# Does OAuth verification / CASA apply to gmail.readonly via domain-wide delegation only?

**URL:** <https://discuss.google.dev/t/does-oauth-verification-casa-apply-to-gmail-readonly-via-domain-wide-delegation-only/412371>\
**Category:** Q&A\
**Tags:** gmail\
**Created:** [November 9, 2026, 5:28pm UTC](https://discuss.google.dev/t/does-oauth-verification-casa-apply-to-gmail-readonly-via-domain-wide-delegation-only/412371 "2026-11-09T17:28:56Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![aurican](https://d3byx8b92xw3lq.cloudfront.net/user_avatar/discuss.google.dev/aurican/32/286965_2.png) [@aurican](https://discuss.google.dev/u/aurican)\
**Post date:** [November 9, 2026, 5:28pm UTC](https://discuss.google.dev/t/does-oauth-verification-casa-apply-to-gmail-readonly-via-domain-wide-delegation-only/412371/1 "2026-11-09T17:28:56Z")

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We’re building a B2B SaaS. A service account reads Gmail with gmail.readonly only, through domain-wide delegation that each customer’s Google Workspace super admin authorises in their Admin console. There’s no OAuth consent screen or user sign-in flow, and no Marketplace listing. Does this need OAuth app verification and a CASA assessment? If so, how do we submit it without a consent flow?