FastAPI MCP Server

A Model Context Protocol (MCP) server that provides semantic search capabilities for FastAPI documentation. It fetches the latest FastAPI documentation from GitHub, indexes it in Elasticsearch, and exposes search tools for AI coding assistants.

Architecture Overview

sequenceDiagram
    participant AI as AI Assistant<br/>(Windsurf/Claude)
    participant MCP as FastAPI MCP Server
    participant ES as Elasticsearch
    participant GH as GitHub<br/>(FastAPI Repo)
    participant FS as File System

    Note over AI,FS: Server Initialization
    AI->>MCP: Start MCP Server
    MCP->>ES: Check if index exists
    alt Index doesn't exist
        MCP->>GH: Clone FastAPI repository
        GH-->>FS: Download docs to /tmp/fastapi_repo
        MCP->>FS: Process markdown files
        FS-->>MCP: Extracted content & metadata
        MCP->>ES: Index documentation chunks
        ES-->>MCP: Indexing complete
    else Index exists
        MCP-->>AI: Server ready
    end

    Note over AI,FS: Search Operations
    AI->>MCP: search_fastapi_docs("async dependencies")
    MCP->>ES: Semantic search query
    ES-->>MCP: Ranked results with highlights
    MCP-->>AI: Formatted search results

    AI->>MCP: get_fastapi_doc_by_id("doc_123")
    MCP->>ES: Fetch document by ID
    ES-->>MCP: Full document content
    MCP-->>AI: Complete documentation section

    Note over AI,FS: Refresh Operations
    AI->>MCP: refresh_fastapi_docs()
    MCP->>GH: Pull latest changes
    GH-->>FS: Updated documentation
    MCP->>FS: Re-process changed files
    MCP->>ES: Update index
    ES-->>MCP: Refresh complete
    MCP-->>AI: "Documentation updated successfully"

Loading

Features

• Automatic Documentation Fetching: Clones/updates the latest FastAPI documentation from the official GitHub repository
• Elasticsearch Integration: Indexes documentation with semantic search capabilities
• Smart Content Processing: Extracts and chunks documentation with proper tagging
• MCP Compatible: Works with Windsurf, Claude Desktop, and other MCP-compatible AI assistants
• Tag-based Filtering: Search by specific topics (API, Pydantic, async, dependencies, security, etc.)
• Real-time Updates: Refresh documentation on demand

Prerequisites

All Platforms

• Python 3.11+
• Docker and Docker Compose (for Elasticsearch)
• uv (Python package manager)

Windows 11 Specific

• PowerShell 5.1+ or PowerShell Core 7+
• Windows Terminal (recommended)
• Docker Desktop for Windows

Quick Start

1. Start Elasticsearch

Linux/macOS:

docker-compose up -d

Windows (PowerShell):

docker-compose up -d

Wait for Elasticsearch to be healthy:

docker-compose ps

2. Install Dependencies

All Platforms:

uv sync

3. Run the MCP Server

Linux/macOS:

# Using the wrapper script (recommended for MCP clients)
./run_mcp.sh

# Or directly
uv run python main.py

Windows:

# Using PowerShell wrapper (recommended for MCP clients)
.\run_mcp.ps1

# Using batch file
.\run_mcp.bat

# Or directly
uv run python main.py

The server will automatically:

• Connect to Elasticsearch
• Check if documentation index exists
• Clone FastAPI repository and index documentation if needed
• Start the MCP server on stdio transport

Available Tools

search_fastapi_docs

Search FastAPI documentation with semantic search.

Parameters:

• query (str): Search query (e.g., "how to create API endpoints")
• tags (List[str], optional): Filter by tags
• max_results (int): Maximum results to return (default: 10)

Example:

{
  "query": "pydantic models validation",
  "tags": ["pydantic", "api"],
  "max_results": 5
}

get_fastapi_doc_by_id

Get a specific documentation section by ID.

Parameters:

• doc_id (str): Document ID from search results

refresh_fastapi_docs

Refresh documentation by fetching the latest version from GitHub.

Returns: Status of the refresh operation

get_available_tags

Get all available tags for filtering searches.

Available Tags:

• api: API endpoints and routing
• http-methods: HTTP methods (GET, POST, PUT, DELETE, etc.)
• pydantic: Pydantic models and validation
• async: Asynchronous programming
• dependencies: Dependency injection
• security: Authentication and authorization
• database: Database integration
• testing: Testing FastAPI applications
• deployment: Deployment and Docker

Integration with AI Assistants

Windsurf

Linux/macOS - Add to your Windsurf MCP configuration (~/.codeium/windsurf/mcp_config.json):

{
  "fastapi-docs": {
    "command": "/path/to/fastapi-mcp/run_mcp.sh",
    "args": []
  }
}

Windows - Add to your Windsurf MCP configuration (%USERPROFILE%\.codeium\windsurf\mcp_config.json):

{
  "fastapi-docs": {
    "command": "powershell.exe",
    "args": ["-ExecutionPolicy", "Bypass", "-File", "C:\\path\\to\\fastapi-mcp\\run_mcp.ps1"]
  }
}

Claude Desktop

Linux/macOS - Add to your Claude Desktop configuration:

{
  "mcpServers": {
    "fastapi-docs": {
      "command": "/path/to/fastapi-mcp/run_mcp.sh",
      "args": []
    }
  }
}

Windows - Add to your Claude Desktop configuration (%APPDATA%\Claude\claude_desktop_config.json):

{
  "mcpServers": {
    "fastapi-docs": {
      "command": "powershell.exe",
      "args": ["-ExecutionPolicy", "Bypass", "-File", "C:\\path\\to\\fastapi-mcp\\run_mcp.ps1"]
    }
  }
}

Note: Replace the paths with the actual absolute path to your installation directory.

Development

Project Structure

fastapi-mcp/
├── src/                     # Source code modules
│   ├── config.py           # Configuration settings
│   ├── mcp_server.py       # Main MCP server implementation
│   ├── search_engine.py    # Elasticsearch integration
│   ├── document_fetcher.py # GitHub repository fetching
│   ├── document_processor.py # Documentation processing
│   └── data_loader.py      # Data loading and indexing
├── tests/                  # Test suite
├── scripts/                # Utility scripts
│   ├── data_loader_cli.py  # CLI for data loading
│   └── setup_kibana_dashboard.py # Kibana dashboard setup
├── dashboards/             # Kibana dashboards
│   └── kibana-dashboard.ndjson
├── docs/                   # Additional documentation
│   └── AI_ASSISTANT_INTEGRATION.md
├── main.py                 # Entry point
├── run_mcp.sh             # MCP wrapper script (Linux/macOS)
├── run_mcp.ps1            # MCP wrapper script (Windows PowerShell)
├── run_mcp.bat            # MCP wrapper script (Windows Batch)
├── docker-compose.yml     # Elasticsearch setup
├── pyproject.toml         # Dependencies and project config
└── README.md              # This file

Testing the Server

1. Start Elasticsearch:

Linux/macOS:

docker-compose up -d

Windows (PowerShell):

docker-compose up -d

2. Run the server directly:

Linux/macOS:

uv run python main.py

Windows (PowerShell):

uv run python main.py

3. Test with MCP client tools (available when connected to an AI assistant):

• search_fastapi_docs: Search documentation
• get_fastapi_doc_by_id: Get specific document
• refresh_fastapi_docs: Update documentation
• get_available_tags: List available tags

Customization

Edit src/config.py to customize:

• Elasticsearch URL: Change ELASTICSEARCH_URL (default: http://localhost:9200)
• Index Name: Modify INDEX_NAME (default: fastapi_docs)
• Repository Path: Adjust TEMP_REPO_PATH (default: /tmp/fastapi_repo)
• FastAPI Repository: Change FASTAPI_REPO_URL if using a fork

Additional Tools

CLI Data Loader

Use the CLI tool to manually load or refresh documentation:

Linux/macOS:

uv run python scripts/data_loader_cli.py

Windows (PowerShell):

uv run python scripts/data_loader_cli.py

Kibana Dashboard

Set up Kibana for monitoring and visualization:

Linux/macOS:

uv run python scripts/setup_kibana_dashboard.py

Windows (PowerShell):

uv run python scripts/setup_kibana_dashboard.py

Troubleshooting

Elasticsearch Connection Issues

• Ensure Docker is running: docker ps
• Check Elasticsearch health: curl http://localhost:9200/_cluster/health
• View logs: docker-compose logs elasticsearch

Repository Clone Issues

• Check internet connectivity
• Verify GitHub access
• Clear temp directory: rm -rf /tmp/fastapi_repo

Memory Issues

• Increase Elasticsearch heap size in docker-compose.yml
• Reduce max_results in search queries

MCP Configuration Issues

Linux/macOS:

• Ensure the wrapper script has execute permissions: chmod +x run_mcp.sh
• Use absolute paths in MCP configuration
• Check that Elasticsearch is running before starting the MCP server

Windows:

• Ensure PowerShell execution policy allows script execution: Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
• Use absolute paths with proper Windows path format (e.g., C:\path\to\file)
• For PowerShell scripts in MCP config, use powershell.exe with -ExecutionPolicy Bypass flag
• Check that Docker Desktop is running before starting the MCP server

License

This project is open source and available under the MIT License.