Configure automatic channel failover for a Vonage Messages API send (e.g. RCS or WhatsApp falling back to SMS).
domain: developer.vonage.com · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Build the primary message object as usual (e.g. channel: rcs or whatsapp).
Add a failover array containing one or more complete alternate message objects (e.g. mms, then sms).
Send once — Vonage automatically tries each failover entry in order if the prior one is rejected.
Read message_uuid (initial message) and workflow_id (whole failover chain) from the response.
Correlate status webhooks by their workflow object (workflow_id, items_number, items_total) to see which step in the chain fired.
Known gotchas
Failover is server-side and built into the Messages API — don't build your own webhook-driven retry logic for this case.
Each failover entry is a full message object; per-channel content (e.g. template vs plain text) must be valid for that specific channel.
items_number in the workflow webhook is 1-indexed (1 = initial message, 2 = first failover, etc.).
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