Chromium CodeSearch

You can use the Chromium CodeSearch MCP Server to enable AI-assisted code exploration and Gerrit/issue analysis for Chromium, with direct search, symbol lookup, Gerrit integration, and PDFsupport. It provides fast, structured access to code, reviews, and issues so you can work with the Chromium codebase more efficiently through an MCP-enabled AI assistant.

How to use

You connect your MCP-enabled AI assistant to the Chromium CodeSearch MCP server to perform code searches, symbol lookups, and Gerrit or PDFium related tasks. The server exposes tools that you can call from prompts, allowing you to search code, fetch file contents, check Gerrit CL status and comments, view diffs, and retrieve issue and commit information. Use the AI to issue prompts like: “Search for LOG(INFO) usage in the codebase” or “Get the diff for PDFium CL 130850,” and the MCP server will return structured results that you can act on within your workflow.

Two usage patterns are available:

• Direct CLI/tooling workflow via the CLI MCP client for automated scripting and local development.
• MCP server endpoint for AI assistants like Claude Desktop to query Chromium data programmatically.

How to install

Prerequisites: you need Node.js 18+ and npm or yarn to run the CLI tools and the MCP server locally.

Install and run the MCP server using the standard npm-based flow described here. If you want to run the CLI tool directly, you can use npx chromium-helper for immediate use without installation.

Step-by-step setup for the MCP server via local runtime (stdio configuration): install the MCP server package and run it with a local command.

Core MCP server configuration and usage

MCP configuration is exposed to Claude Desktop (or any MCP client) to enable a local or remote server connection. You can add a configuration entry that starts the server via npx or directly invoking the MCP binary.

The following runtime configurations are demonstrated for the Chromium CodeSearch MCP server. You can use either the npx-driven approach or the direct binary invocation.

Tools exposed by the MCP server

The MCP server exposes a suite of tools to perform code searches, symbol lookups, file retrieval, and Gerrit/PDFium related queries. These tools enable you to:

• Search Chromium code with advanced filters
• Look up symbol definitions and usages
• Retrieve file contents with line ranges
• Check Gerrit CL status, view review comments, and fetch diffs
• Retrieve CI/build errors and patchset files
• List Gerrit or PDFium CLs with authentication when needed
• Query issues and commit histories
• Discover code ownership information

Configuration details for MCP client integration

Two MCP server connection methods are shown for Claude Desktop:
1) Using npx to launch the MCP server with the CLI tool:
2) Invoking the MCP server binary directly if it is installed globally.

Troubleshooting and tips

If authentication is required for certain Gerrit or PDFium endpoints, follow the established authentication flow to obtain and reuse cookies or tokens. Use JSON output formats for scripting and AI integration to simplify downstream processing.

Notes on security and usage

Only use MCP endpoints that are explicitly configured and intended for your environment. Do not share authentication cookies or tokens in unsecured channels. Ensure your AI prompts are scoped to the data you have access to and respect repository access controls.

Example prompts for the MCP server

Examples you can run through Claude or any MCP client:

• "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 authentication)"

Available MCP tools and endpoints

Core endpoints include: search_chromium_code, find_chromium_symbol, get_chromium_file, get_gerrit_cl_status, get_gerrit_cl_comments, get_gerrit_cl_diff, get_gerrit_patchset_file, get_gerrit_cl_bot_errors, get_ci_build_errors, list_gerrit_cls, get_pdfium_gerrit_cl_status, get_pdfium_gerrit_cl_comments, get_pdfium_gerrit_cl_diff, get_pdfium_gerrit_patchset_file, list_pdfium_gerrit_cls, get_chromium_issue, search_chromium_issues, search_chromium_commits, find_chromium_owners_file.

Installation sources and starting the MCP server

Install the MCP server locally using npm and run it with Node.js. The MCP server can be started via standard npm scripts or node dist/index.js depending on your setup.

Documentation and further learning

For ongoing workflows, integrate your AI assistant with the MCP server to automate Chromium code searches, Gerrit reviews, and issue tracking tasks.

Available tools

search_chromium_code

Advanced code search with Google syntax, filters, and pagination to locate code patterns and symbols.

find_chromium_symbol

Resolve symbol definitions and usages across the Chromium codebase.

get_chromium_file

Retrieve file contents with optional line ranges for context.

get_gerrit_cl_status

Fetch Gerrit CL status, test results, and submission readiness.

get_gerrit_cl_comments

Obtain review comments with context and threading for a CL.

get_gerrit_cl_diff

View diffs and file changes for a CL.

get_gerrit_patchset_file

Get the content of files from a specific patchset.

get_gerrit_cl_bot_errors

Show detailed error messages from failed try-bots with traces.

get_ci_build_errors

Retrieve CI build error details for a given build.

list_gerrit_cls

List Gerrit CLs that you have access to (requires authentication).

get_pdfium_gerrit_cl_status

Check PDFium CL status and test results.

get_pdfium_gerrit_cl_comments

Fetch PDFium review comments and code context.

get_pdfium_gerrit_cl_diff

Show PDFium code changes for a CL.

get_pdfium_gerrit_patchset_file

Get PDFium file content from a patchset.

list_pdfium_gerrit_cls

List PDFium Gerrit CLs with authentication (requires cookies).

get_chromium_issue

Retrieve detailed issue information with browser automation.

search_chromium_issues

Full-text search for Chromium issues with pagination.

search_chromium_commits

Commit history search with date filters.

find_chromium_owners_file

Locate OWNERS files for code ownership context.