Upload file attachments to a conversation

POST 
/api/conversations/:conversationId/attachments

Uploads one or more files against a conversation as PENDING attachments (not yet bound to a message). Send the returned attachment ids as attachment_ids in a subsequent sendMessage call to bind them to a message in the SAME conversation. Use either the file field for a single upload or the files[] field for several.

Each file is validated by its DETECTED mime type (a renamed binary cannot pose as an allowed type) and per-file size; the allowlist, size cap, and max count come from the tenant's effective attachment policy. Authorized through the conversation's reply ability — a cross-tenant conversation is invisible (404).

Request

Responses

201

The stored (pending) attachments.

401

Not authenticated. code: account_disabled means the member's seat was deactivated in this workspace: the session is over even though the token was not revoked (clients sign out and clean up).

403

Authenticated but not allowed.

404

Resource not found (or not visible to the current tenant).

422

The request failed validation.