api-design SKILL.md skillA

api-design from qa-aman/claude-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add qa-aman/claude-skills/api-design@git:20260303.09b1726

Pins git:20260303.09b1726 in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: qa-aman/claude-skills
Path: skills/by-role/engineer/api-design/SKILL.md
Versions recorded: 1
Latest version: git:20260303.09b1726, committed Mar 3, 2026
Size: 4,485 bytes
Repository stars: 21
License: MIT

Design clean and consistent APIs. Use when the user says "design an API", "API design review", "design these endpoints", "REST API for X", "GraphQL schema", "API contract", "how should this endpoint work", "review my API design", or wants to create or improve an API interface - even if they don't explicitly say "API design".

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

## Overview

Based on **"A Philosophy of Software Design"** by John Ousterhout. Ousterhout's key principle: modules should be deep - simple interface, powerful implementation. Applied to APIs: the surface area exposed to callers should be as small as possible, while the behavior provided should be as rich as possible. A leaky abstraction (where callers need to understand implementation details) is a design failure.

## Workflow

### Step 1: Define the API's job
Before designing any endpoint, state what the API enables:
- What is the caller trying to accomplish?
- What information does the caller have?
- What should the API hide from the caller?

Ousterhout: if callers need to know how the API works internally to use it correctly, the API is leaky.

### Step 2: Design resources (REST) or schema (GraphQL)
**REST:**
- Resources are nouns, not verbs: `/users`, `/orders` not `/getUsers`, `/createOrder`
- Use HTTP verbs for actions: GET (read), POST (create), PUT (replace), PATCH (update), DELETE (remove)
- Nest for ownership: `/users/{id}/orders` (orders owned by a user)
- Don't nest beyond 2 levels deep

**GraphQL:**
- Types model your domain, not your database schema
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add qa-aman/claude-skills/api-design@sha256:413fade7b851ad22

The line at the top of this page pins the label git:20260303.09b1726, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

[![mdr](https://markdownregistry.com/badge/art_62mtp5rfzfemty3f.svg)](https://markdownregistry.com/a/art_62mtp5rfzfemty3f)

1 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 1 version of this file, committed on Mar 3, 2026.

version	committed	commit	size	audit
git:20260303.09b1726 latest	2026-03-03	09b1726	4,485 B	A	view

Audit of the latest version

A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.

pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (4485 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag

Source

GitHub

qa-aman/claude-skills · 21 stars · license MIT · pushed 2026-10-19 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_62mtp5rfzfemty3f
GET https://markdownregistry.com/api/v1/resolve?ref=qa-aman/claude-skills/api-design
GET https://markdownregistry.com/api/v1/blob/413fade7b851ad226a105bc3db9e24ebe2c3af7b3f14166250269be93fdb56ab

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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