Google has released updated documentation for the Google Postmaster v2 API, including clearer guidance and expanded code examples in the “Quickstart” and “How Do I” sections. This update strongly suggests that Google is actively transitioning away from the v1 API, with deprecation likely in the near future. Teams relying on Postmaster data via the v1 endpoint should begin reviewing and adjusting their integrations accordingly.

Google has finally updated the Google Postmaster v2 API documentation, adding clearer guidance and additional code examples to the "Quickstart" and "How Do I" sections.
It appears Google is actively phasing out the v1 API, suggesting deprecation in the near future.
Plan accordingly.