# Insomnia collection
source: https://developer.mastercard.com/unified-installments/documentation/developer-tools/insomnia-collection/index.md

Use Insomnia to test Mastercard Installments 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 [Integration and Testing guide](https://developer.mastercard.com/unified-installments/tutorial/integration-and-testing/index.md).

## Overview {#overview}

The Insomnia guide covers how to set up Mastercard Installments 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.