Gustavo Valverde
8a5046b6d5
Client ID Metadata Documents are the registration mechanism the MCP 2026-07-28 spec recommends, and dynamic client registration the one it deprecates, but the `application_type` redirect URI constraint reached only the deprecated path: the field was dropped by the metadata document allowlist before validation ran. `type` and `application_type` both describe the client profile, so a registration sending both must keep them consistent. Cite RFC 8252 for the native redirect URI rule actually enforced; OIDC Registration predates claimed https links and does not permit them.
Better Auth
Better Auth is a framework-agnostic authentication (and authorization) framework 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.