Crabbox

Provider Selection Contract

Provider selection is configuration resolution, not testing policy. Run crabbox config show from the exact worktree being tested; a session may have started in another checkout whose repository config or skill text is stale. A request to "use Crabbox" does not authorize a provider override. When the user does not name a backend, omit --provider and preserve the resolved provider, including values supplied by user config or CRABBOX_PROVIDER.

Test scope, expected duration, and hydration failures do not select a provider. Override the resolved provider only when the user explicitly names a different backend. If that provider cannot perform the requested test, report the blocker instead of silently selecting another backend.

Use the Crabbox wrapper for validation execution, environment lifecycle, sync, logs/results, cache inspection, and lease cleanup.