An explicit set of tests to run for a deployment, in place of matching stored plans by label. mabl runs them as one synthesized plan whose identity is scoped to the event, so the runs appear on the deployment results page like any other deployment run. Supports browser or API tests, without mixing types. Each test runs at its version on the selection's mabl branch, falling back to master when it has none there. That branch is the event's branch (or source_control_tag), else the deployment's branch, else the snapshot action's from, else the environment's branch, else master, and must be the same for every deployment that can run the selected test type. A branch mabl does not have is not an error: every test runs at master, and resolved_tests shows it. The snapshot action's from is the exception and must name an existing branch. A test with no version on the branch or master is refused. An environment's snapshot branch has no master fallback, so a test missing from the snapshot is refused. Each enabled test requires a compatible deployment. The first run runs the versions in resolved_tests. Retries, from retry_failed_tests or a manual rerun, resolve the branch again and run any later edit. Flows are not pinned; they resolve on the branch when each test starts.