# BranchId

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

Branch identifier in one world lineage.

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

[language/library/src/runtime/lineage.ds:8](https://github.com/destack-sh/destack/blob/main/language/library/src/runtime/lineage.ds#L8)