Pact

Pact is an open source framework for consumer-driven contract testing. It checks that the services and apps that call an API still match what the API provides, without running every service together.

In Pact, the consumer writes a test that records the requests it makes and the responses it expects. Those expectations become a contract that the provider must meet. Pact generates API stubs from the contract, so the consumer can be tested offline. The Pact Broker stores and shares contracts between teams, and the can-i-deploy check tells you when a component is safe to release. It works for REST APIs, message-driven systems and serverless code, and it fits into CI and CD pipelines.

• Test REST APIs, message systems and serverless code
• Work offline with API stubs built from contracts
• Share and promote contracts through the Pact Broker
• Use can-i-deploy to check if a release is safe
• Run contract checks in CI and CD pipelines

Microservice teams and backend developers who want to release services independently will find it valuable. QA engineers who want fewer large integration environments can also use Pact to reduce that need.

The framework is open source and free to use. PactFlow, the hosted option, is a premium service with added authentication and access control. Pact checks interactions, not every behaviour, so it complements rather than replaces other tests.