---
title: "validate(_:publicKey:)"
framework: storekittest
role: symbol
role_heading: Instance Method
path: "storekittest/skadtestsession/validate(_:publickey:)"
---

# validate(_:publicKey:)

Validates an impression for a view-through ad.

## Declaration

```swift
func validate(_ impression: SKAdImpression, publicKey: String) throws
```

## Parameters

- `impression`: An doc://com.apple.documentation/documentation/StoreKit/SKAdImpression instance, representing your ad impression.
- `publicKey`: The public key of the elliptic curve cryptographic key pair you used to generate the signature for the ad impression.

## Discussion

Discussion The cryptographic key pair you use for testing may be a different key pair than you use in production. For testing, use keys from the same key pair to sign the ad impression for testing and call validate(_:publicKey:). For more information about signing ad impressions, see Signing and providing ads.

## See Also

### Validating impressions

- [validateImpression(parameters:publicKey:)](storekittest/skadtestsession/validateimpression(parameters:publickey:).md)
- [validateWebAdImpressionPayload(_:publicKey:)](storekittest/skadtestsession/validatewebadimpressionpayload(_:publickey:).md)