gemini-mcp-rs

A high-performance Rust implementation of MCP (Model Context Protocol) server that wraps the Gemini CLI for AI-driven tasks.

Note: This is a Rust port of the original Python implementation geminimcp. It offers the same functionality with improved performance and lower resource usage.

Features

• MCP Protocol Support: Implements the official Model Context Protocol using the Rust SDK
• Gemini Integration: Wraps the Gemini CLI to enable AI-driven tasks through MCP
• Session Management: Supports multi-turn conversations via session IDs
• Sandbox Safety: Configurable sandbox mode for isolated execution
• Async Runtime: Built on Tokio for efficient async I/O
• Cross-platform: Works on Windows, Linux, and macOS

Prerequisites

• Rust 1.90+ (uses 2021 edition)
• Gemini CLI installed and configured
• Claude Code or another MCP client

Building

# Debug build
cargo build

# Release build
cargo build --release

Running

The server communicates via stdio transport:

cargo run

Or after building:

./target/release/gemini-mcp-rs

Command-Line Options

# Display help information
./target/release/gemini-mcp-rs --help

# Display version information
./target/release/gemini-mcp-rs --version

The --help flag provides comprehensive documentation including:

• Environment variables
• MCP client configuration examples
• All supported tool parameters
• GEMINI.md configuration file support
• Return structure format
• Best practices and security information

Installation

Option 1: Quick Install (Linux/macOS)

Install the latest release with a single command:

curl -sSL https://raw.githubusercontent.com/missdeer/gemini-mcp-rs/master/scripts/install.sh | bash

Or install a specific version:

curl -sSL https://raw.githubusercontent.com/missdeer/gemini-mcp-rs/master/scripts/install.sh | bash -s v0.1.0

This script will:

• Detect your platform and architecture
• Download the appropriate binary from GitHub releases
• Install it to ~/.local/bin (or /usr/local/bin if needed)
• Automatically add it to your Claude MCP configuration

Option 2: Build from Source

git clone https://github.com/missdeer/gemini-mcp-rs.git
cd gemini-mcp-rs
cargo build --release
claude mcp add gemini-rs -s user --transport stdio -- $(pwd)/target/release/gemini-mcp-rs

Option 3: Install from Release

Download the appropriate binary for your platform from the releases page, extract it, and add to your MCP configuration:

claude mcp add gemini-rs -s user --transport stdio -- /path/to/gemini-mcp-rs

Tool Usage

The server provides a single gemini tool with the following parameters:

Required Parameters

• PROMPT (string): Instruction for the task to send to gemini

Optional Parameters

• sandbox (bool): Run in sandbox mode. Defaults to False
• SESSION_ID (string): Resume the specified session of the gemini. Defaults to empty string, start a new session
• return_all_messages (bool): Return all messages (e.g. reasoning, tool calls, etc.) from the gemini session. Set to False by default, only the agent's final reply message is returned
• model (string): The model to use for the gemini session. This parameter is strictly prohibited unless explicitly specified by the user

Return Structure

Success:

{
  "success": true,
  "SESSION_ID": "session-uuid",
  "agent_messages": "Gemini's reply content..."
}

With return_all_messages enabled:

{
  "success": true,
  "SESSION_ID": "session-uuid",
  "agent_messages": "Gemini's reply content...",
  "all_messages": [...]
}

Failure:

{
  "success": false,
  "error": "Error description"
}

Best Practices

• Always capture and reuse SESSION_ID for multi-turn interactions
• Enable sandbox mode when file modifications should be isolated
• Use return_all_messages only when detailed execution traces are necessary (increases payload size)
• Only pass model when the user has explicitly requested a specific model

Configuration

Environment Variables

• GEMINI_BIN: Override the Gemini CLI binary path. By default, the server uses gemini from your PATH. This is useful for:

  • Using a specific Gemini installation location
  • Testing with a custom binary
  • Development environments with multiple Gemini versions

  Example:

  export GEMINI_BIN=/usr/local/bin/gemini-custom
  cargo run

Testing

# Run all tests
cargo test

# Run with output
cargo test -- --nocapture

# Test with a custom Gemini binary
GEMINI_BIN=/path/to/gemini cargo test

Architecture

The project follows a modular architecture:

• src/main.rs: Entry point that parses CLI arguments and starts the MCP server
• src/lib.rs: Library root that exports modules
• src/server.rs: MCP server implementation and tool handlers
• src/gemini.rs: Gemini CLI execution and result parsing

Comparison with Python Implementation

Feature	gemini-mcp-rs (Rust)	geminimcp (Python)
Language	Rust	Python
Performance	⭐⭐⭐⭐⭐	⭐⭐⭐
Memory Usage	⭐⭐⭐⭐⭐	⭐⭐⭐
Binary Size	Medium	N/A
Startup Time	⭐⭐⭐⭐⭐	⭐⭐⭐
Session Management	✓	✓
Sandbox Support	✓	✓

Related Projects

• geminimcp - Original Python implementation
• codex-mcp-rs - Rust MCP server for Codex CLI

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License - Copyright (c) 2025 missdeer

See LICENSE for details.