Muse Codex gateway

[!WARNING]
Experimental and source-only. Muse Codex currently supports Apple-silicon
macOS and exactly Muse Code 1.0.3-R2198.1. Other Muse versions are rejected.
No public binary release is available.

[!IMPORTANT]
Muse Codex is not affiliated with, endorsed by, or distributed by Meta or
OpenAI. Install and license Muse Code separately through Meta's official
channel.

What it does

Muse Codex keeps the unmodified Muse executable in charge of the terminal UI,
sessions, prompts, tools, approvals, sandbox, skills, subagents, and worktrees.
It replaces only the model connection with a private loopback gateway backed by
the pinned OpenAI Codex client.

• Preserves the host: normal Muse commands and provider-independent behavior
  stay in the stock executable.
• Isolates credentials: Muse receives a short-lived loopback token, never an
  OpenAI credential.
• Keeps tools local: the gateway translates model traffic but never executes
  a model-requested tool.
• Fails closed: unsupported Muse builds, conflicting providers, unsafe
  endpoints, and unverifiable release artifacts are rejected.

Ownership boundary

Stock Muse owns	Muse Codex owns	Not included here
TUI and exec mode	CLI routing and version gate	The proprietary Muse bi