The testRTC-client repository is a customizable tool for integrating WebRTC video and audio into applications, allowing developers to measure performance indicators in a video API. The repository comes bundled with an app that can be deployed to Netlify, two fundamental test scripts, and instructions on how to run tests against the deployment. To use the tool, developers need to set up free accounts with GitHub, Daily, Netlify, and testRTC, obtain a Daily API key, deploy the application to Netlify, and import the test scripts into their testRTC account. Once deployed, users can run performance tests, customize the tests, or even write their own, and view detailed results that include scores, CPU and memory usage, jitter, packet loss, and more.