Messaging Service
What is Messaging Service?
A Messaging Service is Orbit's named sender container — a binding that supplies a default sending identity plus per-message settings such as the status callback URL and the message validity period. When you pass a messaging service ID on a send, its sender fills in only if you didn't pass a sender yourself, so the same caller can opt into the container or override it message-by-message. The Messaging Service is the Twilio Messaging Service parity object inside Orbit's sender-resolution chain.
More detail
The sender-resolution chain that decides who a message actually sends from is a small ordered sequence — a direct from number first, then a sender pool, then a messaging service — referenced by ID with `messaging_service_id`. A wrong or missing reference surfaces as a `SENDER_REQUIRED` error rather than a routing guess.
A Messaging Service also carries its own per-message send-rate cap — `MESSAGING_SERVICE_MPS_EXCEEDED` surfaces when a service exceeds its configured per-second message budget — so you bind a rate ceiling to the container instead of duplicating it on each `from` reference.
Frequently asked
- How does a Messaging Service pick the sender number?
- By resolution chain — it fills the sender only when the request left `from` blank, in the order direct sender → sender pool → messaging service. A wrong reference fails as `SENDER_REQUIRED`, not a wrong-sender fallback.
- Is a Messaging Service a sender pool?
- No — a sender pool is a collection of numbers for rotation and distribution, while a Messaging Service is a named sender container with a default identity and per-message settings. They both participate in the sender-resolution chain a send goes through.
See also
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