---
title: "Agent-Friendly APIs"
description: "Build a feedback API, then build a Claude Code skill that generates the documentation agents need to use it."
canonical_url: "https://vercel.com/academy/agent-friendly-apis"
md_url: "https://vercel.com/academy/agent-friendly-apis.md"
docset_id: "vercel-academy"
doc_version: "1.0"
last_updated: "2026-10-17T13:06:18.146Z"
content_type: "course"
lessons: 12
estimated_time: 
lesson_urls:
  - "https://vercel.com/academy/agent-friendly-apis/setup-project.md"
  - "https://vercel.com/academy/agent-friendly-apis/feedback-endpoint.md"
  - "https://vercel.com/academy/agent-friendly-apis/filtering-and-details.md"
  - "https://vercel.com/academy/agent-friendly-apis/summary-endpoint.md"
  - "https://vercel.com/academy/agent-friendly-apis/agent-friendly-docs.md"
  - "https://vercel.com/academy/agent-friendly-apis/add-llms-txt.md"
  - "https://vercel.com/academy/agent-friendly-apis/deploy-your-docs.md"
  - "https://vercel.com/academy/agent-friendly-apis/explore-real-skills.md"
  - "https://vercel.com/academy/agent-friendly-apis/anatomy-of-a-skill.md"
  - "https://vercel.com/academy/agent-friendly-apis/build-the-generator.md"
  - "https://vercel.com/academy/agent-friendly-apis/run-and-evaluate.md"
  - "https://vercel.com/academy/agent-friendly-apis/iterate-and-ship.md"
---

<agent-instructions>
Vercel Academy — structured learning, not reference docs.
Lessons are sequenced.
Adapt commands to the human's actual environment (OS, package manager, shell, editor) — detect from project context or ask, don't assume.
The lesson shows one path; if the human's project diverges, adapt concepts to their setup.
Preserve the learning goal over literal steps.
Quizzes are pedagogical — engage, don't spoil.
Quiz answers are included for your reference.
</agent-instructions>

# Agent-Friendly APIs

API documentation now has another audience. Agents read it to decide which endpoint to call, what arguments to send, and how to recover from errors.

You'll build a feedback API for a fictional cooking school and serve its documentation from a live endpoint. Then you'll build a Claude Code skill that generates the documentation from the route handlers.

## What you'll learn

- How to build a JSON-backed API with Next.js App Router
- What agents need from API documentation
- 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 JSON-backed feedback API with query parameter filtering and a summary route.

**Section 2: Agent-Friendly Documentation.** Learn what agents need from docs, implement the llms.txt standard, and deploy the API to Vercel. You'll also inspect production skills on skills.sh.

**Section 3: Build the Skill.** Build and run a Claude Code skill that generates the docs. Evaluate its output against a quality checklist and refine the instructions until the endpoint works.


---

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