agent-bridge-mcp

An MCP server and HTTP gateway that dispatches coding tasks to Claude Code, Codex, and Antigravity (agy) CLI sessions, keeps track of those sessions, and optionally runs an implement → review → verify loop against a real repository.

Status: experimental. This started as a personal orchestration rig and is published in the hope that the session-routing and evidence-gate parts are useful to others. Interfaces will change.

What it does

• Session routing — starts and resumes Claude Code / Codex sessions per project and topic, so follow-up prompts land in the same context.

• Task tracking — every dispatch becomes a task with status, output, and exit code.

• Evidence gate — runs the test commands you specify in a repository and reports whether the change is actually backed by passing tests before you accept it.

• Review loop — dispatches an implementer agent and a reviewer agent in turn, up to a revision limit, gated on the evidence check.

• Gateway — the same capabilities over HTTP + WebSocket, so a remote client (for example a phone) can dispatch work and stream output.

Install

npm install -g @yukinuma/agent-bridge-mcp

Requires Node.js 20+, plus whichever agent CLIs you intend to drive (claude, codex, and/or agy) already installed and authenticated.

A note on the antigravity agent

agy runs an internal language server and expects a real terminal. Started from an ordinary pipe it shuts down before it answers, which from the caller's side is indistinguishable from a hang. On Windows this adapter therefore runs it under winpty (bundled with Git for Windows) and keeps stdin open for the duration of the call.

Two consequences worth knowing:

• winpty aborts on its own assertion while tearing down, so its exit code does not reflect what agy did. When running through a pty the adapter judges success by whether a response came back, not by the exit code, and filters the assertion text out of the captured output.

• On timeout the process tree is killed by PID. Killing by image name would take out any interactive agy you have open elsewhere, so that is deliberately not done.

Set WINPTY_PATH or AGY_PATH if either binary is somewhere non-standard. On non-Windows platforms agy is launched directly, which is untested.

Use as an MCP server

{
  "mcpServers": {
    "agent-bridge": {
      "command": "agent-bridge-mcp",
      "env": {
        "AGENT_BRIDGE_WORKSPACE": "/path/to/your/projects"
      }
    }
  }
}

Tools exposed: agent_send, agent_status, agent_sessions, agent_cancel.

Use as a gateway

export ABC_AUTH_TOKEN="$(openssl rand -hex 24)"
export AGENT_BRIDGE_WORKSPACE="/path/to/your/projects"
agent-bridge-gateway

The gateway refuses to start without ABC_AUTH_TOKEN. There is no default token.

Endpoints

/api/dispatch, /api/git/commit-push, and /api/review-loop require an explicit target — either cwd, or a project that resolves inside the workspace. They return 400 rather than falling back to a default directory, and project values that escape the workspace are rejected.

Security

This service runs coding agents with their safety prompts turned off. That is what makes unattended dispatch work — an agent that stops to ask for approval simply hangs when nobody is at the keyboard — but it means anyone who can reach the API can run arbitrary code as the user running the gateway.

Specifically, the CLI adapters pass:

Both default to bypassing. The opt-outs are adapter-level options; they are not yet plumbed through the MCP tools or the REST API, so over HTTP the bypass is currently unconditional.

Treat this as a privileged local daemon:

• It binds to 127.0.0.1 by default. Setting AGENT_BRIDGE_HOST to anything else exposes task dispatch, sandbox-free code execution, and git push to your network.

• The auth token is a single shared secret, sent as a bearer header or a token query parameter. Query parameters end up in logs — prefer the header where you can. Compromising that one token is equivalent to handing over a shell.

• There is no sandboxing between projects beyond the workspace path check.

• /api/git/commit-push pushes to whatever remote the target repository has configured. It does not ask again before pushing.

Do not expose this to an untrusted network, and do not run it as a user with more access than the work actually needs.

Development

npm install
npm run typecheck
npm run build

License

MIT