Opencode Chatgpt Bridge

A standalone local MCP bridge that lets ChatGPT control opencode sessions running on your own computer.

ChatGPT / ChatGPT Mobile
  -> HTTPS tunnel
  -> opencode-chatgpt-bridge /mcp
  -> local opencode serve
  -> local repository

This project is intentionally separate from LocalAnt. It is focused only on the ChatGPT <-> opencode bridge use case.

Quick start

git clone https://github.com/yuga-hashimoto/opencode-chatgpt-bridge.git
cd opencode-chatgpt-bridge
pnpm install
pnpm run build
pnpm run init -- --allowed-roots /Volumes/MOVESPEED/Documents/GitHub
pnpm start

init creates a ready-to-use .env with a random bridge token, your allowed repo roots, automatic port fallback, and Tailscale Funnel enabled by default.

When the bridge starts, it prints a setup guide with:

• local health URL
• local MCP URL
• automatic fallback port when the preferred port is already in use
• public HTTPS MCP URL when tunnel is enabled; Tailscale background service defaults to port 10000 to avoid LocalAnt using 443 and other active Funnel listeners
• ChatGPT settings link
• connector name, description, and URL to paste
• header auth and URL-token fallback
• opencode CLI status and setup notes
• first ChatGPT prompt to try

Requirements

• Node.js 20+
• pnpm 10+
• opencode installed and authenticated locally
• cloudflared for the default tunnel flow, or your own HTTPS tunnel

Check opencode:

opencode --version
opencode

Run opencode once inside a repo and make sure your model provider is configured before expecting ChatGPT to drive it. The bridge starts opencode serve for each repo and talks to it over HTTP. After creating a bridge session, call opencode_capabilities from ChatGPT to inspect connected providers, available auth methods, and default model configuration.

Commands

opencode-chatgpt-bridge init --allowed-roots /path/to/repos
opencode-chatgpt-bridge start
opencode-chatgpt-bridge doctor

From source, use pnpm:

pnpm run init -- --allowed-roots /path/to/repos
pnpm start
pnpm run doctor

Background mode on macOS

You do not need to keep a terminal open. Install the bridge as a user LaunchAgent:

pnpm run build
pnpm run install-service
pnpm run service-status

Logs are written to:

~/.opencode-chatgpt-bridge/bridge.log
~/.opencode-chatgpt-bridge/bridge.err.log

To stop background mode:

pnpm run uninstall-service

The service uses this repository directory as its working directory, loads .env, starts the bridge, and keeps it alive after login.

ChatGPT setup

Open ChatGPT Web and go to:

https://chatgpt.com/#settings/Connectors

Manual path:

Settings -> Apps & Connectors -> Advanced settings -> enable Developer mode
Settings -> Connectors -> Create

Use the values printed by the bridge. They look like this:

Connector name: opencode local bridge
Description: Control local opencode sessions, inspect diffs, and manage local coding tasks.
Connector URL: https://example.trycloudflare.com/mcp?token=<generated-token>

If your ChatGPT connector UI supports auth headers, you can use the plain /mcp URL and set:

Authorization: Bearer <OPENCODE_BRIDGE_TOKEN>

If not, use the printed ?token= URL fallback.

Once linked on ChatGPT Web, the connector should be available in ChatGPT mobile apps as well.

opencode setup

No extra opencode project configuration is required by the bridge, but opencode itself must be usable locally.

The bridge starts opencode like this:

OPENCODE_SERVER_USERNAME=opencode \
OPENCODE_SERVER_PASSWORD=<generated-or-env-password> \
opencode serve --hostname 127.0.0.1 --port <auto>

Notes:

• If OPENCODE_SERVER_PASSWORD is not set, the bridge generates a random password per managed opencode server.
• If OPENCODE_BASE_URL is set, the bridge uses that existing opencode server instead of spawning one.
• The opencode server is kept on 127.0.0.1; only the bridge is exposed to ChatGPT.
• Provider/model login is handled by opencode. Run opencode in a terminal first and confirm it can answer/edit before using ChatGPT.

Features

• Streamable HTTP MCP endpoint at /mcp for ChatGPT connectors and MCP clients.
• Per-repository opencode serve process management.
• Safe repository allow-listing with realpath checks.
• Bridge bearer token for exposed/tunneled use.
• URL-token fallback for connector UIs that do not support custom headers.
• Persistent bridge session mapping in ~/.opencode-chatgpt-bridge/sessions.json.
• Tools for session creation, async prompts, polling, message retrieval, diff review, abort, permission responses, file reads, file search, VCS status, agents, slash commands, and provider/model diagnostics.
• Optional Cloudflare quick tunnel launcher.
• TypeScript, strict typecheck, and unit tests.

MCP tools

Bridge and project tools

• bridge_health - inspect bridge config and managed opencode processes.
• list_projects - list Git repos under the allowed roots.

opencode process/session tools

• opencode_start - start or reuse an opencode serve process for a repo.
• opencode_stop - stop one or all managed opencode servers.
• opencode_create_session - create a new opencode session and return a bridgeSessionId.
• opencode_list_sessions - list bridge sessions known to this bridge.
• opencode_get_session_status - poll status for a session.
• opencode_send_message - send a prompt; defaults to async mode.
• opencode_get_messages - fetch session transcript/messages.
• opencode_get_diff - fetch file diffs for a session.
• opencode_abort - abort a running session.
• opencode_respond_permission - respond to opencode permission prompts.

project inspection tools

• opencode_read_file - read a file through opencode.
• opencode_find_files - fuzzy-find files through opencode.
• opencode_vcs_status - get VCS and file status.
• opencode_capabilities - list opencode agents, slash commands, providers, auth methods, and default model config.

Example ChatGPT prompt

Use opencode local bridge. First call bridge_health and list_projects.
Then create a session for /Volumes/MOVESPEED/Documents/GitHub/my-repo,
ask opencode to fix the README, poll status, and show opencode_get_diff.

Security model

This bridge can cause local code modifications through opencode. Treat it as a local automation gateway.

Default protections:

• opencode itself is bound to 127.0.0.1.
• Repositories must be under OPENCODE_BRIDGE_ALLOWED_ROOTS.
• The bridge supports bearer-token authentication and URL-token fallback.
• No arbitrary shell execution tool is exposed by this bridge.
• Diffs are first-class so clients can inspect changes before committing.

Strongly recommended:

• Always set OPENCODE_BRIDGE_TOKEN before exposing through any tunnel.
• Do not bind the bridge to 0.0.0.0 unless you know exactly what network can reach it.
• Keep OPENCODE_BRIDGE_ALLOWED_ROOTS narrow.
• Review opencode_get_diff before committing or pushing generated changes.

Development

pnpm install
pnpm run typecheck
pnpm test
pnpm run build
pnpm run validate

License

MIT