API Token

Overview

An API token is a credential value presented with API requests to represent an authenticated client, user, session, or delegated set of permissions. API Token is a broad credential label whose issuer, subject, scope, format, expiry, and verification rules must be stated; it is not necessarily an API key or JWT. Sensitive token claims should not be exposed through unnecessary logging or error responses. The API Token recovery process should restore access without bypassing the original identity and authorization controls.

Clients should store tokens securely, transmit them only over TLS, minimize exposure, and refresh through protected flows. APIs must validate every required claim, enforce scopes and object authorization, limit lifetime, monitor use, and support revocation or key rotation. They are often issued after authentication so long-lived secrets do not accompany every application request. Tokens may be opaque references or self-contained signed objects and can carry scopes, audience, issuer, subject, and expiration. Monitoring for API Token should track failed use, unusual scope or audience, expiry, rotation status, and attempts involving revoked credentials.

An audit trail for API Token should link the contract and client version, principal, request identifier, sanitized payload evidence, response, callbacks, retries, overrides, provider references, and final state. Failing to validate signature, issuer, audience, time, scope, and token type can accept credentials intended for another service or context. Most tokens are bearer credentials, so theft permits use until expiration or revocation. The API Token boundary should identify the principal, credential or key, permitted audience, scope, lifetime, and revocation path.