secondsky/api-contract-testing
Verifies API contracts between services using consumer-driven contracts, schema validation, and tools like Pact. Use when testing microservices communication, preventing breaking changes, or validating OpenAPI specifications.
This is a copy. The original lives at comeonoliver/api-contract-testing.
npx skills add https://github.com/secondsky/claude-skills --skill api-contract-testingVerify that APIs honor their contracts between consumers and providers without requiring full integration tests.
| Term | Definition |
|------|------------|
| Consumer | Service that calls an API |
| Provider | Service that exposes an API |
| Contract | Agreed request/response format |
| Pact | Consumer-driven contract testing tool |
| Schema | Structure definition (OpenAPI, JSON Schema) |
| Broker | Central repository for contracts |
import { PactV3, MatchersV3 } from '@pact-foundation/pact';
const provider = new PactV3({
consumer: 'OrderService',
provider: 'UserService'
});
describe('User API Contract', () => {
it('returns user by ID', async () => {
await provider
.given('user 123 exists')
.uponReceiving('a request for user 123')
.withRequest({ method: 'GET', path: '/users/123' })
.willRespondWith({
status: 200,
body: MatchersV3.like({
id: '123',
name: MatchersV3.string('John'),
email: MatchersV3.email('[email protected]')
})
})
.executeTest(async (mockServer) => {
const response = await fetch(`${mockServer.url}/users/123`);
expect(response.status).toBe(200);
});
});
it('returns 404 for non-existent user', async () => {
await provider
.given('user does not exist')
.uponReceiving('a request for non-existent user')
.withRequest({ method: 'GET', path: '/users/999' })
.willRespondWith({
status: 404,
body: MatchersV3.like({
error: { code: 'NOT_FOUND', message: MatchersV3.string() }
})
})
.executeTest(async (mockServer) => {
const response = await fetch(`${mockServer.url}/users/999`);
expect(response.status).toBe(404);
});
});
});
import { Verifier } from '@pact-foundation/pact';
new Verifier({
provider: 'UserService',
providerBaseUrl: 'http://localhost:3000',
pactBrokerUrl: process.env.PACT_BROKER_URL,
publishVerificationResult: true,
providerVersion: process.env.GIT_SHA,
stateHandlers: {
'user 123 exists': async () => {
await db.users.create({ id: '123', name: 'John' });
},
'user does not exist': async () => {
await db.users.deleteAll();
}
}
}).verifyProvider();
const OpenApiValidator = require('express-openapi-validator');
app.use(OpenApiValidator.middleware({
apiSpec: './openapi.yaml',
validateRequests: true,
validateResponses: true,
validateSecurity: true
}));
Do:
Don't:
Take secondsky/api-contract-testing from the repository into ~/.claude/skills for personal
use, or into .claude/skills inside a project.
The agent identifies a skill by the name field in its header. Two skills with the
same name cannot sit side by side — one of them will be ignored.