Open Messaging API - Inbound Normalization Failure - RFC 7638 Compliance Issue

Hi all,

We’re encountering intermittent failures in inbound message normalization through the Open Messaging API - specifically with WhatsApp Business API messages. The root cause, as far as I can tell, isn’t a straightforward schema mismatch, but a discrepancy between the expected message structure and what RFC 7638 defines for a compliant WhatsApp message payload. Think of it like trying to fit a square peg in a round hole - the system attempts to map the incoming data to an internal format, but the peg’s dimensions aren’t quite right, leading to an outright rejection.

The issue surfaces only with messages containing complex rich media - specifically those with multiple embedded buttons. Simple text messages normalize without incident. It seems the parser isn’t handling the nested array structure of the interactive_components object correctly. The error manifests as a 400 Bad Request when attempting to process the normalized message in an Architect flow. The data action is configured to write the normalized message to a custom data table.

I’ve isolated the problematic payload below - note the structure of the interactive_components array. We’re using the Genesys Cloud CXone Open Messaging API v2.0.3 and the associated Python SDK v1.2.1. I’ve checked the normalization configuration within the CXone UI. Everything appears to be set up to handle the expected JSON.

Here’s the error payload received from the API:

{
 "error_code": "VALIDATION_ERROR",
 "message": "Invalid message payload. Failed to normalize WhatsApp message. Error: 'list' object has no attribute 'append'.",
 "details": [
 {
 "field": "normalized_message",
 "message": "Failed to parse interactive_components array. Check payload structure against RFC 7638."
 }
 ],
 "request_id": "req-6e9f4d3a-1b2c-4a5d-9e10-f1a2b3c4d5e6"
}

To further investigate, I’ve created a bullet table summarizing observed failures:

The SDK isn’t providing much detail beyond the generic “Failed to normalize” message. The core issue is likely within the internal parsing logic. I need to confirm if this is a known limitation or a genuine bug within the normalization process itself.