Skip to main content
Bazel is Google’s Open Source Build and Test system, which supports many languages. This reference documentation guides you through usage with specific languages and ecosystems. Aspect maintains a collection of high-quality, open-source rulesets that bring modern toolchains and developer workflows into Bazel’s hermetic, incremental build engine.
New to Bazel?
  • Start with Bazel 101 for a language-agnostic introduction.
  • Pick a language section below to get started quickly.
  • Sign up for commercial support, provided by Aspect as a shared Slack channel.

​
Languages & ecosystems

JavaScript & TypeScript

Build JS and TS projects with pnpm workspaces, rules_js, and rules_ts. Includes integrations for esbuild, webpack, Jest, Cypress, Vite, and Next.js.

Python

Hermetic Python interpreters, pinned dependencies via uv, and Gazelle-generated BUILD files. Covers testing, virtualenvs, containers, and cross-builds.

Ruby

Build Ruby libraries, binaries, and tests with rules_ruby. Includes Bundler integration and Rails test helpers.

Shell

Declare and test shell scripts with rules_shell. Shell is the example language used in Bazel 101.

Utility

Language-agnostic tools: file manipulation, data transformation, and much more