Bazel MCP server

The Model Context Protocol (MCP) server for Bazel provides a convenient way to interact with Bazel projects directly from AI assistants and applications that support the MCP protocol. It offers tools for building targets, analyzing dependencies, finding source files, and running tests within Bazel workspaces.

Installation

You can easily install the MCP Bazel server using Go's package manager:

# Ensure your Go environment is set up (GOPATH, GOBIN, etc.)
go install github.com/aaomidi/mcp-bazel@latest

This will compile and install the mcp-bazel binary. By default, it's placed in your $GOPATH/bin directory or $HOME/go/bin if GOPATH is not set. Make sure this location is in your system's PATH.

Setting Up with Claude Desktop

Configure Claude Desktop

Add the MCP server configuration to your Claude Desktop settings file (claude_desktop_config.json):

{
  "mcpServers": {
    "mcp-bazel": {
      "command": "/path/to/your/go/bin/mcp-bazel"
    }
  }
}

Replace /path/to/your/go/bin/mcp-bazel with the actual path to the installed binary. You can usually access the config file via the app's settings menu by clicking "Open Config Folder".

After saving the configuration, restart Claude Desktop to activate the Bazel tools.

Available Tools

Build Targets

The build tool allows you to build specified Bazel targets:

build //path/to:target

Analyze Dependencies

The deps tool finds dependencies of a given Bazel target:

deps //path/to:target [--depth=n]

The optional depth parameter limits how far down the dependency tree to search.

Find Reverse Dependencies

The rdeps tool identifies all targets that depend on a specified target or file:

rdeps //path/to:target [--depth=n]

You can also use a file path instead of a target specification.

List Source Files

The sources tool finds direct source files associated with a target:

sources //path/to:target

Run Tests

The test tool executes tests for a specified Bazel target:

test //path/to:target

Usage Tips

• All commands expect standard Bazel target notation (//path/to:target)
• For dependencies and reverse dependencies, you can control the depth of analysis
• Commands are executed within your current Bazel workspace

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "mcp-bazel" '{"command":"/path/to/your/go/bin/mcp-bazel"}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "mcp-bazel": {
            "command": "/path/to/your/go/bin/mcp-bazel"
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "mcp-bazel": {
            "command": "/path/to/your/go/bin/mcp-bazel"
        }
    }
}

3. Restart Claude Desktop for the changes to take effect