Agent Antigravity MCP Server

Model Context Protocol (MCP) server for Google Gemini Antigravity Agent.

Features

• Autonomous Code Execution: Run shell, Python, Node.js commands in remote Linux sandbox.

• Web Browsing & Search: Integrated google_search and url_context.

• Multimodal Inputs: Process text instructions and base64 images.

• Custom Functions: Support turn-based custom function calling.

• Remote MCP Servers: Connect external MCP servers to Antigravity agent.

• Model Selection: Choose between gemini-3.6-flash, gemini-3.5-flash-lite, and other Gemini models.

• Background Execution: Async interactions with background=True polling and max_total_tokens budget cap.

• Environment Config: Build remote sandbox config with file sources (inline/git/gcs) and network allowlist.

• Cron Triggers: Create, list, pause/resume, delete, run, and audit scheduled recurring interactions.

• GitHub PR Workflow: Point at a repo (public/private) + base branch; agent branches, does the task, pushes, opens the PR. Token injected via sandbox network allowlist, never in the prompt.

• Managed Agents: Register reusable named agents (system_instruction, default tools, base_environment) and invoke them by ID.

• Environments API: List/inspect/delete sandbox environments directly, and download a sandbox's full filesystem as a .tar.

• Hooks Config: Mount a hooks.json (pre/post code_execution/file-op interception, allow/deny) into the sandbox via an inline environment source — format documented in create_interaction's environment arg.

Tools

Note: the Interactions API supports stream=true for real-time step deltas via the google-genai SDK directly (AntigravityClient.create_interaction(..., stream=True)), but it's not exposed as an MCP tool — MCP tool calls are synchronous request/response, so there's no way to surface incremental deltas over this transport.

Installation

Clone it somewhere and note the full path:

git clone https://github.com/bgembalczyk/agent-antigravity-mcp.git
cd agent-antigravity-mcp && pwd

Every client below runs the server the same way — uv run --project <that path> agent-antigravity over stdio — so you need uv installed, but no manual venv or pip install step. In every snippet, replace PATH_TO_REPO with the pwd output above (full path, not ~).

Claude Code (as a plugin, recommended)

No local clone needed — Claude Code clones it straight from GitHub:

/plugin marketplace add bgembalczyk/agent-antigravity-mcp
/plugin install agent-antigravity@agent-antigravity-mcp

Export GEMINI_API_KEY/GITHUB_TOKEN in your shell profile before launching Claude Code — the plugin's .mcp.json reads them via ${GEMINI_API_KEY}/${GITHUB_TOKEN}.

Antigravity CLI / IDE

File: ~/.gemini/config/mcp_config.json

"agent-antigravity": {
  "command": "uv",
  "args": ["run", "--project", "PATH_TO_REPO", "agent-antigravity"],
  "env": { "GEMINI_API_KEY": "${GEMINI_API_KEY}", "GITHUB_TOKEN": "${GITHUB_TOKEN}" }
}

Paste that inside the top-level "mcpServers": { ... } object (create it with just {"mcpServers": {}} if the file doesn't exist yet).

Codex CLI

File: ~/.codex/config.toml

[mcp_servers.agent-antigravity]
command = "uv"
args = ["run", "--project", "PATH_TO_REPO", "agent-antigravity"]

[mcp_servers.agent-antigravity.env]
GEMINI_API_KEY = "your_gemini_api_key"
GITHUB_TOKEN = "your_github_pat_with_repo_scope"

Append that to the end of the file — TOML tables don't care what's above them. Codex doesn't expand shell vars here, so put the real key values in.

GitHub Copilot CLI

File: ~/.copilot/mcp-config.json

"agent-antigravity": {
  "type": "local",
  "command": "uv",
  "args": ["run", "--project", "PATH_TO_REPO", "agent-antigravity"],
  "env": { "GEMINI_API_KEY": "your_gemini_api_key", "GITHUB_TOKEN": "your_github_pat_with_repo_scope" },
  "tools": ["*"]
}

Paste inside "mcpServers": { ... } (create the file with {"mcpServers": {}} if needed). Takes effect immediately, no restart. Same as Codex, real values in env — Copilot CLI doesn't expand shell vars here either.

OpenCode

File: ~/.config/opencode/.opencode.json (global) or opencode.json in a project root (project-scoped).

"agent-antigravity": {
  "type": "local",
  "command": ["uv", "run", "--project", "PATH_TO_REPO", "agent-antigravity"],
  "environment": { "GEMINI_API_KEY": "{env:GEMINI_API_KEY}", "GITHUB_TOKEN": "{env:GITHUB_TOKEN}" }
}

Paste inside "mcp": { ... } (create with {"mcp": {}} if needed). {env:VAR_NAME} expands from your shell environment at startup. Restart OpenCode (or reload config) after saving.

Any other MCP client / standalone

Any client that speaks MCP over stdio can launch this server the same way: uv run --project PATH_TO_REPO agent-antigravity. If you'd rather manage the virtualenv yourself instead of letting uv run do it:

uv venv --clear venv
uv pip install -e .
venv/bin/agent-antigravity

Configuration

Create .env file:

GEMINI_API_KEY=your_gemini_api_key
GITHUB_TOKEN=your_github_pat_with_repo_scope

GITHUB_TOKEN fallback used by create_github_pr_task when no github_token param given. Needs repo scope for private repos.

Optional:

AGENT_ANTIGRAVITY_LOG_LEVEL=INFO
AGENT_ANTIGRAVITY_SESSIONS_DB=/custom/path/sessions.db
AGENT_ANTIGRAVITY_TRANSPORT=stdio        # stdio | sse | streamable-http
AGENT_ANTIGRAVITY_HOST=127.0.0.1         # sse/streamable-http only
AGENT_ANTIGRAVITY_PORT=8000              # sse/streamable-http only
AGENT_ANTIGRAVITY_MAX_REQUESTS_PER_MINUTE=60  # 0 disables limiting

Usage

Once registered with any client above, the server starts automatically over stdio whenever that client launches — nothing to run manually. In Claude Code, the agent-antigravity skill (skills/agent-antigravity/SKILL.md) also auto-activates when a task matches, on top of the raw MCP tools being available.

Reliability

• Every API call tries the google-genai SDK first, falls back to direct REST on failure (logged at WARNING). REST calls retry on 429/5xx/transport errors with exponential backoff (3 attempts).

• Interaction session cache is SQLite-backed (~/.agent-antigravity/sessions.db by default) and survives process restarts.

• CI (.github/workflows/test.yml) runs the test suite on every push/PR.

Testing

uv pip install -e ".[dev]"
pytest -q

Credit

Structure and tool/resource/prompt patterns inspired by jules-mcp-server, an MCP server for Google Jules.

License

MIT — see LICENSE.