gemini-cli-mcp-slim

A thin, auditable MCP server wrapping the Gemini CLI.

Why

Existing Gemini MCP servers tend to either hide the underlying CLI behind opaque parameters or hard-code the supported flags so new gemini CLI options require code changes. This project takes a different approach:

• Single file, ~290 lines — auditable in one sitting
• One third-party dependency (mcp) — minimal supply-chain surface
• Forward-compatible — any new or uncommon gemini CLI flag is reachable via extra_args without touching this server
• Configurable binary path — $GEMINI_CMD lets you swap or wrap the gemini binary
• Workspace-aware — first-class include_directories so you can analyze multiple repositories from one invocation
• Transparent — every invocation logs the exact argv to stderr

Installation

Requires the gemini CLI to be installed and on $PATH (or pointed to via $GEMINI_CMD).

# Run directly without installing
uvx gemini-cli-mcp-slim

# Install from PyPI
pip install gemini-cli-mcp-slim

# Run from GitHub HEAD
uvx --from git+https://github.com/tksfjt1024/gemini-cli-mcp-slim gemini-cli-mcp-slim

Usage as an MCP server

Claude Code

claude mcp add gemini-cli-mcp-slim uvx gemini-cli-mcp-slim

Or manually in ~/.claude.json:

{
  "mcpServers": {
    "gemini-cli-mcp-slim": {
      "type": "stdio",
      "command": "uvx",
      "args": ["gemini-cli-mcp-slim"]
    }
  }
}

Other MCP clients

Any MCP-compatible client can launch the server via stdio:

uvx gemini-cli-mcp-slim

Tools

consult_gemini

Run a single Gemini CLI invocation with full forward-compatibility.

consult_gemini_with_files

Same parameters as consult_gemini plus a files: string[] parameter. File paths are appended to the prompt as @path tokens (gemini's file reference syntax). Absolute paths inside directory are converted to relative @-paths.

web_search

Convenience wrapper that prepends a "use your built-in web search" instruction to the query.

Configuration

Cross-repository analysis example

The killer feature: analyze multiple repositories from a single MCP invocation.

{
  "name": "consult_gemini",
  "arguments": {
    "query": "Compare the API surface between these services",
    "directory": "/path/to/service-a",
    "include_directories": [
      "/path/to/service-b",
      "/path/to/service-c"
    ],
    "model": "flash",
    "approval_mode": "plan"
  }
}

This launches gemini with --include-directories=/path/to/service-b,/path/to/service-c, giving the model read access to all three workspaces in one session.

Forward-compatibility example

If a future gemini CLI release adds a new flag (say --super-mode), you can use it immediately without updating this server:

{
  "name": "consult_gemini",
  "arguments": {
    "query": "...",
    "directory": "...",
    "extra_args": ["--super-mode", "--some-other-new-flag"]
  }
}

Comparison with alternatives

Development

# Install dev dependencies
pip install -e ".[test,dev]"

# Lint
ruff check .

# Test
pytest

License

MIT © tksfjt1024