Velocity (2025)

When you’re working in a large, multi-module Swift codebase, the project-file overhead becomes its own engineering problem. Adding a new module shouldn’t require editing .pbxproj files. Adding a SwiftPM dependency shouldn’t trigger a five-minute version resolution dance every time you open the project. Adding an image to an asset catalog shouldn’t mean typing the literal string "my_image_name" into Swift code with no compile-time safety.

Velocity is a CLI that handles all of that. It sits on top of XcodeGen and SwiftPM and automates the parts of multi-module project setup that I kept doing by hand.

The big pieces:

• pull-dependencies reads a dependencies.yml, fetches the SwiftPM packages it lists, and stores them locally so Xcode treats them as path-based dependencies. This skips remote resolution entirely on every subsequent build.
• Module and dependency code generation scans your modules’ source files for imports and autogenerates imports.yml, project-modules.yml, and project-dependencies.yml — the YAML that XcodeGen consumes to build the actual .xcodeproj. Adding a new module is just creating a folder.
• Dependency injection wiring generates the registration functions for the Inject library so modules can advertise themselves at app launch without manual glue.
• generate-resources emits typed Swift extensions on UIImage and UIColor for every entry in your .xcassets — type-safe resource access without writing it by hand.
• sanitize-xcodegen-project quietly cleans up build artifacts and project timestamps when nothing’s actually changed, to avoid spurious rebuilds.

It’s pretty opinionated, but the opinions are the ones I wanted enforced across a large codebase. The cost of adding a new module dropped from “edit six files” to “create a folder and run the generator.”

Source on github.