Messaging Window

This page covers the rules, timers, and state machine lifecycle governing Meta’s 24-hour customer service window.

Session Lifecycle & Window Rules

Content coming soon.

User-Initiated Conversations (UIC) vs. Business-Initiated Conversations (BIC)
24-hour sliding window mechanics calculated from the last user message
Freeform conversational messages vs. pre-approved HSM template constraints

Session State Machine

Content coming soon.

States: IDLE, ACTIVE_24H, EXPIRED, TEMPLATE_PENDING
Transitions triggered by inbound messages, timer expirations, and template replies

Expiration Handling & Fallbacks

Content coming soon.

Graceful degradation when the window closes mid-workflow
Automatic re-engagement via approved utility templates