# CheckpointId

`import { CheckpointId } from "destack:runtime";`

Checkpoint identifier in one world lineage.

```ds title="CheckpointId"
export newtype CheckpointId = uint64
```

[language/library/src/runtime/lineage.ds:14](https://github.com/destack-sh/destack/blob/main/language/library/src/runtime/lineage.ds#L14)