Step one: the inbound WhatsApp flow routes template responses into a Studio digital queue, then hits a SNIPPET action to strip the wa_id and message_id before forwarding to an internal intent classifier. CXone 24.03 runs the backend with REST Proxy v4.6.0 in the London region. The SNIPPET logic looks like this: let payload = interaction.channels.messaging.whatsapp; return { sender: payload.from_id, msg_ref: payload.message_id, ts: Date.now() };. It’s been processing standard text replies fine for months.
Step two: template opt-in replies are breaking the mapping. The REST Proxy endpoint expects a strict JSON schema, but the SNIPPET output returns null on the msg_ref field when a customer taps a quick reply button. Console throws a 400 Bad Request with {"error_code": "INVALID_PAYLOAD_STRUCTURE", "message": "Expected string at 'msg_ref' but found null"}. We’ve tried adding a fallback like payload.message_id || 'temp_ref_' + Date.now(), yet the proxy still rejects it.
Step three: raw Edge Gateway logs show the message_id actually sits under message.interactive.message_id for template responses. The SNIPPET action doesn’t traverse that nested path correctly. Updated the script to handle both structures, but the proxy validation layer keeps failing. Morning queue backup hit 140 messages and agents are doing jack all while waiting for retries.
The REST Proxy schema validation is stricter than the Studio runtime, and the SNIPPET action isn’t catching the nested interactive payload. Version 4.6.0 might have changed how it parses WhatsApp quick reply objects. The logs just show the 400 error repeating every 2 seconds.