EchoHub/docs/auriondocs/Code/src/EchoHub.Client/Services/OutgoingAttachment.cs.md

OutgoingAttachment

File: src/EchoHub.Client/Services/OutgoingAttachment.cs
Kind: record

public sealed record OutgoingAttachment(
    Stream Stream,
    string FileName,
    string? DeclaredKind = null,
    string? EncryptedPreview = null)

Parameters:

Parameter	Type	Default
Stream	Stream	—
FileName	string	—
DeclaredKind	string?	null
EncryptedPreview	string?	null

OutgoingAttachment is a compact, immutable data carrier that bundles the pieces needed to upload a file as part of a message: the content as a Stream and the original FileName. When using end-to-end encrypted channels, DeclaredKind signals the attachment type (image, audio, or file) and EncryptedPreview holds the room-encrypted ASCII preview for images; on normal channels, only Stream and FileName are populated.

Remarks

As a record, OutgoingAttachment provides value-based equality, making attachments easy to compare, cache, or deduplicate as they traverse the messaging pipeline. The optional DeclaredKind and EncryptedPreview fields separate transport payload from encryption/presentation concerns, keeping encoding logic out of the transport object.

Notes

• If DeclaredKind is provided for an encrypted attachment, ensure EncryptedPreview is also supplied to avoid inconsistent previews.