Project site https://github.com/google/google-api-objectivec-client-for-rest
Discussion group http://groups.google.com/group/google-api-objectivec-client

Written by Google, this library is a flexible and efficient Objective-C framework for accessing JSON APIs.

This is the recommended library for accessing JSON-based Google APIs for iOS, macOS, tvOS, and watchOS applications.

To get started with Google APIs and the Objective-C client library, please read USING.md for detailed information. The example applications can also help answer some questions, but there isn't an example for every service as there are just too many services.

Generated interfaces for Google APIs are in the GeneratedServices folder.

In addition to the pre generated classes included with the library, you can generate your own source for other services that have a discovery document by using the ServiceGenerator.

If you have a problem or want a new feature to be included in the library, please join the discussion group. Be sure to include http logs for requests and responses when posting questions. Bugs may also be submitted on the issues list.

Externally-included projects: The library is built on top of code from the separate project GTM Session Fetcher. To work with some remote services, it also needs Authentication/Authorization.

Google Data APIs: The much older library for XML-based APIs is still available.

Other useful classes for Mac and iOS developers are available in the Google Toolbox for Mac.