GitHub-compatible Actions: what actually matches
An honest compatibility note on workflow syntax, runners, caching, and artifacts, including the places where Trylle deliberately differs.
Alan · Co-Founder1 min readCompatibility claims are easy to make and hard to keep. So here is the specific version: your existing workflow files run, and we will tell you where they do not.
What runs unchanged
Workflow and job syntax, matrix builds, reusable workflows, expressions, job dependencies, artifacts, and the caching API all behave the way your team already expects. Most repositories migrate by pointing at a new remote and nothing else.
Where we differ on purpose
Runner images are pinned to explicit digests rather than rolling tags, so a green run stays reproducible. Secrets are scoped to the repository and the bot that requested them, which means a workflow cannot read credentials it was never granted. Both differences will surface as errors rather than silent behaviour changes.