To start development quickly, there is an open source fhir-client JavaScript library that takes care of the OAuth2 handshake and provides a built-in library to call FHIR resources. The library is usable but has several known issues in previous versions. One particular issue is around the usage of the sessionStorage property. Cerner requires that you upgrade the library to version v0.1.10 or higher to correct a known patient safety issue. You also must download and include this additional code into your project to correct this issue.
Other additional FHIR clients are available:
Thanks,