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FrontMCP includes a built-in OAuth 2.1 authorization server for self-contained authentication scenarios.
The built-in login page accepts any email format without validation. Replace with a real identity provider for production use.

Basic Configuration

Configuration Options


OAuth Endpoints

Local mode exposes standard OAuth 2.1 endpoints:

Authorization Request

Token Exchange


Key Management

Auto-Generated Keys

By default, FrontMCP generates RS256 keys at startup:
Auto-generated keys are lost on restart. Existing tokens become invalid.

Persistent Keys

Provide keys for stable token validation:

ES256 Keys

Use ES256 for smaller tokens:

Dynamic Client Registration

DCR allows clients to register programmatically. DCR is enabled by default in development.

Registration Request

Registration Response

DCR is intended for development only. In production, pre-register clients. DCR only allows localhost redirect URIs by default.

Per-App Configuration

Configure local auth per app with splitByApp: true:

Token Storage

In-Memory (Development)

Redis (Production)


Enable and customize the consent UI:

Complete Example


Troubleshooting

Auto-generated keys are lost on restart. Either:
  • Provide persistent keys via local.signKey
  • Use Redis for token storage
  • Accept that users must re-authenticate
Ensure you’re using S256 challenge method and the code_verifier matches the original code_challenge.
When running multiple server instances, use Redis for token storage to share session state.

Next Steps

Remote OAuth

Connect to external identity providers

Progressive Authorization

Implement incremental app authorization

Production Checklist

Security requirements for deployment

Tokens & Sessions

Configure token lifetimes