# Testing
source: https://developer.mastercard.com/mdes-token-connect/documentation/testing/index.md

Use this page to plan and execute Sandbox (MTF) validation for the MDES Token Connect API. It covers the recommended workflow, positive and negative coverage, and the reference guides you need for endpoint-level execution.

## Choose a testing method {#choose-a-testing-method}

Choose a testing method that best matches how you want to validate requests:

* Use Insomnia to test Token Connect APIs. Get the Insomnia collection:
  [testing-use-cases-v2_insomnia.json](https://static.developer.mastercard.com/content/mdes-token-connect/insomnia/testing-use-cases-v2_insomnia.json) (38KB). Import its requests, configure your environment, and validate API calls. For setup instructions, see the [Insomnia Collection Guide](https://developer.mastercard.com/platform/documentation/developer-tools/insomnia-collection/).

* Custom API Client generated as per guideline in API Basics.

## Prepare and Implement {#prepare-and-implement}

* **Set up a Sandbox project:** Follow the [Quick Start Guide](https://developer.mastercard.com/mdes-token-connect/documentation/quick-start-guide/index.md) to create a project, obtain credentials, and make your first API call.
* **Prepare API requests:** See [API Basics](https://developer.mastercard.com/mdes-token-connect/documentation/api-basics/index.md) for OAuth 1.0a signing, payload encryption, and generating an MDES Token Connect API client.

### Endpoint Test Cases {#endpoint-test-cases}

Use these test cases to validate request/response behavior for each endpoint during integration and regression testing.
Run the scenarios in order from happy-path to error-path to confirm both functional correctness and resiliency handling.
This improves release confidence, reduces production defects, and helps teams troubleshoot API issues faster.

Use the following endpoint test-case pages:

1. [getEligibleTokenRequestors](https://developer.mastercard.com/mdes-token-connect/documentation/testing/get-eligible-token-requestors-test-case/index.md)
2. [getAsset](https://developer.mastercard.com/mdes-token-connect/documentation/testing/get-asset-test-case/index.md)
3. [PushMultipleAccounts](https://developer.mastercard.com/mdes-token-connect/documentation/testing/push-multiple-accounts-test-case/index.md)

## Next Steps {#next-steps}

* If a test request fails, see [Code and Formats](https://developer.mastercard.com/mdes-token-connect/documentation/code-and-formats/index.md#error-codes) for explanations of response reason codes and recommended resolutions.
* To check operation requirements and request/response formats, see the [API Reference](https://developer.mastercard.com/mdes-token-connect/documentation/api-reference/index.md).