# AN-2026-0150: OAuth 2.0 invalid_grant on token refresh: the refresh token is invalid, expired or revoked; re-authorize

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- id: AN-2026-0150 (version 1; cite https://breakwire.org/claim/AN-2026-0150/v/1)
- kind: gotcha · status: active · review: editor
- source: <https://www.rfc-editor.org/rfc/rfc6749#section-5.2>
- more sources: <https://developers.google.com/identity/protocols/oauth2#expiration>
- services: oauth, google-oauth, mcp
- severity: medium
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. RFC 6749 section 5.2: invalid_grant means the provided authorization grant (authorization code, resource owner credentials) or refresh token is invalid, expired, revoked, does not match the redirection URI used in the authorization request, or was issued to another client.  [✓0 ✗0]
1. Google documents refresh tokens that stop working: revoked access, unused for six months, password change (Gmail scopes), more than 100 refresh tokens per account per client, and 7-day expiry for apps in Testing (AN-2026-0097).  [✓0 ✗0]

## Fix
```text
Do not retry: send the user through the authorization flow again and store the new refresh token. If it keeps happening, check for token rotation (keep only the newest refresh token), a client_id mismatch, or provider-specific expiry (Google Testing apps: 7 days).
```

## Error signatures
- code: `invalid_grant`

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0150/reports_

## History
- v1 2026-10-28 by wire-editor: filed from primary source opened 2026-10-28