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api-design Cursor ruleA

api-design from darknecrocities/skillbuilder is a Cursor rule: instructions the Cursor agent follows in that repo.

Install it, pinned

mdr add darknecrocities/skillbuilder/.cursor/rules/api-design.mdc@git:20261029.1aa6bef

Pins git:20261029.1aa6bef in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 14 of 14 checks passed
Kind: Cursor rule
Repository: darknecrocities/skillbuilder
Path: .cursor/rules/api-design.mdc
Versions recorded: 1
Latest version: git:20261029.1aa6bef, committed Oct 29, 2026
Size: 4,871 bytes
Repository stars: 13
License: none declared

API contract design and OpenAPI 3.1 specification skill. Enforces RFC 7807 problem details, idempotency headers, and consistent status codes.

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 Contract Design & OpenAPI 3.1 (`/api-design`)

> **Philosophy**: *APIs are permanent contracts. Design first. Standardize errors with RFC 7807. Enforce idempotency on state-changing operations. Paginate with cursors, never unbounded offsets.*

This skill establishes API contract standards, RESTful resource modeling, OpenAPI 3.1 specifications, uniform error semantics, and backward-compatibility rules.

---

## 1. Quick Navigation & Progressive Disclosure

| Resource Type | Document | Description |
| :--- | :--- | :--- |
| **Reference** | [references/rfc-7807-problem-details.md](references/rfc-7807-problem-details.md) | Standardized error schemas, type URIs, problem detail envelopes. |
| **Reference** | [references/idempotency-and-versioning.md](references/idempotency-and-versioning.md) | Idempotency keys, state caching, URI versioning, deprecation headers. |
| **Utility** | [scripts/validate_openapi_spec.py](scripts/validate_openapi_spec.py) | CLI linter auditing OpenAPI specs for RFC 7807 compliance and security schemes. |

---

## 2. RESTful Contract Architecture

```mermaid
flowchart LR
    A["Client Request (+ Idempotency-Key)"] --> B["OpenAPI 3.1 Route Definition"]
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add darknecrocities/skillbuilder/.cursor/rules/api-design.mdc@sha256:fae658176283396b

The line at the top of this page pins the label git:20261029.1aa6bef, 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_27q5opzd3uvxah62.svg)](https://markdownregistry.com/a/art_27q5opzd3uvxah62)

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

Versions

The registry has recorded 1 version of this file, committed on Oct 29, 2026.

version	committed	commit	size	audit
git:20261029.1aa6bef latest	2026-10-29	1aa6bef	4,871 B	A	view

Audit of the latest version

A 14 of 14 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.

pass: Size between 200 bytes and 200 KB (4871 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

darknecrocities/skillbuilder · 13 stars · license none declared · pushed 2026-10-29 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_27q5opzd3uvxah62
GET https://markdownregistry.com/api/v1/resolve?ref=darknecrocities/skillbuilder/.cursor/rules/api-design.mdc
GET https://markdownregistry.com/api/v1/blob/fae658176283396b9a2fdd492edbda83841c712805e6f00b284fa5410eabc1b3

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: Cursor rules vs AGENTS.md · which agent file does what.

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