The Chameleon Edition

One Command, Both Modes

gemini-faf-mcp reads its environment and adapts. Run it locally and it speaks stdio — the transport uvx and MCP clients expect. Set a PORT (as Google Cloud Run does) and the same binary serves modern Streamable HTTP: stateless, JSON, no SSE. No flags. No second package. No config. The server decides.

uvx gemini-faf-mcp        →  stdio   (local / MCP client)
PORT=8080  →  python app  →  Streamable HTTP  (Cloud Run)

Twelve tools either way. Identical behavior. The only thing that changes is the door it answers.

Why a Chameleon

A chameleon doesn't change what it is — it changes how it meets its surroundings. Same here: one codebase, 12 tools, one main() shared by the console script and the container. What shifts is the transport, chosen by where it runs.

Under the hood, the entry point passes the transport explicitly (transport="stdio" when local), instead of leaning on a framework default. The payoff is real: a strict MCP client that used to stall mid-handshake now connects cleanly — initialize, tools/list, tools/call, every time.

Drop It Into Google Antigravity

Google's agentic IDE, Antigravity, reads one MCP config file — and it accepts both of gemini-faf-mcp's modes. This is where "decided by its environment" stops being a metaphor.

Local (stdio) — in ~/.gemini/config/mcp_config.json:

{
  "mcpServers": {
    "gemini-faf": { "command": "uvx", "args": ["gemini-faf-mcp"] }
  }
}

Hosted (Streamable HTTP) — same file, the running endpoint:

{
  "mcpServers": {
    "gemini-faf": { "serverUrl": "https://mcpaas.live/gemini/mcp/v1" }
  }
}

One gotcha worth knowing: Antigravity expects serverUrl — not url, not httpUrl. The same config also works in the Gemini CLI, which converges into the Antigravity CLI. Local devs point at uvx; agentic and remote setups point at the URL. Same server, the environment picks.

Try It

Or point any MCP client at the hosted endpoint — tools execute on Google Cloud Run, fronted at the edge:

The Numbers

• v2.4.0 — Released June 7, 2026
• 12 tools — identical across both transports
• 221/221 — tests passing (FastMCP 3.4)
• 2 transports, 1 binary — stdio + Streamable HTTP
• Google Cloud Run — tools execute hosted (us-east1)
• PyPI + MCP Registry + Gemini Extensions — all on 2.4.0