I took a look at the quickstart with aim of running this locally and found that an API key is needed for the importance ranking.

What exactly is importance ranking? Does the verification layer still exists without this ranking?

Importance ranking is just a heuristic pass that scores/prioritizes elements (size, visibility, role, state) so the snapshot stays small and focused. It’s deterministic, not ML.

The verification layer absolutely still exists without it — assertions, predicates, retries, and artifacts all work locally. The API-backed ranking just improves pruning quality on very dense pages, but it’s not required for correctness.

You can set use_api = False in the SnapshotOptions to avoid using the api