# GoogleMobileAds Framework Reference

# GADSignal


    @interface GADSignal : NSObject

A signal that can be used as input in a server-to-server ad request.
- `


  ### [signalString](https://developers.google.com/ad-manager/mobile-ads-sdk/ios/api/reference/Classes/GADSignal#/c:objc(cs)GADSignal(py)signalString)


  ` Signal string used in a server-to-server ad request.

  #### Declaration

  Swift

      var signal: String { get }

  Objective-C

      @property (nonatomic, readonly, nonnull) NSString *signalString;

[## Initialization](https://developers.google.com/ad-manager/mobile-ads-sdk/ios/api/reference/Classes/GADSignal#/Initialization)

- `


  ### [-init](https://developers.google.com/ad-manager/mobile-ads-sdk/ios/api/reference/Classes/GADSignal#/c:objc(cs)GADSignal(im)init)


  ` Unavailable
  Unavailable. An instance of this class will be returned when generating a signal.

  #### Declaration

  Objective-C

      - (nonnull instancetype)init;