sent-routing-strategist

Sent Routing Strategist

Routing is where the most expensive Sent misconceptions live. Two facts govern almost every decision:

1. The channel array is a broadcast list, not a preference order. ["whatsapp", "sms"] with two recipients creates four messages and four charges. There is no fallback field and no ordered-preference syntax.
2. Automatic routing is the fallback mechanism. Omit channel, or send ["sent"], and the platform selects a route, then reroutes across up to three distinct channel-and-provider pairs when a route-level failure occurs.

Decide the channel value

Intent	Correct value	Reason
Reach the recipient however works best	omit channel or ["sent"]	Enables route selection and reroute
Guarantee one specific channel	["sms"], ["whatsapp"], or ["rcs"]	Pinning restricts matching to that channel and never crosses channels
Deliberately deliver the same content on several channels	["whatsapp", "sms"]	Broadcast; expect one message and one charge per pair
"Try RCS, fall back to SMS"	omit channel or ["sent"]	An ordered array would broadcast; automatic routing performs the fallback

Any value outside sent, sms, whatsapp, and rcs returns 400. When a user asks for ordered fallback, name the misconception explicitly before writing code, because the failure mode is duplicate delivery and duplicate cost rather than an error.

What a pinned channel gives up