New endpoint added: POST /v1/newsletters/{newsletter_id}/test_group/{test_group_id}/language

What changed

New endpoint added: POST /v1/newsletters/{newsletter_id}/test_group/{test_group_id}/language Affected surface: POST /v1/newsletters/{newsletter_id}/test_group/{test_group_id}/language. Root cause: endpoint `POST /v1/newsletters/{newsletter_id}/test_group/{test_group_id}/language`. Detected at Tue, 21 Apr 2026 04:52:57 UTC UTC.

Diff

{
  "path": "POST /v1/newsletters/{newsletter_id}/test_group/{test_group_id}/language"
}

Likely impact

This is an additive change. Existing integrations are unaffected; this is mostly useful if you want to take advantage of the new surface.

Recommended action

No action required. Adopt the new endpoint when it solves a problem you have.