Api Contract Testing

What it does

This skill enables AI agents to perform contract testing against API endpoints, ensuring that service implementations align with defined interface specifications before deployment. It validates request and response structures to prevent integration failures caused by breaking changes in upstream or downstream services.

When to use it

• Pre-deployment validation: Run tests immediately before pushing code changes to catch regressions early.
• Microservices integration: Verify compatibility when connecting new microservices to existing legacy systems.
• CI/CD pipelines: Integrate automated contract checks into build workflows to block non-compliant builds.
• Third-party API consumption: Ensure external vendor APIs meet expected data formats and behavior standards.

Key capabilities

• Validates request payloads against JSON Schema definitions
• Checks response structures for required fields and types
• Detects breaking changes in API contracts automatically
• Supports both synchronous and asynchronous endpoint testing

Example prompts

• "Run contract tests on the /users endpoint to verify it matches our latest OpenAPI specification."
• "Check if the payment service API has any breaking changes compared to the registered contract."
• "Validate that the new authentication response includes all required fields defined in the schema."

Tips & gotchas

Ensure your API contracts are properly versioned and stored in an accessible location before running tests. The skill requires valid JSON Schema definitions; incomplete or malformed schemas will cause validation failures even if the API works correctly.