The Azure Cosmos DB Emulator provides a local environment that emulates the Azure Cosmos DB service for development purposes. Using the Azure Cosmos DB Emulator, you can develop and test your application locally, without creating an Azure subscription or incurring any costs. When you’re satisfied with how your application is working in the Azure Cosmos DB Emulator, you can switch to using an Azure Cosmos DB account in the cloud.
The Azure Cosmos DB Emulator for DevOps is easy to install :
You can Attach Azure CosmosDB Emulator in Visual Studio Code
When your development and testing in Azure CosmosDB Emulator is Done and Ready
for the Cloud, you can Move it to CosmosDB in Azure.
More information on Microsoft Azure CosmosDB Emulator on Docs.
Here you see What’s New in Azure Cosmos DB Video :