Execution harness · your own ChatGPT subscription
Run your chats on OpenAI Codex
Pick OpenAI Codex as the harness in any thread and the round runs on the Codex CLI under your ChatGPT subscription or OpenAI API key — the mesh tools, nodes and context you already have, driven by a different engine.
What installing does
Installing places the harness in your chat picker only — it lands at {you}/Harness/Codex.
It never appears for users who haven't opted in, because it needs a personal ChatGPT subscription
or OpenAI API key: there is no shared key and nothing is billed to the mesh.
- Get the plugin — the harness appears in your thread's harness picker.
- Pick it in a thread, then run
/loginto connect your ChatGPT account (a device code you confirm in the browser) or paste an OpenAI API key. - Chat as usual — same threads, same tools, same mesh content.
Uninstalling removes it from your picker again; threads that had selected it fall back to the standard MeshWeaver agent path, so nothing breaks and no history is lost.
Good to know
- It is a harness, not an agent: it changes what executes the round, not which agent you talk to.
- Each thread is one Codex thread: every round resumes it, so the CLI keeps the thread's context and tool results itself. Command runs, MCP tool calls, file changes and web searches show up in the thread as tool calls; the model's reasoning summaries stream alongside the answer.
- How the harness drives the CLI: @@("AppServerProtocol").
- Nothing is shared. Your subscription, your login, your picker.