Google Wallet API - Digitale Campuscard Tutorials https://developers.google.com/wallet/generic/getting-started/onboarding-guide#1.-sign-up-for-a-google-wallet-api-issuer-account https://developers.google.com/wallet/generic/getting-started/auth/rest Codebeispiele https://github.com/google-wallet/rest-samples