Your WhatsApp session travels light
Compact encrypted session files become the default, with pending-message replay and redacted session diagnostics.
Developers and operators
OpenWA 5.3 made compact authentication the default. An encrypted {sessionId}.data.json file stores auth and data, replacing the need to retain a large persistent browser profile for the current compact-session path.
Pending messages replay through onMessage and are acknowledged after handlers finish. Retries are at least once, so applications must deduplicate effects such as database writes or external notifications. Existing filename, path, seed and S3 settings use the same storage transport, and session payloads and S3 credentials are redacted from debug responses.
At that release, the adapter was WhatsApp-build-gated and live browser/S3 acceptance and complete crash recovery remained unverified. This is a historical summary, not a new acceptance claim. Current setup uses 5.5.1; 5.4 added operator-provided session keys and 5.5.1 improved invalid saved-file recovery.