CXone Personal Connection API outbound call returning 400

Hey everyone,

I’m trying to kick off an outbound call using the CXone Personal Connection API. We’ve got a hybrid setup, so I need to trigger this from an external script rather than through Studio directly.

I’m hitting the standard endpoint for outbound calls. Here’s the JSON payload I’m sending in the body:

{
 "from": "+15551234567",
 "to": "+15559876543",
 "scriptId": "abc-123-def",
 "callbackUrl": "https://our-server.com/webhook"
}

The request returns a 400 Bad Request immediately. The error message is pretty vague, just saying “Invalid request body.” I’ve double-checked the scriptId and it matches exactly what’s in the Studio environment. The phone numbers are in E.164 format, so that shouldn’t be the issue.

Is there a specific header or format I’m missing? I’m using curl for testing right now before moving this into our Python integration. Any ideas on what might be causing the validation error?