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API Documentation Generator

A skill that scans source code for endpoints and produces Markdown or OpenAPI 3.0 API documentation.

Dev & CodingIntermediate★ 1,136⑂ 398AI score 6/10Last updated: Jul 23, 2026

What it does

  • Scans route definitions, controllers and handler functions (Express, FastAPI and similar) to locate API endpoints.
  • Extracts HTTP method, path, parameters (path/query/body), request/response schemas and auth requirements.
  • Renders per-endpoint docs plus an index page from templates, and can emit an OpenAPI 3.0 spec on request.
  • Ships helper commands to auto-detect routes and validate the generated OpenAPI spec.

Who it's for

  • Backend teams whose APIs have missing or stale documentation
  • Developers who must hand an API reference to frontend teams or external partners
  • Anyone needing a first-draft OpenAPI spec to power Swagger UI

Example uses

  1. "Document every route in this Express project" → per-endpoint Markdown files plus an index
  2. "Generate an OpenAPI 3.0 spec from this FastAPI code" → openapi.yaml draft, then run the validation script
  3. "Add only the new payments API to the existing docs" → new section formatted with the same standard template

· · · Install guide · · ·

Try it now, no install

Paste this into Claude to use the skill without installing anything.

Read the instructions in this file and follow them to help me:
https://raw.githubusercontent.com/huangjia2019/claude-code-engineering/HEAD/04-Skills/projects/02-progressive-skill/SKILL.md

What I want: (describe your task here)

If Claude can't open the link, open it yourself and paste the contents instead.

↓ If it works for you, download the ZIP below and install it. Then it runs on its own — no pasting each time.

Install in the Claude app (no terminal)
  1. Download the ZIP with the button below.
  2. In Claude, open Settings → Capabilities and turn on 'Code execution and file creation'. (one time)
  3. Go to Customize → Skills → + → 'Upload a skill' and upload the ZIP.
↓ Download ZIP
Install in Claude Code

Let Claude do it — paste this into Claude Code

Install the skill I found on Claude Skill Mart.
Copy the 04-Skills/projects/02-progressive-skill folder from the GitHub repo huangjia2019/claude-code-engineering into my ~/.claude/skills/huangjia2019-api-documenting/.
When it's done, tell me in one line what this skill can do.

Install with a command instead

git clone https://github.com/huangjia2019/claude-code-engineering.git && mkdir -p ~/.claude/skills/api-documenting && cp -r claude-code-engineering/04-Skills/projects/02-progressive-skill/* ~/.claude/skills/api-documenting/

⚠ This is a third-party skill. Check the source repository before installing.

  1. Open a terminal and clone the repo: git clone https://github.com/huangjia2019/claude-code-engineering.git
  2. Create the skill folder: mkdir -p ~/.claude/skills/api-documenting
  3. Copy the skill files: cp -r claude-code-engineering/04-Skills/projects/02-progressive-skill/* ~/.claude/skills/api-documenting/
  4. Run ls ~/.claude/skills/api-documenting and confirm SKILL.md plus PATTERNS.md, STANDARDS.md, templates/ and scripts/ are present; if any are missing you must create them or ignore those references.
  5. Python 3 is required for scripts/detect_routes.py; make shell helpers executable with chmod +x ~/.claude/skills/api-documenting/scripts/*.sh
  6. Restart Claude Code and ask something like "document the APIs in this project" to trigger the skill.
View source on GitHub ↗