mcp-auth-adapter - bridge the gap between your IdP and the MCP World

[velias]

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So you've got your existing OAuth/OIDC IdP (Keycloak, Auth0, Okta, Azure AD, whatever) and now you want your MCP servers to use it for auth. You point Claude Code or Cursor at it, aaand... things break. Scope explosions on the consent screen, missing PKCE defaults, clients demanding Dynamic Client Registration your IdP doesn't serve the way MCP expects. Sound familiar?

MCP Auth Adapter provides very thin and stateless adapter, which sits in front of your IdP, and adapts it for the MCP world. Your MCP Servers announce it as their Authorization server, and that's it. All the authentication and token issuing is performed by your IdP still, not this adapter.

Relevant Links

• Blog post
• Source repository