The API client that speaks C# and tests your database.

NuGet-powered scripting, database assertions, and a smart mock gateway all Git-native and offline-first. Built for .NET teams, useful for anyone tired of 200 OK lying to them.

C# + NuGet Scripting

Import your favorite .NET libraries into pre/post scripts

Database Assertions 1.0

Verify SQL Server, Postgres, MySQL & SQLite actually wrote the row

Smart Mock Gateway 1.0

Hybrid proxy/mock routing for contract & integration tests

Perpetual Fallback License

Every Pro feature you've paid for keeps working, forever

Star on GitHub

Free core Pro $5/mo 12-month perpetual fallback license

ApiCourier light theme desktop app preview.

ApiCourier dark theme desktop app preview.

Why .NET teams pick ApiCourier

C# scripting, database assertions, and a smart mock gateway - the things Postman and Bruno don’t do.

How ApiCourier compares

Parity on the basics. Real asymmetry where it matters - C#, databases, and mocks.

1.0 = shipping in the v1.0 release. Available to insiders as builds roll out.

Get started in under 3 minutes

From an OpenAPI spec to a C# test suite in your own Git repo.

Pricing that respects developers

JetBrains-style licensing: After 12 consecutive paid months, keep a covered fallback version forever. No remote kill switches, no surprise bills.

Perpetual fallback after 12 months. After 12 consecutive paid months, you keep a perpetual license to the versions covered by your fallback cutoff date. Renewals give you newer versions and updates.

Frequently asked questions

Quick answers to common questions about ApiCourier