ContextPacker MCP Server

Give any MCP-compatible AI agent instant access to any GitHub repository — without pasting files manually.

"How does authentication work in expressjs/express?"
→ agent fetches exactly the relevant files, packed within your token budget

Works with Claude Desktop, Cursor, Windsurf, VS Code (GitHub Copilot), and any other MCP client.

Hosted API: contextpacker.com — 100 free requests, no card required. This is early software. If something doesn't work as expected, please open an issue — feedback is very welcome.

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Tools

Tool	Description
get_context(repo_url, query, max_tokens?)	Selects and packs the most relevant files for a question
get_skeleton(repo_url)	Returns the full annotated file tree (repo map) without file contents

Both tools support public repos out of the box. For private repos, add a GitHub PAT (see below).

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Quick start

Note: The package is not yet on PyPI. Use Option B (run from source) for now. PyPI / uvx support is coming soon.

Option A — uvx (coming soon)

uvx contextpacker-mcp

Option B — run from source (works now)

git clone https://github.com/rozetyp/contextpacker-mcp
cd contextpacker-mcp
python -m venv .venv && source .venv/bin/activate
pip install -e .
python server.py  # verify it starts

Then point your MCP client at the server.py file (see Configure your MCP client).

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Get an API key

Get a free key (100 requests, no card required) at contextpacker.com.

For running without an API key, see Self-hosting.

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Configure your MCP client

First clone the repo and note the full path to server.py (e.g. /Users/you/contextpacker-mcp/server.py). Replace that path and cp_live_your_key_here with your actual values in the snippets below.

Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "contextpacker": {
      "command": "python3",
      "args": ["/path/to/contextpacker-mcp/server.py"],
      "env": {
        "CONTEXTPACKER_API_KEY": "cp_live_your_key_here"
      }
    }
  }
}

Cursor

Create or edit ~/.cursor/mcp.json (global) or .cursor/mcp.json in your project:

{
  "mcpServers": {
    "contextpacker": {
      "command": "python3",
      "args": ["/path/to/contextpacker-mcp/server.py"],
      "env": {
        "CONTEXTPACKER_API_KEY": "cp_live_your_key_here"
      }
    }
  }
}

Windsurf

Edit ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "contextpacker": {
      "command": "python3",
      "args": ["/path/to/contextpacker-mcp/server.py"],
      "env": {
        "CONTEXTPACKER_API_KEY": "cp_live_your_key_here"
      }
    }
  }
}

VS Code (GitHub Copilot)

Add to .vscode/mcp.json in your project:

{
  "servers": {
    "contextpacker": {
      "type": "stdio",
      "command": "python3",
      "args": ["/path/to/contextpacker-mcp/server.py"],
      "env": {
        "CONTEXTPACKER_API_KEY": "cp_live_your_key_here"
      }
    }
  }
}

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Private repositories

Add your GitHub Personal Access Token (needs repo scope) to the env block:

"env": {
  "CONTEXTPACKER_API_KEY": "cp_live_your_key_here",
  "GITHUB_PAT": "ghp_your_token_here"
}

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Environment variables

Variable	Required	Default	Description
CONTEXTPACKER_API_KEY	Yes (hosted)	—	API key from contextpacker.com
CONTEXTPACKER_API_URL	No	https://contextpacker.com	Override for self-hosted instances
GITHUB_PAT	No	—	GitHub PAT for private repo access (repo scope)

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Self-hosting

Run the full ContextPacker server locally — no API key needed:

git clone https://github.com/rozetyp/contextpacker
cd contextpacker
python -m venv .venv && source .venv/bin/activate
pip install -r requirements.txt
export LLM_API_KEY=your_gemini_or_openai_key
uvicorn context_packer.main:app --port 8000

Then in your MCP client config, omit CONTEXTPACKER_API_KEY and add:

"env": {
  "CONTEXTPACKER_API_URL": "http://localhost:8000"
}

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How it works

get_context(repo_url, "how does routing work?")
    ↓
Shallow clone (depth=1) — or warm cache hit (~1s)
    ↓
Build file tree, extract AST symbols per file
    ↓
LLM ranks and selects the most relevant files
    ↓
Pack selected files into Markdown within your token budget
    ↓
Return context with per-file reason comments

First call for a repo: 3–10s (clone + index). Subsequent calls: ~1s.

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Development

git clone https://github.com/rozetyp/contextpacker-mcp
cd contextpacker-mcp
python3 -m venv .venv && source .venv/bin/activate
pip install -e .

Test with the MCP Inspector:

npx @modelcontextprotocol/inspector python3 server.py
# Opens http://localhost:6274 — test tools directly in your browser

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Feedback

This is early software under active development. If you:

• Can't get it working → open an issue
• Get bad context results for a repo → let us know with a minimal example
• Want to request a new MCP client config or feature → open an issue

A ⭐ on GitHub helps more developers find this.

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Contributing

Bug reports and pull requests are welcome. Please open an issue first for larger changes.

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License

MIT — see LICENSE.