Lefthook

Lefthook is an open-source tool that manages Git hooks for a project. It provides a centralized, language-agnostic way to run project-specific scripts in response to Git events such as commits and pushes. By replacing or augmenting the native .git/hooks, Lefthook ensures that checks like tests, linters, or formatting run consistently across developer machines.

Configuration is done in a YAML file named lefthook.yml placed at the repository root. The file defines hooks for events (for example pre-commit, pre-push, commit-msg) and the commands to run for each event. Lefthook installs corresponding scripts into the repository’s .git/hooks directory so that Git triggers them automatically. The tool is designed to work with multiple programming languages and can run commands from diverse toolchains without requiring project-specific wrappers.

Installation and basic usage typically involve adding Lefthook to the project’s development tooling and running an install command to generate the Git hooks. Once installed, developers attempting to commit or push will have Lefthook execute the configured commands, and failing hooks can block the operation until issues are resolved. This helps enforce code quality gates such as passing tests or linting before integration.

Lefthook emphasizes portability across operating systems and is commonly used in both open-source and commercial projects. It competes with other Git hooks managers and has a community-maintained ecosystem of configurations and examples. See also Git hooks; Husky; pre-commit.