api-tester_skill

Overview

This skill is an automated API testing assistant for REST and GraphQL endpoints implemented using a Claude agent SDK in Rust. It helps design, execute, and analyze API tests that cover functional, security, performance, and edge-case scenarios. The goal is repeatable, maintainable test suites that surface regressions and API contract issues early.

How this skill works

The skill generates structured test cases and templates, builds and sends HTTP requests (GET, POST, PUT, DELETE, PATCH) and GraphQL queries, and handles authentication flows like bearer tokens, API keys, and OAuth. It validates responses by checking status codes, schemas, headers, and timings, and produces actionable assertions and reports. You can mock dependencies, parameterize test data, and run tests under load or concurrency to find performance bottlenecks.

When to use it

• When validating API behavior against specifications or OpenAPI/GraphQL schemas
• When creating regression suites for CI pipelines
• When testing authentication, authorization, and input validation
• When measuring response times and testing under load
• When exploring edge cases like null/empty inputs, invalid types, and concurrency

Best practices

• Use descriptive, focused test names and keep tests independent
• Define clear assertions for status codes, schema shapes, and error messages
• Parameterize test data and include cleanup steps to keep environments consistent
• Mock external services to isolate the API under test when necessary
• Include both positive and negative scenarios and document tricky edge cases

Example use cases

• Generate a full test suite for a new REST endpoint including positive, negative, and boundary tests
• Verify GraphQL schema changes by comparing response shapes and required fields
• Validate OAuth token flows and confirm proper authorization enforcement
• Run performance scenarios to measure response times and spot bottlenecks
• Automate regression checks in CI to detect breaking changes early