Demerzels-lab API Docs Generator
Your API has 50 endpoints and zero documentation. This tool reads your route files and generates proper docs, either markdown for humans or OpenAPI specs for tools.
One command. Zero config. Just works.
Quick Start
npx ai-api-docs ./src/routes/
What It Does
- Scans your route files and extracts endpoint information
- Generates clean markdown documentation
- Outputs OpenAPI 3.0 specs for Swagger and other tools
- Documents request/response shapes automatically
Usage Examples
# Generate markdown docs
npx ai-api-docs ./src/routes/
# → API_DOCS.md
# Generate OpenAPI spec
npx ai-api-docs ./src/routes/ --format openapi -o spec.yaml
# Custom output path
npx ai-api-docs ./src/api/ -o docs/api.md
# Scan multiple directories
npx ai-api-docs ./routes ./handlers
Best Practices
- Keep routes organized - cleaner code means better docs
- Use TypeScript - type info improves generated descriptions
- Review and edit - AI gets structure right, you add context
- Regenerate on changes - make it part of your CI
When to Use This
- You inherited a codebase with no API docs
- Shipping an MVP and docs are the last thing on your list
- Need to generate Swagger UI quickly
- Onboarding new developers to your API
Part of the LXGIC Dev Toolkit
This is one of 110+ free developer tools built by LXGIC Studios. No paywalls, no sign-ups, no API keys on free tiers. Just tools that work.
Find more:
- GitHub: https://github.com/LXGIC-Studios
- Twitter: https://x.com/lxgicstudios
- Substack: https://lxgicstudios.substack.com
- Website: https://lxgicstudios.com
Requirements
No install needed. Just run with npx. Node.js 18+ recommended. Needs OPENAI_API_KEY environment variable.
npx ai-api-docs --help
How It Works
Parses your route files to extract HTTP methods, paths, and handler code. Then uses GPT-4o-mini to infer request/response shapes, add descriptions, and format everything according to markdown or OpenAPI standards.
License
MIT. Free forever. Use it however you want.