create_chat

When the chat whose chatKey is main, the one every site comes with, is closed, this opens it again instead of starting another chat. That works on every plan, Free included: it comes back empty, called New chat unless you pass a title, keeps the mode it had, so mode is ignored, and the answer carries chatId main. See Close a chat.

Otherwise multiple chats are a paid plan feature. A site on a paid plan can have up to 10 open chats, and up to 4 of them run at once, each in its own copy of the site, and their changes are merged into the site when each turn ends. See Multiple chats.

A new chat is called New chat until a message names it, unless you pass a title, and it starts in build mode unless you pass mode. Creating it spends nothing: send the first message with send_message and the chatId you get back. The response also carries the chat's summary in chat, in the same shape as an entry of list_chats.

When it is refused

Status	When	The message
403	The workspace is on the Free plan and the site's chat is already open	Multiple chats are part of the paid plans!
403	The site already has the most open chats its plan allows, 10 on a paid plan	This site already has the most chats your plan allows!
409	The site's first build is still running	Wait for the first build to finish before starting another chat!
409	The site has not been built yet, for example because its first build was stopped or failed	Send a message to build the site before starting another chat!
403	The site is locked for going over the plan's site limit	This project is locked because it goes over the plan's site limit, so chat cannot change it until the plan is upgraded!
400	title is longer than 80 characters	A chat title must be 1 to 80 characters!
409	Another chat is being created on the same site at that moment	Another chat is being created on this site. Try again in a moment!
409	The site's main chat is closed and somebody is still closing it at that moment	Wait for this chat to finish first!

The last two are safe to try again in a moment. When the call opens the site's closed main chat again, only a title that is too long and that last 409 can refuse it. When two calls open it at the same moment, both get chatId main.

Inputs

Input	Type	Required	Description
projectId	string	Yes	The site id, from list_sites or get_site.
title	string	No	The title of the chat, at most 80 characters. Leave it out to have the chat named from its messages.
mode	string	No	build, where the agent makes the change, or plan, where it proposes a plan for you to approve first. Defaults to build, and is ignored when the call opens main again.