Spectral, created at Stoplight, became the de facto standard for API governance linting and is the reason automated governance became real for most organizations. Its ruleset format is the lingua franca of the category.
Vacuum, from Dave Shanley, is Spectral-compatible — it runs existing Spectral rulesets — and is dramatically faster. The performance difference matters more than it sounds. When linting is fast enough, governance can run everywhere it needs to: in the editor as you type, on every save, on every pull request, across an entire portfolio in a batch. When it is slow, governance gets relegated to a nightly job whose output nobody reads.
Vacuum also extends the rule itself with properties Spectral lacks — a stable rule ID, a category, and how-to-fix text. Those three fields do more for adoption than any individual rule, because they turn a failure message from an accusation into instruction. Categories let you group rules so a developer sees “three security issues” rather than a flat list of forty findings, which is a real reduction in cognitive load.
Practically: if you already have Spectral rulesets, you can run them under Vacuum without rewriting them, so this is not a migration decision so much as an engine choice. There is no single tool for governance regardless — you will end up running several things in the pipeline.
