Introduction

MysticMind.PostgresEmbed runs a real PostgreSQL server, extensions included, from .NET code and tests. It downloads the binaries for your platform, sets up a data folder, starts the server on a free port and stops it when you are done. There is no Docker to run and no Postgres to install.

Why

• Real Postgres. Tests run against the same server your app uses in production, not an in-memory stand-in, so SQL, types, extensions and query plans behave the same.
• Works where Docker does not. Laptops and CI runners without Docker, or without the right to install packages, only need the .NET SDK.
• Fast after the first run. The binaries are downloaded once and shared; a server starts in about a second afterwards, and a named instance that is already running is attached to in milliseconds.

Requirements

• .NET 8 or later (the package targets .NET 8, 9, 10 and 11).
• Windows x64, Linux x64 or arm64 (glibc or musl), macOS x64 or arm64. Windows on Arm runs the x64 build under emulation.
• Postgres refuses to run as root or Administrator, so run your tests as a regular user. This matters in Docker containers: add a user and run as that user.

The binaries

By default the library uses the minimal binaries published by zonkyio/embedded-postgres-binaries to Maven Central. They hold what a server needs and are much smaller than the official downloads. The full list of versions is on mvnrepository.com; click a version to see the platforms it is published for.

From the command line too

pgembed is a command-line tool built on this library: named instances, SQL with readable results, schema inspection and an MCP server for AI assistants. It shares the library's cache, so a server started with pgembed start app is the one your tests attach to.