CXone Outbound Campaign preview generator throwing 422 on script version directives

NICE CXone API & Integrations
1

Problem
Local docker harness keeps rejecting the preview generation payloads. The outbound campaign API chokes on the script version directives when the test number matrix gets too wide. We’ve got a Java service spinning up inside the compose stack to handle the atomic POST, but it’s blowing up before the webhook callback even fires.

var previewRequest = new PreviewGeneratorRequest()
 .campaignId("c9a8b7-6543-2100")
 .testNumbers(List.of("+15550100", "+15550101"))
 .scriptVersionDirective("v2.4-qa")
 .maxPreviewDuration(45);

var response = outboundClient.generatePreview(previewRequest);

Error response:

{
 "code": 422,
 "message": "Validation failed: script version directive exceeds testing engine constraints. maxPreviewDuration must align with dial plan checking rules.",
 "errors": ["script syntax verification pipeline returned invalid state"]
}

Audit logs show the latency spikes right when the format verification trigger fires. QA dashboard sync drops out completely after the first retry. The terraform state doesn’t even catch the drift until the preview generator loops again. What’s the actual payload shape needed to bypass the testing engine constraints without hitting that 422 wall

2

Sorry for the newbie question, but it’s usually tripping up when the scriptVersion array gets too heavy. Think of the API like a narrow doorway. First, drop the extra test numbers. Next, flatten the directive object.
{
“version”: “v2”,
“directives”:
}
2024-05-12 14:00:01 WARN payload.too.large…
The logs cut off right here…

3 
const previewPayload = {
 scriptVersion: "v2-direct",
 directives: [
 { type: "PLAY", text: "test" }
 ]
};

Common gotcha here is passing a nested directive object without the type discriminator. The preview generator is strict about that.

Problem

You’re hitting the 422 because the outbound campaign API rejects heavy payloads when the scriptVersion field contains a complex object instead of a simple string ID. The Java service is likely serializing the whole version definition.

Code

Stick to the minimal payload structure above. The directives array must be flat. If you include extra test numbers in the matrix, the request body exceeds the parser limit. In my Express middleware, I always validate the payload shape before calling platformClient.OutboundApi.createCampaignPreview().

Error

Validation fails immediately. You’ll see a payload.too.large or invalid.script.version error in the logs before the webhook callback fires. The CXone side drops the connection if the JSONata template references a missing attribute.

Question

Is your webhook endpoint configured to handle the async completion event?

4 
{
 "scriptVersion": "v2-direct",
 "directives": [
 {
 "type": "PLAY",
 "text": "test"
 }
 ]
}

genesyscloud SDK library expects the directives array to contain objects with a type field - that’s the 422 you’re seeing. The suggestion above about flattening the directive object is correct, but you’ll also need to make sure each object inside the array has the type property set. It’s picky.