zk-kit-mcp

MCP server for ZK-Kit, zero-knowledge toolkit by PSE at the Ethereum Foundation. Gives LLMs structured access to ~30 packages across TypeScript, Circom, Solidity, Noir, and Rust.

Tools

Discovery & Navigation

• list_packages - List and search packages. Filter by keyword, language, or category.
• get_ecosystem_overview - High-level map of all packages grouped by language and category.
• compare_packages - Side-by-side comparison of two or more packages.
• get_cross_language_coverage - Concept * language matrix showing which implementations exist and where gaps are.
• get_dependency_graph - Internal dependency graph between ZK-Kit packages, with reverse dependencies.

Documentation & Source

• get_package_readme - Full README with API docs, examples, and audit status. Supports a summary mode.
• get_package_api - Main entry/export file (src/index.ts, src/lib.rs, main contract, main circuit).
• get_package_source - Browse directory tree or read any file in a package.
• get_package_changelog - Version-by-version changes, breaking changes, and migration notes.
• search_code - Search across ZK-Kit source code using GitHub Code Search.

Package Health & Activity

• get_releases - Recent releases for a repo or filtered by package.
• get_package_commits - Recent commits for a specific package.
• get_package_downloads - Download stats from npm or crates.io.
• get_build_status - Latest CI/CD workflow runs from GitHub Actions.
• get_repo_stats - Stars, forks, open issues, last push date, license, and topics.

Dependencies & Issues

• get_package_dependencies - Runtime, dev, and peer dependencies from the package manifest.
• search_issues - Search GitHub issues across ZK-Kit repositories. Scope by package, language, or repo.

Prompts & Resources

Prompts

1. zk-integration-guide - Guided workflow for integrating a ZK-Kit package into your project.
2. zk-concept-explainer - Learn about a ZK concept (Merkle trees, Poseidon, EdDSA, etc.) through ZK-Kit implementations.
3. troubleshoot-package - Guided troubleshooting for issues with a ZK-Kit package.
4. migration-guide - Upgrade to a newer version or switch to a different language implementation.

All prompts support package name autocomplete.

Resources

• zk-kit://overview - Static ecosystem overview of all packages.
• zk-kit://packages/{language}/{dirName} - Package details with language and directory name completions.

Installation

npx

npx zk-kit-mcp

Global install

npm install -g zk-kit-mcp

From source

git clone https://github.com/zk-kit/zk-kit-mcp.git
cd zk-kit-mcp
npm install
npm run build
node build/index.js

Configuration

Claude Desktop

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "zk-kit": {
      "command": "npx",
      "args": ["-y", "zk-kit-mcp"],
      "env": {
        "GITHUB_TOKEN": "your-token-here"
      }
    }
  }
}

VS Code

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

{
  "servers": {
    "zk-kit": {
      "command": "npx",
      "args": ["-y", "zk-kit-mcp"],
      "env": {
        "GITHUB_TOKEN": "your-token-here"
      }
    }
  }
}

Cursor

Add to your Cursor MCP config:

{
  "mcpServers": {
    "zk-kit": {
      "command": "npx",
      "args": ["-y", "zk-kit-mcp"],
      "env": {
        "GITHUB_TOKEN": "your-token-here"
      }
    }
  }
}

Claude Code

claude mcp add zk-kit -- npx -y zk-kit-mcp

With a GitHub token:

claude mcp add zk-kit --env GITHUB_TOKEN=your-token-here -- npx -y zk-kit-mcp

GitHub Token

Optional but recommended. Set GITHUB_TOKEN as an environment variable.

• Without token: 60 requests/hour (GitHub API anonymous limit)
• With token: 5,000 requests/hour

A fine-grained personal access token with no permissions is sufficient, all ZK-Kit repos are public.

READMEs are fetched from raw.githubusercontent.com, which is not rate-limited by the GitHub API.

How It Works

1. Discovers packages from 5 GitHub repos at startup (zk-kit, zk-kit.circom, zk-kit.solidity, zk-kit.noir, zk-kit.rust)
2. Reads manifests (package.json, Cargo.toml, Nargo.toml) for metadata
3. Holds everything in memory. No database, no config files
4. Fetches READMEs and changelogs on demand, caches with 10-minute TTL

Startup takes 2-4 seconds. If a repo is unavailable, packages from other repos still load.

Development

npm run dev          # run via tsx (no build needed)
npm test             # vitest (343 tests)
npm run lint         # biome check
npm run build        # tsc + chmod
npx @modelcontextprotocol/inspector node build/index.js  # interactive testing

License

MIT