agy-image

An MCP server that generates images using the Google AI Pro quota already logged in to the Antigravity CLI (agy) on your machine — without spinning up the agy agent loop.

It calls the image generation endpoint directly, so a picture takes seconds instead of tens of seconds, and it works headlessly from any MCP client (Claude Code, Cursor, etc.).

⚠️ This targets an internal Google endpoint, not a public supported API. It reuses the credentials and quota of your own agy login. Use at your own risk.

How it works

1. Reads your existing login. agy stores an OAuth token at ~/.gemini/jetski-standalone-oauth-token. That file's refresh_token is the only thing this server needs from you — it's produced by logging into the Antigravity CLI once.

2. Refreshes the access token when needed. To do that it needs an OAuth client (id + secret). It reads that pair out of the agy binary installed on your machine, verifies it against Google's token endpoint, and caches the working pair at ~/.cache/agy-image/credentials.json. Nothing is bundled with this package, so no single OAuth client gets shared by everyone who installs it.

3. Calls the endpoint directly.

   POST https://daily-cloudcode-pa.googleapis.com/v1internal:generateContent
   Authorization: Bearer <access token>
   Content-Type: application/json
   
   {
     "project": "aicode-consumers",
     "requestId": "image_gen/<epoch_ms>/<uuid>/1",
     "request": {
       "contents": [{ "role": "user", "parts": [{ "text": "<prompt>" }] }],
       "generationConfig": {
         "candidateCount": 1,
         "imageConfig": { "aspectRatio": "1:1" }
       }
     },
     "model": "gemini-3.1-flash-image",
     "userAgent": "antigravity",
     "requestType": "image_gen"
   }

4. Writes the image to disk. The response carries the image inline as base64, which is decoded and saved to the path you asked for.

5. Falls back to the agent if the direct call breaks. If the request shape ever changes underneath us, it runs agy in print mode and lets that agent generate the image instead. Slower, but it keeps working. Disable with AGY_FALLBACK=0.

Related MCP server: MCP Image Generator

Install

{
  "mcpServers": {
    "agy-image": {
      "command": "npx",
      "args": ["-y", "agy-image"]
    }
  }
}

No credentials or environment variables needed — they're read from your local agy install.

Requirements:

• Antigravity CLI installed and logged in at least once, so ~/.gemini/jetski-standalone-oauth-token exists and contains a refresh_token.

• Node.js 18+.

Tools

Configuration

All optional.

Troubleshooting

• HTTP 429 QUOTA_EXHAUSTED — the image model's quota is spent. It's separate from chat quota, and the error message includes the reset time. Fixed window, not a rolling one from your last request.

• HTTP 403 SUBSCRIPTION_REQUIRED — image models other than gemini-3.1-flash-image require an enterprise license.

• HTTP 403 on an otherwise valid request — a malformed requestId is reported this way. The server always generates it correctly; this only shows up if you craft requests by hand.

• Authentication error: ... token ... — the agy login is gone. Run agy interactively once to log in again.

• File is .png but contains JPEG — the model returns JPEG regardless of the extension you asked for. The response says so whenever the two disagree.

• Prompt looks different from what you sent — agy itself enriches prompts before calling the model; this server sends yours verbatim, so results can differ slightly from the CLI.

License

MIT