api-design SKILL.md skillA

api-design from majiayu000/spellbook is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add majiayu000/spellbook/api-design@git:20260605.a09e45c

Pins git:20260605.a09e45c in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: majiayu000/spellbook
Path: skills/api-design/SKILL.md
Versions recorded: 2
Latest version: git:20260605.a09e45c, committed Jun 5, 2026
First version recorded: Dec 17, 2025
Size: 8,543 bytes
Repository stars: 288
License: MIT

REST/GraphQL/gRPC API design best practices. Use when designing APIs, defining contracts, handling versioning. Covers OpenAPI 3.2, GraphQL Federation, gRPC streaming.

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

# API Design

## Core Principles

- **Contract-First** — Define API spec before implementation
- **OpenAPI 3.2** — Use OpenAPI for REST API documentation
- **URL Versioning** — Version in path `/v1/`, with Sunset headers
- **Idempotency** — PUT/DELETE must be idempotent, POST uses Idempotency-Key
- **Cursor Pagination** — Avoid offset-based pagination
- **RFC 7807 Errors** — Standard Problem Details format
- **No backwards compatibility** — Delete, don't deprecate

---

## Quick Reference

### When to Use What

| Scenario | Choice | Reason |
|----------|--------|--------|
| Public API / MVP | REST | Simple, universal, easy debugging |
| Frontend-driven / Mobile | GraphQL | Fetch exactly what you need |
| Microservices internal | gRPC | High performance, strong typing |
| Real-time data | gRPC / GraphQL Subscriptions | Bidirectional streaming |

---

## REST API Design

### Resource Naming

```
# Good
GET  /users              # List users
GET  /users/123          # Get user
POST /users              # Create user
PUT  /users/123          # Replace user
PATCH /users/123         # Update user
DELETE /users/123        # Delete user

# Nested resources
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add majiayu000/spellbook/api-design@sha256:36bcb620e85df71f

The line at the top of this page pins the label git:20260605.a09e45c, 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_t3tfrcw6wbco66w2.svg)](https://markdownregistry.com/a/art_t3tfrcw6wbco66w2)

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

Versions

The registry has recorded 2 versions of this file, between Dec 17, 2025 and Jun 5, 2026, about one every 170 days.

version	committed	commit	size	audit
git:20260605.a09e45c latest	2026-06-05	a09e45c	8,543 B	A	view · diff
git:20251217.8299b48	2025-12-17	8299b48	8,261 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 (8543 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

majiayu000/spellbook · 288 stars · license MIT · pushed 2026-10-08 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_t3tfrcw6wbco66w2
GET https://markdownregistry.com/api/v1/resolve?ref=majiayu000/spellbook/api-design
GET https://markdownregistry.com/api/v1/blob/36bcb620e85df71f55990fc5d61f2c34e24513827154e37fe51a379b89fb7b85

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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