---
title: checkpointDirectory
framework: realitykit
role: symbol
role_heading: Instance Property
path: realitykit/objectcapturesession/configuration-swift.struct/checkpointdirectory
---

# checkpointDirectory

An optional directory to store data about session progress which may be used to speed up on-device reconstruction by passing into the PhotogrammetrySession.Configuration. If you provide a value for checkpointDirectory, it also needs to point to an empty, writable directory. If the directory is not writable or already contains data, the session moves to the .failed(Error) state.

## Declaration

```swift
var checkpointDirectory: URL?
```