# Insomnia Collection
source: https://developer.mastercard.com/locations-merchants/documentation/developer-tools/insomnia-collection/index.md

Use Insomnia to test Mastercard APIs with a ready-made workflow for importing requests, configuring environments, and validating calls in Sandbox or Production.

For the full step-by-step guide, see the [Insomnia tutorial](https://developer.mastercard.com/platform/tutorial/use-insomnia-rest-client-for-mastercard-apis/).

## Overview {#overview}

The Insomnia guide covers how to set up Mastercard API requests in Insomnia, including plugin installation, workspace import options, environment configuration, and request execution.

## Prerequisites {#prerequisites}

* Access to a Mastercard Developers project with the credentials required by the API you are testing
* Insomnia installed on your machine
* The correct authentication and encryption details for the service you want to call

## What You Will Find {#what-you-will-find}

* Plugin installation options for Insomnia
* Import guidance for collections and workspace templates
* Environment setup for OAuth 1.0a, OAuth 2.0, and JWE-enabled flows
* Practical steps for sending and validating requests in Sandbox and Production

## Next Steps {#next-steps}

* Follow the [Testing Workflow](https://developer.mastercard.com/locations-merchants/documentation/integration-and-testing/index.md#testing-workflow) to validate every Location Services endpoint, including success and failure criteria.
* Use the [Sandbox Test Data](https://developer.mastercard.com/locations-merchants/documentation/integration-and-testing/index.md#sandbox-test-data) for ready-made request payloads.
* Prefer Postman? See the [Postman Collection](https://developer.mastercard.com/locations-merchants/documentation/developer-tools/postman-collection/index.md).