List the contacts this account has blocked

GET 
/api/sessions/:sessionId/contacts/blocked

The read half of the block/unblock endpoints. A bare array of neutral contact ids — ids only, because that is the honest common subset: whatsapp-web.js resolves full contact models but Baileys' blocklist query answers bare jids, and inventing the other fields on one engine would make the two engines claim different things about the same account.

Request

Responses

200

Blocked contact ids

409

The session is not connected — an engine exists for it but is not ready: disconnected, reconnecting, or still initializing, so the request never reached WhatsApp. Wait for ready and retry. A session that was never started answers 400 instead, and the session lifecycle routes answer 409 for a conflicting state rather than this. One window answers this while the session still reads ready: WhatsApp Web periodically reloads its own page and the engine re-injects into it — for those few seconds the answer is a 409 naming the reload; retry shortly.

503

WhatsApp did not answer the blocklist query — retry shortly