tokenrefresh

TokenRefresh refers to the process of obtaining a new access token after the current one expires, using a separate credential known as a refresh token. It is a common mechanism in OAuth 2.0 and OpenID Connect, designed to keep users authenticated without requiring them to re-enter credentials frequently. Access tokens are typically short-lived for security, while refresh tokens are longer-lived and capable of issuing new access tokens.

The basic flow involves the client securely storing a refresh token and, upon access token expiration, contacting the authorization server’s token endpoint with grant_type=refresh_token. The server validates the refresh token, checks the client identity and scope, and issues a new access token. Often a new refresh token is also returned, and the previous one may be invalidated (token rotation) to reduce the risk of token leakage. The client then resumes API calls using the fresh access token.

Security considerations are central to TokenRefresh. Refresh tokens are highly sensitive and should be protected in secure storage, transmitted only over TLS, and monitored for unusual usage. Providers may support revocation endpoints and token rotation to mitigate theft. Implementations often bind tokens to a specific device or client and employ PKCE in public clients to reduce risk. Shorter lifetimes, limited scopes, and careful logout procedures help minimize potential damage from token compromise.

Variants and lifecycle policies vary by provider, but the goal remains consistent: maintain user sessions securely by issuing new access tokens without repeated prompts while safeguarding the refresh token itself.