Microsoft has released an experimental, browser-based Azure Cosmos DB Playground for learning SQL queries. Built on the vNext emulator and the open-source codapi project, it requires zero setup or cloud costs. Developers can instantly test queries against pre-loaded data or upload their own JSON files, making it a frictionless tool for experimentation.

Developers can generate shareable links, restore previous sessions, and embed runnable examples into documentation. The containerized setup uses an ephemeral query environment for each execution, ensuring isolation. While not a production tool, it addresses a common need for quick, cost-free database testing without provisioning actual cloud resources.

Running on a Dockerized architecture with nginx and Python, the playground spawns temporary containers for each run. The Cosmos DB vNext Emulator mimics the live service locally, while codapi manages sandboxing. After execution, containers are cleaned up, though the project notes performance limits for larger datasets. Users can deploy their own instances via GitHub instructions.