CodexMCP
Allows offloading mechanical and output-heavy tasks (boilerplate, type generation, summarization) to OpenAI's API.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type
@followed by the MCP server name and your instructions, e.g., "@CodexMCPGenerate a TypeScript interface for a User"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
CodexMCP
Personal MCP server that exposes a query_offload tool to Claude. Lets Claude delegate mechanical, output-heavy tasks (boilerplate, type generation, summarisation) to OpenAI while keeping reasoning in-context.
Setup
1. Install dependencies
npm install2. Make codexmcp available globally
npm linkThis creates a global codexmcp binary pointing at bin/codexmcp.js.
3. Configure environment
cp .env.example .envEdit .env and fill in:
Variable | Description |
| Your Tailscale Funnel URL (e.g. |
| Any random 32+ character string |
| Port to listen on (default |
Inference runs through the Codex CLI, not an OpenAI API key. Install it and run
codex login(ChatGPT subscription) on the host machine before starting the server —query_offloadshells out tocodex exec.
4. Tailscale Funnel (T480)
Tailscale Funnel exposes a local port on a stable public HTTPS URL — no dynamic DNS, no port forwarding.
# On the T480, run once (survives reboots if you enable it):
tailscale funnel 3000Get your permanent URL:
tailscale funnel status
# Example output: https://t480.tail1234.ts.net -> localhost:3000Copy that URL into TUNNEL_URL in your .env.
5. Start the server
codexmcpExpected output:
codexmcp running on http://0.0.0.0:3000
MCP endpoint (add to claude.ai): https://t480.tail1234.ts.net/mcp6. Verify
curl http://localhost:3000/health
# {"status":"ok","server":"codexmcp","version":"0.0.1"}7. Connect to claude.ai
Go to claude.ai → Settings → Connectors → Add custom connector
Paste your
TUNNEL_URL/mcp(e.g.https://t480.tail1234.ts.net/mcp)Complete the OAuth flow — it auto-approves (single-user server)
8. Create a Claude Project
Create a new Project in claude.ai
Add the codexmcp connector to it
Paste the system prompt below into Project Instructions
Related MCP server: codex-buddy-for-claude
Permanent deployment with systemd (T480)
Copy the repo to the T480, install, link, and deploy the service:
# On T480
git clone <repo> ~/codexmcp
cd ~/codexmcp
npm install
npm link
# Copy and enable the service
sudo cp offload-mcp.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable offload-mcp
sudo systemctl start offload-mcp
# Check status
sudo systemctl status offload-mcp
journalctl -u offload-mcp -fThe ExecStart in offload-mcp.service points to /usr/local/bin/codexmcp (where npm link installs the global binary on Linux). Adjust if your npm prefix is different (npm prefix -g to check).
Claude Project system prompt
Paste this verbatim into the Project Instructions field:
## Behavior
- Never glaze. Be direct, honest, no sycophancy.
- Make no assumptions. Use the MCQ tool to clarify before proceeding. If skipped, pick the best option yourself.
- Format all responses carefully in clean markdown.
- Think before responding unless the query is trivial.
- When asked for opinions, be unbiased — say what is true, not what I want to hear.
## Task Routing
For every response, mentally split the task first:
1. Pure mechanical output (boilerplate, type generation, bulk code, summarizing large text, repetitive patterns) → call query_offload, return the result directly.
2. Mixed task (reasoning + output) → handle the reasoning yourself, call query_offload for the output part.
3. Pure reasoning (debugging, architecture, review, explanation) → answer directly, no tool call.
Call query_offload automatically. Never ask if you should use it.Development
npm run dev # node --watch src/server.jsThis server cannot be deployed
Maintenance
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One MCP endpoint for Claude, GPT & Gemini: 100+ tools + no-code connectors + agent workers.
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No-data MCP handoff for local Claude Code to Codex harness moves. $49 lifetime.
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