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.Documentation Index
Fetch the complete documentation index at: https://docs.aspect.build/llms.txt
Use this file to discover all available pages before exploring further.
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

