Claude Code Relay

A small toolkit that lets Claude Code (Anthropic CLI) quickly switch environments and optionally talk to OpenAI Codex CLI (GPT Code) through an Anthropic-compatible proxy. In addition to the experimental GPT Code path, the toolkit includes two stable modes: Claude (native) and GLM via z.ai.

⚠️ Experimental: the GPT Code / Codex CLI path may be limited by vendor changes and may break without notice. Recommended for POC/Debug only — not for production workloads.

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1) Architecture

                 ┌──────────────────────────────────────────────────────┐
                 │                    Claude Code (CLI)                 │
                 │  reads ~/.claude/settings.json → env (models/routes) │
                 └───────────────┬──────────────────────────────────────┘
                                 │
             ┌───────────────────┼─────────────────────┐
             │                   │                     │
     (A) Claude Native     (B) GLM via z.ai      (C) GPT Code via Relay (experimental)
     ─────────────────      ───────────────      ───────────────────────────────────────
   ANTHROPIC_BASE_URL     ANTHROPIC_BASE_URL     ANTHROPIC_BASE_URL → http://127.0.0.1:9001
   unset (Anthropic)      https://api.z.ai/...   ANTHROPIC_AUTH_TOKEN → local-dev
   tokens: Anthropic      tokens: z.ai key       Claude → Relay (SSE) → Codex CLI (subprocess)
   API: /v1/messages      API: /v1/messages      Relay emits SSE: message_start/delta/stop
                                                Health: GET /health, Logs: proxy_debug.log

Components

• tools/env_switcher.py — ENV switcher (claude / glm_zai / gpt_code_via_relay).
• proxy/relay_server.py — Relay (Flask + SSE) that shells out to Codex CLI via subprocess.
• .env.example — config for CODEX_WORKDIR, CODEX_MAX_RUN_SEC, CODEX_IDLE_AFTER_TURN_SEC.
• examples/request.json — Anthropic-like request payload for testing.

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2) Tech & Decisions

• Python 3.10+
• Flask to expose endpoints:
  • POST /v1/messages — SSE streaming (Anthropic-compatible).
  • POST /v1/messages/count_tokens — mock token counter so the Claude UI does not crash.
  • GET /health — report status & runtime config.
• Subprocess Codex CLI (codex exec --json -) instead of Realtime WS (public models lack realtime support).
• CWD chosen in this order:
  1. A line in the user message: Working directory: D:\...
  2. .env variable CODEX_WORKDIR
  3. The current process CWD (where you run the relay)
• Logging: console + file proxy_debug.log (append mode).
• Windows-friendly: advise chcp 65001 or PYTHONIOENCODING=utf-8 if emoji logs cause encoding errors.

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3) Installation

3.1 Codex CLI (only if using GPT Code)

npm i -g @openai/codex
codex login

3.2 Switch profile with the ENV Switcher

python tools/env_switcher.py
# 1) claude   2) glm_zai   3) gpt_code_via_relay

The switcher auto-GETs http://127.0.0.1:9001/health; it only sets the relay profile if the relay is running. (Use --force to set the relay profile anyway.)

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4) Run the Relay (GPT Code path)

copy .env.example .env
# Edit .env if needed:
# CODEX_WORKDIR=D:\Works\Bitbucket\your-repo
# CODEX_MAX_RUN_SEC=0            # 0 = no hard cutoff; rely on idle-after-turn
# CODEX_IDLE_AFTER_TURN_SEC=10   # seconds to close stream after turn.completed

python proxy/relay_server.py

# Health check
curl http://127.0.0.1:9001/health

Open a real repo (e.g., D:\Works\Bitbucket\my-repo), run claude, and type hi to test.
Want to pin CWD per session? Add this line in the first prompt: Working directory: D:\\Works\\Bitbucket\\my-repo

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5) Troubleshooting

• Claude UI “undefined is not an object (H.map)”: the SSE stream is missing fields or wrong order — compare raw SSE in proxy_debug.log.
• UnicodeEncodeError (emoji): use chcp 65001 / PYTHONIOENCODING=utf-8 or remove emojis in your app’s logger.
• Not inside a trusted directory: relay passes --skip-git-repo-check to Codex; ensure the CLI has sufficient rights.
• Hangs: verify CWD exists, adjust CODEX_MAX_RUN_SEC, and check if turn.completed was seen (relay closes after idle).

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6) Layout

claude-code-relay-en/
├─ proxy/
│  └─ relay_server.py
├─ tools/
│  └─ env_switcher.py
├─ examples/
│  └─ request.json
├─ .env.example
├─ LICENSE
└─ README.md

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7) License

MIT © 2025 BT Automate