Hi Apple Team and Community, We've encountered a sudden and widespread failure with the App Attest service starting today across multiple production apps and regions. The previously working implementation is now consistently returning the following error on iOS: The operation couldn’t be completed. (com.apple.devicecheck.error error 4.) (serverUnavailable) Despite the green status on Apple’s System Status page, this appears to be a backend issue—possibly infrastructure or DNS-related. Notably: The issue affects multiple apps. It is reproducible across different geographies. No code changes were made recently to the attestation logic. We previously reported a similar concern in this thread: App Attest Attestation Failing, but this new occurrence seems unrelated to any client-side cause. Update: An Apple engineer in this thread(https://developer.apple.com/forums/thread/782987) confirmed that the issue was due to a temporary DNS problem and has now been resolved. Can anyone else confirm seeing this today? Any insights from Apple would be appreciated to ensure continued stability. Thanks!

Hi, I'm looking at adding App Attest to an app, and I think I understand the mechanics of the attestation process, but I'm having trouble figuring out how development and testing are supposed to work. Two main questions: The "App Attest Environment" -- the documentation says that attestation requests made in the .development sandbox environment don't affect the app's risk metrics, but I'm not sure how to actually use this sandbox. My understanding is that one of the things App Attest does is to ensure that your app has been appropriately signed by the App Store, so it knows that it hasn't been tampered with. But the docs say that App Store builds (and Test Flight and Developer Enterprise Program) always use the .production environment. Does App Attest actually work for local developer-build apps if you have this entitlement set? Presumably only on hardware devices since it requires the Secure Enclave? Does our headend have to do something different when verifying the public key and subsequent attested requests for an app that's using the .development sandbox? The docs do mention that a headend server should potentially track two keys per device/user pair so that it can have a production and development key. How does the headend know if a key is from the sandbox environment? Thanks!

Hi, I’m currently implementing App Attest attestation validation on the development server. However, I’m receiving a 403 Forbidden response when I POST a CBOR-encoded payload to the following endpoint: curl -X POST -H "Content-Type: application/cbor" --data-binary @payload.cbor 'https://data-development.appattest.apple.com' Here’s how I’m generating the CBOR payload in Java: Map<String, Object> payload = new HashMap<>(); payload.put("attestation", attestationBytes); // byte[] from DCAppAttestService payload.put("clientDataHash", clientDataHash); // SHA-256 hash of the challenge (byte[]) payload.put("keyId", keyIdBytes); // Base64-decoded keyId (byte[]) payload.put("appId", TEAM_ID + "." + BUNDLE_ID); // e.g., "ABCDE12345.com.example.app" ObjectMapper cborMapper = new ObjectMapper(new CBORFactory()); byte[] cborBody = cborMapper.writeValueAsBytes(payload); I’m unsure whether the endpoint is rejecting the payload format or if the endpoint itself is incorrect for this stage. I’d appreciate clarification on the following: 1. Is https://data-development.appattest.apple.com the correct endpoint for key attestation in a development environment? 2. Should this endpoint accept CBOR-encoded payloads, or is it only for JSON-based assertion validation? 3. Is there a current official Apple documentation that lists: • the correct URLs for key attestation and assertion validation (production and development), • or any server-side example code (e.g., Java, Python) for handling attestation/validation on the backend? So far, I couldn’t find an official document that explicitly describes the expected HTTP endpoints for these operations. If there’s a newer guide or updated API reference, I’d appreciate a link. Thanks in advance for your help.

Hello, We are working on integrating app integrity verification into our service application, following Apple's App Attest and DeviceCheck guide. Our server issues a challenge to the client, which then sends the challenge, attestation, and keyId in CBOR format to Apple's App Attest server for verification. However, we are unable to reach both https://attest.apple.com and https://attest.development.apple.com due to network issues. These attempts have been made from both our internal corporate network and mobile hotspot environments. Despite adjusting DNS settings and other configurations, the issue persists. Are there alternative methods or solutions to address this problem? Any recommended network configurations or guidelines to successfully connect to Apple's App Attest servers would be greatly appreciated. Thank you.

Hello, We are working on integrating app integrity verification into our service application, following Apple's App Attest and DeviceCheck guide. Our server issues a challenge to the client, which then sends the challenge, attestation, and keyId in CBOR format to Apple's App Attest server for verification. However, we are unable to reach both https://attest.apple.com and https://attest.development.apple.com due to network issues. These attempts have been made from both our internal corporate network and mobile hotspot environments. Despite adjusting DNS settings and other configurations, the issue persists. Are there alternative methods or solutions to address this problem? Any recommended network configurations or guidelines to successfully connect to Apple's App Attest servers would be greatly appreciated. Thank you.

I'm a bit confused about if using App Attest is possible in enterprise builds. It shows up under identifiers in the apple dev portal and I can add it to my provisioning file and entitlements file. But if I go to keys I cannot create a key for it. This page implies it can be used for enterprise builds: After distributing your app through TestFlight, the App Store, or the Apple Developer Enterprise Program, your app ignores the entitlement you set and uses the production environment.

Hi, We're in the process of implementing Apple's App Integrity, but am getting stalled due to missing documents. Can anyone assist with this? We've been following https://developer.apple.com/documentation/devicecheck/validating-apps-that-connect-to-your-server to make the necessary updates, but have come up short with where the document references decoding the Attestation Object. Can we get more information here and how the decoding process work?