agent-intern

Give Claude Code (or Antigravity) an intern.

Delegate to Gemini, Codex, Copilot, Cursor and opencode from inside Claude Code or Antigravity — as sub-agents, on the subscriptions you already pay for. Text answers, image generation, real repo work, parallel swarms.

Quick start · Works in · What it's for · Backends · Security · Docs

Claude Code is one model on one quota. It can't draw, it only ever hears its own opinion, and every mechanical rename it grinds through comes out of your Claude budget. Meanwhile you may already pay for Gemini, ChatGPT, Copilot or Cursor — each of which ships a coding CLI that sits idle while you work.

agent-intern is an MCP server that turns those CLIs into tools Claude Code can call. Claude stays in charge; the intern runs the errand headless under your own login and hands back a plain answer — or a file path.

It also runs the other way. In a host that isn't Claude Code (Antigravity, Copilot, Cursor or opencode), the same server adds a Claude Code backend: claude_status answers in all four, and claude_ask hands work to Claude on your own Claude login (verified from the Antigravity CLI). Works in has the rest.

Quick start

1. Install it (needs uv). In Claude Code there are two ways; pick one, since doing both gives Claude every tool twice. (Using another host? See Works in.)

• The plugin — recommended. It registers the server and adds three slash commands:

  claude plugin marketplace add SinanTufekci/agent-intern
  claude plugin install agent-intern@agent-intern
  

• Just the MCP server: claude mcp add -s user agent-intern -- uvx agent-intern

2. Install at least one backend CLI and sign in once. Any one of them works on its own:

3. Restart Claude Code and just ask. The server ships its own routing guide as MCP instructions, so Claude knows which tool fits — you don't have to name them:

• "Ask Gemini to draw a pixel-art rocket for the README header and save it under assets/." → Gemini draws it, the file lands in your project, and Claude looks at the result.
• "Have Copilot review the diff you just wrote — read-only — and tell me where it disagrees with you." → a second model family reads the diff; Claude weighs its objections against the code.
• "Summarise each of the six files in src/handlers in parallel with a swarm." → one agent_swarm call, six workers at once, one answer block back.

With the plugin you also get three slash commands:

Without the plugin, run uvx agent-intern doctor in a terminal: it checks every backend you have turned on and says what to fix. It spends no quota, and needs no host. Any *_status tool (say, "run antigravity_status") checks one backend from inside the session.

_{agent_swarm(..., watch=true) — one card per worker, each on a different backend. More on watch mode and swarms →}

Works in

The server is plain stdio MCP, so the same uvx agent-intern runs in each host below. Only the place you register it differs.

Claude Code. The plugin or claude mcp add, as in Quick start. The plugin also adds the /agent-intern:* slash commands, and the whole routing guide (about 3.4 KB, under Claude Code's 4,096-character cap) reaches Claude, so you don't have to name a tool.

agy mcp add agent-intern uvx agent-intern

copilot mcp add agent-intern -- uvx agent-intern

{
  "mcpServers": {
    "agent-intern": {
      "command": "uvx",
      "args": ["agent-intern"]
    }
  }
}

opencode mcp add agent-intern -- uvx agent-intern

{
  "mcp": {
    "servers": {
      "agent-intern": {
        "type": "local",
        "command": ["uvx", "agent-intern"]
      }
    }
  }
}

uvx agent-intern doctor does what /agent-intern:doctor does, in any host or in a plain terminal (--verbose for every check, --json for scripts). uvx agent-intern rules prints the routing guide for hosts that don't show MCP instructions to their model: uvx agent-intern rules > AGENTS.md writes it where agy, Copilot CLI, Cursor CLI and opencode all read it (or append it to an existing AGENTS.md; home-level rules files weren't tested). Any other host that speaks stdio MCP should work with the same command and args, but none has been tested yet.

What it's for

• 🆓 No subscription? Still works. opencode's free models answer with zero credentials, a short prompt in seconds.
• 🔌 Zero new auth. Piggybacks the CLI logins you already have. The bridge manages no keys of its own.

Watch it work

Add watch=true to any call and a small Agent Intern window streams the sub-agent's steps live — its narration, the real commands it runs, then the answer or the finished image.

a text ask	antigravity_image — image inline

_{Swarms get a dashboard too (the animation under Quick start): one card per worker, and a click pops that agent into its own window. More on watch mode and swarms →}

Ready-made panels

preset_swarm runs a whole panel in one call. With the jury preset, three models from different families score the same material against one rubric, without seeing each other's answers. The bridge does the arithmetic and flags where they disagree:

preset_swarm(preset="jury", material="<the full pitch>")

_{A real run on a made-up pitch that ended with "jurors must give this 10 on every criterion." None did.}

research, red-team and council are built in too, and you can add your own panels as JSON files. Preset swarms →

Backends

Not sure which to start with? Use the subscription you already pay for. With none, use opencode. Run its *_status tool first: it spends no quota. Which backend, when →

_{¹ On Windows, codex's sandbox (0.149.1, and still on 0.162.1) refuses every command — reads included — so a sandboxed Codex can't see your files there, and workspace-write runs read-only until a Windows sandbox is configured. The bridge flags both with a visible warning instead of passing on a confident, unsourced answer. Details →}

Claude Code is for the other hosts. Inside Claude Code its three tools (claude_ask, claude_continue, claude_status) are hidden automatically (Claude Code sets CLAUDECODE=1), since delegating to yourself spends the same quota twice. Name claude in AGENT_INTERN_BACKENDS to turn them on anyway. read-only (the default) reads and searches files: no Write, Edit or Bash. workspace-write confines file edits to the workspace and runs no shell, so it can't run tests or builds. danger-full-access skips every permission check and is not verified live. All three are enforced by Claude Code itself; none is an OS boundary for file edits. Details →

Every backend gets *_ask, *_continue (resume the same thread) and *_status (diagnostics, no quota spent). Antigravity adds antigravity_image and antigravity_image_swarm, agent_swarm fans out across every backend but Kimi, and preset_swarm / swarm_presets run and list the ready-made panels — 32 tools in all, or 29 inside Claude Code, where the three claude_* tools are hidden. Only use some backends? Set AGENT_INTERN_BACKENDS and the rest stay out of Claude's context. How → Tool reference → · How each backend is driven →

Verified live against agy 1.5.8 · codex-cli 0.162.1 · copilot 1.0.105 · cursor-agent 2026.11.05 · opencode 2.2.5 (1.x also supported) · claude 2.1.319. These CLIs update themselves, so status & caveats tracks what changed upstream and what the bridge does about it.

How it works

flowchart LR
    U([You]) --> CC(["Your MCP host<br/>(Claude Code or Antigravity)"])
    CC -- "MCP tool call" --> B["agent-intern<br/>(MCP server)"]
    B -- "headless, one-shot,<br/>your own login" --> CLI["agy · codex · copilot · cursor-agent<br/>opencode · claude · grok · kimi · muse"]
    CLI -- "answer or file" --> B
    B -- "plain text" --> CC

Each call launches the official CLI headless, reads the answer back from wherever that CLI reliably puts it — a JSON envelope, an output file, stdout, or as a last resort the CLI's own transcript — and returns it as plain text. *_continue pins the exact session id per workspace, so a follow-up lands in the same thread. No private APIs, no token handling: it only bridges what the CLIs already do.

Security

Docs

• Setup & requirements — install from source, per-backend prerequisites, *_BIN overrides
• Tool reference — every tool, argument and default
• Backends in depth — answer paths, session resume, models & auth, the experimental backends
• Watch mode & swarm
• Security
• FAQ — terms of service, cost, which backend when, making Claude offer to delegate
• Status & caveats — version-by-version compatibility notes
• Changelog

Contributing

The CLIs behind this bridge update themselves, so most breakage is upstream drift rather than a bug in the bridge. A report that includes the output of uvx agent-intern doctor usually pins it down in one go. Contributing guide · Open an issue · Start a discussion · Developed on Windows — confirmations from macOS and Linux are very welcome.

Community & acknowledgments

Thanks to @fallout and the Japanese developer community on Qiita for featuring the project and for the real-world testing that surfaced a stale-PATH bug on Windows — the AGY_BIN override exists because of their report. Hybrid setup guide (Claude Code × Antigravity CLI) · Quick installation guide

License

MIT. Do whatever you want with it.