# Qe API Testing Patterns

Comprehensive API testing patterns including contract testing, REST/GraphQL testing...

- Repository: https://github.com/proffesor-for-testing/agentic-qe (521 stars)
- Category: Design
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add proffesor-for-testing/agentic-qe --skill qe-api-testing-patterns -g -a claude-code -y`
Codex: `npx skills add proffesor-for-testing/agentic-qe --skill qe-api-testing-patterns -g -a codex -y`
Cursor: `npx skills add proffesor-for-testing/agentic-qe --skill qe-api-testing-patterns -g -a cursor -y`
Gemini CLI: `npx skills add proffesor-for-testing/agentic-qe --skill qe-api-testing-patterns -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add proffesor-for-testing/agentic-qe`

## Description

Comprehensive API testing patterns including contract testing, REST/GraphQL testing, and integration testing. Use when testing APIs or designing API test strategies.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# API Testing Patterns

<default_to_action>
When testing APIs or designing API test strategy:
1. IDENTIFY testing level: contract, integration, or component
2. TEST the contract, not implementation (consumer perspective)
3. VALIDATE auth, input, errors, idempotency, concurrency
4. AUTOMATE in CI/CD with schema validation
5. MONITOR production APIs for contract drift

**Quick Pattern Selection:**
- Microservices → Consumer-driven contracts (Pact)
- REST APIs → CRUD + pagination + filtering tests
- GraphQL → Query validation + complexity limits
- External deps → Mock with component testing
- Performance → Load test critical endpoints

**Critical Success Factors:**
- APIs are contracts - test from consumer perspective
- Always test error scenarios, not just happy paths
- Version your API tests to prevent breaking changes
</default_to_action>

## Quick Reference Card

### When to Use
- Testing REST or GraphQL APIs
- Validating microservice contracts
- Designing API test strategies
- Preventing breaking API changes

### Testing Levels
| Level | Purpose | Dependencies | Speed |
|-------|---------|--------------|-------|
| Contract | Provider-consumer agreement | None | Fast |
| Component | API in isolation | Mocked | Fast |
| Integration | Real dependencies | Database, services | Slower |

### Critical Test Scenarios
| Scenario | Must Test | Example |
|----------|----------|---------|
| Auth | 401/403 handling | Expired token, wrong user |
| Input | 400 validation | Missing fields, wrong types |
| Errors | 500 graceful handling | DB down, timeout |
| Idempotency | Duplicate prevention | Same idempotency key |
| Concurrency | Race conditions | Parallel checkout |

### Tools
- **Contract**: Pact, Spring Cloud Contract
- **REST**: Supertest, REST-assured, Playwright
- **Load**: k6, Artillery, JMeter

The rest: https://github.com/proffesor-for-testing/agentic-qe/blob/HEAD/.kiro/skills/qe-api-testing-patterns/SKILL.md