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Contract Testing

proffesor-for-testing/agentic-qe

  • 106 installs
  • 433 repo stars
  • Updated August 4, 2026
  • proffesor-for-testing/agentic-qe

contract-testing is a Claude Code skill for testing & qa.

About

contract-testing is a Claude Code skill for testing & qa. It helps solo builders move faster with AI-assisted development.

  • contract-testing
  • Testing & QA
  • AI-coding skill

Contract Testing by the numbers

  • 106 all-time installs (skills.sh)
  • +4 installs in the week ending Aug 4, 2026 (Skillselion tracking)
  • Ranked #978 of 2,153 Testing & QA skills by installs in the Skillselion catalog
  • Data as of Aug 5, 2026 (Skillselion catalog sync)
npx skills add https://github.com/proffesor-for-testing/agentic-qe --skill contract-testing

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Installs106
repo stars★ 433
Last updatedAugust 4, 2026
Repositoryproffesor-for-testing/agentic-qe ↗

How do I helps with testing & qa tasks.?

Helps with testing & qa tasks.

Who is it for?

Best when you're working on testing & qa and need structured help with contract testing.

Skip if: Teams with no testing & qa needs, or anyone wanting a generic chat assistant without this specific workflow.

When should I use this skill?

When you need to helps with testing & qa tasks., or when contract-testing is a claude code skill for testing & qa.

What you get

Structured output aligned to contract-testing: contract-testing, Testing & QA.

Files

SKILL.mdMarkdownGitHub ↗

Contract Testing

<default_to_action> When testing API contracts or microservices: 1. DEFINE consumer expectations (what consumers actually need) 2. VERIFY provider fulfills contracts (Pact verification) 3. DETECT breaking changes before deployment (CI/CD integration) 4. VERSION APIs semantically (breaking = major bump) 5. MAINTAIN backward compatibility for supported versions

Quick Contract Testing Steps:

  • Consumer: Define expected request/response pairs
  • Provider: Verify against all consumer contracts
  • CI/CD: Block deploys that break contracts
  • Versioning: Document supported versions and deprecation

Critical Success Factors:

  • Consumers own the contract (they define what they need)
  • Provider must pass all consumer contracts before deploy
  • Breaking changes require coordination, not surprise

</default_to_action>

Quick Reference Card

When to Use

  • Microservices communication
  • Third-party API integrations
  • Distributed team coordination
  • Preventing breaking changes

Consumer-Driven Contract Flow

Consumer → Defines Expectations → Contract
                    ↓
Provider → Verifies Contract → Pass/Fail
                    ↓
CI/CD → Blocks Breaking Changes

Breaking vs Non-Breaking Changes

Change TypeBreaking?Semver
Remove field✅ YesMajor
Rename field✅ YesMajor
Change type✅ YesMajor
Add optional field❌ NoMinor
Add new endpoint❌ NoMinor
Bug fix❌ NoPatch

Tools

ToolBest For
PactConsumer-driven contracts
OpenAPI/SwaggerAPI-first design
JSON SchemaSchema validation
GraphQLSchema-first contracts

---

Consumer Contract (Pact)

// Consumer defines what it needs
const { Pact } = require('@pact-foundation/pact');

describe('Order API Consumer', () => {
  const provider = new Pact({
    consumer: 'CheckoutUI',
    provider: 'OrderService'
  });

  beforeAll(() => provider.setup());
  afterAll(() => provider.finalize());

  it('creates an order', async () => {
    await provider.addInteraction({
      state: 'products exist',
      uponReceiving: 'a create order request',
      withRequest: {
        method: 'POST',
        path: '/orders',
        body: { productId: 'abc', quantity: 2 }
      },
      willRespondWith: {
        status: 201,
        body: {
          orderId: like('order-123'),  // Any string matching pattern
          total: like(19.99)           // Any number
        }
      }
    });

    const response = await orderClient.create({ productId: 'abc', quantity: 2 });
    expect(response.orderId).toBeDefined();
  });
});

---

Provider Verification

// Provider verifies it fulfills all consumer contracts
const { Verifier } = require('@pact-foundation/pact');

describe('Order Service Provider', () => {
  it('fulfills all consumer contracts', async () => {
    await new Verifier({
      provider: 'OrderService',
      providerBaseUrl: 'http://localhost:3000',
      pactUrls: ['./pacts/checkoutui-orderservice.json'],
      stateHandlers: {
        'products exist': async () => {
          await db.products.create({ id: 'abc', price: 9.99 });
        }
      }
    }).verifyProvider();
  });
});

---

Breaking Change Detection

// Agent detects breaking changes
await Task("Contract Validation", {
  currentContract: 'openapi-v2.yaml',
  previousContract: 'openapi-v1.yaml',
  detectBreaking: true,
  calculateSemver: true,
  generateMigrationGuide: true
}, "qe-api-contract-validator");

// Output:
// Breaking changes found: 2
// - Removed field: order.discount
// - Type change: order.total (number → string)
// Recommended version: 3.0.0 (major bump)

---

CI/CD Integration

name: Contract Tests
on: [push]

jobs:
  consumer-tests:
    steps:
      - run: npm run test:contract
      - name: Publish Pacts
        run: npx pact-broker publish ./pacts --broker-base-url $PACT_BROKER

  provider-verification:
    needs: consumer-tests
    steps:
      - name: Verify Provider
        run: npm run verify:contracts
      - name: Can I Deploy?
        run: npx pact-broker can-i-deploy --pacticipant OrderService --version $VERSION

---

Agent Coordination Hints

Memory Namespace

aqe/contract-testing/
├── contracts/*           - Current contracts
├── breaking-changes/*    - Detected breaking changes
├── versioning/*          - Version compatibility matrix
└── verification-results/* - Provider verification history

Fleet Coordination

const contractFleet = await FleetManager.coordinate({
  strategy: 'contract-testing',
  agents: [
    'qe-api-contract-validator',  // Validation, breaking detection
    'qe-test-generator',          // Generate contract tests
    'qe-security-scanner'         // API security
  ],
  topology: 'sequential'
});

---

Agent CLI & Advanced Patterns

For v3 agent-specific commands (aqe contract ...), GraphQL contracts, event contracts, and Pact Broker integration, see references/agent-commands.md.

Related Skills

  • api-testing-patterns - API testing strategies
  • shift-left-testing - Early contract validation
  • cicd-pipeline-qe-orchestrator - Pipeline integration

---

Remember

Consumers own the contract. They define what they need; providers must fulfill it. Breaking changes require major version bumps and coordination. CI/CD blocks deploys that break contracts. Use Pact for consumer-driven, OpenAPI for API-first.

With Agents: Agents validate contracts, detect breaking changes with semver recommendations, and generate migration guides. Use agents to maintain contract compliance at scale.

Gotchas

  • Pact broker URL must be configured before running — agent will generate tests that silently skip verification without it
  • Consumer tests pass locally but fail in CI when provider states aren't set up — always verify both sides
  • Adding a required field to a response is a BREAKING change even though provider tests pass — consumer didn't expect it
  • Agent may generate contracts from API docs instead of actual consumer usage — contracts must reflect real consumer needs
  • GraphQL contract testing requires schema stitching awareness — fragments may reference types from other services

Related skills

mattpocockTddFollow test-driven development with a strict red-green-refactor loop when creating reliable features or fixing bugs.544k196kobraTest Driven DevelopmentEnforce writing failing tests before any production implementation code.181k264kmattpocockQaRun conversational QA sessions that turn user-reported bugs into well-written, domain-aware GitHub issues without manual ticket writing.179k196kmattpocockMigrate To ShoehornAutomatically update TypeScript test files that rely on unsafe `as` type assertions by replacing them with type-safe partial objects from @total-typescript/shoehorn.164k196kanthropicsWebapp TestingVerify frontend behavior, debug UI issues, capture screenshots, and inspect logs of a running local web application using Playwright.123k165kmicrosoftPlaywright CliRun browser automation, generate element snapshots, inspect DOM attributes, and execute Playwright tests from the terminal.102k12.3k

FAQ

What does contract-testing do?

contract-testing is a Claude Code skill for testing & qa.

When should I use contract-testing?

When you need to helps with testing & qa tasks., or when contract-testing is a claude code skill for testing & qa.

What are the main capabilities?

contract-testing; Testing & QA; AI-coding skill.

Testing & QAtesting
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