Claude Skills are folders with instructions, scripts, and resources that teach Claude specific tasks. Skills can include executable code and are loaded only when needed, allowing you to maintain hundreds without performance impact. Multiple skills can run together for complex tasks like document creation, code testing, and data analysis.

---
name: api-tester
description: Test REST APIs and validate responses
---

# API Tester

Test HTTP endpoints and validate response structures.

## When to Use This Skill

Use this skill when you need to test API endpoints and verify response data.

## Instructions

When testing an API:

1. Send a request to the specified endpoint
2. Check the response status code
3. Validate the response body structure
4. Report any errors or unexpected results

## Response Validation

- Verify required fields exist
- Check data types match expected values
- Confirm nested objects have correct structure

See the official repo and creation guide for more details.

• anthropics/docx - Create, edit, and analyze Word documents
• anthropics/doc-coauthoring - Collaborative document editing and co-authoring
• anthropics/pptx - Create, edit, and analyze PowerPoint presentations
• anthropics/xlsx - Create, edit, and analyze Excel spreadsheets
• anthropics/pdf - Extract text, create PDFs, and handle forms

• anthropics/algorithmic-art - Create generative art using p5.js with seeded randomness
• anthropics/canvas-design - Design visual art in PNG and PDF formats
• anthropics/frontend-design - Frontend design and UI/UX development tools
• anthropics/slack-gif-creator - Create animated GIFs optimized for Slack size constraints
• anthropics/theme-factory - Style artifacts with professional themes or generate custom themes

• anthropics/web-artifacts-builder - Build complex claude.ai HTML artifacts with React and Tailwind
• anthropics/mcp-builder - Create MCP servers to integrate external APIs and services
• anthropics/webapp-testing - Test local web applications using Playwright

• anthropics/brand-guidelines - Apply Anthropic's brand colors and typography to artifacts
• anthropics/internal-comms - Write status reports, newsletters, and FAQs

• anthropics/skill-creator - Guide for creating skills that extend Claude's capabilities
• anthropics/template - Basic template for creating new skills

• notiondevs/Notion Skills for Claude - Skills for working with Notion
• PleasePrompto/notebooklm-skill - Interact with NotebookLM for document-based conversations
• obra/superpowers-lab - Lab environment for Claude superpowers
• obra/brainstorming - Generate and explore ideas
• obra/writing-plans - Create strategic documentation
• obra/executing-plans - Implement and run strategic plans
• obra/dispatching-parallel-agents - Coordinate multiple simultaneous agents
• obra/sharing-skills - Distribute and communicate capabilities
• obra/using-superpowers - Leverage core platform capabilities
• ComposioHQ/content-research-writer - Enhance writing with research
• ComposioHQ/meeting-insights-analyzer - Analyze meeting communication patterns
• ComposioHQ/competitive-ads-extractor - Analyze competitor advertising
• ComposioHQ/image-enhancer - Improve image quality
• wrsmith108/linear-claude-skill - Manage Linear issues, projects, and teams with MCP tools, SDK scripts, and GraphQL fallbacks

• zxkane/aws-skills - AWS development with infrastructure automation and cloud architecture patterns
• conorluddy/ios-simulator-skill - Control iOS Simulator
• sanjay3290/postgres - Execute safe read-only SQL queries against PostgreSQL databases with multi-connection support
• jthack/ffuf-claude-skill - Web fuzzing with ffuf
• lackeyjb/playwright-skill - Browser automation with Playwright
• scarletkc/vexor - Vector-powered CLI for semantic file search with a Claude/Codex skill
• obra/test-driven-development - Write tests before implementing code
• ComposioHQ/changelog-generator - Transform git commits into release notes
• obra/subagent-driven-development - Development using multiple sub-agents
• obra/systematic-debugging - Methodical problem-solving in code
• obra/root-cause-tracing - Investigate and identify fundamental problems
• obra/testing-skills-with-subagents - Collaborative testing approaches
• obra/testing-anti-patterns - Identify ineffective testing practices
• obra/finishing-a-development-branch - Complete Git code branches
• obra/requesting-code-review - Initiate code review processes
• obra/receiving-code-review - Process and incorporate code feedback
• obra/using-git-worktrees - Manage multiple Git working trees
• obra/verification-before-completion - Validate work before finalizing
• obra/condition-based-waiting - Manage conditional pauses or delays
• obra/commands - Create and manage command structures
• obra/writing-skills - Develop and document capabilities
• fvadicamo/dev-agent-skills - Git and GitHub workflow skills: git-commit (Conventional Commits), github-pr-creation, github-pr-merge, github-pr-review, plus creating-skills guide
• omkamal/pypict-skill - Pairwise test generation
• alinaqi/claude-bootstrap - Opinionated project initialization with security-first guardrails, spec-driven atomic todos, LLM testing patterns, and CLI tool orchestration (gh, vercel, supabase)

• muratcankoylan/context-fundamentals - Understand what context is, why it matters, and the anatomy of context in agent systems
• muratcankoylan/context-degradation - Recognize patterns of context failure: lost-in-middle, poisoning, distraction, and clash
• muratcankoylan/context-compression - Design and evaluate compression strategies for long-running sessions
• muratcankoylan/context-optimization - Apply compaction, masking, and caching strategies
• muratcankoylan/multi-agent-patterns - Master orchestrator, peer-to-peer, and hierarchical multi-agent architectures
• muratcankoylan/memory-systems - Design short-term, long-term, and graph-based memory architectures
• muratcankoylan/tool-design - Build tools that agents can use effectively, including architectural reduction patterns
• muratcankoylan/evaluation - Build evaluation frameworks for agent systems

• K-Dense-AI/claude-scientific-skills - Scientific research and analysis skills
• NotMyself/claude-win11-speckit-update-skill - Windows 11 system management
• sanjay3290/imagen - Generate images using Google Gemini's API for UI mockups, icons, and visual assets
• jeffersonwarrior/claudisms - SMS messaging integration
• SHADOWPR0/security-bluebook-builder - Build a concise, normative security Blue Book for sensitive apps (threat model, data classes, auth/session, logging/audit, retention, IR, security gates)
• obra/defense-in-depth - Multi-layered security approaches
• haunchen/n8n-skill - Enables AI assistants to understand and operate n8n workflows with information on 542 nodes and 20 templates.
• materials-simulation-skills - Agent skills for computational materials science: numerical stability, time-stepping, linear solvers, mesh generation, simulation validation, parameter optimization, and post-processing.
• wrsmith108/varlock-claude-skill - Secure environment variable management ensuring secrets are never exposed in Claude sessions, terminals, logs, or git commits

• Claude Skills Quickstart - Get started with Claude Skills
• Claude Skills Best Practices - Best practices for creating skills
• Skills Cookbook - Skills examples and guides
• What Are Skills - Introduction to Claude Skills
• Using Skills in Claude - How to use skills in Claude
• How to Create Custom Skills - Step-by-step guide to creating skills
• Create a Skill Through Conversation - Create skills by talking to Claude
• Claude for Financial Services Skills - Industry-specific skills for financial services
• Equipping Agents for the Real World - Technical deep dive into agent skills
• Teach Claude Your Way of Working - Customize Claude with your workflow

• Simon Willison: Claude Skills - Introduction to Claude Skills
• Nick Nisi: Claude Skills - Getting started with Claude Skills
• Young Leaders: Skills, Commands, Subagents, Plugins - Comparison of Claude features

• Claude Skills Just 10x'd My AI Agents by Greg Isenberg
• Claude Skills: Build Your Own AI Experts (Full Breakdown)
• Agent Skills: Specialized capabilities you can customize
• Claude Skills—From TOY to TOOL: Grab My Tutorial
• Claude Skills: Glimpse of Continual Learning?
• Stop Using MCP... Use NEW Claude Skills Instead
• Claude Skills explained: How to create reusable AI workflows

We welcome contributions! See CONTRIBUTING.md for guidelines.

• Submit new skills via PR
• Improve existing definitions
• Add new docs & videos & articles

• This is a curated list. We do not audit, endorse, or guarantee the security or correctness of listed projects.