Webhooks: tell your other systems what happens

1. In Settings, under Webhooks, enter the address (https://) and choose Every event or the ones you want, then Add webhook.
2. Copy the signing secret now (it’s shown once) into the system that receives the messages. Send a test sends a “ping”.

Events: screen paired, unpaired, offline, back online, stuck downloading and caught up; photo or video ready or failed; a new contact from a “join our list” QR code. Each message is JSON with id, type, created and data.

To check a message came from Dislab, take the Dislab-Signature header (t=…,v1=…), work out HMAC-SHA256 of t, a full stop and the raw body, keyed with your secret, and compare it with v1; also check t is within a few minutes. In Node: createHmac('sha256', secret).update(`${t}.${body}`).digest('hex'). Answer with any 2xx. Anything else is tried again after 1, 5 and 30 minutes, then 2, 6 and 12 hours.