Yes, the Dagger engine is open source. Note that the engine on its own is not a CI replacement: it provides a runtime for your pipelines, but you still need an external system to trigger pipelines from git events. This decoupling is intentional, because CI should not be tightly coupled to git events. Sometimes you want to run a pipeline after pushing; but sometimes you need it before pushing, or even before committing. The pipeline runtime therefore should operate at a different layer than git events.

In practice this means you can combine Dagger with, say, Github Actions or another "legacy" CI platform. And use it as runner & event infrastructure for your portable Dagger pipelines.

We also offer a complete Dagger-native CI platform, which combines hosted Dagger engines, git triggers, and all the infrastructure necessary to run your CI end-to-end. That is in early access as part of Dagger Cloud, our commercial offering.