoHub.Client/UI/Chat/ChatLine.cs

@@ -7,6 +7,16 @@ using Attribute = Terminal.Gui.Drawing.Attribute;
 
 namespace EchoHub.Client.UI.Chat;
 
+/// <summary>An action a click on an attachment line can trigger.</summary>
+public enum AttachmentAction
+{
+    OpenImage,
+    SaveImage,
+}
+
+/// <summary>Inclusive column range on a chat line that triggers an attachment action when clicked.</summary>
+public readonly record struct AttachmentActionSpan(int StartCol, int EndCol, AttachmentAction Action);
+
 /// <summary>
 /// A single line in the chat, composed of colored segments.
 /// </summary>
@@ -18,11 +28,44 @@ public partial class ChatLine
     public bool IsMention { get; set; }
     public string? AttachmentUrl { get; set; }
     public string? AttachmentFileName { get; set; }
-    public MessageType? Type { get; set; }
+    public AttachmentKind? AttachmentKind { get; set; }
     public string? SenderUsername { get; set; }
+
+    /// <summary>
+    /// Set on a reply's quote line: activating the line jumps to this message
+    /// if it is in the loaded history.
+    /// </summary>
+    public Guid? JumpToMessageId { get; set; }
+
+    /// <summary>
+    /// Clickable sub-line targets (e.g. the "[open]" and "[save original]" brackets under an
+    /// image). Columns are relative to the unwrapped line, so only the first wrapped line
+    /// keeps them. Null means the whole line uses the kind's default action.
+    /// </summary>
+    public List<AttachmentActionSpan>? ActionSpans { get; set; }
+
     /// <summary>Number of spaces to prepend on continuation lines when this line is word-wrapped.</summary>
     public int ContinuationIndent { get; set; }
 
+    /// <summary>
+    /// Colored segments to prepend on continuation lines instead of plain spaces
+    /// (e.g. the nick-column rail "                   │ "). When set, takes
+    /// precedence over <see cref="ContinuationIndent"/>.
+    /// </summary>
+    public List<ChatSegment>? ContinuationPrefixSegments { get; set; }
+
+    /// <summary>
+    /// When set, this line is a horizontal separator rule (date change, unread marker).
+    /// The view regenerates it to the current viewport width instead of word-wrapping.
+    /// </summary>
+    public string? RuleLabel { get; set; }
+
+    /// <summary>Color for a rule line; null falls back to <see cref="ChatColors.DateRuleAttr"/>.</summary>
+    public Attribute? RuleAttr { get; set; }
+
+    /// <summary>True for the "new messages" unread-marker rule so it can be removed on channel switch.</summary>
+    public bool IsUnreadMarker { get; set; }
+
     public ChatLine(string plainText)
     {
         Segments = [new ChatSegment(plainText, null)];
@@ -43,9 +86,14 @@ public partial class ChatLine
     /// </summary>
     public List<ChatLine> Wrap(int width, int continuationIndent = 0)
     {
-        if (width <= 0 || TextLength <= width)
+        // Rules are regenerated to viewport width by the view; never word-wrap them.
+        if (RuleLabel is not null || width <= 0 || TextLength <= width)
             return [this];
 
+        var prefixSegments = ContinuationPrefixSegments;
+        if (prefixSegments is not null)
+            continuationIndent = prefixSegments.Sum(s => s.Text.GetColumns());
+
         var tokens = new List<(string grapheme, Attribute? color)>();
         foreach (var segment in Segments)
             foreach (var g in GraphemeHelper.GetGraphemes(segment.Text))
@@ -91,8 +139,13 @@ public partial class ChatLine
             }
 
             var segments = new List<ChatSegment>();
-            if (!firstLine && continuationIndent > 0)
+            if (!firstLine)
-                segments.Add(new ChatSegment(new string(' ', continuationIndent), null));
+            {
+                if (prefixSegments is not null)
+                    segments.AddRange(prefixSegments);
+                else if (continuationIndent > 0)
+                    segments.Add(new ChatSegment(new string(' ', continuationIndent), null));
+            }
 
             // Rebuild segments by grouping consecutive same-color tokens.
             var sb = new StringBuilder();
@@ -120,15 +173,22 @@ public partial class ChatLine
             return [this];
 
         // Propagate metadata to all wrapped lines so they remain clickable
+        // and keep the mention highlight across continuation lines
         foreach (var wrapped in results)
         {
             wrapped.AttachmentUrl = AttachmentUrl;
             wrapped.AttachmentFileName = AttachmentFileName;
-            wrapped.Type = Type;
+            wrapped.AttachmentKind = AttachmentKind;
             wrapped.MessageId = MessageId;
             wrapped.SenderUsername = SenderUsername;
+            wrapped.IsMention = IsMention;
+            wrapped.JumpToMessageId = JumpToMessageId;
         }
 
+        // Span columns only line up with the first wrapped line; later lines fall
+        // back to the kind's default action.
+        results[0].ActionSpans = ActionSpans;
+
         return results;
     }
 

src/EchoHub.Client/UI/Chat/ChatListSource.cs

@@ -65,6 +65,13 @@ public class ChatListSource : IListDataSource
 
         var chatLine = _lines[item];
         var normalAttr = listView.GetAttributeForRole(VisualRole.Normal);
+
+        // Highlight the selected row (whole width) while the list has focus — used by the
+        // F6 selection flow and right-click. The custom source must draw this itself.
+        var focusAttr = selected && listView.HasFocus
+            ? listView.GetAttributeForRole(VisualRole.Focus)
+            : (Attribute?)null;
+
         var mentionBg = chatLine.IsMention ? ChatColors.MentionHighlightAttr.Background : (Color?)null;
 
         int charPos = 0;
@@ -72,11 +79,19 @@ public class ChatListSource : IListDataSource
 
         foreach (var segment in chatLine.Segments)
         {
-            var attr = segment.Color ?? normalAttr;
+            Attribute attr;
-            if (attr.Background == Color.None)
+            if (focusAttr is { } focus)
-                attr = attr with { Background = normalAttr.Background };
+            {
-            if (mentionBg.HasValue)
+                attr = focus;
-                attr = attr with { Background = mentionBg.Value };
+            }
+            else
+            {
+                attr = segment.Color ?? normalAttr;
+                if (attr.Background == Color.None)
+                    attr = attr with { Background = normalAttr.Background };
+                if (mentionBg.HasValue)
+                    attr = attr with { Background = mentionBg.Value };
+            }
             listView.SetAttribute(attr);
 
             foreach (var grapheme in GraphemeHelper.GetGraphemes(segment.Text))
@@ -91,7 +106,8 @@ public class ChatListSource : IListDataSource
             }
         }
 
-        var fillAttr = mentionBg.HasValue ? new Attribute(normalAttr.Foreground, mentionBg.Value) : normalAttr;
+        var fillAttr = focusAttr
+            ?? (mentionBg.HasValue ? new Attribute(normalAttr.Foreground, mentionBg.Value) : normalAttr);
         listView.SetAttribute(fillAttr);
         for (int i = drawnChars; i < width; i++)
             listView.AddStr(" ");

src/EchoHub.Client/UI/Chat/ChatMessageManager.cs

@@ -1,5 +1,7 @@
+using System.Text;
 using System.Text.RegularExpressions;
 using EchoHub.Client.UI.Helpers;
+using EchoHub.Core.Constants;
 using EchoHub.Core.DTOs;
 using EchoHub.Core.Models;
 using Terminal.Gui.Drawing;
@@ -15,8 +17,20 @@ namespace EchoHub.Client.UI.Chat;
 /// </summary>
 public sealed class ChatMessageManager
 {
+    /// <summary>Columns reserved for the right-aligned nick column (WeeChat-style).</summary>
+    public const int NickColWidth = 12;
+
+    /// <summary>Columns before message text starts: "HH:mm " + nick column + " │ ".</summary>
+    public const int ContentIndentCols = 6 + NickColWidth + 3;
+
     private readonly Dictionary<string, List<ChatLine>> _channelMessages = [];
     private readonly Dictionary<string, int> _channelUnread = [];
+    private readonly Dictionary<string, DateTime> _channelLastDate = [];
+    private readonly HashSet<string> _markedChannels = [];
+    private readonly Dictionary<string, Guid> _markerAnchor = [];
+    private readonly HashSet<string> _mentionChannels = [];
+    private readonly Dictionary<string, Guid> _lastRead = [];
+    private readonly Dictionary<string, Guid> _channelNewestId = [];
 
     private string _currentUser = string.Empty;
     private string _currentChannel = string.Empty;
@@ -33,7 +47,18 @@ public sealed class ChatMessageManager
     public string CurrentChannel
     {
         get => _currentChannel;
-        set => _currentChannel = value;
+        set
+        {
+            if (_currentChannel == value)
+                return;
+
+            // Leaving a channel consumes its "new messages" marker so the next
+            // unread burst gets a fresh one (irssi behavior), and everything
+            // visible up to now counts as read.
+            RemoveUnreadMarker(_currentChannel);
+            MarkRead(_currentChannel);
+            _currentChannel = value;
+        }
     }
 
     public string CurrentUser => _currentUser;
@@ -57,10 +82,27 @@ public sealed class ChatMessageManager
     public void ClearUnread(string channelName)
     {
         _channelUnread[channelName] = 0;
+        _mentionChannels.Remove(channelName);
+        MarkRead(channelName);
+    }
+
+    /// <summary>
+    /// Last message the user has read per channel — persisted by the orchestrator so
+    /// unread/mention state can be seeded from history on the next connect.
+    /// </summary>
+    public IReadOnlyDictionary<string, Guid> LastReadIds => _lastRead;
+
+    private void MarkRead(string channelName)
+    {
+        if (!string.IsNullOrEmpty(channelName) && _channelNewestId.TryGetValue(channelName, out var newest))
+            _lastRead[channelName] = newest;
     }
 
     internal Dictionary<string, int> GetUnreadCounts() => _channelUnread;
 
+    /// <summary>Channels with an unread @mention of the current user (cleared by <see cref="ClearUnread"/>).</summary>
+    public IReadOnlySet<string> MentionChannels => _mentionChannels;
+
     // ── Mutations ────────────────────────────────────────────────────
 
     /// <summary>
@@ -75,19 +117,39 @@ public sealed class ChatMessageManager
             _channelMessages[message.ChannelName] = messages;
         }
 
+        // Day boundary → horizontal date rule
+        var msgDate = message.SentAt.ToLocalTime().Date;
+        if (!_channelLastDate.TryGetValue(message.ChannelName, out var lastDate) || lastDate != msgDate)
+        {
+            messages.Add(DateRule(msgDate));
+            _channelLastDate[message.ChannelName] = msgDate;
+        }
+
+        var isCurrent = message.ChannelName == _currentChannel;
+        _channelNewestId[message.ChannelName] = message.Id;
+        if (isCurrent)
+            _lastRead[message.ChannelName] = message.Id;
+
+        // First unread message in an inactive channel → "new messages" marker,
+        // anchored to this message so a history reload can re-place it
+        if (!isCurrent && _markedChannels.Add(message.ChannelName))
+        {
+            messages.Add(UnreadMarkerRule());
+            _markerAnchor[message.ChannelName] = message.Id;
+        }
+
         foreach (var line in lines)
             messages.Add(line);
 
-        if (message.ChannelName == _currentChannel)
+        if (!isCurrent)
-        {
-            MessagesChanged?.Invoke(message.ChannelName);
-        }
-        else
         {
             _channelUnread.TryGetValue(message.ChannelName, out var count);
             _channelUnread[message.ChannelName] = count + 1;
-            MessagesChanged?.Invoke(message.ChannelName);
+            if (lines.Any(l => l.IsMention))
+                _mentionChannels.Add(message.ChannelName);
         }
+
+        MessagesChanged?.Invoke(message.ChannelName);
     }
 
     /// <summary>
@@ -101,24 +163,20 @@ public sealed class ChatMessageManager
             _channelMessages[channelName] = messages;
         }
 
-        var time = DateTimeOffset.Now.ToString("HH:mm");
+        var time = FormatTime(DateTimeOffset.Now);
         var textLines = text.Split('\n');
 
-        messages.Add(new ChatLine(
+        var header = SystemHeaderSegments(time);
-        [
+        header.Add(new(textLines[0].TrimEnd('\r'), ChatColors.SystemAttr));
-            new($"[{time}] ", ChatColors.TimestampAttr),
+        messages.Add(new ChatLine(header) { ContinuationPrefixSegments = RailPrefix() });
-            new($"** {textLines[0].TrimEnd('\r')}", ChatColors.SystemAttr)
-        ]));
 
-        var indent = new string(' ', $"[{time}] ** ".Length);
         for (int i = 1; i < textLines.Length; i++)
         {
             var line = textLines[i].TrimEnd('\r');
             if (string.IsNullOrWhiteSpace(line)) continue;
-            messages.Add(new ChatLine(
+            var segments = RailPrefix();
-            [
+            segments.Add(new(line, ChatColors.SystemAttr));
-                new($"{indent}{line}", ChatColors.SystemAttr)
+            messages.Add(new ChatLine(segments) { ContinuationPrefixSegments = RailPrefix() });
-            ]));
         }
 
         if (channelName == _currentChannel)
@@ -130,19 +188,16 @@ public sealed class ChatMessageManager
     /// </summary>
     public void AddStatusMessage(string channelName, string username, string status)
     {
-        var time = DateTimeOffset.Now.ToString("HH:mm");
+        var time = FormatTime(DateTimeOffset.Now);
-        var segments = new List<ChatSegment>
+        var segments = SystemHeaderSegments(time);
-        {
+        segments.Add(new($"{username} is now {status}", ChatColors.SystemAttr));
-            new($"[{time}] ", ChatColors.TimestampAttr),
-            new($"** {username} is now {status}", ChatColors.SystemAttr)
-        };
 
         if (!_channelMessages.TryGetValue(channelName, out var messages))
         {
             messages = [];
             _channelMessages[channelName] = messages;
         }
-        messages.Add(new ChatLine(segments));
+        messages.Add(new ChatLine(segments) { ContinuationPrefixSegments = RailPrefix() });
 
         if (channelName == _currentChannel)
             MessagesChanged?.Invoke(channelName);
@@ -169,6 +224,9 @@ public sealed class ChatMessageManager
         if (_channelMessages.TryGetValue(channelName, out var messages))
         {
             messages.Clear();
+            _channelLastDate.Remove(channelName);
+            _markedChannels.Remove(channelName);
+            _markerAnchor.Remove(channelName);
             if (channelName == _currentChannel)
                 MessagesChanged?.Invoke(channelName);
         }
@@ -176,14 +234,90 @@ public sealed class ChatMessageManager
 
     /// <summary>
     /// Load historical messages into a channel, replacing any existing messages.
+    /// When <paramref name="lastReadId"/> is given (persisted from a previous session),
+    /// messages after it seed the unread count, @mention highlight, and the
+    /// "new messages" marker — so activity that happened while offline still lights up.
     /// </summary>
-    public void LoadHistory(string channelName, List<MessageDto> messages)
+    public void LoadHistory(string channelName, List<MessageDto> messages, Guid? lastReadId = null)
     {
-        var formatted = messages.SelectMany(FormatMessage).ToList();
+        var formatted = FormatWithDateRules(messages, out var lastDate);
+
+        if (messages.Count > 0)
+            _channelNewestId[channelName] = messages[^1].Id;
+
+        // Re-place the "new messages" marker at its anchor — channel selection
+        // reloads history, which would otherwise wipe the marker right when the
+        // user switches in to read the unread backlog.
+        if (_markedChannels.Contains(channelName))
+        {
+            var anchorIdx = _markerAnchor.TryGetValue(channelName, out var anchorId)
+                ? formatted.FindIndex(l => l.MessageId == anchorId)
+                : -1;
+            if (anchorIdx >= 0)
+            {
+                formatted.Insert(anchorIdx, UnreadMarkerRule());
+            }
+            else
+            {
+                // Anchor fell outside the fetched history window — drop the marker
+                _markedChannels.Remove(channelName);
+                _markerAnchor.Remove(channelName);
+            }
+        }
+        else if (lastReadId is { } lastRead && messages.Count > 0)
+        {
+            SeedUnreadFromHistory(channelName, messages, formatted, lastRead);
+        }
+
         _channelMessages[channelName] = formatted;
 
+        if (lastDate is { } date)
+            _channelLastDate[channelName] = date;
+        else
+            _channelLastDate.Remove(channelName);
+
+        MessagesChanged?.Invoke(channelName);
+    }
+
+    /// <summary>
+    /// Reconstructs unread state from a persisted last-read message id: places the
+    /// "new messages" marker before the first unread message and, for inactive
+    /// channels, seeds the unread count and @mention highlight. A last-read id that
+    /// is no longer inside the fetched window treats the whole window as unread.
+    /// </summary>
+    private void SeedUnreadFromHistory(string channelName, List<MessageDto> messages,
+        List<ChatLine> formatted, Guid lastReadId)
+    {
+        // FindIndex miss (-1 → 0) means the last-read message is older than the fetched
+        // window: everything in the window counts as unread.
+        var firstUnread = messages.FindIndex(m => m.Id == lastReadId) + 1;
+        if (firstUnread >= messages.Count)
+            return; // everything read
+
+        var anchor = messages[firstUnread];
+        var lineIdx = formatted.FindIndex(l => l.MessageId == anchor.Id);
+        if (lineIdx < 0)
+            return;
+
+        formatted.Insert(lineIdx, UnreadMarkerRule());
+        _markedChannels.Add(channelName);
+        _markerAnchor[channelName] = anchor.Id;
+
+        // The active channel shows the marker but is being read right now —
+        // badges and mention highlights are only for background channels.
         if (channelName == _currentChannel)
-            MessagesChanged?.Invoke(channelName);
+            return;
+
+        _channelUnread[channelName] = messages.Count - firstUnread;
+
+        if (!string.IsNullOrEmpty(_currentUser))
+        {
+            var pattern = $@"@{Regex.Escape(_currentUser)}\b";
+            if (messages.Skip(firstUnread).Any(m =>
+                    Regex.IsMatch(m.Content, pattern, RegexOptions.IgnoreCase)
+                    || (m.ReplyTo is { } reply && reply.SenderUsername.Equals(_currentUser, StringComparison.OrdinalIgnoreCase))))
+                _mentionChannels.Add(channelName);
+        }
     }
 
     /// <summary>
@@ -200,14 +334,23 @@ public sealed class ChatMessageManager
             .Select(l => l.MessageId!.Value)
             .ToHashSet();
 
-        var newLines = olderMessages
+        var fresh = olderMessages.Where(m => !existingIds.Contains(m.Id)).ToList();
-            .Where(m => !existingIds.Contains(m.Id))
+        var newLines = FormatWithDateRules(fresh, out var lastBatchDate);
-            .SelectMany(FormatMessage)
-            .ToList();
 
         if (newLines.Count == 0)
             return;
 
+        // The buffer's leading date rule is redundant when the prepended batch
+        // ends on the same day — the batch already carries that day's rule.
+        if (lastBatchDate is { } batchDate
+            && existing.Count > 0
+            && existing[0].RuleLabel is { } label
+            && !existing[0].IsUnreadMarker
+            && label == DateRuleLabel(batchDate))
+        {
+            existing.RemoveAt(0);
+        }
+
         existing.InsertRange(0, newLines);
 
         if (channelName == _currentChannel)
@@ -226,6 +369,12 @@ public sealed class ChatMessageManager
     {
         _channelMessages.Clear();
         _channelUnread.Clear();
+        _channelLastDate.Clear();
+        _markedChannels.Clear();
+        _markerAnchor.Clear();
+        _mentionChannels.Clear();
+        _lastRead.Clear();
+        _channelNewestId.Clear();
         _currentChannel = string.Empty;
         _currentUser = string.Empty;
     }
@@ -234,74 +383,120 @@ public sealed class ChatMessageManager
 
     private List<ChatLine> FormatMessage(MessageDto message)
     {
-        var time = message.SentAt.ToLocalTime().ToString("HH:mm");
+        var time = FormatTime(message.SentAt);
-        var senderName = message.SenderUsername + ":";
+        // Show the display name, but keep color + click identity keyed to the username
-        var senderColor = HexColorHelper.ParseHexColor(message.SenderNicknameColor);
+        // so they stay consistent with the user list and profile lookups.
+        var senderName = message.SenderDisplayName ?? message.SenderUsername;
+        var senderColor = HexColorHelper.ParseHexColor(message.SenderNicknameColor)
+            ?? NickColorHelper.GetAttribute(message.SenderUsername);
 
         var lines = new List<ChatLine>();
+        var hasContent = !string.IsNullOrWhiteSpace(message.Content);
+        var attachments = message.Attachments ?? [];
 
-        switch (message.Type)
+        // Reply → dim quote line above the message; activating it jumps to the original
+        if (message.ReplyTo is { } replyTo)
+            lines.Add(ReplyQuoteLine(replyTo));
+
+        // /me action → "* nick waves" (CTCP ACTION content)
+        string? actionText = null;
+        var isAction = hasContent && MessageConventions.TryParseAction(message.Content, out actionText);
+        if (isAction)
         {
-            case MessageType.Image:
+            var actionLines = EmojiHelper.ReplaceEmoji(actionText!).Split('\n');
-                lines.Add(BuildChatLine(time, senderName, senderColor, " [Image]"));
+            var header = ActionHeaderSegments(time);
-                if (!string.IsNullOrWhiteSpace(message.Content))
+            header.Add(new(senderName, senderColor));
-                {
+            header.Add(new(" ", null));
-                    foreach (var artLine in message.Content.Split('\n'))
+            header.AddRange(ChatColors.SplitMentions(actionLines[0].TrimEnd('\r')));
+            lines.Add(new ChatLine(header));
+
+            for (int i = 1; i < actionLines.Length; i++)
+            {
+                var segments = RailPrefix();
+                segments.AddRange(ChatColors.SplitMentions(actionLines[i].TrimEnd('\r')));
+                lines.Add(new ChatLine(segments));
+            }
+        }
+
+        // Header line: caption text, or a summary when the message is attachments-only
+        if (isAction)
+        {
+            // already rendered above
+        }
+        else if (hasContent)
+        {
+            var displayContent = EmojiHelper.ReplaceEmoji(message.Content);
+            var contentLines = displayContent.Split('\n');
+
+            var header = HeaderSegments(time, senderName, senderColor);
+            header.AddRange(ChatColors.SplitMentions(contentLines[0].TrimEnd('\r')));
+            lines.Add(new ChatLine(header));
+
+            for (int i = 1; i < contentLines.Length; i++)
+            {
+                var segments = RailPrefix();
+                segments.AddRange(ChatColors.SplitMentions(contentLines[i].TrimEnd('\r')));
+                lines.Add(new ChatLine(segments));
+            }
+        }
+        else
+        {
+            var summary = attachments.Count switch
+            {
+                0 => " ",
+                1 => $"[{attachments[0].Kind.ToString().ToLowerInvariant()}]",
+                _ => $"[{attachments.Count} attachments]",
+            };
+            var header = HeaderSegments(time, senderName, senderColor);
+            header.Add(new(summary, null));
+            lines.Add(new ChatLine(header));
+        }
+
+        foreach (var l in lines)
+            l.ContinuationPrefixSegments = RailPrefix();
+
+        // One block per attachment — every block hangs off the nick-column rail
+        foreach (var attachment in attachments)
+        {
+            switch (attachment.Kind)
+            {
+                case Core.Models.AttachmentKind.Image:
+                    if (!string.IsNullOrWhiteSpace(attachment.AsciiPreview))
                     {
-                        var trimmed = artLine.TrimEnd('\r');
+                        foreach (var artLine in attachment.AsciiPreview.Split('\n'))
-                        if (ChatLine.HasColorTags(trimmed))
+                        {
-                            lines.Add(ChatLine.FromColoredText("       " + trimmed));
+                            var trimmed = artLine.TrimEnd('\r');
-                        else
+                            var segments = RailPrefix();
-                            lines.Add(new ChatLine($"       {trimmed}"));
+                            if (ChatLine.HasColorTags(trimmed))
+                                segments.AddRange(ChatLine.FromColoredText(trimmed).Segments);
+                            else
+                                segments.Add(new(trimmed, null));
+                            lines.Add(new ChatLine(segments));
+                        }
                     }
-                }
+                    lines.Add(ImageActionLine(attachment));
-                break;
+                    break;
 
-            case MessageType.Audio:
+                case Core.Models.AttachmentKind.Audio:
-                var audioName = message.AttachmentFileName ?? "unknown";
+                    lines.Add(AttachmentActionLine(
-                var audioSize = FormatFileSize(message.AttachmentFileSize);
+                        $"♪ [Audio: {attachment.FileName}] [{FormatFileSize(attachment.FileSize)}]",
-                var audioLine = BuildChatLineColored(time, senderName, senderColor,
+                        ChatColors.AudioAttr, attachment));
-                    $" \u266a [Audio: {audioName}] [{audioSize}]", ChatColors.AudioAttr);
+                    break;
-                audioLine.AttachmentUrl = message.AttachmentUrl;
-                audioLine.AttachmentFileName = audioName;
-                audioLine.Type = MessageType.Audio;
-                lines.Add(audioLine);
-                break;
 
-            case MessageType.File:
+                default:
-                var fileName = message.AttachmentFileName ?? "unknown";
+                    lines.Add(AttachmentActionLine(
-                var fileSize = FormatFileSize(message.AttachmentFileSize);
+                        $"[File: {attachment.FileName}] [{FormatFileSize(attachment.FileSize)}]",
-                var fileLine = BuildChatLineColored(time, senderName, senderColor,
+                        ChatColors.FileAttr, attachment));
-                    $" [File: {fileName}] [{fileSize}]", ChatColors.FileAttr);
+                    break;
-                fileLine.AttachmentUrl = message.AttachmentUrl;
+            }
-                fileLine.AttachmentFileName = fileName;
+        }
-                fileLine.Type = MessageType.File;
-                lines.Add(fileLine);
-                break;
 
-            case MessageType.Text:
+        // Link embeds (from caption URLs)
-            default:
+        if (message.Embeds is { Count: > 0 })
-                var displayContent = EmojiHelper.ReplaceEmoji(message.Content);
+        {
-                var contentLines = displayContent.Split('\n');
+            var chatWidth = _chatWidth > 0 ? _chatWidth : 80;
-                var firstLine = contentLines[0].TrimEnd('\r');
+            foreach (var embed in message.Embeds)
-                lines.Add(BuildChatLineWithMentions(time, senderName, senderColor, $" {firstLine}"));
+                lines.AddRange(FormatEmbed(embed, chatWidth));
-                var indent = new string(' ', $"[{time}] {senderName} ".Length);
-                for (int i = 1; i < contentLines.Length; i++)
-                {
-                    var contText = $"{indent}{contentLines[i].TrimEnd('\r')}";
-                    lines.Add(new ChatLine(ChatColors.SplitMentions(contText)));
-                }
-
-                foreach (var l in lines)
-                    l.ContinuationIndent = indent.Length;
-
-                if (message.Embeds is { Count: > 0 })
-                {
-                    var chatWidth = _chatWidth > 0 ? _chatWidth : 80;
-                    foreach (var embed in message.Embeds)
-                        lines.AddRange(FormatEmbed(embed, indent, chatWidth));
-                }
-                break;
         }
 
         foreach (var line in lines)
@@ -310,10 +505,14 @@ public sealed class ChatMessageManager
             line.SenderUsername = message.SenderUsername;
         }
 
-        if (!string.IsNullOrEmpty(_currentUser) && message.Type == MessageType.Text)
+        if (!string.IsNullOrEmpty(_currentUser))
         {
+            // Being replied to counts as a mention, same as an explicit @nick
+            var isReplyToMe = message.ReplyTo is { } reply
+                && reply.SenderUsername.Equals(_currentUser, StringComparison.OrdinalIgnoreCase);
             var pattern = $@"@{Regex.Escape(_currentUser)}\b";
-            if (Regex.IsMatch(message.Content, pattern, RegexOptions.IgnoreCase))
+            if (isReplyToMe
+                || ((hasContent || isAction) && Regex.IsMatch(message.Content, pattern, RegexOptions.IgnoreCase)))
             {
                 foreach (var line in lines)
                     line.IsMention = true;
@@ -323,58 +522,229 @@ public sealed class ChatMessageManager
         return lines;
     }
 
-    private static ChatLine BuildChatLine(string time, string senderName, Attribute? senderColor, string suffix)
+    /// <summary>
+    /// Builds the action line below an image preview: "[open] [↓ save original] name [size]".
+    /// Each bracket is an <see cref="AttachmentActionSpan"/> so a mouse click can target it;
+    /// keyboard activation (Enter) uses the default action, open.
+    /// </summary>
+    private static ChatLine ImageActionLine(AttachmentDto attachment)
     {
-        var segments = new List<ChatSegment>
+        var segments = RailPrefix();
+        var col = segments.Sum(s => s.Text.GetColumns());
+        var spans = new List<AttachmentActionSpan>();
+
+        void AddAction(string text, AttachmentAction action)
         {
-            new($"[{time}] ", ChatColors.TimestampAttr),
+            var width = text.GetColumns();
-            new(senderName, senderColor),
+            spans.Add(new AttachmentActionSpan(col, col + width - 1, action));
-            new(suffix, null)
+            segments.Add(new(text, ChatColors.FileAttr));
+            col += width;
+        }
+
+        AddAction("[open]", AttachmentAction.OpenImage);
+        segments.Add(new(" ", null));
+        col += 1;
+        AddAction("[↓ save original]", AttachmentAction.SaveImage);
+        segments.Add(new($" {attachment.FileName} [{FormatFileSize(attachment.FileSize)}]", ChatColors.FileAttr));
+
+        return new ChatLine(segments)
+        {
+            AttachmentUrl = attachment.Url,
+            AttachmentFileName = attachment.FileName,
+            AttachmentKind = attachment.Kind,
+            ActionSpans = spans,
+            ContinuationPrefixSegments = RailPrefix(),
         };
-        return new ChatLine(segments);
     }
 
-    private static ChatLine BuildChatLineColored(string time, string senderName, Attribute? senderColor, string suffix, Attribute suffixColor)
+    /// <summary>
+    /// Builds a clickable attachment line carrying the metadata the message list uses to
+    /// route activation (play audio, download file, save original image).
+    /// </summary>
+    private static ChatLine AttachmentActionLine(string text, Attribute color, AttachmentDto attachment)
     {
-        var segments = new List<ChatSegment>
+        var segments = RailPrefix();
+        segments.Add(new(text, color));
+        return new ChatLine(segments)
         {
-            new($"[{time}] ", ChatColors.TimestampAttr),
+            AttachmentUrl = attachment.Url,
-            new(senderName, senderColor),
+            AttachmentFileName = attachment.FileName,
-            new(suffix, suffixColor)
+            AttachmentKind = attachment.Kind,
+            ContinuationPrefixSegments = RailPrefix(),
         };
-        return new ChatLine(segments);
     }
 
-    private static ChatLine BuildChatLineWithMentions(string time, string senderName, Attribute? senderColor, string suffix)
+    /// <summary>
+    /// Leading segments of a message header line: dim "HH:mm ", the right-aligned
+    /// nick column, and the " │ " rail. Message text follows at <see cref="ContentIndentCols"/>.
+    /// </summary>
+    private static List<ChatSegment> HeaderSegments(string time, string nick, Attribute? nickColor) =>
+    [
+        new($"{time} ", ChatColors.TimestampAttr),
+        new(PadNick(nick), nickColor),
+        new(" │ ", ChatColors.RailAttr),
+    ];
+
+    /// <summary>Header variant for system/status lines: "--" in the nick column.</summary>
+    private static List<ChatSegment> SystemHeaderSegments(string time) =>
+    [
+        new($"{time} ", ChatColors.TimestampAttr),
+        new(PadNick("--"), ChatColors.TimestampAttr),
+        new(" │ ", ChatColors.RailAttr),
+    ];
+
+    /// <summary>Header variant for /me actions: "*" in the nick column, "* nick text" content.</summary>
+    private static List<ChatSegment> ActionHeaderSegments(string time) =>
+    [
+        new($"{time} ", ChatColors.TimestampAttr),
+        new(PadNick("*"), ChatColors.TimestampAttr),
+        new(" │ ", ChatColors.RailAttr),
+    ];
+
+    /// <summary>
+    /// The dim "┌ nick: snippet" line above a reply. Carries the original message id so
+    /// activating it jumps there. Room-encrypted snippets arrive already decrypted (or as
+    /// the locked placeholder) — this only truncates for display.
+    /// </summary>
+    private static ChatLine ReplyQuoteLine(ReplyRefDto replyTo)
     {
-        var segments = new List<ChatSegment>
+        const int maxSnippetCols = 60;
+
+        var snippet = replyTo.Content.Replace('\n', ' ').Replace('\r', ' ');
+        if (MessageConventions.TryParseAction(snippet, out var actionText))
+            snippet = $"* {replyTo.SenderUsername} {actionText}";
+
+        snippet = EmojiHelper.ReplaceEmoji(snippet);
+        if (snippet.GetColumns() > maxSnippetCols)
         {
-            new($"[{time}] ", ChatColors.TimestampAttr),
+            var sb = new StringBuilder();
-            new(senderName, senderColor),
+            int used = 0;
+            foreach (var g in GraphemeHelper.GetGraphemes(snippet))
+            {
+                var gCols = Math.Max(g.GetColumns(), 1);
+                if (used + gCols > maxSnippetCols - 1) break;
+                sb.Append(g);
+                used += gCols;
+            }
+            snippet = sb.Append('…').ToString();
+        }
+
+        var segments = RailPrefix();
+        segments.Add(new("┌ ", ChatColors.RailAttr));
+        segments.Add(new($"{replyTo.SenderUsername}: ", NickColorHelper.GetAttribute(replyTo.SenderUsername)));
+        segments.Add(new(snippet, ChatColors.SystemAttr));
+
+        return new ChatLine(segments)
+        {
+            JumpToMessageId = replyTo.MessageId,
+            ContinuationPrefixSegments = RailPrefix(),
         };
-        segments.AddRange(ChatColors.SplitMentions(suffix));
-        return new ChatLine(segments);
     }
 
-    private static List<ChatLine> FormatEmbed(EmbedDto embed, string indent, int chatWidth)
+    /// <summary>
+    /// Indent segments aligning continuation/attachment/embed lines under the message
+    /// text, extending the │ rail. Returns a fresh mutable list each call.
+    /// </summary>
+    private static List<ChatSegment> RailPrefix() =>
+    [
+        new(new string(' ', 6 + NickColWidth + 1), null),
+        new("│ ", ChatColors.RailAttr),
+    ];
+
+    /// <summary>
+    /// Right-aligns a nick into the fixed nick column, truncating over-long nicks
+    /// with an ellipsis. Grapheme/column aware.
+    /// </summary>
+    internal static string PadNick(string nick)
+    {
+        var cols = nick.GetColumns();
+        if (cols > NickColWidth)
+        {
+            var sb = new StringBuilder();
+            int used = 0;
+            foreach (var g in GraphemeHelper.GetGraphemes(nick))
+            {
+                var gCols = Math.Max(g.GetColumns(), 1);
+                if (used + gCols > NickColWidth - 1) break;
+                sb.Append(g);
+                used += gCols;
+            }
+            sb.Append('…');
+            nick = sb.ToString();
+            cols = used + 1;
+        }
+        return new string(' ', NickColWidth - cols) + nick;
+    }
+
+    internal static string DateRuleLabel(DateTime date) => date.ToString("ddd, MMM d yyyy");
+
+    private static ChatLine DateRule(DateTime date)
+    {
+        var label = DateRuleLabel(date);
+        return new ChatLine([new($"── {label} ──", ChatColors.DateRuleAttr)])
+        {
+            RuleLabel = label,
+            RuleAttr = ChatColors.DateRuleAttr,
+        };
+    }
+
+    private static ChatLine UnreadMarkerRule() =>
+        new([new("── new messages ──", ChatColors.UnreadMarkerAttr)])
+        {
+            RuleLabel = "new messages",
+            RuleAttr = ChatColors.UnreadMarkerAttr,
+            IsUnreadMarker = true,
+        };
+
+    private void RemoveUnreadMarker(string channel)
+    {
+        if (string.IsNullOrEmpty(channel) || !_markedChannels.Remove(channel))
+            return;
+
+        _markerAnchor.Remove(channel);
+        if (_channelMessages.TryGetValue(channel, out var messages))
+            messages.RemoveAll(l => l.IsUnreadMarker);
+    }
+
+    /// <summary>
+    /// Formats a chronological batch of messages, inserting a date rule before the
+    /// first message and at every day boundary. Outputs the batch's last local date.
+    /// </summary>
+    private List<ChatLine> FormatWithDateRules(List<MessageDto> messages, out DateTime? lastDate)
+    {
+        var lines = new List<ChatLine>();
+        lastDate = null;
+
+        foreach (var message in messages)
+        {
+            var date = message.SentAt.ToLocalTime().Date;
+            if (lastDate != date)
+            {
+                lines.Add(DateRule(date));
+                lastDate = date;
+            }
+            lines.AddRange(FormatMessage(message));
+        }
+
+        return lines;
+    }
+
+    private static List<ChatLine> FormatEmbed(EmbedDto embed, int chatWidth)
     {
         var lines = new List<ChatLine>();
         const string border = "\u258f "; // ▏ + space
         const int borderCols = 2;
-        int indentCols = indent.GetColumns();
+        int textWidth = chatWidth - ContentIndentCols - borderCols;
-        int textWidth = chatWidth - indentCols - borderCols;
         if (textWidth < 20) textWidth = 20;
 
         var borderAttr = HexColorHelper.ParseHexColor(embed.ThemeColor) ?? ChatColors.EmbedBorderAttr;
 
         void AddTextLine(string text, Attribute? color)
         {
-            lines.Add(new ChatLine(
+            var segments = RailPrefix();
-            [
+            segments.Add(new ChatSegment(border, borderAttr));
-                new ChatSegment(indent, null),
+            segments.Add(new ChatSegment(text, color));
-                new ChatSegment(border, borderAttr),
+            lines.Add(new ChatLine(segments));
-                new ChatSegment(text, color)
-            ]));
         }
 
         if (!string.IsNullOrWhiteSpace(embed.SiteName))
@@ -425,6 +795,12 @@ public sealed class ChatMessageManager
         return result;
     }
 
+    // Timestamps are compact HH:mm — the calendar day is carried by date rules,
+    // inserted at every local-day boundary. Convert to local first so a message
+    // near midnight lands under the right date rule.
+    private static string FormatTime(DateTimeOffset timestamp) =>
+        timestamp.ToLocalTime().ToString("HH:mm");
+
     internal static string FormatFileSize(long? bytes)
     {
         if (bytes is null or 0)

src/EchoHub.Client/UI/Chat/WelcomeBanner.cs

@@ -0,0 +1,103 @@
+using Terminal.Gui.Drawing;
+using Terminal.Gui.Text;
+using Attribute = Terminal.Gui.Drawing.Attribute;
+
+namespace EchoHub.Client.UI.Chat;
+
+/// <summary>
+/// The MOTD-style splash rendered into the chat pane when no channel is selected —
+/// a gold-gradient ASCII logo with version and key hints, in the spirit of classic
+/// IRC client greetings.
+/// </summary>
+internal static class WelcomeBanner
+{
+    // "ECHOHUB" in FIGlet ANSI-Shadow (58 columns)
+    private static readonly string[] BigLogo =
+    [
+        "███████╗ ██████╗██╗  ██╗ ██████╗ ██╗  ██╗██╗   ██╗██████╗ ",
+        "██╔════╝██╔════╝██║  ██║██╔═══██╗██║  ██║██║   ██║██╔══██╗",
+        "█████╗  ██║     ███████║██║   ██║███████║██║   ██║██████╔╝",
+        "██╔══╝  ██║     ██╔══██║██║   ██║██╔══██║██║   ██║██╔══██╗",
+        "███████╗╚██████╗██║  ██║╚██████╔╝██║  ██║╚██████╔╝██████╔╝",
+        "╚══════╝ ╚═════╝╚═╝  ╚═╝ ╚═════╝ ╚═╝  ╚═╝ ╚═════╝ ╚═════╝ ",
+    ];
+
+    // Compact box-drawing fallback for narrow panes (21 columns)
+    private static readonly string[] SmallLogo =
+    [
+        "┌─┐┌─┐┬ ┬┌─┐┬ ┬┬ ┬┌┐ ",
+        "├┤ │  ├─┤│ │├─┤│ │├┴┐",
+        "└─┘└─┘┴ ┴└─┘┴ ┴└─┘└─┘",
+    ];
+
+    // Vertical gold gradient, bright at the top fading to bronze — matches the
+    // EchoHub brand color used in the status bar.
+    private static readonly Color[] Gradient =
+    [
+        new(255, 215, 105),
+        new(245, 199, 89),
+        new(232, 183, 74),
+        new(216, 165, 60),
+        new(198, 146, 48),
+        new(178, 128, 38),
+    ];
+
+    private static readonly Attribute HintKeyAttr = new(new Color(140, 170, 200), Color.None);
+    private static readonly Attribute HintTextAttr = new(new Color(120, 120, 120), Color.None);
+    private static readonly Attribute TaglineAttr = new(new Color(160, 160, 160), Color.None);
+
+    private static readonly (string Key, string Hint)[] Hints =
+    [
+        ("Server → Connect", "join a server"),
+        ("Ctrl+K          ", "search channels & users"),
+        ("F2              ", "toggle the users panel"),
+        ("/help           ", "all commands"),
+    ];
+
+    /// <summary>
+    /// Builds banner lines centered for the given viewport width.
+    /// </summary>
+    public static List<ChatLine> Build(int width, string version)
+    {
+        var logo = width >= BigLogo[0].GetColumns() + 2 ? BigLogo : SmallLogo;
+        int logoWidth = logo[0].GetColumns();
+        var pad = new string(' ', Math.Max((width - logoWidth) / 2, 0));
+
+        var lines = new List<ChatLine> { new(""), new("") };
+
+        for (int i = 0; i < logo.Length; i++)
+        {
+            // Scale the gradient across however many rows the chosen logo has
+            var color = Gradient[Math.Min(i * Gradient.Length / logo.Length, Gradient.Length - 1)];
+            lines.Add(new ChatLine([
+                new ChatSegment(pad, null),
+                new ChatSegment(logo[i], new Attribute(color, Color.None)),
+            ]));
+        }
+
+        lines.Add(new ChatLine(""));
+
+        var tagline = $"v{version} — terminal chat with that old IRC soul";
+        lines.Add(Centered(tagline, width, TaglineAttr));
+        lines.Add(new ChatLine(""));
+
+        int hintWidth = Hints.Max(h => h.Key.Length + 2 + h.Hint.Length);
+        var hintPad = new string(' ', Math.Max((width - hintWidth) / 2, 0));
+        foreach (var (key, hint) in Hints)
+        {
+            lines.Add(new ChatLine([
+                new ChatSegment(hintPad, null),
+                new ChatSegment(key, HintKeyAttr),
+                new ChatSegment("  " + hint, HintTextAttr),
+            ]));
+        }
+
+        return lines;
+    }
+
+    private static ChatLine Centered(string text, int width, Attribute attr)
+    {
+        var pad = new string(' ', Math.Max((width - text.GetColumns()) / 2, 0));
+        return new ChatLine([new ChatSegment(pad, null), new ChatSegment(text, attr)]);
+    }
+}

src/EchoHub.Client/UI/Dialogs/ChannelPasswordDialog.cs

@@ -0,0 +1,72 @@
+using Terminal.Gui.App;
+using Terminal.Gui.ViewBase;
+using Terminal.Gui.Views;
+
+namespace EchoHub.Client.UI.Dialogs;
+
+/// <summary>
+/// Prompts for a channel password when joining a protected channel.
+/// Returns the entered password, or null if the user cancels.
+/// </summary>
+public sealed class ChannelPasswordDialog
+{
+    public static string? Show(IApplication app, string channelName, string? message = null)
+    {
+        string? result = null;
+
+        var dialog = new Dialog { Title = $"Join #{channelName}", Width = 50, Height = 10, CommandsToBubbleUp = [] };
+
+        var infoLabel = new Label
+        {
+            Text = message ?? $"#{channelName} is password protected.",
+            X = 1,
+            Y = 1
+        };
+
+        var passwordLabel = new Label { Text = "Password:", X = 1, Y = 3 };
+        var passwordField = new TextField { X = 11, Y = 3, Width = Dim.Fill(2), Secret = true };
+
+        var joinButton = new Button
+        {
+            Text = "Join",
+            IsDefault = true,
+            X = Pos.Center() - 9,
+            Y = 5
+        };
+
+        var cancelButton = new Button
+        {
+            Text = "Cancel",
+            X = Pos.Center() + 2,
+            Y = 5
+        };
+
+        joinButton.Accepting += (s, e) =>
+        {
+            var password = passwordField.Text;
+            if (string.IsNullOrEmpty(password))
+            {
+                MessageBox.ErrorQuery(app, "Error", "Password is required.", "OK");
+                return;
+            }
+
+            result = password;
+            e.Handled = true;
+            app.RequestStop();
+        };
+
+        cancelButton.Accepting += (s, e) =>
+        {
+            result = null;
+            e.Handled = true;
+            app.RequestStop();
+        };
+
+        dialog.Add(infoLabel, passwordLabel, passwordField, joinButton, cancelButton);
+
+        passwordField.SetFocus();
+        app.Run(dialog);
+
+        return result;
+    }
+}

src/EchoHub.Client/UI/Dialogs/ConnectDialog.cs

@@ -11,7 +11,8 @@ namespace EchoHub.Client.UI.Dialogs;
 /// </summary>
 public record ConnectDialogResult(
     string ServerUrl, string Username, string Password,
-    bool IsRegister, bool RememberMe, string? SavedRefreshToken);
+    bool IsRegister, bool RememberMe, string? SavedRefreshToken,
+    string? DisplayName = null, string? InviteCode = null);
 
 /// <summary>
 /// A Terminal.Gui dialog for entering server connection and authentication details.
@@ -29,7 +30,7 @@ public sealed class ConnectDialog
         savedServers ??= [];
 
         var hasSavedServers = savedServers.Count > 0;
-        var dialogHeight = hasSavedServers ? 22 : 18;
+        var dialogHeight = hasSavedServers ? 24 : 20;
 
         var dialog = new Dialog { Title = "Connect to Server", Width = 60, Height = dialogHeight };
 
@@ -153,26 +154,41 @@ public sealed class ConnectDialog
             Width = Dim.Fill(2)
         };
 
+        // Only needed on servers with invite-gated registration; harmless elsewhere
+        var inviteLabel = new Label
+        {
+            Text = "Invite Code:",
+            X = 1,
+            Y = yOffset + 11
+        };
+        var inviteField = new TextField
+        {
+            Text = "",
+            X = 15,
+            Y = yOffset + 11,
+            Width = Dim.Fill(2)
+        };
+
         var loginButton = new Button
         {
             Text = "Login",
             IsDefault = true,
             X = Pos.Center() - 20,
-            Y = yOffset + 11
+            Y = yOffset + 13
         };
 
         var registerButton = new Button
         {
             Text = "Register",
             X = Pos.Center() - 5,
-            Y = yOffset + 11
+            Y = yOffset + 13
         };
 
         var cancelButton = new Button
         {
             Text = "Cancel",
             X = Pos.Center() + 10,
-            Y = yOffset + 11
+            Y = yOffset + 13
         };
 
         // Wire saved server selection to auto-fill fields
@@ -262,7 +278,11 @@ public sealed class ConnectDialog
                 return;
             }
 
-            result = new ConnectDialogResult(url, user, pass, IsRegister: true, rememberMe, SavedRefreshToken: null);
+            var displayName = displayField.Text?.Trim();
+            var inviteCode = inviteField.Text?.Trim();
+            result = new ConnectDialogResult(url, user, pass, IsRegister: true, rememberMe, SavedRefreshToken: null,
+                DisplayName: string.IsNullOrEmpty(displayName) ? null : displayName,
+                InviteCode: string.IsNullOrEmpty(inviteCode) ? null : inviteCode);
             e.Handled = true;
             app.RequestStop();
         };
@@ -276,6 +296,7 @@ public sealed class ConnectDialog
 
         dialog.Add(urlLabel, urlField, userLabel, userField, passLabel, passField,
             tokenHintLabel, rememberMeCheckbox, displayLabel, displayField,
+            inviteLabel, inviteField,
             loginButton, registerButton, cancelButton);
 
         if (hasSavedServers && savedServerList is not null)

src/EchoHub.Client/UI/Dialogs/CreateChannelDialog.cs

@@ -4,7 +4,7 @@ using Terminal.Gui.ViewBase;
 
 namespace EchoHub.Client.UI.Dialogs;
 
-public record CreateChannelResult(string Name, string? Topic, bool IsPublic);
+public record CreateChannelResult(string Name, string? Topic, bool IsPublic, string? Password);
 
 public sealed class CreateChannelDialog
 {
@@ -12,7 +12,7 @@ public sealed class CreateChannelDialog
     {
         CreateChannelResult? result = null;
 
-        var dialog = new Dialog { Title = "Create Channel", Width = 50, Height = 14, CommandsToBubbleUp = [] };
+        var dialog = new Dialog { Title = "Create Channel", Width = 50, Height = 16, CommandsToBubbleUp = [] };
 
         var nameLabel = new Label { Text = "Name:", X = 1, Y = 1 };
         var nameField = new TextField { X = 10, Y = 1, Width = Dim.Fill(2) };
@@ -20,19 +20,22 @@ public sealed class CreateChannelDialog
         var topicLabel = new Label { Text = "Topic:", X = 1, Y = 3 };
         var topicField = new TextField { X = 10, Y = 3, Width = Dim.Fill(2) };
 
+        var passwordLabel = new Label { Text = "Password:", X = 1, Y = 5 };
+        var passwordField = new TextField { X = 11, Y = 5, Width = Dim.Fill(2), Secret = true };
+
         var publicCheckbox = new CheckBox
         {
             Text = "Public (visible to all users)",
             X = 1,
-            Y = 5,
+            Y = 7,
             Value = CheckState.Checked
         };
 
         var hintLabel = new Label
         {
-            Text = "Lowercase letters, digits, hyphens, underscores (2-100 chars)",
+            Text = "Name: a-z, 0-9, -, _ (2-100 chars). Empty password = open channel.",
             X = 1,
-            Y = 7,
+            Y = 9,
         };
 
         var createButton = new Button
@@ -40,14 +43,14 @@ public sealed class CreateChannelDialog
             Text = "Create",
             IsDefault = true,
             X = Pos.Center() - 10,
-            Y = 9
+            Y = 11
         };
 
         var cancelButton = new Button
         {
             Text = "Cancel",
             X = Pos.Center() + 5,
-            Y = 9
+            Y = 11
         };
 
         createButton.Accepting += (s, e) =>
@@ -63,8 +66,12 @@ public sealed class CreateChannelDialog
             if (string.IsNullOrWhiteSpace(topic))
                 topic = null;
 
+            var password = passwordField.Text;
+            if (string.IsNullOrWhiteSpace(password))
+                password = null;
+
             var isPublic = publicCheckbox.Value == CheckState.Checked;
-            result = new CreateChannelResult(name, topic, isPublic);
+            result = new CreateChannelResult(name, topic, isPublic, password);
             e.Handled = true;
             app.RequestStop();
         };
@@ -76,7 +83,8 @@ public sealed class CreateChannelDialog
             app.RequestStop();
         };
 
-        dialog.Add(nameLabel, nameField, topicLabel, topicField, publicCheckbox, hintLabel, createButton, cancelButton);
+        dialog.Add(nameLabel, nameField, topicLabel, topicField, passwordLabel, passwordField,
+            publicCheckbox, hintLabel, createButton, cancelButton);
 
         nameField.SetFocus();
         app.Run(dialog);

src/EchoHub.Client/UI/Dialogs/UpdateProgressDialog.cs

@@ -1,61 +0,0 @@
-using Terminal.Gui.App;
-using Terminal.Gui.Views;
-using Terminal.Gui.ViewBase;
-
-namespace EchoHub.Client.UI.Dialogs;
-
-public sealed class UpdateProgressDialog
-{
-    private readonly Dialog _dialog;
-    private readonly ProgressBar _progressBar;
-    private readonly Label _infoLabel;
-    private readonly IApplication _app;
-
-    public UpdateProgressDialog(IApplication app, string newVersion)
-    {
-        _app = app;
-
-        _dialog = new Dialog { Title = $"Updating to {newVersion}", Width = 50, Height = 10 };
-
-        _infoLabel = new Label
-        {
-            Text = "Preparing update...",
-            X = 1,
-            Y = 1,
-            Width = Dim.Fill(2)
-        };
-
-        _progressBar = new ProgressBar
-        {
-            X = 1,
-            Y = 3,
-            Width = Dim.Fill(2),
-            Fraction = 0f
-        };
-
-        var cancelButton = new Button
-        {
-            Text = "Cancel",
-            X = Pos.Center(),
-            Y = 6
-        };
-
-        _dialog.Add(_infoLabel, _progressBar);
-    }
-
-    public void UpdateProgress(float fraction, string statusText)
-    {
-        _progressBar.Fraction = fraction;
-        _infoLabel.Text = statusText;
-    }
-
-    public void Show()
-    {
-        _app.Run(_dialog);
-    }
-
-    public void Close()
-    {
-        _app.RequestStop();
-    }
-}

src/EchoHub.Client/UI/Helpers/DroppedFileParser.cs

@@ -0,0 +1,104 @@
+using System.Text;
+
+namespace EchoHub.Client.UI.Helpers;
+
+/// <summary>
+/// Recognizes a dragged-and-dropped file (or files) that a terminal delivers into the input as an
+/// absolute path. Terminals differ: some paste the whole path at once, others send it character by
+/// character; either way this checks whether the current input text resolves to existing file(s).
+/// </summary>
+public static class DroppedFileParser
+{
+    /// <summary>
+    /// Cheap pre-check so callers only stat the filesystem when the input plausibly holds a path:
+    /// a quoted path, a Windows drive path (<c>X:\</c>/<c>X:/</c>), a UNC path (<c>\\</c>), or a
+    /// POSIX absolute path (<c>/</c>). Normal chat text never starts this way.
+    /// </summary>
+    public static bool LooksLikePath(string text)
+    {
+        var t = text.TrimStart();
+        if (t.Length < 3)
+            return false;
+        if (t[0] is '"' or '/')
+            return true;
+        if (t.StartsWith(@"\\", StringComparison.Ordinal))
+            return true;
+        return char.IsLetter(t[0]) && t[1] == ':' && (t[2] == '\\' || t[2] == '/');
+    }
+
+    /// <summary>
+    /// Returns true when <paramref name="text"/> resolves to one or more existing files.
+    /// Handles a single path (quoted or not, possibly containing spaces) and multiple
+    /// space-separated (optionally quoted) paths. <paramref name="fileExists"/> is injectable
+    /// for testing; production passes <see cref="File.Exists"/>.
+    /// </summary>
+    public static bool TryGetFiles(string text, out List<string> files, Func<string, bool>? fileExists = null)
+    {
+        fileExists ??= File.Exists;
+        files = [];
+
+        var trimmed = text.Trim();
+        if (trimmed.Length < 3 || trimmed.Length > 4096 || trimmed.Contains('\n'))
+            return false;
+
+        // Single path, possibly quoted and/or containing spaces.
+        var unquoted = StripQuotes(trimmed);
+        if (Path.IsPathFullyQualified(unquoted) && fileExists(unquoted))
+        {
+            files.Add(unquoted);
+            return true;
+        }
+
+        // Multiple files: space-separated tokens, each optionally quoted.
+        foreach (var token in TokenizeQuoted(trimmed))
+        {
+            if (!Path.IsPathFullyQualified(token) || !fileExists(token))
+            {
+                files.Clear();
+                return false;
+            }
+            files.Add(token);
+        }
+
+        return files.Count > 0;
+    }
+
+    private static string StripQuotes(string s) =>
+        s.Length >= 2 && ((s[0] == '"' && s[^1] == '"') || (s[0] == '\'' && s[^1] == '\''))
+            ? s[1..^1]
+            : s;
+
+    private static IEnumerable<string> TokenizeQuoted(string input)
+    {
+        var current = new StringBuilder();
+        var quote = '\0';
+
+        foreach (var c in input)
+        {
+            if (quote != '\0')
+            {
+                if (c == quote) quote = '\0';
+                else current.Append(c);
+            }
+            else if (c is '"' or '\'')
+            {
+                quote = c;
+            }
+            else if (c == ' ')
+            {
+                if (current.Length > 0)
+                {
+                    yield return current.ToString();
+                    current.Clear();
+                }
+            }
+            else
+            {
+                current.Append(c);
+            }
+        }
+
+        if (current.Length > 0)
+            yield return current.ToString();
+    }
+}

src/EchoHub.Client/UI/Helpers/NickColorHelper.cs

@@ -0,0 +1,60 @@
+using Terminal.Gui.Drawing;
+using Attribute = Terminal.Gui.Drawing.Attribute;
+
+namespace EchoHub.Client.UI.Helpers;
+
+/// <summary>
+/// Deterministic per-nick colors for users who haven't picked a nickname color.
+/// The same nick always maps to the same palette entry (classic IRC client behavior),
+/// so a busy channel stays scannable without any configuration.
+/// </summary>
+public static class NickColorHelper
+{
+    // Medium-saturation truecolor values chosen to stay readable on both dark and
+    // light backgrounds. Order matters: changing it re-colors everyone.
+    private static readonly Attribute[] Palette =
+    [
+        new(new Color(224, 108, 117), Color.None), // soft red
+        new(new Color(152, 195, 121), Color.None), // green
+        new(new Color(229, 192, 123), Color.None), // sand
+        new(new Color(97, 175, 239), Color.None),  // blue
+        new(new Color(198, 120, 221), Color.None), // magenta
+        new(new Color(86, 182, 194), Color.None),  // teal
+        new(new Color(255, 160, 122), Color.None), // salmon
+        new(new Color(130, 170, 255), Color.None), // periwinkle
+        new(new Color(195, 232, 141), Color.None), // lime
+        new(new Color(137, 221, 255), Color.None), // sky
+        new(new Color(255, 203, 107), Color.None), // amber
+        new(new Color(240, 130, 170), Color.None), // rose
+    ];
+
+    /// <summary>
+    /// Stable palette index for a nick: case-insensitive FNV-1a over the nick,
+    /// reduced modulo <paramref name="paletteSize"/>. Pure function (no Terminal.Gui
+    /// types) so it is unit-testable without a display driver.
+    /// </summary>
+    public static int GetPaletteIndex(string nick, int paletteSize)
+    {
+        if (paletteSize <= 0)
+            return 0;
+
+        const uint fnvOffset = 2166136261;
+        const uint fnvPrime = 16777619;
+
+        uint hash = fnvOffset;
+        foreach (var ch in nick)
+        {
+            hash ^= char.ToLowerInvariant(ch);
+            hash *= fnvPrime;
+        }
+
+        return (int)(hash % (uint)paletteSize);
+    }
+
+    /// <summary>
+    /// The color attribute for a nick. Used as a fallback when the user has no
+    /// explicit nickname color set.
+    /// </summary>
+    public static Attribute GetAttribute(string nick) =>
+        Palette[GetPaletteIndex(nick, Palette.Length)];
+}

src/EchoHub.Client/UI/ListSources/ChannelListSource.cs

@@ -16,6 +16,10 @@ public class ChannelListSource : IListDataSource
 {
     private readonly List<string> _channelNames = [];
     private readonly Dictionary<string, int> _unreadCounts = [];
+    private readonly HashSet<string> _protectedChannels = [];
+    private readonly HashSet<string> _mentionChannels = [];
+    private readonly HashSet<string> _privateChannels = [];
+    private readonly HashSet<string> _systemChannels = [];
     private string _activeChannel = string.Empty;
 
     public event NotifyCollectionChangedEventHandler? CollectionChanged;
@@ -27,14 +31,31 @@ public class ChannelListSource : IListDataSource
     private static readonly Attribute UnreadAttr = new(Color.BrightCyan, Color.None);
     private static readonly Attribute NormalAttr = new(Color.DarkGray, Color.None);
     private static readonly Attribute BadgeAttr = new(Color.BrightYellow, Color.None);
+    private static readonly Attribute MentionAttr = new(new Color(230, 140, 60), Color.None);
+    // System channels (e.g. the live log room) render in green to set them apart from user rooms.
+    private static readonly Attribute SystemAttr = new(Color.BrightGreen, Color.None);
 
-    public void Update(List<string> channels, Dictionary<string, int> unread, string activeChannel)
+    public void Update(List<string> channels, Dictionary<string, int> unread, string activeChannel,
+        IReadOnlySet<string>? protectedChannels = null, IReadOnlySet<string>? mentionChannels = null,
+        IReadOnlySet<string>? privateChannels = null, IReadOnlySet<string>? systemChannels = null)
     {
         _channelNames.Clear();
         _channelNames.AddRange(channels);
         _unreadCounts.Clear();
         foreach (var kv in unread)
             _unreadCounts[kv.Key] = kv.Value;
+        _protectedChannels.Clear();
+        if (protectedChannels is not null)
+            _protectedChannels.UnionWith(protectedChannels);
+        _mentionChannels.Clear();
+        if (mentionChannels is not null)
+            _mentionChannels.UnionWith(mentionChannels);
+        _privateChannels.Clear();
+        if (privateChannels is not null)
+            _privateChannels.UnionWith(privateChannels);
+        _systemChannels.Clear();
+        if (systemChannels is not null)
+            _systemChannels.UnionWith(systemChannels);
         _activeChannel = activeChannel;
         MaxItemLength = channels.Count > 0 ? channels.Max(c => c.Length + 6) : 0;
         if (!SuspendCollectionChangedEvent)
@@ -56,8 +77,15 @@ public class ChannelListSource : IListDataSource
 
         var normalAttr = listView.GetAttributeForRole(VisualRole.Normal);
         var focusAttr = listView.GetAttributeForRole(VisualRole.Focus);
-        var prefix = isActive ? "> " : "  ";
+        var isSystem = _systemChannels.Contains(name);
+        // System channels get a leading rule so they read as a pinned, separate group at the top.
+        var prefix = isSystem ? (isActive ? "▌ " : "▎ ") : (isActive ? "> " : "  ");
+        // Trailing * marks password-protected (+k) channels; ~ marks private (unlisted) ones
         var channelText = $"#{name}";
+        if (_protectedChannels.Contains(name))
+            channelText += "*";
+        if (_privateChannels.Contains(name))
+            channelText += "~";
         var badge = hasUnread ? $" ({unread})" : "";
 
         // Resolve Transparent backgrounds to the view's actual background
@@ -73,15 +101,24 @@ public class ChannelListSource : IListDataSource
         }
         else
         {
-            listView.SetAttribute(Resolve(isActive ? ActiveAttr : NormalAttr));
+            // System channels are green so they stand apart from user rooms; that green also
+            // colors the leading rule and (dimmer) prefix.
+            listView.SetAttribute(Resolve(isSystem ? SystemAttr : isActive ? ActiveAttr : NormalAttr));
             drawnChars = RenderHelpers.WriteText(listView, prefix, drawnChars, width);
 
-            listView.SetAttribute(Resolve(isActive ? ActiveAttr : hasUnread ? UnreadAttr : NormalAttr));
+            // Mentions escalate above plain unread: the whole entry turns orange
+            var hasMention = _mentionChannels.Contains(name);
+            var nameAttr = isSystem ? SystemAttr
+                : isActive ? ActiveAttr
+                : hasMention ? MentionAttr
+                : hasUnread ? UnreadAttr
+                : NormalAttr;
+            listView.SetAttribute(Resolve(nameAttr));
             drawnChars = RenderHelpers.WriteText(listView, channelText, drawnChars, width);
 
             if (hasUnread)
             {
-                listView.SetAttribute(Resolve(BadgeAttr));
+                listView.SetAttribute(Resolve(isSystem ? SystemAttr : hasMention ? MentionAttr : BadgeAttr));
                 drawnChars = RenderHelpers.WriteText(listView, badge, drawnChars, width);
             }
         }

src/EchoHub.Core/Constants/HubConstants.cs

@@ -4,6 +4,12 @@ public static class HubConstants
 {
     public const string ChatHubPath = "/hubs/chat";
     public const string DefaultChannel = "general";
+
+    /// <summary>
+    /// Connection-id prefix for IRC gateway connections. The presence tracker uses it to
+    /// tell IRC-only users apart from native (SignalR) clients.
+    /// </summary>
+    public const string IrcConnectionIdPrefix = "irc-";
     public const int DefaultHistoryCount = 100;
     public const int MaxMessageLength = 2000;
     public const int MaxImageSizeBytes = 10 * 1024 * 1024; // 10 MB
@@ -11,6 +17,7 @@ public static class HubConstants
     public const int MaxFileSizeBytes = 100 * 1024 * 1024; // 100 MB
     public const int MaxAvatarSizeBytes = 2 * 1024 * 1024; // 2 MB
     public const int MaxMessageNewlines = 30;
+    public const int MaxAttachmentsPerMessage = 10;
     public const int MaxConsecutiveNewlines = 1;
     public const int AsciiArtWidth = 80;
     public const int AsciiArtHeight = 40;

src/EchoHub.Core/Constants/MessageConventions.cs

@@ -0,0 +1,31 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace EchoHub.Core.Constants;
+
+/// <summary>
+/// Cross-protocol message conventions. Action messages (<c>/me</c>) use the IRC CTCP ACTION
+/// wire format 0x01 + "ACTION " + text + 0x01 as the stored content, so IRC clients
+/// interoperate natively (irssi's /me arrives in exactly this shape) and the TUI renders
+/// "* nick text". In end-to-end encrypted rooms the marker encrypts along with the text.
+/// </summary>
+public static class MessageConventions
+{
+    public const string ActionPrefix = "\u0001ACTION ";
+    public const string ActionSuffix = "\u0001";
+
+    public static string FormatAction(string text) => $"{ActionPrefix}{text}{ActionSuffix}";
+
+    public static bool TryParseAction(string content, [NotNullWhen(true)] out string? actionText)
+    {
+        if (content.Length > ActionPrefix.Length + ActionSuffix.Length
+            && content.StartsWith(ActionPrefix, StringComparison.Ordinal)
+            && content.EndsWith(ActionSuffix, StringComparison.Ordinal))
+        {
+            actionText = content[ActionPrefix.Length..^ActionSuffix.Length];
+            return actionText.Length > 0;
+        }
+
+        actionText = null;
+        return false;
+    }
+}

src/EchoHub.Core/Constants/ValidationConstants.cs

@@ -9,6 +9,7 @@ public static partial class ValidationConstants
     public const string HexColorPattern = @"^#[0-9a-fA-F]{6}$";
 
     public const int MaxPasswordLength = 128;
+    public const int MinChannelPasswordLength = 3;
     public const int MaxDisplayNameLength = 100;
     public const int MaxBioLength = 500;
     public const int MaxStatusMessageLength = 100;

src/EchoHub.Core/Contracts/IChannelService.cs

@@ -6,17 +6,29 @@ public interface IChannelService
 {
     // Channel CRUD
     Task<PaginatedResponse<ChannelDto>> GetChannelsAsync(Guid userId, int offset, int limit);
-    Task<ChannelOperationResult> CreateChannelAsync(Guid creatorUserId, string name, string? topic, bool isPublic);
+    Task<ChannelOperationResult> CreateChannelAsync(Guid creatorUserId, string name, string? topic, bool isPublic,
+        string? password = null, string? encryptionSalt = null, string? wrappedRoomKey = null);
     Task<ChannelOperationResult> UpdateTopicAsync(Guid callerUserId, string channelName, string? topic);
+    Task<ChannelOperationResult> SetChannelPasswordAsync(Guid callerUserId, string channelName, string? password);
+    Task<ChannelOperationResult> RekeyChannelAsync(Guid callerUserId, string channelName,
+        string oldPassword, string newPassword, string newEncryptionSalt, string newWrappedRoomKey);
     Task<ChannelOperationResult> DeleteChannelAsync(Guid callerUserId, string channelName);
 
     // Channel queries
     Task<(string? Topic, bool Exists)> GetChannelTopicAsync(string channelName);
     Task<List<ChannelListItem>> GetChannelListAsync();
     Task<ChannelDto?> GetChannelByNameAsync(string channelName);
+    Task<ChannelMetaDto?> GetChannelMetaAsync(string channelName);
+    Task<ChannelCryptoDto?> GetChannelCryptoAsync(string channelName);
+    Task<(string? EncryptionSalt, string? WrappedRoomKey)> GetChannelKeyEnvelopeAsync(string channelName);
 
     // Membership
-    Task<(bool Success, string? Error)> EnsureChannelMembershipAsync(Guid userId, string channelName);
+    Task<(bool Success, string? Error, bool PasswordRequired)> EnsureChannelMembershipAsync(Guid userId, string channelName, string? password = null);
+
+    // System channels (server-managed, e.g. the live server-log room). Creates the channel
+    // if missing and reclaims a same-named regular channel so server content never lands in
+    // a user-owned room.
+    Task<ChannelDto> EnsureSystemChannelAsync(string channelName, string? topic = null);
 }
 
-public record ChannelListItem(string Name, string? Topic, int OnlineCount);
+public record ChannelListItem(string Name, string? Topic, int OnlineCount, bool IsPublic = true, bool IsProtected = false);

src/EchoHub.Core/Contracts/IChatBroadcaster.cs

@@ -4,7 +4,14 @@ namespace EchoHub.Core.Contracts;
 
 public interface IChatBroadcaster
 {
-    Task SendMessageToChannelAsync(string channelName, MessageDto message);
+    /// <summary>
+    /// Broadcast a chat message to a channel. <paramref name="excludeConnectionId"/> is the
+    /// connection the message originated from (IRC convention: never echo a message back to
+    /// the connection that sent it — its client already displayed it locally). Other
+    /// connections of the same user (e.g. an IRC session alongside a TUI session) still
+    /// receive the message.
+    /// </summary>
+    Task SendMessageToChannelAsync(string channelName, MessageDto message, string? excludeConnectionId = null);
     Task SendUserJoinedAsync(string channelName, string username, UserPresenceDto? presence, string? excludeConnectionId = null);
     Task SendUserLeftAsync(string channelName, string username);
     Task SendChannelUpdatedAsync(ChannelDto channel, string? channelName = null);
@@ -12,6 +19,7 @@ public interface IChatBroadcaster
     Task SendUserKickedAsync(string channelName, string username, string? reason);
     Task SendUserBannedAsync(string username, string? reason);
     Task SendMessageDeletedAsync(string channelName, Guid messageId);
+    Task SendChannelDeletedAsync(string channelName);
     Task SendChannelNukedAsync(string channelName);
     Task SendErrorAsync(string connectionId, string message);
     Task ForceDisconnectUserAsync(List<string> connectionIds, string reason);

src/EchoHub.Core/Contracts/IChatService.cs

@@ -10,11 +10,14 @@ public interface IChatService
     Task<string?> UserDisconnectedAsync(string connectionId);
 
     // Channel operations
-    Task<(List<MessageDto> History, string? Error)> JoinChannelAsync(string connectionId, Guid userId, string username, string channelName);
+    Task<(List<MessageDto> History, string? Error, bool PasswordRequired)> JoinChannelAsync(string connectionId, Guid userId, string username, string channelName, string? password = null);
     Task LeaveChannelAsync(string connectionId, string username, string channelName);
 
-    // Messaging
+    // Messaging. originConnectionId identifies the connection the message came from so
-    Task<string?> SendMessageAsync(Guid userId, string username, string channelName, string content);
+    // broadcasters can avoid echoing it back to that one connection (IRC convention);
+    // the sender's other sessions still receive it. replyToMessageId references the message
+    // being replied to; it must exist in the same channel.
+    Task<string?> SendMessageAsync(Guid userId, string username, string channelName, string content, string? originConnectionId = null, Guid? replyToMessageId = null);
     Task<List<MessageDto>> GetChannelHistoryAsync(string channelName, int count, int offset = 0);
 
     // Presence
@@ -24,6 +27,7 @@ public interface IChatService
     // Broadcasting (used by controllers and IRC gateway)
     Task BroadcastMessageAsync(string channelName, MessageDto message);
     Task BroadcastChannelUpdatedAsync(ChannelDto channel, string? channelName = null);
+    Task BroadcastChannelDeletedAsync(string channelName);
 
     // Query operations (used by IRC gateway for WHOIS)
     Task<List<string>> GetChannelsForUserAsync(string username);

src/EchoHub.Core/Contracts/IEchoHubClient.cs

@@ -15,6 +15,7 @@ public interface IEchoHubClient
     Task UserKicked(string channelName, string username, string? reason);
     Task UserBanned(string username, string? reason);
     Task MessageDeleted(string channelName, Guid messageId);
+    Task ChannelDeleted(string channelName);
     Task ChannelNuked(string channelName);
     Task ForceDisconnect(string reason);
     Task Error(string message);

src/EchoHub.Core/Contracts/IMessageEncryptionService.cs

@@ -2,6 +2,12 @@ namespace EchoHub.Core.Contracts;
 
 public interface IMessageEncryptionService
 {
+    /// <summary>
+    /// Prefix marking transport/at-rest encrypted content. <see cref="Decrypt"/> is a
+    /// pass-through for values without it.
+    /// </summary>
+    const string CiphertextPrefix = "$ENC$v1$";
+
     /// <summary>
     /// Whether database content should be encrypted at rest (server setting).
     /// </summary>

src/EchoHub.Core/Contracts/IUserService.cs

@@ -4,7 +4,9 @@ namespace EchoHub.Core.Contracts;
 
 public interface IUserService
 {
-    Task<UserOperationResult> RegisterUserAsync(string username, string password, string? displayName = null);
+    // inviteCode is required when the server runs with Server:Registration = "invite";
+    // "closed" refuses all new accounts. Both REST and the IRC gateway funnel through here.
+    Task<UserOperationResult> RegisterUserAsync(string username, string password, string? displayName = null, string? inviteCode = null);
     Task<UserOperationResult> AuthenticateUserAsync(string username, string password);
     Task<UserProfileDto?> GetUserProfileAsync(string username);
     Task<UserProfileDto?> GetUserByIdAsync(Guid userId);

src/EchoHub.Core/DTOs/AccountDtos.cs

@@ -0,0 +1,30 @@
+namespace EchoHub.Core.DTOs;
+
+/// <summary>Password re-confirmation for destructive self-service account actions.</summary>
+public record DeleteAccountRequest(string Password);
+
+/// <summary>
+/// Everything the server holds about a user, as stored. For end-to-end encrypted rooms the
+/// message content in here is room ciphertext — the server cannot include plaintext it never had.
+/// </summary>
+public record UserDataExportDto(
+    DateTimeOffset ExportedAt,
+    string ServerName,
+    UserProfileDto Profile,
+    List<ExportedMessageDto> Messages,
+    List<ExportedAttachmentDto> Attachments);
+
+public record ExportedMessageDto(
+    Guid Id,
+    string ChannelName,
+    DateTimeOffset SentAt,
+    string Content,
+    Guid? ReplyToMessageId);
+
+public record ExportedAttachmentDto(
+    string FileName,
+    string Url,
+    long FileSize,
+    string Kind,
+    string ChannelName,
+    DateTimeOffset SentAt);

src/EchoHub.Core/DTOs/AuthDtos.cs

@@ -1,6 +1,6 @@
 namespace EchoHub.Core.DTOs;
 
-public record RegisterRequest(string Username, string Password, string? DisplayName = null);
+public record RegisterRequest(string Username, string Password, string? DisplayName = null, string? InviteCode = null);
 
 public record LoginRequest(string Username, string Password);
 

src/EchoHub.Core/DTOs/ChatDtos.cs

@@ -8,12 +8,34 @@ public record MessageDto(
     string SenderUsername,
     string? SenderNicknameColor,
     string ChannelName,
-    MessageType Type,
-    string? AttachmentUrl,
-    string? AttachmentFileName,
     DateTimeOffset SentAt,
-    long? AttachmentFileSize = null,
+    List<AttachmentDto>? Attachments = null,
-    List<EmbedDto>? Embeds = null);
+    List<EmbedDto>? Embeds = null,
+    string? SenderDisplayName = null,
+    ReplyRefDto? ReplyTo = null);
+
+/// <summary>
+/// Reference to the message a reply targets. <see cref="Content"/> is treated exactly like
+/// message content on the wire: transport-encrypted, and for end-to-end encrypted rooms it is
+/// room ciphertext the client must decrypt (the server truncates only plaintext snippets).
+/// Null on a <see cref="MessageDto"/> when the original message no longer exists.
+/// </summary>
+public record ReplyRefDto(
+    Guid MessageId,
+    string SenderUsername,
+    string Content);
+
+/// <summary>
+/// A file attached to a message. <see cref="AsciiPreview"/> holds the color-tag art for
+/// images (null otherwise). For end-to-end encrypted channels the content behind
+/// <see cref="Url"/> and the preview are ciphertext the server cannot read.
+/// </summary>
+public record AttachmentDto(
+    AttachmentKind Kind,
+    string Url,
+    string FileName,
+    long FileSize,
+    string? AsciiPreview = null);
 
 public record ChannelDto(
     Guid Id,
@@ -21,7 +43,10 @@ public record ChannelDto(
     string? Topic,
     bool IsPublic,
     int MessageCount,
-    DateTimeOffset CreatedAt);
+    DateTimeOffset CreatedAt,
+    bool IsProtected = false,
+    bool IsEncrypted = false,
+    bool IsSystem = false);
 
 public record UserDto(
     Guid Id,
@@ -33,13 +58,58 @@ public record UserDto(
 
 public record SendMessageRequest(string ChannelName, string Content);
 
-public record CreateChannelRequest(string Name, string? Topic = null, bool IsPublic = true);
+public record CreateChannelRequest(
+    string Name,
+    string? Topic = null,
+    bool IsPublic = true,
+    string? Password = null,
+    string? EncryptionSalt = null,
+    string? WrappedRoomKey = null);
+
+/// <summary>
+/// Public crypto metadata for a channel — enough for a client to derive its join
+/// credential from a passphrase. Never includes the wrapped room key.
+/// </summary>
+public record ChannelCryptoDto(bool IsEncrypted, string? EncryptionSalt);
+
+/// <summary>
+/// Human-facing summary of a channel (the <c>/meta</c> command). For encrypted channels the
+/// server still knows these figures — count, timestamps, and stored blob sizes — even though it
+/// cannot read the content itself. <see cref="EstimatedSizeBytes"/> is the sum of stored
+/// attachment blob sizes plus message text length, so it is an estimate, not an exact on-disk total.
+/// </summary>
+public record ChannelMetaDto(
+    Guid Id,
+    string Name,
+    string? Topic,
+    bool IsEncrypted,
+    bool IsProtected,
+    int MessageCount,
+    int UniqueUserCount,
+    long EstimatedSizeBytes,
+    DateTimeOffset CreatedAt);
+
+/// <summary>
+/// Passphrase change for an encrypted channel: the client proves knowledge of the old
+/// passphrase (old auth key), then supplies the re-wrapped room key under the new one.
+/// </summary>
+public record RekeyChannelRequest(
+    string OldPassword,
+    string NewPassword,
+    string NewEncryptionSalt,
+    string NewWrappedRoomKey);
 
 public record UpdateTopicRequest(string? Topic);
 
 public record SendUrlRequest(string Url);
 
-public record JoinChannelResult(bool Success, List<MessageDto> History, string? Error = null);
+public record JoinChannelResult(
+    bool Success,
+    List<MessageDto> History,
+    string? Error = null,
+    bool PasswordRequired = false,
+    string? EncryptionSalt = null,
+    string? WrappedRoomKey = null);
 
 public record EmbedDto(
     string? SiteName,

src/EchoHub.Core/DTOs/InviteDtos.cs

@@ -0,0 +1,11 @@
+namespace EchoHub.Core.DTOs;
+
+public record CreateInviteRequest(int? MaxUses = null, int? ExpiresInHours = null);
+
+public record InviteDto(
+    string Code,
+    string CreatedByUsername,
+    DateTimeOffset CreatedAt,
+    DateTimeOffset? ExpiresAt,
+    int MaxUses,
+    int UseCount);

src/EchoHub.Core/DTOs/ProfileDtos.cs

@@ -30,6 +30,7 @@ public record UserPresenceDto(
     string? NicknameColor,
     UserStatus Status,
     string? StatusMessage,
-    ServerRole Role);
+    ServerRole Role,
+    bool IsIrc = false);
 
 public record AvatarUploadResponse(string AvatarAscii);

src/EchoHub.Core/DTOs/ServerDtos.cs

@@ -1,5 +1,10 @@
 namespace EchoHub.Core.DTOs;
 
-public record ServerStatusDto(string Name, string? Description, int OnlineUsers, int TotalChannels);
+public record ServerStatusDto(
+    string Name,
+    string? Description,
+    int OnlineUsers,
+    int TotalChannels,
+    string RegistrationMode = "open");
 
 public record EncryptionKeyResponse(string Key);

src/EchoHub.Core/EchoHub.Core.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
@@ -6,4 +6,8 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.12" />
+  </ItemGroup>
+
 </Project>

src/EchoHub.Core/Models/Attachment.cs

@@ -0,0 +1,28 @@
+namespace EchoHub.Core.Models;
+
+/// <summary>
+/// A file attached to a message (image, audio, or any file). A message may carry
+/// zero or more attachments alongside its text content (Discord-style).
+/// </summary>
+public class Attachment
+{
+    public Guid Id { get; set; }
+    public Guid MessageId { get; set; }
+    public Message? Message { get; set; }
+
+    public AttachmentKind Kind { get; set; }
+
+    /// <summary>Relative download URL, e.g. <c>/api/files/{fileId}</c>.</summary>
+    public required string Url { get; set; }
+    public required string FileName { get; set; }
+
+    /// <summary>Stored blob size in bytes (ciphertext size for encrypted channels).</summary>
+    public long FileSize { get; set; }
+
+    /// <summary>
+    /// Rendered ASCII-art preview for images (color-tag format). Null for audio/files.
+    /// Stored encrypted-at-rest when database encryption is enabled, and room-encrypted
+    /// for end-to-end encrypted channels.
+    /// </summary>
+    public string? AsciiPreview { get; set; }
+}

src/EchoHub.Core/Models/AttachmentKind.cs

@@ -0,0 +1,12 @@
+namespace EchoHub.Core.Models;
+
+/// <summary>
+/// The kind of a message attachment. Determines how the client renders it
+/// (ASCII preview for images, a play affordance for audio, a download line for files).
+/// </summary>
+public enum AttachmentKind
+{
+    Image,
+    Audio,
+    File
+}

src/EchoHub.Core/Models/Channel.cs

@@ -6,6 +6,17 @@ public class Channel
     public required string Name { get; set; }
     public string? Topic { get; set; }
     public bool IsPublic { get; set; } = true;
+
+    // Server-managed channel (e.g. the live server-log room): auto-created, read-only for
+    // every role, visible only to roles the owning feature allows. Users can never create one.
+    public bool IsSystem { get; set; }
+    public string? PasswordHash { get; set; }
+
+    // End-to-end encryption envelope (client-generated; server cannot decrypt room content).
+    // EncryptionSalt: PBKDF2 salt for passphrase-derived keys. WrappedRoomKey: the room
+    // content key encrypted under the passphrase-derived key-encryption key.
+    public string? EncryptionSalt { get; set; }
+    public string? WrappedRoomKey { get; set; }
     public DateTimeOffset CreatedAt { get; set; } = DateTimeOffset.UtcNow;
     public Guid CreatedByUserId { get; set; }
 

src/EchoHub.Core/Models/InviteCode.cs

@@ -0,0 +1,20 @@
+namespace EchoHub.Core.Models;
+
+/// <summary>
+/// A registration invite code. When the server runs with <c>Server:Registration = "invite"</c>,
+/// new accounts (REST and IRC alike) require a valid, unexpired, not-fully-used code.
+/// </summary>
+public class InviteCode
+{
+    public Guid Id { get; set; }
+    public required string Code { get; set; }
+    public Guid CreatedByUserId { get; set; }
+    public string CreatedByUsername { get; set; } = string.Empty;
+    public DateTimeOffset CreatedAt { get; set; } = DateTimeOffset.UtcNow;
+
+    /// <summary>Null means the code never expires.</summary>
+    public DateTimeOffset? ExpiresAt { get; set; }
+
+    public int MaxUses { get; set; } = 1;
+    public int UseCount { get; set; }
+}

src/EchoHub.Core/Models/Message.cs

@@ -3,11 +3,10 @@ namespace EchoHub.Core.Models;
 public class Message
 {
     public Guid Id { get; set; }
+
+    /// <summary>The message text/caption. May be empty when the message only carries attachments.</summary>
     public required string Content { get; set; }
-    public MessageType Type { get; set; } = MessageType.Text;
+
-    public string? AttachmentUrl { get; set; }
-    public string? AttachmentFileName { get; set; }
-    public long? AttachmentFileSize { get; set; }
     public string? EmbedJson { get; set; }
     public DateTimeOffset SentAt { get; set; } = DateTimeOffset.UtcNow;
 
@@ -16,4 +15,19 @@ public class Message
 
     public Guid SenderUserId { get; set; }
     public required string SenderUsername { get; set; }
+
+    /// <summary>Message this one replies to, if any. The target may since have been deleted.</summary>
+    public Guid? ReplyToMessageId { get; set; }
+
+    /// <summary>Files attached to this message. Empty for a plain text message.</summary>
+    public List<Attachment> Attachments { get; set; } = [];
+
+    // ── Legacy columns (pre-attachments model) ──────────────────────────────
+    // Retained so the one-time startup data migration can fold old single-attachment
+    // messages into Attachments. New code never writes these; they are nulled out
+    // once migrated. Not exposed in DTOs. See DataMigrationService.MigrateLegacyAttachmentsAsync.
+    public MessageType Type { get; set; } = MessageType.Text;
+    public string? AttachmentUrl { get; set; }
+    public string? AttachmentFileName { get; set; }
+    public long? AttachmentFileSize { get; set; }
 }

src/EchoHub.Core/Security/RoomCrypto.cs

@@ -0,0 +1,132 @@
+using System.Security.Cryptography;
+using System.Text;
+
+namespace EchoHub.Core.Security;
+
+/// <summary>
+/// Client-side envelope encryption for private (end-to-end encrypted) channels.
+///
+/// Design: at creation the client generates a random 256-bit room content key (RCK)
+/// that encrypts all room content. The RCK is stored on the server *wrapped*
+/// (AES-GCM encrypted) by a key derived from the passphrase, next to a BCrypt hash
+/// of a separately derived auth key used as the join gate. The passphrase, the
+/// key-encryption key, and the RCK never leave the client, so the server can gate
+/// joins and count/measure content without being able to read it. Changing the
+/// passphrase only re-wraps the RCK — history is never re-encrypted.
+///
+/// Derivation: PBKDF2-SHA256(passphrase, salt, 210000 iterations) → 64 bytes;
+/// first 32 bytes are the auth key (sent to the server as lowercase hex),
+/// last 32 bytes are the key-encryption key (never sent).
+/// </summary>
+public static class RoomCrypto
+{
+    public const string CiphertextPrefix = "$RC1$";
+
+    private const int Pbkdf2Iterations = 210_000;
+    private const int SaltSizeBytes = 16;
+    private const int KeySizeBytes = 32;
+    private const int NonceSizeBytes = 12;
+    private const int TagSizeBytes = 16;
+
+    public sealed record DerivedKeys(string AuthKeyHex, byte[] KeyEncryptionKey);
+
+    public static byte[] GenerateSalt() => RandomNumberGenerator.GetBytes(SaltSizeBytes);
+
+    public static byte[] GenerateRoomKey() => RandomNumberGenerator.GetBytes(KeySizeBytes);
+
+    /// <summary>
+    /// Derives the auth key (join gate credential) and key-encryption key from a passphrase.
+    /// </summary>
+    public static DerivedKeys DeriveKeys(string passphrase, byte[] salt)
+    {
+        var okm = Rfc2898DeriveBytes.Pbkdf2(
+            Encoding.UTF8.GetBytes(passphrase), salt, Pbkdf2Iterations,
+            HashAlgorithmName.SHA256, KeySizeBytes * 2);
+
+        var authKey = Convert.ToHexString(okm.AsSpan(0, KeySizeBytes)).ToLowerInvariant();
+        var kek = okm[KeySizeBytes..];
+        CryptographicOperations.ZeroMemory(okm.AsSpan(0, KeySizeBytes));
+        return new DerivedKeys(authKey, kek);
+    }
+
+    /// <summary>Encrypts UTF-8 text with the room key. Output: $RC1$base64(nonce||tag||ciphertext).</summary>
+    public static string EncryptText(string plaintext, byte[] key) =>
+        CiphertextPrefix + Convert.ToBase64String(EncryptBytes(Encoding.UTF8.GetBytes(plaintext), key));
+
+    /// <summary>
+    /// Decrypts text produced by <see cref="EncryptText"/>. Returns false when the input
+    /// is not room ciphertext or the key does not match.
+    /// </summary>
+    public static bool TryDecryptText(string content, byte[] key, out string plaintext)
+    {
+        plaintext = string.Empty;
+        if (!IsRoomCiphertext(content))
+            return false;
+
+        try
+        {
+            var blob = Convert.FromBase64String(content[CiphertextPrefix.Length..]);
+            plaintext = Encoding.UTF8.GetString(DecryptBytes(blob, key));
+            return true;
+        }
+        catch (Exception ex) when (ex is FormatException or CryptographicException or ArgumentException)
+        {
+            return false;
+        }
+    }
+
+    public static bool IsRoomCiphertext(string? content) =>
+        content is not null && content.StartsWith(CiphertextPrefix, StringComparison.Ordinal);
+
+    /// <summary>Encrypts a binary blob (file contents) with the room key: nonce||tag||ciphertext.</summary>
+    public static byte[] EncryptBytes(byte[] plaintext, byte[] key)
+    {
+        var nonce = RandomNumberGenerator.GetBytes(NonceSizeBytes);
+        var ciphertext = new byte[plaintext.Length];
+        var tag = new byte[TagSizeBytes];
+
+        using var aes = new AesGcm(key, TagSizeBytes);
+        aes.Encrypt(nonce, plaintext, ciphertext, tag);
+
+        var blob = new byte[NonceSizeBytes + TagSizeBytes + ciphertext.Length];
+        nonce.CopyTo(blob, 0);
+        tag.CopyTo(blob, NonceSizeBytes);
+        ciphertext.CopyTo(blob, NonceSizeBytes + TagSizeBytes);
+        return blob;
+    }
+
+    /// <summary>Decrypts a blob produced by <see cref="EncryptBytes"/>. Throws <see cref="CryptographicException"/> on key mismatch.</summary>
+    public static byte[] DecryptBytes(byte[] blob, byte[] key)
+    {
+        if (blob.Length < NonceSizeBytes + TagSizeBytes)
+            throw new CryptographicException("Ciphertext blob is too short.");
+
+        var nonce = blob.AsSpan(0, NonceSizeBytes);
+        var tag = blob.AsSpan(NonceSizeBytes, TagSizeBytes);
+        var ciphertext = blob.AsSpan(NonceSizeBytes + TagSizeBytes);
+        var plaintext = new byte[ciphertext.Length];
+
+        using var aes = new AesGcm(key, TagSizeBytes);
+        aes.Decrypt(nonce, ciphertext, tag, plaintext);
+        return plaintext;
+    }
+
+    /// <summary>Wraps the room content key under the key-encryption key for server storage.</summary>
+    public static string WrapRoomKey(byte[] roomKey, byte[] kek) =>
+        Convert.ToBase64String(EncryptBytes(roomKey, kek));
+
+    /// <summary>Unwraps the stored room content key. Returns false when the KEK (passphrase) is wrong.</summary>
+    public static bool TryUnwrapRoomKey(string wrappedRoomKey, byte[] kek, out byte[] roomKey)
+    {
+        roomKey = [];
+        try
+        {
+            roomKey = DecryptBytes(Convert.FromBase64String(wrappedRoomKey), kek);
+            return roomKey.Length == KeySizeBytes;
+        }
+        catch (Exception ex) when (ex is FormatException or CryptographicException or ArgumentException)
+        {
+            return false;
+        }
+    }
+}

src/EchoHub.Core/Services/AsciiBannerService.cs

@@ -0,0 +1,104 @@
+using System.Text;
+
+namespace EchoHub.Core.Services;
+
+/// <summary>
+/// Renders short text as a 5-row block-character banner (the <c>/banner</c> command).
+/// Entirely local — a hand-rolled figlet-style font, no dependencies, no network.
+/// Output is plain message content, so it travels (and encrypts) like any other text.
+/// </summary>
+public static class AsciiBannerService
+{
+    public const int MaxInputLength = 20;
+    private const int Rows = 5;
+
+    /// <summary>
+    /// Renders <paramref name="text"/> as banner lines joined with '\n'.
+    /// Returns null when the input is empty or contains no renderable characters.
+    /// Characters outside the font (letters, digits, and basic punctuation) are skipped.
+    /// </summary>
+    public static string? Render(string text)
+    {
+        if (string.IsNullOrWhiteSpace(text))
+            return null;
+
+        text = text.Trim();
+        if (text.Length > MaxInputLength)
+            text = text[..MaxInputLength];
+
+        var glyphs = new List<string[]>();
+        foreach (var ch in text.ToUpperInvariant())
+        {
+            if (Font.TryGetValue(ch, out var glyph))
+                glyphs.Add(glyph);
+        }
+
+        if (glyphs.Count == 0 || glyphs.All(g => g == Font[' ']))
+            return null;
+
+        var lines = new StringBuilder();
+        for (var row = 0; row < Rows; row++)
+        {
+            if (row > 0)
+                lines.Append('\n');
+            for (var i = 0; i < glyphs.Count; i++)
+            {
+                if (i > 0)
+                    lines.Append(' ');
+                lines.Append(glyphs[i][row].Replace('#', '█').Replace('.', ' '));
+            }
+        }
+
+        // Trim trailing spaces per line — cheaper payload, identical rendering
+        return string.Join('\n', lines.ToString().Split('\n').Select(l => l.TrimEnd()));
+    }
+
+    // Glyphs are authored with '#' (ink) and '.' (blank); all rows of a glyph share one width.
+    private static readonly Dictionary<char, string[]> Font = new()
+    {
+        [' '] = ["..", "..", "..", "..", ".."],
+        ['A'] = [".##.", "#..#", "####", "#..#", "#..#"],
+        ['B'] = ["###.", "#..#", "###.", "#..#", "###."],
+        ['C'] = [".###", "#...", "#...", "#...", ".###"],
+        ['D'] = ["###.", "#..#", "#..#", "#..#", "###."],
+        ['E'] = ["####", "#...", "###.", "#...", "####"],
+        ['F'] = ["####", "#...", "###.", "#...", "#..."],
+        ['G'] = [".###", "#...", "#.##", "#..#", ".###"],
+        ['H'] = ["#..#", "#..#", "####", "#..#", "#..#"],
+        ['I'] = ["###", ".#.", ".#.", ".#.", "###"],
+        ['J'] = ["..##", "...#", "...#", "#..#", ".##."],
+        ['K'] = ["#..#", "#.#.", "##..", "#.#.", "#..#"],
+        ['L'] = ["#...", "#...", "#...", "#...", "####"],
+        ['M'] = ["#...#", "##.##", "#.#.#", "#...#", "#...#"],
+        ['N'] = ["#...#", "##..#", "#.#.#", "#..##", "#...#"],
+        ['O'] = [".##.", "#..#", "#..#", "#..#", ".##."],
+        ['P'] = ["###.", "#..#", "###.", "#...", "#..."],
+        ['Q'] = [".##.", "#..#", "#..#", "#.##", ".###"],
+        ['R'] = ["###.", "#..#", "###.", "#.#.", "#..#"],
+        ['S'] = [".###", "#...", ".##.", "...#", "###."],
+        ['T'] = ["###", ".#.", ".#.", ".#.", ".#."],
+        ['U'] = ["#..#", "#..#", "#..#", "#..#", ".##."],
+        ['V'] = ["#...#", "#...#", "#...#", ".#.#.", "..#.."],
+        ['W'] = ["#...#", "#...#", "#.#.#", "##.##", "#...#"],
+        ['X'] = ["#...#", ".#.#.", "..#..", ".#.#.", "#...#"],
+        ['Y'] = ["#...#", ".#.#.", "..#..", "..#..", "..#.."],
+        ['Z'] = ["####", "...#", "..#.", ".#..", "####"],
+        ['0'] = [".##.", "#.##", "##.#", "#..#", ".##."],
+        ['1'] = [".#.", "##.", ".#.", ".#.", "###"],
+        ['2'] = [".##.", "#..#", "..#.", ".#..", "####"],
+        ['3'] = ["###.", "...#", ".##.", "...#", "###."],
+        ['4'] = ["#..#", "#..#", "####", "...#", "...#"],
+        ['5'] = ["####", "#...", "###.", "...#", "###."],
+        ['6'] = [".##.", "#...", "###.", "#..#", ".##."],
+        ['7'] = ["####", "...#", "..#.", ".#..", ".#.."],
+        ['8'] = [".##.", "#..#", ".##.", "#..#", ".##."],
+        ['9'] = [".##.", "#..#", ".###", "...#", ".##."],
+        ['!'] = ["#", "#", "#", ".", "#"],
+        ['?'] = [".##.", "#..#", "..#.", "....", "..#."],
+        ['.'] = [".", ".", ".", ".", "#"],
+        [','] = ["..", "..", "..", ".#", "#."],
+        ['-'] = ["....", "....", "####", "....", "...."],
+        ['\''] = ["#", "#", ".", ".", "."],
+        [':'] = [".", "#", ".", "#", "."],
+    };
+}

src/EchoHub.Core/Services/FileValidationHelper.cs

@@ -1,4 +1,4 @@
-namespace EchoHub.Server.Services;
+namespace EchoHub.Core.Services;
 
 public static class FileValidationHelper
 {

src/EchoHub.Core/Services/ImageToAsciiService.cs

@@ -4,7 +4,7 @@ using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing;
 
-namespace EchoHub.Server.Services;
+namespace EchoHub.Core.Services;
 
 public class ImageToAsciiService
 {

src/EchoHub.Server.Irc/IrcBroadcaster.cs

@@ -14,16 +14,24 @@ public class IrcBroadcaster : IChatBroadcaster
         _encryption = encryption;
     }
 
-    public async Task SendMessageToChannelAsync(string channelName, MessageDto message)
+    public async Task SendMessageToChannelAsync(string channelName, MessageDto message, string? excludeConnectionId = null)
     {
-        // Decrypt content for IRC clients (they can't handle app-layer encryption)
+        // Decrypt transport-encrypted content for IRC clients (they can't handle
-        var decryptedMessage = message with { Content = _encryption.Decrypt(message.Content) };
+        // app-layer encryption). E2E room ciphertext ($RC1$) passes through untouched.
-        var lines = IrcMessageFormatter.FormatMessage(decryptedMessage);
+        var decryptedMessage = message with
+        {
+            Content = _encryption.Decrypt(message.Content),
+            ReplyTo = message.ReplyTo is { } reply ? reply with { Content = _encryption.Decrypt(reply.Content) } : null,
+        };
+        var lines = IrcMessageFormatter.FormatMessage(decryptedMessage, _gateway.Options.PublicBaseUrl);
 
         foreach (var conn in _gateway.GetConnectionsInChannel(channelName))
         {
-            // IRC convention: don't echo sender's own message
+            // IRC convention: don't echo a message back to the connection that sent it
-            if (conn.Nickname == message.SenderUsername)
+            // (its client already displayed it locally). Match by connection id, not
+            // nickname — the same account may also be online via the TUI or a second
+            // IRC client, and those sessions must still receive the message.
+            if (conn.ConnectionId == excludeConnectionId)
                 continue;
 
             foreach (var line in lines)
@@ -93,6 +101,14 @@ public class IrcBroadcaster : IChatBroadcaster
         }
     }
 
+    public async Task SendChannelDeletedAsync(string channelName)
+    {
+        foreach (var conn in _gateway.GetConnectionsInChannel(channelName))
+        {
+            await conn.SendAsync($":{_gateway.Options.ServerName} NOTICE {conn.Nickname ?? "*"} :Channel #{channelName} has been deleted");
+        }
+    }
+
     public async Task SendChannelNukedAsync(string channelName)
     {
         foreach (var conn in _gateway.GetConnectionsInChannel(channelName))

src/EchoHub.Server.Irc/IrcClientConnection.cs

@@ -1,5 +1,6 @@
 using System.Net.Sockets;
 using System.Text;
+using EchoHub.Core.Constants;
 
 namespace EchoHub.Server.Irc;
 
@@ -14,7 +15,7 @@ public sealed class IrcClientConnection : IAsyncDisposable
     private readonly SemaphoreSlim _writeLock = new(1, 1);
 
     // Connection identity
-    public string ConnectionId { get; } = $"irc-{Guid.NewGuid()}";
+    public string ConnectionId { get; } = $"{HubConstants.IrcConnectionIdPrefix}{Guid.NewGuid()}";
 
     // Registration state
     public string? Nickname { get; set; }

src/EchoHub.Server.Irc/IrcCommandHandler.cs

@@ -329,7 +329,7 @@ public sealed class IrcCommandHandler
         await _conn.SendNumericAsync(ServerName, IrcNumericReply.RPL_MYINFO,
             $"{ServerName} EchoHub-IRC o o");
         await _conn.SendNumericAsync(ServerName, IrcNumericReply.RPL_ISUPPORT,
-            "CHANTYPES=# NICKLEN=50 CHANNELLEN=100 :are supported by this server");
+            "CHANTYPES=# CHANMODES=b,k,, NICKLEN=50 CHANNELLEN=100 :are supported by this server");
 
         await SendMotdAsync();
     }
@@ -371,8 +371,17 @@ public sealed class IrcCommandHandler
 
         var channels = msg.Parameters[0].Split(',', StringSplitOptions.RemoveEmptyEntries);
 
-        foreach (var rawChannel in channels)
+        // RFC 1459: optional second parameter carries comma-separated channel keys,
+        // paired with channels by position (JOIN #a,#b key1,key2).
+        var keys = msg.Parameters.Count > 1
+            ? msg.Parameters[1].Split(',')
+            : [];
+
+        for (var i = 0; i < channels.Length; i++)
         {
+            var rawChannel = channels[i];
+            var key = i < keys.Length && !string.IsNullOrEmpty(keys[i]) ? keys[i] : null;
+
             var channelName = IrcToEchoHubChannel(rawChannel);
             if (channelName is null)
             {
@@ -381,13 +390,41 @@ public sealed class IrcCommandHandler
                 continue;
             }
 
-            var (history, error) = await _chatService.JoinChannelAsync(
+            // End-to-end encrypted channels can't be read over IRC (the gateway would
-                _conn.ConnectionId, _conn.UserId!.Value, _conn.Nickname!, channelName);
+            // have to hold the room key server-side, defeating the privacy guarantee).
+            var crypto = await _channelService.GetChannelCryptoAsync(channelName);
+            if (crypto?.IsEncrypted == true)
+            {
+                await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_BADCHANNELKEY,
+                    $"#{channelName} :Cannot join channel — end-to-end encrypted, use the EchoHub client");
+                continue;
+            }
+
+            // System channels (e.g. the live log room) stream over SignalR only — the IRC
+            // gateway never carries their content, so block joins outright.
+            var channelInfo = await _channelService.GetChannelByNameAsync(channelName);
+            if (channelInfo?.IsSystem == true)
+            {
+                await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_NOSUCHCHANNEL,
+                    $"#{channelName} :Cannot join channel — server-managed, use the EchoHub client");
+                continue;
+            }
+
+            var (history, error, passwordRequired) = await _chatService.JoinChannelAsync(
+                _conn.ConnectionId, _conn.UserId!.Value, _conn.Nickname!, channelName, key);
 
             if (error is not null)
             {
-                await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_NOSUCHCHANNEL,
+                if (passwordRequired)
-                    $"#{channelName} :{error}");
+                {
+                    await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_BADCHANNELKEY,
+                        $"#{channelName} :Cannot join channel (+k) — {error}");
+                }
+                else
+                {
+                    await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_NOSUCHCHANNEL,
+                        $"#{channelName} :{error}");
+                }
                 continue;
             }
 
@@ -405,8 +442,12 @@ public sealed class IrcCommandHandler
             // Replay history (decrypt — history is encrypted for SignalR transport)
             foreach (var m in history)
             {
-                var decrypted = m with { Content = _encryption.Decrypt(m.Content) };
+                var decrypted = m with
-                var lines = IrcMessageFormatter.FormatMessage(decrypted);
+                {
+                    Content = _encryption.Decrypt(m.Content),
+                    ReplyTo = m.ReplyTo is { } reply ? reply with { Content = _encryption.Decrypt(reply.Content) } : null,
+                };
+                var lines = IrcMessageFormatter.FormatMessage(decrypted, _options.PublicBaseUrl);
                 foreach (var line in lines)
                     await _conn.SendAsync(line);
             }
@@ -459,7 +500,7 @@ public sealed class IrcCommandHandler
         if (channelName is null) return;
 
         var error = await _chatService.SendMessageAsync(
-            _conn.UserId!.Value, _conn.Nickname!, channelName, content);
+            _conn.UserId!.Value, _conn.Nickname!, channelName, content, _conn.ConnectionId);
 
         if (error is not null)
         {
@@ -512,8 +553,22 @@ public sealed class IrcCommandHandler
         }
         else
         {
-            await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_CHANOPRIVSNEEDED,
+            var topic = msg.Parameters[1];
-                $"#{channelName} :Topic can only be changed by the channel creator via the API");
+            var result = await _channelService.UpdateTopicAsync(
+                _conn.UserId!.Value, channelName, string.IsNullOrWhiteSpace(topic) ? null : topic);
+
+            if (!result.IsSuccess)
+            {
+                var numeric = result.Error == ChannelError.NotFound
+                    ? IrcNumericReply.ERR_NOSUCHCHANNEL
+                    : IrcNumericReply.ERR_CHANOPRIVSNEEDED;
+                await _conn.SendNumericAsync(ServerName, numeric, $"#{channelName} :{result.ErrorMessage}");
+                return;
+            }
+
+            // Notify SignalR clients and echo the change back to the IRC client
+            await _chatService.BroadcastChannelUpdatedAsync(result.Channel!, channelName);
+            await _conn.SendAsync($":{_conn.Hostmask} TOPIC #{channelName} :{result.Channel!.Topic ?? ""}");
         }
     }
 
@@ -627,10 +682,12 @@ public sealed class IrcCommandHandler
 
         var channels = await _channelService.GetChannelListAsync();
 
-        foreach (var ch in channels)
+        // Private channels are hidden from discovery, matching the SignalR client's channel list
+        foreach (var ch in channels.Where(c => c.IsPublic))
         {
+            var lockHint = ch.IsProtected ? "[+k] " : "";
             await _conn.SendNumericAsync(ServerName, IrcNumericReply.RPL_LIST,
-                $"#{ch.Name} {ch.OnlineCount} :{ch.Topic ?? ""}");
+                $"#{ch.Name} {ch.OnlineCount} :{lockHint}{ch.Topic ?? ""}");
         }
 
         await _conn.SendNumericAsync(ServerName, IrcNumericReply.RPL_LISTEND,
@@ -644,15 +701,94 @@ public sealed class IrcCommandHandler
 
         var target = msg.Parameters[0];
 
-        if (target.StartsWith('#'))
+        if (!target.StartsWith('#'))
-        {
-            await _conn.SendNumericAsync(ServerName, IrcNumericReply.RPL_CHANNELMODEIS,
-                $"{target} +");
-        }
-        else
         {
             await _conn.SendNumericAsync(ServerName, IrcNumericReply.RPL_UMODEIS, "+");
+            return;
         }
+
+        var channelName = IrcToEchoHubChannel(target);
+        if (channelName is null)
+        {
+            await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_NOSUCHCHANNEL,
+                $"{target} :No such channel");
+            return;
+        }
+
+        // Query: MODE #channel
+        if (msg.Parameters.Count == 1)
+        {
+            var channel = await _channelService.GetChannelByNameAsync(channelName);
+            if (channel is null)
+            {
+                await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_NOSUCHCHANNEL,
+                    $"#{channelName} :No such channel");
+                return;
+            }
+
+            await _conn.SendNumericAsync(ServerName, IrcNumericReply.RPL_CHANNELMODEIS,
+                $"#{channelName} {(channel.IsProtected ? "+k" : "+")}");
+            return;
+        }
+
+        var modes = msg.Parameters[1];
+
+        // Clients commonly probe the ban list on join — reply with an empty list
+        if (modes is "b" or "+b")
+        {
+            await _conn.SendNumericAsync(ServerName, IrcNumericReply.RPL_ENDOFBANLIST,
+                $"#{channelName} :End of channel ban list");
+            return;
+        }
+
+        switch (modes)
+        {
+            case "+k":
+                if (msg.Parameters.Count < 3)
+                {
+                    await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_NEEDMOREPARAMS,
+                        "MODE :Not enough parameters");
+                    return;
+                }
+
+                var key = msg.Parameters[2];
+                var setResult = await _channelService.SetChannelPasswordAsync(_conn.UserId!.Value, channelName, key);
+                if (!setResult.IsSuccess)
+                {
+                    await SendModeErrorAsync(channelName, setResult);
+                    return;
+                }
+
+                await _conn.SendAsync($":{_conn.Hostmask} MODE #{channelName} +k {key}");
+                return;
+
+            case "-k":
+                var clearResult = await _channelService.SetChannelPasswordAsync(_conn.UserId!.Value, channelName, null);
+                if (!clearResult.IsSuccess)
+                {
+                    await SendModeErrorAsync(channelName, clearResult);
+                    return;
+                }
+
+                await _conn.SendAsync($":{_conn.Hostmask} MODE #{channelName} -k *");
+                return;
+
+            default:
+                await _conn.SendNumericAsync(ServerName, IrcNumericReply.ERR_UNKNOWNMODE,
+                    $"{modes} :is unknown mode char to me for #{channelName}");
+                return;
+        }
+    }
+
+    private async Task SendModeErrorAsync(string channelName, ChannelOperationResult result)
+    {
+        var numeric = result.Error switch
+        {
+            ChannelError.NotFound => IrcNumericReply.ERR_NOSUCHCHANNEL,
+            ChannelError.Forbidden => IrcNumericReply.ERR_CHANOPRIVSNEEDED,
+            _ => IrcNumericReply.ERR_KEYSET,
+        };
+        await _conn.SendNumericAsync(ServerName, numeric, $"#{channelName} :{result.ErrorMessage}");
     }
 
     private async Task HandlePingAsync(IrcMessage msg)

src/EchoHub.Server.Irc/IrcMessageFormatter.cs

@@ -1,62 +1,115 @@
 using System.Text;
-using System.Text.RegularExpressions;
+using EchoHub.Core.Constants;
 using EchoHub.Core.DTOs;
 using EchoHub.Core.Models;
+using EchoHub.Core.Security;
 
 namespace EchoHub.Server.Irc;
 
-public static partial class IrcMessageFormatter
+public static class IrcMessageFormatter
 {
     private const int MaxIrcLineContentBytes = 400;
+    private const int MaxReplySnippetLength = 80;
 
     /// <summary>
     /// Format a MessageDto as one or more IRC PRIVMSG lines.
+    /// Attachments are rendered as single link lines \u2014 the widely-supported IRC convention
+    /// (clients auto-preview or open plain http(s) URLs) \u2014 never as terminal color art.
+    /// <paramref name="publicBaseUrl"/> makes the links absolute so any IRC client can open them.
     /// </summary>
-    public static List<string> FormatMessage(MessageDto message)
+    public static List<string> FormatMessage(MessageDto message, string? publicBaseUrl = null)
     {
         var lines = new List<string>();
         var ircChannel = $"#{message.ChannelName}";
         var prefix = $":{message.SenderUsername}!{message.SenderUsername}@echohub";
 
-        switch (message.Type)
+        // Reply reference → the "> nick: snippet" quoting convention IRC users know
+        var replyPrefix = FormatReplyPrefix(message.ReplyTo);
+
+        // Caption text first (may be empty when the message is attachments-only)
+        if (!string.IsNullOrEmpty(message.Content))
         {
-            case MessageType.Text:
+            // /me actions arrive as CTCP ACTION content; each chunk must stay a
-                foreach (var chunk in SplitMessage(message.Content, MaxIrcLineContentBytes))
+            // well-formed CTCP message (\x01ACTION …\x01) or clients render garbage.
+            if (MessageConventions.TryParseAction(message.Content, out var actionText))
+            {
+                if (replyPrefix is not null)
+                    lines.Add($"{prefix} PRIVMSG {ircChannel} :{replyPrefix.TrimEnd(' ', '|', ' ')}");
+
+                foreach (var chunk in SplitMessage(actionText, MaxIrcLineContentBytes))
+                    lines.Add($"{prefix} PRIVMSG {ircChannel} :{MessageConventions.FormatAction(chunk)}");
+            }
+            else
+            {
+                var content = replyPrefix is not null ? replyPrefix + message.Content : message.Content;
+                foreach (var chunk in SplitMessage(content, MaxIrcLineContentBytes))
                     lines.Add($"{prefix} PRIVMSG {ircChannel} :{chunk}");
+            }
+        }
+        else if (replyPrefix is not null)
+        {
+            lines.Add($"{prefix} PRIVMSG {ircChannel} :{replyPrefix.TrimEnd(' ', '|', ' ')}");
+        }
 
-                // Append embed previews if present
+        // One link line per attachment
-                if (message.Embeds is { Count: > 0 })
+        if (message.Attachments is { Count: > 0 })
+        {
+            foreach (var attachment in message.Attachments)
+            {
+                var url = ToAbsoluteUrl(attachment.Url, publicBaseUrl);
+                var tag = attachment.Kind switch
                 {
-                    foreach (var embed in message.Embeds)
+                    AttachmentKind.Image => $"[Image: {attachment.FileName}]",
-                        lines.AddRange(FormatEmbed(prefix, ircChannel, embed));
+                    AttachmentKind.Audio => $"\u266a [Audio: {attachment.FileName}]",
-                }
+                    _ => $"[File: {attachment.FileName}]",
-                break;
+                };
+                lines.Add($"{prefix} PRIVMSG {ircChannel} :{tag} {url}");
+            }
+        }
 
-            case MessageType.Image:
+        // Append embed previews if present
-                lines.Add($"{prefix} PRIVMSG {ircChannel} :[Image: {message.AttachmentFileName}]");
+        if (message.Embeds is { Count: > 0 })
-                if (message.AttachmentUrl is not null)
+        {
-                    lines.Add($"{prefix} PRIVMSG {ircChannel} :Download: {message.AttachmentUrl}");
+            foreach (var embed in message.Embeds)
-
+                lines.AddRange(FormatEmbed(prefix, ircChannel, embed));
-                foreach (var line in message.Content.Split('\n'))
-                {
-                    var trimmed = line.TrimEnd('\r');
-                    if (trimmed.Length > 0)
-                        lines.Add($"{prefix} PRIVMSG {ircChannel} :{ColorTagsToAnsi(trimmed)}");
-                }
-                break;
-
-            case MessageType.File:
-                lines.Add($"{prefix} PRIVMSG {ircChannel} :[File: {message.AttachmentFileName}] {message.AttachmentUrl}");
-                break;
-
-            case MessageType.Audio:
-                lines.Add($"{prefix} PRIVMSG {ircChannel} :\u266a [Audio: {message.AttachmentFileName}] {message.AttachmentUrl}");
-                break;
         }
 
         return lines;
     }
 
+    /// <summary>
+    /// "&gt; nick: snippet | " prefix for replies. Room ciphertext can't be rendered
+    /// (IRC can't join encrypted rooms anyway) and is shown as a placeholder.
+    /// </summary>
+    private static string? FormatReplyPrefix(ReplyRefDto? replyTo)
+    {
+        if (replyTo is null)
+            return null;
+
+        var snippet = RoomCrypto.IsRoomCiphertext(replyTo.Content)
+            ? "[encrypted]"
+            : replyTo.Content.Replace('\n', ' ').Replace('\r', ' ');
+
+        if (MessageConventions.TryParseAction(snippet, out var actionText))
+            snippet = $"* {replyTo.SenderUsername} {actionText}";
+
+        if (snippet.Length > MaxReplySnippetLength)
+            snippet = snippet[..MaxReplySnippetLength] + "…";
+
+        return $"> {replyTo.SenderUsername}: {snippet} | ";
+    }
+
+    /// <summary>
+    /// Joins a relative attachment path onto the configured public base URL.
+    /// Already-absolute URLs and unset base URLs pass through unchanged.
+    /// </summary>
+    public static string ToAbsoluteUrl(string url, string? publicBaseUrl)
+    {
+        if (string.IsNullOrWhiteSpace(publicBaseUrl) || Uri.IsWellFormedUriString(url, UriKind.Absolute))
+            return url;
+        return $"{publicBaseUrl.TrimEnd('/')}/{url.TrimStart('/')}";
+    }
+
     /// <summary>
     /// Format a link embed as IRC PRIVMSG lines (text-only, no ASCII thumbnail).
     /// </summary>
@@ -84,35 +137,6 @@ public static partial class IrcMessageFormatter
         return lines;
     }
 
-    /// <summary>
-    /// Convert printable color tags ({F:RRGGBB}, {B:RRGGBB}, {X}) to ANSI escape codes for IRC clients.
-    /// Also passes through content that already uses ANSI codes unchanged.
-    /// </summary>
-    public static string ColorTagsToAnsi(string text)
-    {
-        if (!text.Contains('{'))
-            return text;
-
-        return ColorTagRegex().Replace(text, match =>
-        {
-            if (match.Groups[1].Success) // {X} reset
-                return "\x1b[0m";
-            if (match.Groups[2].Success) // {F:RRGGBB} or {B:RRGGBB}
-            {
-                var hex = match.Groups[3].Value;
-                var r = Convert.ToInt32(hex[..2], 16);
-                var g = Convert.ToInt32(hex[2..4], 16);
-                var b = Convert.ToInt32(hex[4..6], 16);
-                var code = match.Groups[2].Value == "F" ? "38" : "48";
-                return $"\x1b[{code};2;{r};{g};{b}m";
-            }
-            return match.Value;
-        });
-    }
-
-    [GeneratedRegex(@"\{(?:(X)|(?:(F|B):([0-9A-Fa-f]{6})))\}")]
-    private static partial Regex ColorTagRegex();
-
     /// <summary>
     /// Split a message into chunks of approximately maxBytes (UTF-8), at word boundaries.
     /// </summary>

src/EchoHub.Server.Irc/IrcNumericReply.cs

@@ -42,6 +42,7 @@ public static class IrcNumericReply
     // MODE
     public const string RPL_CHANNELMODEIS = "324";
     public const string RPL_UMODEIS = "221";
+    public const string RPL_ENDOFBANLIST = "368";
 
     // Errors
     public const string ERR_NOSUCHNICK = "401";
@@ -56,6 +57,9 @@ public static class IrcNumericReply
     public const string ERR_NEEDMOREPARAMS = "461";
     public const string ERR_ALREADYREGISTERED = "462";
     public const string ERR_PASSWDMISMATCH = "464";
+    public const string ERR_KEYSET = "467";
+    public const string ERR_UNKNOWNMODE = "472";
+    public const string ERR_BADCHANNELKEY = "475";
     public const string ERR_CHANOPRIVSNEEDED = "482";
 
     // SASL

src/EchoHub.Server.Irc/IrcOptions.cs

@@ -12,4 +12,11 @@ public sealed class IrcOptions
     public string? TlsCertPassword { get; set; }
     public string ServerName { get; set; } = "echohub";
     public string? Motd { get; set; }
+
+    /// <summary>
+    /// Public HTTP(S) base of this EchoHub server (e.g. "https://chat.example.com"),
+    /// used to turn relative attachment URLs into absolute links IRC clients can open.
+    /// When unset, attachment lines fall back to the relative path.
+    /// </summary>
+    public string? PublicBaseUrl { get; set; }
 }