Gemini Bridge

A comprehensive MCP server for Google Gemini that needs NO API key. It combines two free backends so any MCP client (Claude Code, Claude Desktop, …) gets the full Gemini toolbox:

• 🧠 Gemini CLI backend — Q&A, web search, deep research, code/file/URL analysis, structured output, extraction, summarization. Official, robust (no DOM scraping), free with your Google login. The model can autonomously use read-only tools (search, read files/URLs) — it never edits your files (--approval-mode plan).
• 🎨 Web-UI backend — image (Nano Banana) and video (Veo) generation, which the free CLI can't do. Driven via Playwright against gemini.google.com.

Inspired by rlabs-inc/gemini-mcp (feature breadth) and eLyiN/gemini-bridge (CLI bridge) — but API-key-free: it uses the Gemini CLI + the web UI instead of the paid API.

Tools

Tool	Group	Backend	What it does
ask_gemini	core	CLI→web	Ask anything. Attach files and/or a directory of code. Multimodal.
gemini_brainstorm	core	CLI	Brainstorm N concrete ideas for a topic.
gemini_search	research	CLI	Web search → grounded answer with source URLs.
gemini_deep_research	research	CLI	Autonomous multi-step research → structured report + sources.
gemini_youtube	research	CLI	Summarize / analyze a YouTube video.
gemini_analyze_code	analysis	CLI	Review a codebase folder (bugs/security/perf/quality).
gemini_analyze_files	analysis	CLI	Analyze images / PDFs / docs / text (multimodal).
gemini_analyze_url	analysis	CLI	Fetch & analyze a web page.
gemini_compare_urls	analysis	CLI	Fetch & compare multiple pages.
gemini_structured	data	CLI	JSON output matching a schema you give (returns parsed JSON).
gemini_extract	data	CLI	Extract named fields from text as JSON.
gemini_summarize	data	CLI	Summarize text (short/medium/long).
gemini_count_tokens	data	local	Rough, free token estimate (no API call).
generate_image	media	Web UI	Generate image(s) with Nano Banana. Saves PNG(s).
generate_video	media	Web UI	Generate a video with Veo. Saves an MP4.

Requirements

• Node.js 18+
• Gemini CLI for the CLI-backed tools (everything except image/video): npm i -g @google/gemini-cli, then run gemini once to log in with your Google account.
• For image/video only: a Chromium browser (Chrome / Brave / Edge) + a one-time web login (npm run login).

Setup

npm install                       # server deps (no browser download)

# CLI backend (for ask, search, research, analysis, ...):
npm i -g @google/gemini-cli
gemini                            # run once, sign in with Google, then exit

# Web backend (only needed for generate_image / generate_video):
npm run login                     # opens a window; sign in to Gemini once

Use as an MCP server

{
  "mcpServers": {
    "gemini-bridge": {
      "command": "node",
      "args": ["/absolute/path/to/gemini-bridge-mcp/server.js"],
      "env": { "GEMINI_HEADLESS": "1" }
    }
  }
}

Or with the Claude Code CLI:

claude mcp add gemini-bridge --env GEMINI_HEADLESS=1 -- node /absolute/path/to/server.js

Presets (control how many tools are exposed)

15 tools can be a lot of context. Trim them via env vars:

GEMINI_PRESET=minimal     # ask_gemini, gemini_search, generate_image
GEMINI_PRESET=core        # core + media
GEMINI_PRESET=research    # ask + research + URL tools
GEMINI_PRESET=analysis    # ask + analysis + data
GEMINI_PRESET=media       # ask + image/video
GEMINI_PRESET=data        # ask + data tools
GEMINI_PRESET=full        # everything (default)

# Or pick exactly what you want (tool names and/or group names):
GEMINI_TOOLS=ask_gemini,gemini_search,generate_image

Environment variables

Variable	Effect
GEMINI_BACKEND	auto (default: CLI if available, else web), cli, or web — for ask_gemini.
GEMINI_PRESET / GEMINI_TOOLS	Which tools to expose (see above).
GEMINI_HEADLESS=1	Run the web UI invisibly (recommended).
GEMINI_BROWSER_PATH	Path to chrome/brave/edge if auto-detect misses.
GEMINI_PROFILE_DIR	Web login profile folder (default ./.gemini-profile).
GEMINI_OUTPUT_DIR	Where generated media is saved (default ./output).
GEMINI_PORT	HTTP mode port (default 7801).
GEMINI_TLS_CERT / GEMINI_TLS_KEY	Serve HTTP mode over https (else ./certs/cert.pem+key.pem).

CLI (testing)

node server.js tools                    # list enabled tools
node server.js ask "your question"
node server.js search "latest Node LTS?"
node server.js image "a red sports car at sunset"
node server.js video "a balloon over mountains"
node server.js login | check | dump     # web-UI login / diagnostics
node server.js http                      # run over Streamable HTTP

Relation to rlabs-inc/gemini-mcp

This server covers the major capability groups of rlabs-inc/gemini-mcp without an API key (CLI + web UI instead). A few of its tools are intentionally not included because they require the paid API or aren't feasible via the free CLI:

• Text-to-speech (speak, dialogue, voices) — API-only.
• Context caching (create/query/list/delete cache) — API-only (the CLI manages its own context window).
• Image-edit sessions & async video polling — our image/video generation is synchronous (the tool waits and returns the file).
• Python code-execution sandbox — for safety this isn't exposed as a tool; ask ask_gemini with a coding prompt instead.

Everything else (search, deep research, code/text/document/image analysis, URL & YouTube analysis, structured output, extraction, summarization, image & video generation) is here.

⚠️ Locale note

Some web-UI selectors match the German Gemini UI (e.g. Bild erstellen, Video erstellen). If your Gemini UI is in another language, edit SEL in lib/web.js (and the Jetzt ausprobieren regex) — English would be Create image, Create video, etc. node server.js dump prints current labels. The CLI tools are locale-independent.

⚠️ Disclaimer

The web-UI part automates Gemini's web interface of your own account; it uses no official API. Automating Google's web UI may violate Google's Terms of Service — use at your own risk, for personal use only. The CLI part uses Google's official gemini CLI. Provided "as is", without warranty. Not affiliated with Google or Anthropic. "Gemini", "Nano Banana", "Veo" are products/trademarks of Google.

Acknowledgements

• Designed and coded with the help of Claude Code (Anthropic's Claude Opus 4.8, with extended thinking).
• Feature inspiration: rlabs-inc/gemini-mcp and eLyiN/gemini-bridge.

License

MIT