# Insomnia Collection source: https://developer.mastercard.com/india-online-dispute-resolution/documentation/developer-tools/insomnia/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, open the [Insomnia Collection guide](https://developer.mastercard.com/platform/documentation/developer-tools/insomnia-collection/). ## 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