6. Logic, Constraints & Best Practices

1. Upsert Mechanism: Siteti uses the phone number as the unique identifier. If a number already exists, the API updates the first_name, last_name, and segment based on the latest payload.
2. Variable Validation: The number of items in the variables array must match the number of placeholders ( {{1}}, {{2}} ) in your approved Meta template.
3. Phone Formatting: Always provide numbers in international format (e.g., 23480... ) without the + prefix.
4. Meta Billing: Siteti platform fees cover software usage; Meta's per-message template charges are handled directly through your linked Meta Business account.