api-design SKILL.md skillA
api-design from darknecrocities/skillbuilder is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add darknecrocities/skillbuilder/api-design@git:20261025.8aa06bdPins git:20261025.8aa06bd in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- darknecrocities/skillbuilder
- Path
skills/api-design/SKILL.md- Versions recorded
- 2
- Latest version
- git:20261025.8aa06bd, committed Oct 25, 2026
- First version recorded
- Oct 25, 2026
- Size
- 4,225 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. RESTful Contract Architecture
```mermaid
flowchart LR
A["Client Request (+ Idempotency-Key)"] --> B["OpenAPI 3.1 Route Definition"]
B --> C["Strict Schema Parser (Fail-Fast)"]
C --> D{"Success?"}
D -- "Yes" --> E["200 OK / 201 Created (Envelope + Pagination)"]
D -- "No" --> F["RFC 7807 Problem Details (application/problem+json)"]
```
---
## 2. Core API Contract Standards
### 2.1 RFC 7807 Problem Details Error Envelope
Every error response must use Content-Type `application/problem+json`:
```json
{
"type": "https://api.example.com/errors/resource-not-found",
"title": "Resource Not Found",
"status": 404,
"detail": "User with ID 'usr_01HXYZ...' does not exist in the tenant workspace.",
"instance": "/v1/users/usr_01HXYZ...",
…Read the whole file at its exact version.
How to install
mdr add darknecrocities/skillbuilder/api-design@sha256:b9df47b913a3925bThe line at the top of this page pins the label git:20261025.8aa06bd, 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.
[](https://markdownregistry.com/a/art_pjxq2a7cy7l3gehg)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, all committed on Oct 25, 2026.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261025.8aa06bd latest | 2026-10-25 | 8aa06bd | 4,225 B | A | view · diff |
| git:20261025.debe22c | 2026-10-25 | debe22c | 2,475 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4225 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
darknecrocities/skillbuilder · 13 stars · license none declared · pushed 2026-10-29 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_pjxq2a7cy7l3gehg GET https://markdownregistry.com/api/v1/resolve?ref=darknecrocities/skillbuilder/api-design GET https://markdownregistry.com/api/v1/blob/b9df47b913a3925b404a00228bab906dfd5f1dc0c633e5a2ed0f355d47d03b19
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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