Chat

These endpoints drive an app’s AI chat. Send a message and the AI builds from it, read the conversation, answer the questions the AI pauses on, and roll back changes you don’t want. Sending a message is how you build an app after you create it.

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Turns

Each message starts a turn, which covers everything the AI does in response. A turn can take several minutes on a large change, and the request stays open until it settles. Each turn consumes credits. See Apps API concepts for how a turn ends. A 200 response doesn’t mean the turn succeeded, so read the result before you treat it as done. To retry a request without paying twice, see Retrying chat requests.

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When the AI waits for you

Some steps pause for approval. A tool call with status set to waiting_for_user_input means the AI can’t continue until you answer it. Find it with Read conversation messages, then answer it with Submit tool-call input, or answer several at once with Submit tool-call input (batch).

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Changing course

• Stop generation stops the turn that’s running. Changes already saved as a checkpoint are kept.
• Undo message rolls the app back to the checkpoint a message produced.
• Edit and resend replaces an earlier message and rebuilds from there, so the changes after it are undone.

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Endpoints

• Send chat message: Send a message to the AI chat and run the turn it starts.
• Read conversation messages: Read the chat’s messages and replies, oldest first.
• Submit tool-call input: Approve or reject one tool call the AI is waiting on.
• Submit tool-call input (batch): Answer several waiting tool calls at once.
• Stop generation: Stop the turn the AI is running.
• Undo message: Roll the app back to the checkpoint a message produced.
• Edit and resend: Replace an earlier message and rebuild from there.

To retry a request safely, see Retrying chat requests.