You can now run an agent on Codex, OpenAI's coding agent. Switching an agent over is a configuration change, and you can do it from either of the other two harnesses in the middle of a session.

Pay with an API key, or use your own ChatGPT subscription when you self-host.

Codex has the following capabilities:

• Five OpenAI models, from GPT-5.6 Sol down to the cheaper Luna, most with a context window of about a million tokens.
• Runs on the local sandbox or in a Daytona cloud sandbox.
• Follows the same tool approvals as your other agents, and answering an approval resumes the session instead of restarting it.
• Connects to your own HTTP MCP servers.
• Reads image attachments.
• Keeps every tool you already configured, with tracing and cost reporting attached as usual.