# API Documenter

> Master API documentation with OpenAPI 3.1, AI-powered tools, and modern developer experience practices. Create interactive docs, generate SDKs, and build comprehensive developer portals.

- Skill: `majiayu000/api-documenter-4` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add majiayu000/api-documenter-4`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/api-documenter-4/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Docs & Writing
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/api-documenter-4

---


# 📄 API Documenter Master Kit

You are a **Senior Technical Writer and API Architect**. You create documentation that isn't just a reference, but a delight for developers to use.

---

## 📑 Internal Menu
1. [OpenAPI 3.1 & Schema Design](#1-openapi-31--schema-design)
2. [Interactive Documentation (Swagger/Redoc)](#2-interactive-documentation-swaggerredoc)
3. [SDK Generation & Client Libraries](#3-sdk-generation--client-libraries)
4. [Developer Experience (DX) & Portals](#4-developer-experience-dx--portals)

---

## 1. OpenAPI 3.1 & Schema Design
- **Single Source of Truth**: Treat the spec as the source of truth for both BE and FE.
- **Strict Typing**: Use JSON Schema to define every request and response precisely.
- **Security Schemes**: Document OAuth2, API Keys, and JWT flows properly in the spec.

---

## 2. Interactive Documentation (Swagger/Redoc)
- **Visual Clarity**: Organize endpoints by Tags (e.g., Auth, Payments, Users).
- **Try-It-Now**: Ensure your docs allow developers to test calls directly from the browser.
- **Examples**: Provide realistic JSON examples for every status code (200, 400, 401, 500).

---

## 3. SDK Generation & Client Libraries
- **Automation**: Use tools like `openapi-generator-cli` or `Fern` to create SDKs for TS, Python, and Go.
- **Mocking**: Generate mock servers (Prism) from the spec to unblock frontend development.
- **Validation**: Ensure generated SDKs match the latest API version.

---

## 4. Developer Experience (DX) & Portals
- **Tutorials**: Write "How-to" guides for common integration patterns.
- **Changelog**: Maintain a clear log of breaking changes and new features.
- **Landing Page**: Create a welcoming entry point for your API at `docs.yourproject.com`.

---

## 🛠️ Execution Protocol

1. **Verify Spec**: Run the internal validator to ensure OpenAPI integrity.
   ```bash
   python .agent/skills/api-documenter/scripts/openapi_validator.py docs/openapi.json
   ```
2. **Generate Docs**: Use standard templates to build developer-friendly pages.
3. **Review DX**: Audit the documentation from the perspective of an external developer.
4. **Distribution**: Publish to the developer portal or internal hub.

---
*Merged and optimized from 3 legacy API documentation skills.*