JWTd

JWTd is an open-source daemon designed to provide centralized management of JSON Web Tokens (JWT) for authentication and authorization in distributed applications. It can issue, validate, revoke, and inspect tokens, serving as a trusted token service for microservices, API gateways, and other components that rely on token-based access control.

Core features include issuing tokens with configurable claims, signing tokens using symmetric or asymmetric keys, and verifying signatures and claims on incoming tokens. It supports JWKS endpoints for dynamic key distribution, token introspection, and revocation lists or short-lived tokens to mitigate abuse. Typical claim validation covers standard fields such as exp, iss, aud, and sub, with clock-skew tolerance and audit logging for compliance and debugging.

The architecture is designed to run as a background service that exposes interfaces over REST or gRPC. It uses pluggable backends for key storage, revocation data, and logs, enabling deployments that range from single servers to clustered, highly available environments. JWTd can be placed behind reverse proxies or API gateways and scales with additional instances to handle load.

In practice, JWTd is used to centralize authentication workflows in microservice ecosystems. It can integrate with external identity providers, enforce authorization policies, and act as a token broker between services. Typical deployment patterns involve issuing tokens after user authentication, validating incoming tokens at service boundaries, and refreshing or revoking tokens as needed.

Security considerations include protecting private keys, secure configuration management, routine key rotation, access controls, and comprehensive audit trails. Operators should implement rate limiting, monitoring, and proper disaster recovery to minimize risk. The project is community-driven, with ongoing development and documentation to support varied deployment scenarios.