agent-mcp-hub

One MCP server that bridges multiple CLI coding agents — Codex, Cursor, OpenCode, Claude, and Antigravity — into any MCP client.

stdio only — by design. The hub ships no Docker image and no HTTP transport (both were removed during the 0.5.x line). A containerised or remote server cannot see the caller's repository path and cannot reuse the caller's CLI logins — it would break the product contract on both halves. The hub runs as a child process of your MCP client, on your machine, as you.

Tools

Tool	Description
codex	Delegate a prompt to codex exec (prompt piped via stdin)
cursor	Delegate a prompt to cursor-agent -p (prompt piped via stdin)
opencode	Delegate a prompt to opencode run
claude	Delegate a prompt to the Claude Code CLI (prompt piped via stdin)
agy	Delegate a prompt to Google Antigravity (agy --print=…, prompt passed as a flag value)
run_all	Same prompt to all agents in parallel, results side by side
list_agents	Which agent CLIs are installed and on PATH
ping	Health check

Agent tools accept prompt (required), model, cwd, timeoutMs (total runtime cap, default 1800000 = 30 min), and idleTimeoutMs (inactivity cap, default 300000 = 5 min). See Long-running tasks & timeouts.

Known limitation: opencode prompts may not start with - (its CLI could parse them as flags); the tool returns an actionable error instead of guessing.

Choosing models per agent

Model ids are agent-specific and do not overlap. o3 means nothing to agy, gemini-3.6-flash-low means nothing to codex, and opencode namespaces its own (opencode/big-pickle). So a single model value is valid for at most one agent in a fan-out.

• run_all takes models — a per-agent map. Agents you don't list fall back to model, then to their own CLI default.
• review_change takes runnerModel and reviewerModel, so the agent writing the change and the agent judging it can use different engines and tiers. model remains a fallback for both.

{
  "tool": "run_all",
  "arguments": {
    "prompt": "Explain the retry logic in src/exec.ts",
    "models": { "codex": "o3", "agy": "gemini-3.6-flash-low", "claude": "haiku" }
  }
}

An unknown agent name in models is rejected with the list of enabled agents — a typo never silently falls back to the default model.

Where to find valid ids: opencode models, cursor-agent models and agy models list them. codex and claude have no such command — codex reads its default from ~/.codex/config.toml, and claude accepts the documented aliases (opus, sonnet, haiku, fable). Note claude models is not a subcommand: it is treated as a prompt, so its "model list" is generated text, not a source of truth.

Error handling

When a wrapped CLI fails, the hub classifies the failure and returns a clean, ANSI-free, actionable isError result — never a raw terminal dump — naming the class and the exact fix:

Class	Example remediation
not_installed	install the CLI (e.g. npm i -g @openai/codex) / fix PATH
not_authenticated	codex login · cursor-agent login · opencode auth login · claude → /login · agy → sign in on first run (or set the matching API key)
not_configured	set a model/provider in the CLI's config
timed_out	raise timeoutMs, or check the agent/model is responsive
stream_stalled	the agent reached the network but its stream keeps dropping (e.g. cursor behind a TLS-intercepting proxy) — treat that agent as unavailable; raising timeoutMs will not help
server_busy	retry shortly (upstream rate-limit, or the local agent-spawn queue is full)
tool_failure	generic non-zero exit — the message includes (exit N) and a trimmed output tail