Client libraries
The Google Wallet API is built on HTTP and JSON, so any standard HTTP client can send requests to it and parse the responses.
However, the official Google APIs client libraries provide better language integration, improved security, and support for making calls that require user authorization. The client libraries are available in a number of programming languages; by using them you can avoid the need to manually set up HTTP requests and parse the responses.
Visit the Google APIs client libraries website for instructions on setting up in your preferred programming language. Once installed, you can then follow the API samples on GitHub.
Note that some of the API client libraries were previously available here as direct downloads. While these libraries largely contain the same interfaces as the official libraries, they may contain slightly different namespaces which may require updating in your code.
Android Framework Libraries
The following libraries are available for integrating Google Wallet using frameworks such as Flutter and Jetpack Compose: