WhatsApp

Lane.Chat connects to WhatsApp through Meta's WhatsApp Cloud API. Messages to and from your WhatsApp business number land in the same inbox as web and Telegram conversations.

Prerequisites

• A Meta / Facebook Business account with WhatsApp Cloud API enabled.
• A registered phone number ID and a system-user access token.
• Your Meta app secret (used to verify inbound webhook signatures).

How it works

1. In the dashboard, add your WhatsApp number to the application and provide the phone number ID, access token, and app secret. Credentials are stored encrypted per application.
2. Configure Meta's webhook to point at Lane.Chat's WhatsApp endpoint (below).
3. Inbound messages from Meta are verified, normalized, and routed through the standard visitor-message pipeline. Outbound agent/AI/Flow messages are sent via the Cloud API.

Webhook endpoint

GET  https://api.lane.chat/api/v1/whatsapp/webhook/{appId}   # verification handshake
POST https://api.lane.chat/api/v1/whatsapp/webhook/{appId}   # inbound messages

Inbound POSTs are authenticated with Meta's X-Hub-Signature-256 header, which carries sha256= + HMAC_SHA256(app_secret, raw_body). Lane.Chat verifies this against your stored app secret.

The 24-hour window

WhatsApp enforces a customer-service window: free-form outbound messages are only allowed within 24 hours of the customer's last inbound message. Outside that window, Meta only accepts pre-approved template messages. Lane.Chat honors this rule when sending — plan agent follow-ups and Flow messages accordingly.

Media

Inbound media is fetched from Meta's Graph API and re-served through Lane.Chat's media proxy:

GET https://api.lane.chat/api/v1/whatsapp/media/{mediaId}