When working with APIs between teams or external partners, it is especially important that the format of requests and responses remains predictable. Contract testing allows you to verify that both parties - the client and the server - agree to the exchange structure and do not violate it during updates.
We implement contract tests that automatically check API compliance with documentation or consumer expectations - before going into production.
What is an API contract
A contract is an agreement that defines:- which fields contain the request and response
- what data formats are allowed
- which status codes are returned
- what mandatory parameters are required
Contract violation = potential customer or service failure.
How does it work
| Party | What is being tested |
|---|---|
| Provider (API) | API must meet client expectations for response structure |
| Customer (consumer) | The client expects a certain scheme - the test checks that it is met |
| Bidirectional | Two-way testing: both client and server agree to contract |
Tools used: Pact, Spring Cloud Contract, Dredd, Postman Contract Tests.
Benefits of contract testing
Identification of non-conformities prior to depletion- Protect against "silent" changes that break customers
- Safely update API versions
- Increase trust between development teams
- Logging contract change history
How we implement
Define OpenAPI/Pact contracts- CI integration with automatic test runs at each commit
- Visualization and history of contract changes
- Staging/production
- Publishing Contracts for External Integrators
Where especially important
Shared responsibility microservices- Platforms with external B2B integrations
- Working on APIs with Multiple Independent Commands
- Critical systems where error is unacceptable (finance, public services)
Contract testing is a reliable bridge between the server and the client. We will help you build a process in which no update disrupts integration and does not bring unexpected bugs.
Popular Topics
Main Topics
Contact Us
Fill out the form below and we’ll get back to you soon.