Predictive Outbound Campaign 429s during JMeter load test on US1

Does anyone understand why the predictive outbound campaign is throwing rate limit errors during a simple load test? I am trying to validate the API throughput for starting and stopping campaigns using JMeter on Genesys Cloud US1.

When I ramp up to just 10 concurrent threads hitting /api/v2/outbound/campaigns/{campaignId}/start, the responses turn red with 429 Too Many Requests. The headers show Retry-After: 1, but the error persists even with a 1s pause between requests.

My JMeter setup uses basic HTTP Request samplers with OAuth2.0 token authentication. The script works fine for single-thread execution, but fails immediately under concurrency. I suspect the admin_config permissions are correct since manual testing succeeds, but the load pattern seems to trigger a specific throttling mechanism I am not aware of.

Environment details:

  • Genesys Cloud US1
  • JMeter 5.6
  • Campaign Type: Predictive
  • Error: 429 Too Many Requests

Is there a specific limit on campaign state change APIs that applies during load testing? Or is this a standard rate limit for admin_config actions that I need to design around?