iOS SKAdNetwork

SKAdNetwork (SKAN) is Apple's attribution framework for mobile app installs with a focus on privacy. It serves as an alternative way to measure ad performance when a user opts out of tracking and the IDFA is unavailable. Yandex DSP supports iOS SKAdNetwork across all stages of the OpenRTB 2.6 protocol.

With the release of iOS 14.5, Apple restricted access to the identifier for advertisers (IDFA). This changed traditional attribution where the DSP knew who clicked an ad and who installed the app. SKAN shifts the attribution process from mobile measurement platforms (MMPs) to iOS, which confirms the install without revealing user identity.

General workflow

How it works

OpenRTB handles these interactions via the bidrequest.imp.ext.skadn object:

1. Request (Bid Request). When the SSP receives a request from an iOS app, it adds information about SKAdNetwork support:

• The skadnetids field, which is a list of Apple-registered ad network IDs that can join the auction.
• SKAN version that's being used (2.2, 3.0, or 4.0), which controls how much data is sent.

{
  "imp": [{
    "id": "1",
    "ext": {
      "skadn": {
        "version": "4.0",
        "skadnetids": ["example123.skadnetwork", "another456.skadnetwork"],
        "fidelity": [1], 
        "wait": 1
      }
    }
  }]
}

2. Response (Bid Response). If the DSP decides to bid, it must return parameters required by Apple in the bidresponse.seatbid.bid.ext.skadn object:

• itunesitem: ID of the promoted app in the App Store.
• network: Ad network ID.
• campaign: Campaign number (capped in SKAN, such as up to 100, or using a tier system in version 4.0).
• Cryptographic signature so Apple can verify the data hasn't been tampered with.

{
  "id": "bid_123",
  "seatbid": [{
    "bid": [{
      "id": "abc-789",
      "impid": "1",
      "price": 5.0,
      "ext": {
        "skadn": {
          "version": "4.0",
          "network": "example123.skadnetwork",
          "itunesitem": "123456789",
          "sourceapp": "987654321",
          "sourceidentifier": "1234",
          "skadnetid": "example123.skadnetwork",
          "signature": "MEUCID3...base64_encoded_signature...",
          "nonce": "eb2562fd-1e6a-4993-8b77-507973c683b5",
          "timestamp": "1620395200"
        }
      }
    }]
  }]
}

3. Clicks and installs. If a user taps the ad, iOS registers the click. When the app is installed, iOS sends a postback (an install confirmation notification) to the ad network or DSP.

In addition to app installs, SKAdNetwork 4.0 lets you track in-app conversions for your goals: they're sent via extra postbacks. Tracking in-app conversions extends the postback delivery window to up to 35 days.

See Apple's SKAdNetwork documentation.