claudex

claudex

claudex runs the Claude Code harness — same tools, skills, UI, and session — driven by OpenAI's GPT-5.6 Sol, billed against an existing ChatGPT/Codex subscription. It is a deliberate escape hatch for when Anthropic usage runs out: the normal claude command stays untouched, and claudex is a separate zsh alias that reroutes one invocation through a local proxy.

claudex (zsh alias)  ─▶  Claude Code CLI  ─▶  CLIProxyAPI localhost:8317  ─▶  OpenAI Codex backend (your OAuth)

CLIProxyAPI is a local proxy that speaks the Anthropic Messages API on the side facing Claude Code and the OpenAI Codex backend on the other. The harness thinks it is talking to Anthropic; the proxy translates. Nothing about the default claude login changes.

When this fires

Reach for this skill in two situations:

1. First-time setup — the user wants the escape hatch in place (or hits the usage wall and has never set it up). Walk them through the one-time install.
2. Drift / breakage — claudex was working and now fails (empty model list, 401, connection refused, or it answers as Claude). Diagnose against the troubleshooting reference.

This is macOS + Homebrew. On other platforms, the proxy must be run by hand; say so rather than pretending the brew steps apply.

Setup — the one-time path (~10 minutes)

The full, exact steps live in references/setup.md — load it and walk the user through, in order:

1. Prerequisites — Homebrew, Claude Code, and an OpenAI account with Codex access (ChatGPT Plus/Pro). The Codex CLI itself is not required.
2. Install — brew install cliproxyapi.
3. Configure — generate a local proxy key with openssl rand -hex 24, then edit /opt/homebrew/etc/cliproxyapi.conf: bind to 127.0.0.1, set that key under api-keys, and add the reasoning.effort: high override.
4. Start as a login service — brew services start cliproxyapi (registers a launchd LaunchAgent; auto-starts at login). Re-run brew services restart cliproxyapi after any conf edit.
5. Connect OpenAI — cliproxyapi --codex-login opens a browser OAuth tab; credentials land in ~/.cli-proxy-api/ and self-refresh.
6. Verify — curl the proxy's /v1/models and confirm gpt-5.6-sol is listed.
7. Add the alias — append the claudex alias to ~/.zshrc, source it.
8. Smoke test — claudex -p "Reply with exactly: claudex works."

The interactive OAuth step (--codex-login) opens a browser and must be run by the user — it is not a scriptable step. Hand it to them explicitly and wait for confirmation before verifying.

Do not perform the prohibited pieces on the user's behalf: never paste OpenAI credentials into any field, never create the OpenAI account, and never invent or transmit the proxy key beyond writing it into the local conf and alias the user controls. Present the commands; the user runs the ones that authenticate.

Daily use

After setup, type claudex instead of claude. Because the environment variables are inline in the alias, they apply to that one invocation only — plain claude keeps using the Anthropic login. Extra arguments pass through: claudex --continue, claudex -p "…" all work. The startup banner reads gpt-5.6-sol · API Usage Billing, and a "claude.ai connectors disabled" warning is expected (the auth token overrides the claude.ai login for that session).

Troubleshooting

When claudex breaks, load references/troubleshooting.md and match the symptom — empty model list, 401, connection refused on 8317, or claudex answering as Claude. It maps each to the underlying drift (incomplete OAuth, key mismatch, dead launchd service, unloaded alias) and the fix. This is the volatile surface — proxy config, the gpt-5.6-sol model ID, and the OAuth flow all live upstream and can change; keep this reference current when they do.

Relationship to setup

bopen-tools:setup carries a cliproxyapi row (used by claudex) in its CLI audit, so a general harness audit surfaces a missing or dead proxy and points back here. setup only detects and plans — this skill owns the actual steps and the fixes.