Gustavo Valverde
9ceb4c0246
Open the oauth-provider for plugin-based extension via the Plugin
Extension Protocol.
OAuthProviderExtension contract (5 extension points):
- grantTypes: register custom grant type handlers on the token endpoint
- grantTypeURIs: add to allowlist and grant_types_supported metadata
- metadata: contribute fields to discovery endpoints
- tokenClaims: inject claims into access tokens and ID tokens
- tokenEndpointAuthMethods: advertise additional auth methods
Token endpoint:
- Body schema: z.enum() → z.string().trim().min(1) + .passthrough()
- Switch default: dispatches to extension-contributed grant handlers
- GrantType union widened with (string & {}) for custom URIs
Exported utilities for grant handler authors:
- createUserTokens, checkResource, validateClientCredentials,
basicToClientCredentials, getClient, storeToken, getStoredToken
- Types: GrantTypeHandler, OAuthProviderExtension, TokenClaimInfo
Docs:
- New guide: extending-plugins.mdx (full authoring reference)
- Updated oauth-provider docs with extension points section
- Updated plugin index with Building Plugins section
Better Auth
The most comprehensive authentication framework for TypeScript
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About the Project
Better Auth is framework-agnostic authentication (and authorization) library for TypeScript. It provides a comprehensive set of features out of the box and includes a plugin ecosystem that simplifies adding advanced functionalities with minimal code in a short amount of time. Whether you need 2FA, multi-tenant support, or other complex features. It lets you focus on building your actual application instead of reinventing the wheel.
Why Better Auth
Authentication in the TypeScript ecosystem is a half-solved problem. Other open-source libraries often require a lot of additional code for anything beyond basic authentication. Rather than just pushing third-party services as the solution, I believe we can do better as a community—hence, Better Auth.
Contribution
Better Auth is a free and open source project licensed under the MIT License. You are free to do whatever you want with it.
You could help continuing its development by:
Security
If you discover a security vulnerability within Better Auth, please send an e-mail to security@better-auth.com.
All reports will be promptly addressed, and you'll be credited accordingly.