Reference
Remy Reference/interface/chat.createThread
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chat.createThread

Creates a new conversation thread and returns its summary.
chat.createThread() → Promise<ThreadSummary>

Creates an empty thread and returns its ThreadSummary. The title starts null and the platform fills it in from the first exchange. Create one before the first sendMessage, or lazily on the user's first turn.

Start a thread
const thread = await chat.createThread();
await chat.sendMessage(thread.id, 'Help me prep for my review', { onText });