Key concepts
The model behind WhatsApp chats, sends, templates, and events.
Chats are 1:1
Section titled “Chats are 1:1”Each chat represents one customer conversation. You can send by destination and let Linq resolve the chat, or send to a known chat ID.
The customer window controls free-form sends
Section titled “The customer window controls free-form sends”An inbound customer message opens or extends the customer-service window. While it is open, you can send free-form content. Outside it, send an approved template. The API refuses an invalid choice; it never silently substitutes a template or coerces content.
Acceptance is not delivery
Section titled “Acceptance is not delivery”Successful send requests return 202 after durable acceptance. Delivery,
read, and failure receipts arrive later. Treat an unresolved outcome as
unknown; do not blindly resend it.
Events address durable state
Section titled “Events address durable state”SSE and webhooks tell you which chat sequence range moved. The per-chat journal contains the message content and forms the durable recovery source. Account events also have a pageable log for bounded catch-up.
Parts are the content contract
Section titled “Parts are the content contract”Each send currently carries one member of the sealed parts union. The JSON
Schemas served by GET /v1/parts/{type} are authoritative and can be used
directly as tool schemas for your agent.