MessageService

Chatto exposes this service below /api/connect.

Shared message and enum definitions are documented in Shared Types And Enums.

MessageService

Creates messages in room and thread timelines.

FetchLinkPreview

Fetches and caches metadata for a composer URL. Authentication is required to avoid exposing the preview fetcher as an unauthenticated network proxy. Successful responses include a short-lived token accepted by CreateMessage.

POST /api/connect/chatto.api.v1.MessageService/FetchLinkPreview

Input: FetchLinkPreviewRequest

Request to fetch server-side link preview metadata for a URL.

Field	Type	Description
url	string	URL to preview.

Result: FetchLinkPreviewResponse

Result of fetching link preview metadata.

Field	Type	Description
preview	LinkPreview	Preview metadata, or absent when the URL cannot be previewed.
preview_token	string	Short-lived opaque token to pass to CreateMessage.link_preview_token when the user posts this preview.

CreateMessage

Creates a message for the current user. The user must be a room member and must have message.post for room messages or message.post-in-thread for thread replies. Echoing a thread reply also requires message.echo and message.post.

POST /api/connect/chatto.api.v1.MessageService/CreateMessage

Input: CreateMessageRequest

Request to create a message in a room or thread.

Field	Type	Description
room_id	string	Required. Room where the message should be created.
body	string	Message body text. Required unless attachment_asset_ids is non-empty.
attachment_asset_ids	repeated string	Existing room-scoped attachment asset IDs to include with the message.
thread_root_event_id	string	Event ID of the thread root message when posting a thread reply.
in_reply_to	string	Event ID this message replies to for attribution.
also_send_to_channel	bool	True to also echo a thread reply into the main room timeline.
link_preview_token	string	Short-lived token returned by FetchLinkPreview for the selected URL. The server resolves the token to cached, server-fetched metadata during post.

Result: CreateMessageResponse

Result of creating a message.

Field	Type	Description
message	Message	Renderable message created by the request.

UpdateMessage

Edits a message body. Authors can edit their own messages within the edit window. Non-authors need message.manage and cannot change channel echo state.

POST /api/connect/chatto.api.v1.MessageService/UpdateMessage

Input: UpdateMessageRequest

Request to patch a message.

Field	Type	Description
room_id	string	Required. Room containing the message.
event_id	string	Required. Event ID of the message to edit.
body	optional string	New message body text. Omit to preserve the current body.
also_send_to_channel	optional bool	For thread replies, whether a channel echo should exist after saving. Omit to preserve the current echo state.

Result: UpdateMessageResponse

Result of editing a message.

Field	Type	Description
message	Message	Renderable message after the edit.

DeleteMessage

Retracts a message. Authors can delete their own messages. Non-authors need message.manage.

POST /api/connect/chatto.api.v1.MessageService/DeleteMessage

Input: DeleteMessageRequest

Request to retract a message.

Field	Type	Description
room_id	string	Required. Room containing the message.
event_id	string	Required. Event ID of the message to retract.

Result: DeleteMessageResponse

Result of retracting a message.

Field	Type	Description
deleted	bool	True when the delete/retract request was accepted.

DeleteAttachment

Removes one attachment from the author’s own message.

POST /api/connect/chatto.api.v1.MessageService/DeleteAttachment

Input: DeleteAttachmentRequest

Request to remove one attachment from a message.

Field	Type	Description
room_id	string	Required. Room containing the message.
event_id	string	Required. Event ID of the message containing the attachment.
attachment_id	string	Required. Attachment ID to remove from the message.

Result: DeleteAttachmentResponse

Result of removing one attachment from a message.

Field	Type	Description
deleted	bool	True when the attachment removal was accepted.

DeleteLinkPreview

Removes the accepted link preview from the author’s own message.

POST /api/connect/chatto.api.v1.MessageService/DeleteLinkPreview

Input: DeleteLinkPreviewRequest

Request to remove the accepted link preview from a message.

Field	Type	Description
room_id	string	Required. Room containing the message.
event_id	string	Required. Event ID of the message containing the link preview.
url	string	Required. URL of the link preview to remove.

Result: DeleteLinkPreviewResponse

Result of removing a link preview from a message.

Field	Type	Description
deleted	bool	True when the link preview removal was accepted.

GetMessage

Reads one renderable message, including current body, attachment metadata, link preview, reactions, and thread metadata. Authentication and room membership are required. Returns NOT_FOUND when the event does not exist, is not a message, has been retracted, or belongs to a different room.

POST /api/connect/chatto.api.v1.MessageService/GetMessage

Input: GetMessageRequest

Request to read one visible message.

Field	Type	Description
room_id	string	Required. Room containing the message.
event_id	string	Required. Message event ID.

Result: GetMessageResponse

Response containing one renderable message.

Field	Type	Description
message	Message	Renderable message.

BatchGetMessages

Reads many renderable messages in one room. Authentication and room membership are required. Missing, retracted, non-message, and wrong-room event IDs are omitted. Results preserve first-seen request order and repeated event IDs are de-duplicated.

POST /api/connect/chatto.api.v1.MessageService/BatchGetMessages

Input: BatchGetMessagesRequest

Request to read many visible messages in one room.

Field	Type	Description
room_id	string	Required. Room containing the messages.
event_ids	repeated string	Required. Message event IDs. Missing, retracted, non-message, and wrong-room event IDs are omitted from the response.

Result: BatchGetMessagesResponse

Response containing renderable messages.

Field	Type	Description
messages	repeated Message	Renderable messages in first-seen request order.

AddReaction

Adds a reaction to a message. The user must be a room member and have message.react in the target room.

POST /api/connect/chatto.api.v1.MessageService/AddReaction

Input: AddReactionRequest

Request to add the current user’s reaction to a message.

When message_event_id names a channel echo of a thread reply, the server treats it as an alias for the original thread reply and stores the reaction on that original event.

Field	Type	Description
room_id	string	Required. Room containing the message event.
message_event_id	string	Required. Event ID of the message being reacted to, or a channel echo of the message.
emoji	string	Required. Emoji shortcode name, such as “thumbsup” or “heart”.

Result: AddReactionResponse

Result of adding a reaction.

Field	Type	Description
added	bool	True when the reaction was newly added, false when it already existed.
reaction	MessageReaction	Updated aggregate reaction state for this emoji.

RemoveReaction

Removes a reaction from a message. The user must be a room member and have message.react in the target room.

POST /api/connect/chatto.api.v1.MessageService/RemoveReaction

Input: RemoveReactionRequest

Request to remove the current user’s reaction from a message.

When message_event_id names a channel echo of a thread reply, the server treats it as an alias for the original thread reply and removes the reaction from that original event.

Field	Type	Description
room_id	string	Required. Room containing the message event.
message_event_id	string	Required. Event ID of the message whose reaction should be removed, or a channel echo of the message.
emoji	string	Required. Emoji shortcode name, such as “thumbsup” or “heart”.

Result: RemoveReactionResponse

Result of removing a reaction.

Field	Type	Description
removed	bool	True when the reaction was removed, false when it did not exist.
reaction	MessageReaction	Updated aggregate reaction state for this emoji. Empty when no reactions for the emoji remain.