# TestRunnerApi The `TestRunnerApi` retrieves and runs tests programmatically from code inside the project, or inside other packages. `TestRunnerApi` is a [ScriptableObject](https://docs.unity3d.com/ScriptReference/ScriptableObject.html). You can initialize the API like this: ```c# var testRunnerApi = ScriptableObject.CreateInstance(); ``` > **Note**: You can subscribe and receive test results in one instance of the API, even if the run starts from another instance. The `TestRunnerApi` supports the following workflows: * [How to run tests programmatically](./extension-run-tests.md) * [How to get test results](./extension-get-test-results.md) * [How to retrieve the list of tests](./extension-retrieve-test-list.md) ## Public methods | Syntax | Description | | ------------------------------------------ | ------------------------------------------------------------ | | `void Execute(ExecutionSettings executionSettings)` | Starts a test run with a given set of [ExecutionSettings](./reference-execution-settings.md). | | `void RegisterCallbacks(ICallbacks testCallbacks, int priority = 0)` | Sets up a given instance of [ICallbacks](./reference-icallbacks.md) to be invoked on test runs. | | `void UnregisterCallbacks(ICallbacks testCallbacks)` | Unregisters an instance of ICallbacks to no longer receive callbacks from test runs. | | `void RetrieveTestList(TestMode testMode, Action callback)` | Retrieve the full test tree as [ITestAdaptor](./reference-itest-adaptor.md) for a given test mode. | | `void SaveResultToFile(ITestResultAdaptor results, string filePath)` | Save a given set of [ITestResultAdaptor](./reference-itest-result-adaptor.md) to a file at the provided file path. |