server

chromium-code-mcp

An MCP server that provides AI assistants with access to Chromium development services. Covers code search, file retrieval, Gerrit code review, LUCI CI, the issue tracker, and reviewer suggestions — all through a single JSON-RPC interface.

Tools

Code Search

Gerrit (Chromium)

Gerrit (PDFium)

Same capabilities as the Chromium tools above, targeting the PDFium review instance: get_pdfium_gerrit_cl_status, get_pdfium_gerrit_cl_comments, get_pdfium_gerrit_cl_diff, get_pdfium_gerrit_patchset_file, get_pdfium_gerrit_cl_trybot_status, list_pdfium_gerrit_cls

CI / Issue Tracker

Installation

Option 1 — Download a pre-built binary

Grab the latest release from the Releases page and pick the archive for your platform:

Extract and place the binary somewhere on your PATH, e.g.:

tar xzf chromium-code-mcp-<version>-linux-amd64.tar.gz
mv chromium-code-mcp ~/.local/bin/

Option 2 — go install

Prerequisites: Go 1.25+

go install github.com/dgavrilov/chromium-code-mcp/cmd/chromium-code-mcp@latest

The binary is placed in $GOPATH/bin (usually ~/go/bin). Make sure that directory is on your PATH:

export PATH="$PATH:$(go env GOPATH)/bin"

git clone https://github.com/dgavrilov/chromium-code-mcp
cd chromium-code-mcp
go build -ldflags "-X 'github.com/dgavrilov/chromium-code-mcp.Version=1.0.0'" ./cmd/chromium-code-mcp

Configuration

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "chromium": {
      "command": "/path/to/chromium-code-mcp"
    }
  }
}

Claude Code

Add to your project's .mcp.json or run:

claude mcp add chromium /path/to/chromium-code-mcp

Code Search API key (optional)

The server uses a public API key for code search by default. To use your own:

export CHROMIUM_SEARCH_API_KEY=your_key_here

Usage examples

Search for all callers of a function:
  search_chromium_code("TabStripModel::AddWebContents", search_type="function")

Get a file with line range:
  get_chromium_file("chrome/browser/ui/browser.cc", line_start=100, line_end=150)

Check a CL's review status:
  get_gerrit_cl_status("6624568")

See what failed in CI:
  get_gerrit_cl_bot_errors("6624568")

Suggest reviewers:
  suggest_chromium_reviewers("6624568", max_reviewers=3)

Development

Prerequisites: Go 1.25+, Task, golangci-lint

task build                   # build the binary (version = "dev")
task build VERSION=1.0.0     # build with a specific version
task test                    # run all tests
task lint                    # run golangci-lint
task coverage                # generate and display coverage report
task fmt                     # gofmt all source files

Project structure

chromium-code-mcp/     # package server — MCP protocol + tool registry
  server.go            # Run() — starts MCP server over stdio via go-sdk
  tools.go             # registerTools() — wires all 23 tools via mcp.AddTool
  version.go           # Version variable (set via ldflags at build time)
  cmd/chromium-code-mcp/
    main.go            # Binary entry point
  internal/chromium/   # Chromium API clients (package chromium)
    client.go          # HTTP client, bounded FIFO cache, HTTPDoer interface
    utils.go           # Shared utilities (JSON decoding, glob matching, etc.)
    search.go          # Code Search API
    gitiles.go         # Gitiles (file/folder/commits/OWNERS)
    gerrit.go          # Gerrit API
    luci.go            # LUCI / Buildbucket / ResultDB
    issues.go          # Issue tracker
    reviewers.go       # Reviewer suggestion algorithm

Architecture notes

• All internal/chromium exported methods take context.Context as their first parameter and return (string, error). The string is always Markdown-formatted output ready for the MCP caller. User-visible errors (bad input, HTTP 404) are returned as text with nil error; only unexpected failures propagate as non-nil errors.
• HTTP responses are cached in a bounded FIFO in-memory cache (100 entries). The HTTPDoer interface (Do(*http.Request) (*http.Response, error)) allows injecting mock transports in tests.
• Reviewer suggestion uses a greedy set-cover algorithm over OWNERS files, optionally weighted by 6-month commit activity fetched in parallel from Gitiles.

License

BSD 3-Clause. See LICENSE.