ProtoTest is a foundation for integration testing on .NET 8, 9 and 10. One host per suite, one context per test, one trace per run.

Watch ProtoTest in 70 seconds: one real test, from the failure on CI to the proven fix.

Try it

dotnet new install ProtoTest.Templates
dotnet new prototest -n Shop
cd Shop
dotnet test

The template suite is green on a fresh checkout. It hosts the app in process and needs no containers or browsers.

What a test looks like

[Application("Api")]
[ProtoTest]
[SignedInAs]
public async Task RestWritesAreVisibleThroughGraphQL()
{
    using var created = await Proto.Context.Rest()
        .Body(new CreateProjectRequest("atlas"))
        .PostAsync("/api/v1/projects");

    created.Should.HaveHttpStatus(HttpStatusCode.Created);

    using var projects = await Proto.Context.GraphQL()
        .Query("projects", new { first = 10 })
        .ExpectAsync(new
        {
            totalCount = 1,
            nodes = new[] { new { name = "atlas", status = ProjectStatuses.Active } }
        });

    projects.Should.HaveNoErrors();
}

Each test gets its own Proto.Context. It carries the clients, the state and the trace for that test. Setup shared by the suite stays in the host composition. The scenario under test stays visible.

What you get

• One lifecycle independent of the runner. Adapters exist for NUnit, xUnit.net v2, xUnit.net v3, TUnit and MSTest.
• Integrations that share that lifecycle: REST, GraphQL, gRPC, SQL, Entity Framework Core, Playwright, Selenium, RabbitMQ, ASP.NET Core, Testcontainers, background workers and more. The integrations map marks what is supported and what is preview.
• One evidence trace per run. Every run writes a .prototrace file with setup, teardown, operations and checks.

When it fails

The trace is the failure story. Drop the .prototrace file on the viewer and read the run: lifecycle, requests, checks, resources, attachments.

Open the interactive trace

With a coding agent

Your agent fixes and writes tests; ProtoTest judges the result from the trace. The MCP server and the prototest CLI tell the agent where a run left the last green one, prove a fix only when the test failed before, passes now and broke nothing else, and say what each test actually checks. On a pull request, the ProtoTest Evidence action posts what the change broke and fixed. Coding agents covers the setup.

Learn

• Documentation
• Learning demo suite and the Learn track
• Why ProtoTest exists
• Support and sustainability

ProtoTest 1.x stays additive. Preview packages can still change before 1.2; the integrations map says which ones.

License

ProtoTest is MIT. AI assistance is used in development and disclosed per change; see the AI usage notes.