DocumentDB (open source)

DocumentDB is a MongoDB-compatible open source document database built on PostgreSQL. It consists of a BSON core extension, an API extension and a gateway that translates the MongoDB protocol to PostgreSQL, so applications written for MongoDB can store documents in a PostgreSQL-based system.

It is released under the MIT licence, a permissive open source licence, and it is free to use. It can be run self-managed, and Microsoft's documentation says that Azure DocumentDB (vCore) is powered by this open source engine. There is no separate commercial edition, and the project is hosted by the documentdb organisation on GitHub. The maker was not named.

The latest stable tag is v0.117-0, dated 9 September 2026. A release candidate, v1.0-RC1, followed on 28 September 2026, and the project is described as active with version 1.0 in release-candidate stage. Buyers should note that the stable tags are still numbered below 1.0, which suggests the project has not yet declared its first major release, so teams may prefer to wait for 1.0 or test it thoroughly before relying on it.

Because compatibility with MongoDB is the aim rather than an exact copy, teams should check that the drivers, operators and features they use are supported.