INVALID_VALUE on POST /api/v2/analytics/outbound/contactlists

Getting a 400 INVALID_VALUE when trying to create an outbound contact list via the JS SDK. The payload looks valid, but the API complains about the columns array. Here’s the snippet:

const body = {
 name: "Test List",
 sourceType: "manual",
 columns: [{ id: 1, name: "phone_number", type: "phone" }]
};
await platformApi.outboundApi.postOutboundContactList(body);

The error message is generic. Is there a strict schema requirement for the columns object that isn’t documented?