Inbound
The owner writes to the number. zapbip checks the signature of every notification, stores each message once even when WhatsApp delivers it twice, and routes it to one agent with the routing rules.
A message the owner sends opens the 24-hour window. A reaction does not.
If a file cannot be downloaded, the agent receives the message with
media_id: null and media_status: "unavailable", and the owner is asked to send it again.
Outbound
Within the window every kind goes out at once. Outside it the message is queued and the owner receives a notice.
zapbip refuses a send that breaks a limit and the tool returns an error naming the field.
Delivery
Thedelivery of a message moves forward only: sent, delivered, read. A send WhatsApp rejects becomes failed. A message already delivered or read never becomes failed.
Restricted number
When WhatsApp reports that the number is restricted or the account is disabled, zapbip stops sending for 24 hours and the operator is alerted. Messages sent in that time returndelivery: "failed".