WaConnect

Send messagesCheck WhatsApp numbers

Check WhatsApp numbers

Find out if a phone number is on WhatsApp.

Before messaging someone — or to build your own "new chat" screen — check whether their phone number has a WhatsApp account.

POSThttps://api.waconnect.ai/v1/contacts/lookup
curl https://api.waconnect.ai/v1/contacts/lookup \
  -H "Authorization: Bearer wc_live_your_key" \
  -H "Content-Type: application/json" \
  -d '{"numberId":"YOUR_NUMBER_ID","phone":"+14155550123"}'
200 OKjson
{ "phone": "+14155550123", "onWhatsapp": true }
numberIdstring (uuid)required
A connected number of yours; WhatsApp is asked through it.
phonestringrequired
The phone number in international format.

Good to know#

  • Lookups are free — no credits are used.
  • The number you ask through must be connected, otherwise you get 409.
  • WhatsApp usually answers in under a second. If it doesn't answer within 10 seconds, you get 503 — retry shortly.
  • You don't need to look up before sending: POST /v1/messages checks new recipients itself and answers 422 if they aren't on WhatsApp.

Best practice#

Look a number up at the moment someone is about to be messaged — for example when a user types it into your "new chat" screen. WhatsApp treats large batches of lookups as list validation, so checking whole contact lists in one go is best avoided.