Bazel MCP Server

🚀 Bazel MCP Server

A local MCP server that provides the capabilities of the Bazel build system to MCP-enabled AI agents.

This is particularly useful when there are no existing command-line tools in the MCP environment or when the shell environment is misconfigured, preventing the use of Bazel.

✨ Features

The Bazel MCP server offers the following tools:

• bazel_build_target: Build a specified Bazel target.
• bazel_query_target: Query the dependency graph of targets matching a pattern.
• bazel_test_target: Run tests for a specified target.
• bazel_list_targets: List all available targets in the workspace (requires a path parameter, use "//" to indicate all targets).
• bazel_fetch_dependencies: Fetch external dependencies.
• bazel_set_workspace_path: Change the Bazel workspace path at runtime.

Except for bazel_set_workspace_path, each command supports an optional additionalArgs parameter, allowing you to pass extra parameters to the underlying Bazel command. This is useful for specifying flags such as --verbose_failures or --test_output=all.

🚀 Quick Start

📦 Installation

Using with Cursor

Add the following content to .cursor/mcp.json:

You don't need to provide the workspace path because the LLM can change the workspace path at runtime using set_workspace_path.

If you encounter issues, you can use the --bazel_path flag to specify the path to the Bazel binary.

⚠️ Important Note

This method does not work properly when using a remote SSH session in Cursor because the MCP server runs locally.

{
  "mcpServers": {
    "bazel": {
      "command": "npx",
      "args": [
        "-y",
        "github:nacgarg/bazel-mcp-server",

        // If you need to specify the path to the Bazel binary
        "--bazel_path", 
        "/absolute/path/to/your/bazel/binary",

        // If you need to specify the workspace path
        "--workspace_path",
        "/absolute/path/to/your/bazel/workspace"

        // Refer to the configuration table for more options
      ]
    }
  }
}

Using with Claude Desktop

You can use the same configuration with Claude Desktop.

Running Independently

# Run directly from GitHub (no installation required)
npx -y github:nacgarg/bazel-mcp-server

# Run from source code
git clone https://github.com/nacgarg/bazel-mcp-server.git
cd bazel-mcp-server
npm install
npm run build
dist/index.js

Configuration

This MCP server supports multiple configuration methods, used in the following order:

1. Command-line arguments
2. Environment variables
3. Configuration files

Configuration Table

🔧 Technical Details

Set the DEBUG=true environment variable to enable verbose logging.