🚀 CodeAgent MCP

A powerful, hosted Model Context Protocol (MCP) server that gives LLMs (like Claude, Cursor, and Windsurf) the ability to understand, navigate, and query any public GitHub repository.

CodeAgent clones the repository, indexes it using tree-sitter, and exposes a suite of code-intelligence tools via Server-Sent Events (SSE).

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🌟 Vision & What It Is

The Problem: LLMs are great at writing code, but they struggle to explore large, unseen codebases. You can't just paste a 10,000-line repository into a chat window.

The Solution: CodeAgent acts as the "eyes and hands" of the LLM.

1. The user tells the LLM: "Index this GitHub repo"
2. The LLM calls our index_github_repo tool.
3. CodeAgent clones the repo to disk, parses every file into an Abstract Syntax Tree (AST) using tree-sitter, and stores all functions, classes, and imports in a PostgreSQL database.
4. The LLM can now use tools like search_symbols, find_callers, and read_code to navigate the codebase precisely, fetching only the exact lines of code it needs.

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🏗 Architecture

Here is exactly how CodeAgent works under the hood:

graph TD
    subgraph Client [MCP Client]
        LLM[Claude Desktop / Cursor / Web]
    end

    subgraph CodeAgent [CodeAgent Server]
        FastMCP[FastMCP SSE Server]
        SessionMgr[Session Manager]
        Indexer[Tree-Sitter Indexer]
        Tools[Code Intelligence Tools]
    end

    subgraph Storage [Storage Layer]
        DB[(PostgreSQL)]
        Disk[(Local Disk /tmp)]
    end

    LLM <-->|1. SSE Transport| FastMCP
    FastMCP -->|2. Route Request| SessionMgr
    FastMCP -->|4. Execute Tool| Tools
    
    SessionMgr -->|3a. Git Clone| Disk
    SessionMgr -->|3b. Trigger Indexing| Indexer
    
    Indexer -->|Parse AST| Disk
    Indexer -->|Store Symbols & Imports| DB
    
    Tools -->|Query Metadata| DB
    Tools -->|Read File Slices| Disk

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Components

• FastMCP (SSE): The transport layer. Listens for HTTP requests and maintains a streaming connection with the LLM.
• Session Manager: Manages multi-tenant workspaces. Clones repos to /tmp/codeagent_sessions/{id} and cleans them up after 24 hours.
• Tree-Sitter Indexer: Scans the codebase, understands the language syntax (Python, JS, TS, etc.), and extracts symbols.
• Postgres: Stores relational metadata (symbols, imports) for lightning-fast querying across massive codebases.

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🛠 Available MCP Tools

CodeAgent equips the LLM with these exact capabilities:

Tool	Description
index_github_repo(github_url)	Clones and indexes a public repo. Returns a unique session_id.
search_symbols(query, session_id)	Finds functions/classes by partial name using ILIKE search.
list_all_symbols(kind, session_id)	Lists all symbols filtered by kind (e.g., all classes).
find_callers_tool(function_name, session_id)	Greps the codebase for places where a function is called.
read_code(file_path, start_line, end_line, session_id)	Reads exact source code lines directly from disk.
get_imports(file_path, session_id)	Lists all imports recorded for a specific file.
get_session_status(session_id)	Checks if a repository session is ready for querying.

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🚀 Quick Start (Using the Hosted Version)

Want to try it immediately? Add our public hosted endpoint to your MCP client!

Using Claude Desktop

1. Open Claude Desktop.
2. Go to Settings (Gear Icon) → Integrations (or Connectors).
3. Click Add Integration.
4. Enter the Server URL: https://codeagent-mcp.onrender.com/sse
5. Click Connect.

Note: Claude Web (Chrome/Safari) does not support MCP yet. You must use the Claude Desktop macOS/Windows app.

Using Cursor

1. Go to Cursor Settings → Features → MCP.
2. Click Add New MCP Server.
3. Choose SSE as the transport.
4. Enter URL: https://codeagent-mcp.onrender.com/sse

Example Prompt:

"Index this repo: https://github.com/pallets/flask. Then tell me what the main application class looks like."

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💻 Self-Hosting & Deployment

CodeAgent is fully open-source and easy to host yourself.

Prerequisites

• Python 3.11+
• PostgreSQL database (e.g., Neon free tier)
• Git installed on the system

1. Local Development Setup

# Clone the repository
git clone https://github.com/YOUR_USERNAME/CodeAgent-MCP.git
cd CodeAgent-MCP

# Create virtual environment and install
python3 -m venv .venv
source .venv/bin/activate
pip install -e .

# Configure environment
cp .env.example .env
# Edit .env and set your DATABASE_URL

Run the server locally:

python -m code_server.server
# Server will start at http://0.0.0.0:8000/sse

2. Deploy to Railway or Render (Free Tier)

1. Push your code to GitHub.
2. Go to Railway or Render.
3. Create a new service from your GitHub repo.
4. Set the DATABASE_URL environment variable to your Postgres connection string.
5. Deploy! The platforms will automatically detect the Dockerfile and expose port 8000.

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🤝 Instructions for Contributors

We love contributions! If you want to make CodeAgent smarter, faster, or add support for more languages, here is how you can help:

How to Contribute

1. Fork the repo and create your branch from main.
2. Set up locally using the Local Development Setup instructions above.
3. Make your changes. Ensure your code is well-commented and clean.
4. Test your changes by running the server locally and connecting your own Claude Desktop to http://localhost:8000/sse.
5. Issue a Pull Request.

Areas to Improve (Ideas for PRs)

• Add Language Support: Currently, we parse Python, JS, and TS. Help us add Go, Rust, Java, or C++ by updating the indexer.py tree-sitter grammars!
• Smarter Chunking: Improve how read_code returns large files so the LLM context window doesn't get flooded.
• Vector Search: Introduce pgvector to allow semantic searching (e.g., "Find the authentication logic") instead of just exact symbol matching.
• File Tree Tool: Add a tool that returns the directory structure of the cloned repository.

Development Guidelines

• All DB-touching functions live in code_server/tools.py and must accept a session_id.
• Tool wrappers for FastMCP live in code_server/server.py.
• We use asyncpg for database pooling. Never use blocking synchronous calls in the async event loop.
• Use the lifespan hook in server.py for any startup/shutdown logic to avoid event loop is closed errors.

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📄 License

This project is licensed under the MIT License - see the LICENSE file for details.