Godbolt Compiler Explorer MCP

A Model Context Protocol (MCP) server that provides access to the Godbolt Compiler Explorer REST API endpoints. Built with the FastMCP Python library.

Installation

1. Clone this repository:

git clone <repository-url>
cd godbolt-mcp

2. Create and activate a virtual environment:

python -m venv venv
source venv/bin/activate

3. Install dependencies:

pip install -r requirements.txt

Usage

Standalone Usage

Run the MCP server directly:

python godbolt_mcp.py

Adding to MCP-Compatible Agents

Add the server to your MCP configuration (using virtual environment Python):

{
  "mcpServers": {
    "godbolt-compiler-explorer": {
      "command": "/absolute/path/to/godbolt-mcp/venv/bin/python",
      "args": ["/absolute/path/to/godbolt-mcp/godbolt_mcp.py"]
    }
  }
}

Note: Replace /absolute/path/to/godbolt-mcp with the actual absolute path to your installation directory.

Available Tools

Resources (Read-only access)

• resource://languages - List all supported programming languages
• resource://compilers/{language_id} - Get available compilers for a specific language
• resource://libraries/{language_id} - Get available libraries for a specific language
• resource://formats - List available code formatters
• resource://asm/{instruction_set}/{opcode} - Get assembly instruction documentation
• resource://version - Get Compiler Explorer version information

Tools (Actions)

• compile_code(compiler_id, source, user_arguments=None, files=None, libraries=None) - Compile source code
• compile_cmake(compiler_id, source, user_arguments=None, files=None, libraries=None) - Compile CMake project
• format_code(formatter, source) - Format source code

Examples

The examples/ folder contains sample source files you can use to test the MCP server:

• hello.cpp - Simple C++ "Hello World" program
• hello.rs - Simple Rust "Hello World" program

Try these prompts with MCP-compatible agents to generate assembly code for the example files:

For C++ example:

Compile the hello.cpp file from the examples folder with GCC and show me the exact generated assembly code with optimization level -O2.

For Rust example:

Compile the hello.rs file from the examples folder with the latest Rust compiler and show me the exact generated assembly code with release optimizations.

Dependencies

• fastmcp>=0.2.0 - MCP server framework
• httpx>=0.25.0 - HTTP client for API requests