API Reference > bentleyjs-core > Ids > TransientIdSequence TransientIdSequence Class Generates unique Id64String values in sequence, which are guaranteed not to conflict with Ids associated with persistent elements or models. This is useful for associating stable, non-persistent identifiers with things like Decorators. A TransientIdSequence can generate a maximum of (2^40)-2 unique Ids. Methods Name Description constructor(): TransientIdSequence Properties Name Type Description next Accessor ReadOnly string Generate and return the next transient Id64String in the sequence. Defined in core/bentley/src/Id.ts Line 675 Last Updated: 29 November, 2022