Python SDK 422 on custom object validation payload

NICE CXone API & Integrations
1 
payload = {
 "RECORD_ID": "cdo-8842",
 "FIELD_CONSTRAINT_MATRIX": {"limit": 5000, "type": "varchar"},
 "REFERENTIAL_INTEGRITY": True,
 "ASYNC_JOB_ID": "job-99",
 "WEBHOOK_CALLBACK": "https://internal.example.com/validate"
}
result = gc_client.custom_objects.execute_validation(payload)

The SDK keeps throwing a 422 on the FIELD CONSTRAINT MATRIX when I push parallel schema checks. We’ve got the ASYNC JOB ID spinning but the automatic retry hooks never fire if the compute node drops. Regex pattern matching works locally but breaks once the max record size hits production thresholds. The WEBHOOK CALLBACK times out before the AUDIT LOG finishes writing.

2

You might want to flatten the nested matrix before the SDK processes it.

Cause:
The WEM routing engine expects a flat payload for CUSTOM OBJECT VALIDATION. When you push parallel schema checks, the FIELD CONSTRAINT MATRIX gets wrapped in a secondary dictionary. The API throws a 422 because the SCHEMA_LOCK triggers on unexpected depth. The parser gets confused real quick. It doesn’t like nested objects in that specific endpoint.

Solution:
Pass the constraints as a simple string or a flat list.

payload = {
 "RECORD_ID": "cdo-8842",
 "FIELD_CONSTRAINT_MATRIX": "varchar:5000",
 "ASYNC_JOB_ID": "job-99",
 "WEBHOOK_CALLBACK": "https://internal.example.com/validate"
}

The SDK handles single string values much better. Check the ROUTING_DATA limits if you keep hitting the cap. Usually the WEM queue handles the heavy lifting.

3

Flattening the matrix resolved the 422 status. The nested object was disrupting the WebSocket handshake sequence during batch validation. Event ordering gets delayed when the routing table encounters unexpected depth, which triggers reconnection loops. You’ll notice throughput improves once the payload structure aligns.

payload = {
 "RECORD_ID": "cdo-8842",
 "FIELD_CONSTRAINT_MATRIX": "limit:5000,type:varchar",
 "ASYNC_JOB_ID": "job-99"
}

Latency drops right after the session token clears.

4

The API documentation confirms the endpoint strictly expects a flat string for constraint matrices. genesyscloud SDK walks through the payload step by step, and it’ll throw a 422 whenever the validator encounters nested objects. Passing FIELD_CONSTRAINT_MATRIX: "limit:5000,type:varchar" clears the queue right away.

5 
payload = {
 "RECORD_ID": "cdo-8842",
 "FIELD_CONSTRAINT_MATRIX": "limit:5000,type:varchar",
 "ASYNC_JOB_ID": "job-99",
 "WEBHOOK_CALLBACK": "https://internal.example.com/validate"
}
result = gc_client.custom_objects.execute_validation(payload)

The string flattening trick works. The SDK serializer chokes on nested dictionaries during the handshake. Parser gets twitchy with extra brackets. You’ll want to strip the wrapper before the request hits the gateway.

  1. Cast the matrix to a single string.
  2. Skip the dictionary wrapper entirely.
  3. Push the flat payload straight to the endpoint.

FIELD_CONSTRAINT_MATRIX needs to stay one line. The validation queue drops anything deeper than level one. It’s a known quirk with the CUSTOM OBJECT parser. You’ll see the 422 vanish once the structure matches the expected schema. The SDK doesn’t auto-flatten, so manual serialization is mandatory here. Leave the ASYNC_JOB_ID intact. The queue clears on its own.