In reading order.
Unit tests mock what you assume, end-to-end tests tell you too late - consumer-driven contract testing closes the gap, and a small open-source .NET library called Pactify is the clearest way I know to learn how it works. Part 1 of a series.
A walk through Pactify's PactMaker fluent API - the two-interface builder trick that hides Build() from you, why the consumer test always passes, and the uninitialized-object surprise inside WithBody<T>().
An annotated tour of the JSON document Pactify produces - the serializer settings that shape it, the snake_case field inherited from Pact v1, and the unusual decision to ship the consumer's matching options inside the contract itself.
How a pact travels from the consumer's pipeline to the provider's - Pactify's file and HTTP publishers, Pact Broker URL anatomy, and the unchecked response status that makes a failed publish silently pass your build.
The provider side of Pactify - how CreateFor<Startup> hosts your whole API in memory with TestServer, why interactions verify concurrently, the SmartFormat trick behind endpoint templating, and the discovery that Given(...) never runs.
A line-by-line read of Pactify's matching engine - top-level-only body comparison, header names that ignore your casing option, nested objects that can never match, and two format-string bugs that crash the error path.
Pactify.AspNetCore in one sitting: an attribute, an assembly scan, and a /pacts/{provider} endpoint that serves your contract classes as live JSON - plus what a runtime contracts endpoint is really for.
The series retrospective - what a thirty-file library taught me that a full-featured one couldn't, Pactify's honest limit list versus PactNet, the broker maturity ladder, and the org-shaped question hiding under the tooling.
