continuationToken

A continuationToken is an opaque value used by a service to retrieve the next segment of a dataset in paginated responses. It conveys the state necessary to continue a query from where the previous response left off, without requiring the client to re-send the original request parameters.

In typical use, an API response includes a data payload and a continuationToken. To fetch the next page, the client repeats the request and supplies the token, usually as a query parameter or header. The server decodes the token to resume data retrieval, often using cursor-based or keyset pagination rather than simple offset paging. Continuation tokens may encode position, filters, page size, timestamps, and permissions, and are often designed to be URL-safe.

Tokens are usually opaque to clients, meaning applications should treat them as a black box and not attempt to interpret their contents. They may be plain base64-encoded data, JSON blobs, or cryptographically signed tokens. Some systems generate tokens that expire or are invalidated when the underlying data changes, while others rely on stateless decoding.

Security and reliability considerations include preventing token leakage, avoiding exposure of internal identifiers, and handling token expiration or revocation. In some architectures, the service maintains a token store; in others, the state is embedded in the token itself.

Common patterns include cursor-based pagination with a next-token field, and, less commonly, offset-based approaches. Continuation tokens improve performance for large datasets and real-time results but require careful design to handle changes in data and ordering.