Create an onramp iOS attestation challenge
Issues a one-time challenge for the iOS App Attest device-key registration step. Authenticate with a CDP API key. Call this from the partner backend and pass the challenge to the mobile app; do not embed the API key in the client. The project is identified by the API key JWT. The partner app then passes the challenge to DCAppAttestService.attestKey(keyId, clientDataHash: SHA256(challenge)) and submits the resulting attestation to Register Onramp iOS Attestation.
This is distinct from Create Onramp Mobile Challenge, which issues the per-transaction session challenge. Registration is a one-time, per-device-install operation; iOS-only (Android validates Play Integrity inline per request and has no registration step).
Authorizations
A JWT signed using your CDP API Key Secret, encoded in base64. Refer to the Generate Bearer Token section of our Authentication docs for information on how to generate your Bearer Token.
Response
Attestation challenge created successfully.
A cryptographic challenge for iOS App Attest attestation. Used only by iOS clients - Android uses a different flow with Play Integrity Standard API tokens.
Base64-encoded cryptographically secure random challenge (32 bytes). This challenge is one-time use and must be included in the iOS attestation request.
44^[A-Za-z0-9+/]+=*$"YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXoxMjM0NTY="
Timestamp when the challenge expires. Challenges are valid for 5 minutes.
"2026-02-03T10:35:00Z"