A solid primer on Uber's reflection-based DI container, the engine that powers fx. The skill walks you through Provide/Invoke semantics, parameter and result objects with dig.In/dig.Out, named values, value groups, and the difference between dig (just wiring) and fx (wiring plus lifecycle). Best part is the practical advice: keep the container at the composition root, depend on interfaces, validate the graph in tests. The comparison table showing what fx adds on top of dig is genuinely helpful for choosing between them. If you're building a CLI tool or embedding DI into an existing app that manages its own lifecycle, this is the right pick. For long-running services that need signal handling and graceful shutdown, you want fx instead.
npx skills add https://github.com/samber/cc-skills-golang --skill golang-uber-dig