Cosmos DB Rest API reference

Please check the below document as per this link Cosmos DB REST API provides programmatic access to Azure Cosmos DB resources to create, query, and delete databases, document collections, and documents.

https://learn.microsoft.com/en-us/rest/api/cosmos-db/
https://learn.microsoft.com/en-us/rest/api/cosmos-db/http-status-codes-for-cosmosdb

I see you can also use the below API to retrieves the properties of an existing Azure Cosmos DB database account.
https://learn.microsoft.com/en-us/rest/api/cosmos-db-resource-provider/database-accounts/get?view=rest-cosmos-db-resource-provider-2023-11-15&tabs=HTTP