ChatKit is an interface layer
ChatKit supplies customizable chat UI, widgets, attachments, and tool-invocation support. It does not replace the agent runtime or your application’s authentication and authorization. Connect a server-side agent implementation to the interface.
Use a custom server for new integrations
The current ChatKit guide points new work to a custom server integration with ChatKit SDKs and a server-side agent implementation. Treat the UI session and the underlying agent session as separate resources with an explicit ownership mapping.
Agent Builder is being retired
The official guide says Agent Builder is scheduled to shut down on November 30, 2026. Existing hosted workflows can continue during the transition window. ChatKit remains available. An older tutorial that starts a new hosted Agent Builder workflow may no longer be the appropriate path.
Plan a workflow transition
For an existing Builder workflow, inspect nodes, tools, state, and approvals, then follow the official migration guide. Confirm that the new backend preserves the workflow behavior and user access boundaries before switching the interface.
Read the official reference
Check the source for current API fields, account requirements, and service limits.
OpenAI: chatkit