zephyrproject-rtos/west

West is a meta-tool for managing multiple Git repositories under a single directory structure, designed for the Zephyr RTOS project.

West solves the problem of coordinating many interdependent Git repositories by using a manifest file to describe the entire project layout. Instead of cloning repositories individually, developers run west init to set up a workspace from a manifest repository, then west update to fetch and synchronize all repositories named in that manifest. The manifest file, typically named west.yml, is a YAML document that specifies which repositories to clone, their locations, and metadata about the installation. This approach centralizes repository management and allows teams to define custom manifests tailored to their specific needs rather than relying on a single upstream configuration.

Developers working on embedded systems with Zephyr should adopt west if they need to manage multiple interdependent repositories as a cohesive unit. It suits projects that want to minimize their software bill of materials by defining custom manifests rather than pulling in all upstream dependencies. While west historically defaulted to the upstream Zephyr manifest, users are now encouraged to design their own manifests for better control over what gets included. The tool is extensible, allowing new commands to be added without modifying its source code, making it adaptable to project-specific workflows.

The project maintains active test coverage tracking and security scorecard monitoring. Development follows a structured approach to dependency management using frozen lockfiles for reproducible builds. The codebase supports multiple Python versions and is distributed through standard package management channels.