How to connect WhatsApp
Step-by-step guide to connecting WhatsApp to Chatasist — via the official Twilio API or a personal number by QR.
There are two ways to connect WhatsApp. Use Twilio for production volume, or a personal number by QR to get started fast.
Option A — Official API (Twilio)#
Get your Twilio WhatsApp sender
In Twilio, set up a WhatsApp sender. From the Twilio Console Account Dashboard, note your Account SID and Auth Token, plus the sender's phone number.
Use the Auth Token, not a Twilio API Key — Twilio signs its webhooks with the Auth Token, so an API Key would let replies go out but cause every incoming message to be rejected.
Add the channel in Chatasist
Go to Settings → Channels → WhatsApp, choose Twilio, and enter the SID, token, and sender number.
You can change any of these later from the same screen. Leave Twilio Auth Token blank when editing to keep the token already stored, or type a new one to rotate it.
Check the webhooks
Chatasist points your sender's webhooks at itself when you save the channel. If your sender can't be configured over the API — Twilio sandbox numbers, or a sender owned by another Twilio project — the channel screen tells you, and you set them in the Twilio Console yourself:
Inbound: https://api.chatasist.com/webhooks/whatsapp/twilio
Status: https://api.chatasist.com/webhooks/whatsapp/twilio/status
Chatasist verifies each request's signature using your auth token. The status URL is what powers the sent / delivered / read marks under each reply.
Send a test message
Message your WhatsApp number and confirm the conversation appears in the inbox.
Replying outside the 24-hour window#
WhatsApp only lets a business send free-form replies within 24 hours of the customer's last message. That window reopens every time they message you again.
Outside it, WhatsApp accepts only a pre-approved template. To keep replying:
Create a template in Twilio
In Twilio Console → Messaging → Content Template Builder, create a template with a
single variable — for example New message from support: {{1}} — and submit it for
WhatsApp approval.
Add its Content SID to the channel
Copy the template's Content SID (it starts with HX) into Message template Content
SID on the WhatsApp channel. Replies sent outside the window then go out through that
template, with the agent's text as its first variable.
If no template is configured, a reply sent outside the window is not delivered. Chatasist marks the message "not delivered" in the thread and adds a note explaining why, so nobody assumes the customer received it.
WhatsApp templates cannot carry attachments. Photos, voice notes, and documents can only be sent inside the 24-hour window.
Option B — Personal number by QR#
Start the QR connection
In Settings → Channels → WhatsApp, choose the personal-number option.
Scan the code
Scan the QR code with WhatsApp on the phone for that number (Linked devices), similar to WhatsApp Web.
Confirm it's connected
Send a test message. If a session ever drops, administrators get an alert email so you can reconnect.
The QR connection has a hard scaling limit and a 64 MB inbound media cap. Use Twilio for high volume.
Connection details, limits, and webhooks.