Agent-Friendly APIs
Build a feedback API, then build a Claude Code skill that generates the documentation agents actually need to use it well.
Every API you've ever built came with docs that you hoped someone would read. Today, someone finally is. Agents are consuming your API documentation, and they're a very different audience than the humans you wrote it for.
Let's build a feedback API for a fictional cooking school, learn what makes documentation agent-friendly and serve it from a live endpoint, then build a Claude Code skill that generates those docs automatically from your code.
What you'll learn
- How to build a JSON-backed API with Next.js App Router
- What makes documentation "agent-friendly" vs just "developer-friendly"
- How to serve API docs as a markdown endpoint
- How Claude Code skills work: SKILL.md, frontmatter, progressive disclosure
- How to build and test a skill that generates structured documentation
Prerequisites
- Basic TypeScript
- Familiarity with Next.js App Router (API routes)
- A Vercel account
- Claude Code installed
Course sections
Section 1: Build the API. Scaffold a Next.js project and build a feedback API with CRUD endpoints, query param filtering, and a summary route. All backed by a JSON file.
Section 2: Agent-Friendly Documentation. Learn what agents need from docs, implement the llms.txt standard for your API, deploy it to Vercel so it's live at a real URL, then explore production skills on skills.sh.
Section 3: Build the Skill. Build a Claude Code skill that generates agent-friendly docs for your API, run it, evaluate the output against a quality checklist, then iterate until the docs endpoint works.
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