Message replies

A reply is another chat row with parentId set to the parent message id. Same room, same socket.

room.messages.send({ text, replyTo }) sets REST replyTo / parentId / threadParentId (same field). useChat().sendMessage(content, replyTo) is the store path.

await room.messages.send({ text: "reply", replyTo: 42 });

useThread({ roomId, threadParentId: 42 }).sendMessage("reply") is the same parent id.

Max thread depth is 8. Deeper replies return thread_depth_exceeded.

A Stream-style quote (quotedMessageId) cites a message without setting parentId. Use Quote in ChatWindow, not Reply.

Thread typing: room.typing.keystroke(parentId) / useThread().setTyping — does not light the main transcript.

Canvas pins (useThreads, /comment-threads) are a different table. Do not mix them with chat replies.

Full page: Chat reply threads.