Chromium Helper

The ultimate toolkit for exploring Chromium and PDFium source code
CLI tool & MCP server for code search, Gerrit integration, and issue tracking

Features • Quick Start • Documentation • Contributing • License

📋 Table of Contents

• Features

• Quick Start

• Documentation

• CLI Tool Usage

• MCP Server Usage

• Installation

• Development

• Contributing

• License

🎯 Features

Why Use Chromium Helper?

• 🚀 Zero Friction - Start searching immediately with npx, no setup required

• 📊 Real-time Data - Direct access to Google's official APIs, same as source.chromium.org

• 🔍 Smart Search - Full Google CodeSearch syntax with regex, filters, and more

• 🤖 AI-Ready - JSON output and MCP integration for automation

• 📱 Cross-Platform - Works on macOS, Linux, and Windows

What Can You Do?

Two Ways to Use

1. 🔧 CLI Tool (chromium-helper) - Direct terminal access with ch commands

2. 🤖 MCP Server (chromium-codesearch-mcp) - AI integration for Claude Desktop

💡 Why CLI First?

As Armin Ronacher points out, a well-designed CLI is often superior to context-cluttering MCPs. Our CLI works seamlessly with ANY AI coding assistant:

Claude, Cursor, Gemini, or any AI: Just ask them to run:

This dumps comprehensive documentation that the AI can use to help you explore Chromium's codebase without any special configuration or context pollution.

Example AI Prompt:

"Run npx chromium-helper --ai to learn the tool, then help me find all WebRTC-related memory leaks in Chromium"

The AI will:

1. Execute the command to understand all capabilities

2. Use appropriate search commands with filters

3. Analyze results and provide insights

4. All without cluttering your AI's context window!

Real Example in Action:

In this example, the AI assistant:

• First runs npx ch --ai to learn the tool

• Checks CL 6624568 for test status (✅ all 30/30 bots passed)

• Retrieves review comments with proper formatting

• Provides a comprehensive summary of the CL status and reviewer feedback

• All in a clean, organized output!

🚀 Quick Start

CLI Tool - Use Instantly!

🤖 Using with AI Coding Assistants (Claude Code, Cursor, Gemini, etc.)

Simply tell your AI assistant:

Example tasks:

• "Find all uses of base::RefCounted in the codebase"

• "Check if CL 6624568 has passing tests and show me the review comments"

• "Search for recent security fixes in the renderer"

• "Find who owns the password manager code"

• "Help me understand what PDFium CL 130850 does"

• "Show me all failing bots for a specific CL"

MCP Server - For AI Integration

📖 Documentation

CLI Tool Documentation

• Quick Help: Run ch --help for command overview

• AI Guide: Run ch --ai for comprehensive usage guide with examples

• Full Documentation: See CLI README

Example Commands

🔧 CLI Tool Usage

The CLI provides comprehensive access to Chromium's codebase with intuitive commands.

Global Options

• --format <json|table|plain> - Output format (default: plain)

• --debug - Enable debug logging

• --no-color - Disable colored output

• --ai - Show comprehensive AI usage guide

Key Commands

🔐 Authentication for Gerrit Lists

The gerrit list and pdfium list commands require authentication. We've made this super easy!

Manual Cookie Option: If you prefer manual setup:

Output Formats

🤖 MCP Server Usage

The MCP server enables AI assistants like Claude to search and analyze Chromium code.

Claude Desktop Configuration

Add to your claude_desktop_config.json:

Or if installed globally:

Available MCP Tools

Core Search & Navigation

• search_chromium_code - Advanced code search with filtering options

• find_chromium_symbol - Symbol definitions and usage examples

• get_chromium_file - File content with line number ranges

Chromium Gerrit Integration

• get_gerrit_cl_status - CL status, test results, submit requirements

• get_gerrit_cl_comments - Review comments with code context

• get_gerrit_cl_diff - Code changes and file modifications

• get_gerrit_patchset_file - File content from specific patchsets

• get_gerrit_cl_bot_errors - Detailed error messages with stack traces from failed try-bots

• get_ci_build_errors - Detailed error messages from specific CI builds

• list_gerrit_cls - List Gerrit CLs with authentication (requires cookies)

PDFium Gerrit Integration

• get_pdfium_gerrit_cl_status - PDFium CL status and test results

• get_pdfium_gerrit_cl_comments - PDFium review comments

• get_pdfium_gerrit_cl_diff - PDFium code changes

• get_pdfium_gerrit_patchset_file - PDFium file content from patchsets

• list_pdfium_gerrit_cls - List PDFium Gerrit CLs with authentication (requires cookies)

Issue Tracking & History

• get_chromium_issue - Detailed issue information with browser automation

• search_chromium_issues - Search issues with full-text and pagination

• search_chromium_commits - Commit history search with date filtering

• find_chromium_owners_file - Code ownership and reviewer discovery

Example MCP Prompts

Ask Claude to:

• "Search for LOG(INFO) usage in Chromium"

• "Find the definition of Browser::Create"

• "Check the status of Gerrit CL 6624568"

• "Search for memory leak issues"

• "Get the diff for PDFium CL 130850"

• "List my open Gerrit CLs" (requires providing authentication cookie)

📦 Installation

CLI Tool

MCP Server

From Source

🔧 Development

Prerequisites

• Node.js 18+

• TypeScript

• npm or yarn

Development Commands

Project Structure

🤝 Contributing

We welcome contributions! Here's how you can help:

Reporting Issues

• Check existing issues first

• Include reproduction steps

• Mention your OS and Node version

Submitting PRs

1. Fork the repository

2. Create a feature branch (git checkout -b feature/amazing-feature)

3. Commit your changes (git commit -m 'Add amazing feature')

4. Push to the branch (git push origin feature/amazing-feature)

5. Open a Pull Request

Code Style

• Use TypeScript

• Follow existing patterns

• Add tests for new features

• Update documentation

Ideas for Contributions

• Add more search filters

• Improve error messages

• Add new output formats

• Enhance PDFium support

• Add more MCP tools

📊 Technical Details

API Usage

• Chromium CodeSearch: https://grimoireoss-pa.clients6.google.com

• Gerrit API: https://chromium-review.googlesource.com

• Issue Tracker: https://issues.chromium.org

Performance

• Caches API responses

• Parallel request support

• Efficient pagination

• Minimal dependencies

❓ FAQ

Q: Do I need to install anything to use this?

No! Just use npx chromium-helper <command> to run instantly.

Q: What's the difference between the CLI and MCP server?

• CLI: Direct terminal usage for developers

• MCP: Integration with AI assistants like Claude

Q: Can I search PDFium code too?

Yes! Full PDFium support for code search and Gerrit operations.

Q: Is this official Google software?

No, but it uses Google's official public APIs that power source.chromium.org.

Q: How do I see all available commands?

Run ch --ai for a comprehensive guide, or ch --help for a quick overview.

Q: Can I use this in scripts?

Yes! Use --format json for machine-readable output.

Q: What API key do I need?

None required! It uses the public API by default.

📄 License

MIT License - see LICENSE for details.

🌟 Acknowledgments

• Google Chromium team for the amazing CodeSearch API

• PDFium team for their great documentation

• MCP protocol team at Anthropic

• All contributors and users

Made with ❤️ for the Chromium community

NPM (CLI) • NPM (MCP) • Report Issues • Star on GitHub