Templates and the 24 h window

Reply freely for 24 hours after the customer writes. After that, send a template.

The window

WhatsApp lets a business send any message for 24 hours after the customer's last one. Each conversation carries window_expires_at and window.

window	Meaning
`open`	Any message goes through
`closing`	Under two hours left
`closed`	Only a template goes through
`none`	The customer never wrote

A text, media or interactive send outside the window is 422 window_closed.

Sending a template

Templates sync from Meta every 15 minutes. List templates gives each one's header_values and body_values, which say how many variables to send.

1{
2  "conversation_id": "b1c7e0a4-52a3-4a3c-8d0e-6c1b9e5f7a20",
3  "type": "template",
4  "template": {
5    "name": "transfer_ready",
6    "language": "en_US",
7    "variables": { "header": [], "body": ["Ama", "T-42"] }
8  }
9}

variables.body holds one string per {{n}}, in order. language is needed only when the template exists in several. A media header takes { "media_key": "..." } from an upload.

Anything wrong is 422 template_invalid, and details.reason says what: not_found, not_approved, language_required, wrong_variable_count, media_header_required, header_not_media or header_format_unsupported.

NextMedia

The window

Sending a template

When a template is refused