# `AshAuthentication.Oauth2Server.RefreshTokenResource`
[🔗](https://github.com/team-alembic/ash_authentication_oauth2_server/blob/v0.1.0/lib/ash_authentication/oauth2_server/verifier.ex#L5)

Marker extension for an OAuth 2.1 refresh-token resource.

Registers `AshAuthentication.Oauth2Server.RefreshTokenResource.Verifier`,
which checks at compile time that the resource conforms to the contract
the `Token` core depends on for race-safe rotation.

Add to your refresh-token resource:

    use Ash.Resource,
      extensions: [AshAuthentication.Oauth2Server.RefreshTokenResource],
      ...

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*Consult [api-reference.md](api-reference.md) for complete listing*