POST /api/v2/conversations/calls 403 when injecting traceId via custom header

Trying to propagate our OpenTelemetry trace context into outbound calls initiated via POST /api/v2/conversations/calls. The API docs don’t explicitly forbid custom headers, so I added X-Trace-Id to the request metadata. Getting a 403 Forbidden immediately. Is the endpoint stripping unknown headers before validation? Here’s the payload:

{
 "to": { "phoneNumber": "+15550199" },
 "from": { "phoneNumber": "+15550100" },
 "metadata": { "traceId": "abc-123" }
}

The metadata field isn’t in the schema. How do we actually pass tracing data?

The endpoint rejects custom headers to prevent injection attacks. Use the X-Correlation-Id header instead. It’s designed for trace propagation.

POST /api/v2/conversations/calls
X-Correlation-Id: your-otel-trace-id

Check the correlationId field in the returned conversation object to verify it passed through.