bazel

This Bazel MCP Server exposes a set of MCP-enabled tools that bridge Bazel functionality to AI agents. The available tools include: bazel_build_target to build specified Bazel targets, bazel_query_target to query the dependency graph for targets matching a pattern, bazel_test_target to run tests for selected targets, bazel_list_targets to enumerate all targets in the workspace (requires a workspace path), bazel_fetch_dependencies to fetch external dependencies, and bazel_set_workspace_path to switch the Bazel workspace path at runtime. Each command (except bazel_set_workspace_path) accepts optional additionalArgs to pass through to Bazel, enabling flags like --verbose_failures or --test_output=all. Use the provided configuration to point the server at your Bazel binary and workspace, and leverage set_workspace_path to adjust the workspace without restarting the server.

Prerequisites:

• Node.js (with npm) installed on the host
• Git installed (for cloning the repository if needed)
• Access to the internet to fetch the Bazel MCP Server package via npx

Installation steps:

1. Ensure Node.js and npm are installed. You can verify with: node -v npm -v

2. If you have a Bazel MCP Server repository (as in this guide), you can run the server directly via npx without a local install: npx -y github:nacgarg/bazel-mcp-server

3. If you prefer to run from source, clone the repository, install dependencies, and build: git clone https://github.com/nacgarg/bazel-mcp-server.git cd bazel-mcp-server npm install npm run build dist/index.js

4. Start the server using the preferred method (see mcp_config above for the npx usage). If you need to customize paths, you can pass --bazel_path and --workspace_path as shown in the configuration.

5. Optional: set environment variables to control behavior, as described in the configuration table.

Note: If you are using Cursor or remote environments, ensure the workspace and Bazel binaries are accessible from the MCP server process. The server will pick up npx-installed packages automatically in most environments.

Tips:

• Provide explicit paths for the Bazel binary and workspace if the automatic path detection fails in your environment.
• Use bazel_list_targets with a workspace_path to quickly survey available targets; this is particularly helpful when starting with a new repo.
• If you encounter permission or path issues, double-check the MCP_LOG_PATH setting and review the log at the specified location for diagnostics.
• The MCP environment variables (MCP_BAZEL_PATH, MCP_WORKSPACE_PATH, MCP_WORKSPACE_CONFIG, MCP_LOG_PATH) can help you reproduce and debug in different environments.
• When running in minimal containers, ensure that the Bazel binary has execute permissions and that any required shared libraries are available.