# Firebase: Firebase Hosting custom domains API returning 501 errors

> Firebase status incident “Firebase Hosting custom domains API returning 501 errors” on 2026-07-30: impact minor (vendor’s label), 13 h, 3 update(s). Archived by Rewindex.

Canonical: https://rewindex.com/company/firebase/incidents/e1vzivqdlmv9kfgeejjr
Last updated: 2026-07-31T10:20:00Z

- Impact (vendor’s label): minor
- Status: resolved
- Started: 2026-07-30 21:00 UTC · Resolved: 2026-07-31 10:20 UTC · Duration: 13 h
- Updates: 3 · Affected components: Hosting
- [Vendor status page: https://status.firebase.google.com/incidents/e1VziVqDLmv9KFGEejjR](https://status.firebase.google.com/incidents/e1VziVqDLmv9KFGEejjR)
- [Company: Firebase](https://rewindex.com/company/firebase.md)

## Timeline of updates

- **service disruption** 2026-07-31 03:38 UTC: The engineering team is investigating elevated 501 "unimplemented" errors seen in Hosting's API when managing custom domains. It does not appear at this time that the data plane is effected.
- **service disruption** 2026-07-31 04:38 UTC: We believe to have found the root cause and are working to restore this portion of our API. We are more confident now that the data plane is unaffected and that this was limited in scope to the management of Hosting custom domains.
- **resolved** 2026-07-31 05:14 UTC: The fix is being rolled out. The ETA for complete resolution is July 31 at ~11:00 UTC, though some users may have restored functionality before then.

## Cite this

Status incident (vendor impact label: minor) posted by Firebase, started 2026-07-30 21:00 UTC, resolved after 13 h, 3 update(s).

- Canonical URL: https://rewindex.com/company/firebase/incidents/e1vzivqdlmv9kfgeejjr
- Citation: Firebase, “Firebase Hosting custom domains API returning 501 errors” (2026-07-30 21:00 UTC). Archived by Rewindex: https://rewindex.com/company/firebase/incidents/e1vzivqdlmv9kfgeejjr (CC BY 4.0).
- Markdown link: `[Firebase: Firebase Hosting custom domains API returning 501 errors (2026-07-30)](https://rewindex.com/company/firebase/incidents/e1vzivqdlmv9kfgeejjr)`


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Canonical: https://rewindex.com/company/firebase/incidents/e1vzivqdlmv9kfgeejjr · Markdown: https://rewindex.com/company/firebase/incidents/e1vzivqdlmv9kfgeejjr.md · JSON: https://rewindex.com/api/v1/companies/firebase/incidents/e1vzivqdlmv9kfgeejjr · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-11-05T17:20:40.670Z