As Cosmos DB implements the MongoDB wire protocol, you can easily use all your applications that currently use that document database with new instances of Azure Cosmos DB, without changing anything (besides the connection string, of course). While it cannot mimic MongoDB completely yet (the full list of supported operations can be found in the Further reading section), in most cases you will be able to use it seamlessly. As Cosmos DB has a strict requirement regarding security, you will have to use SSL when communicating with it:
mongodb://username:password@host:port/[database]?ssl=true
Here you can see a template for a connection string, where ssl=true is present—it is required when communicating with this Azure service. What is ...