---
title: "open(using:)"
framework: proximityreader
role: symbol
role_heading: Instance Method
path: "proximityreader/customerengagementsession/open(using:)"
---

# open(using:)

Opens the engagement session.

## Declaration

```swift
final func open(using token: CustomerEngagement.Token? = nil) async throws
```

## Parameters

- `token`: `The Customer Engagement token used to authenticate your credentials. If you omit the token, you must have already created a valid doc://com.apple.ProximityReader/documentation/ProximityReader/PaymentCardReaderSession before calling this method.

## Mentioned in

Adding support for Tap to Share to your app

## See Also

### Configuring a session

- [CustomerEngagementSession.Configuration](proximityreader/customerengagementsession/configuration-swift.struct.md)
- [configuration](proximityreader/customerengagementsession/configuration-swift.property.md)
- [close()](proximityreader/customerengagementsession/close().md)
- [CustomerEngagementSession.Token](proximityreader/customerengagementsession/token-swift.struct.md)