---
title: "API Designer - Air Market"
description: "You are about to build an API and the early decisions are the ones that are hard to take back: what the resources are, how you version, how errors come back. This is for working those out. Reach for…"
canonical: "https://airmarket.ai/app/api-designer"
---

[Air Market](/) / [Developer Tools](/category/devtools) / API Designer

Skill by [Jeffallan](/@jeffallan)

# API Designer

Decide the shape of your API before anyone writes a client

## What this does

You are about to build an API and the early decisions are the ones that are hard to take back: what the resources are, how you version, how errors come back. This is for working those out. Reach for it at the planning stage, for REST or GraphQL alike.

### Top 3 things it does for you

- Model the resources in an API
- Pick a versioning strategy
- Settle on pagination and error formats

## Information

**API Designer at a glance**

|  |  |
| --- | --- |
| Kind | Skill |
| Publisher | [Jeffallan](/@jeffallan) |
| Category | [Developer Tools](/category/devtools) |
| Works with | Agent Skills - an open standard supported by 40+ agents |
| Version | 1.1.0 |
| Size | 59 KB |
| Licence | MIT |
| Repository | [Jeffallan/claude-skills](https://github.com/Jeffallan/claude-skills/tree/5e8b6b8ff4007414f91f980771047b6136600c34/skills/api-designer) |
| GitHub stars | 11,146 (as of Nov 2026) |

## Security report

**Verified.** AIR scanned this exact version of API Designer and recorded 0 findings and 2 flagged items. AIR's verdict: **safe**.

**What API Designer's check was run against**

|  |  |
| --- | --- |
| Commit | 5e8b6b8ff4007414f91f980771047b6136600c34 |
| Content hash | cc88f04d2e7dd9bbb1c8398940bd48e6b25c862a4ab80c03b28d3dd885e7ee40 |
| Files read | [Browse the files at this exact commit](https://github.com/Jeffallan/claude-skills/blob/5e8b6b8ff4007414f91f980771047b6136600c34/skills/api-designer/SKILL.md) |

A scan is named by the exact content it read, not by a version number. A different version is a different artifact, and nothing here applies to a version AIR has not scanned.

[Read the full security report for API Designer](/security/api-designer)

## About API Designer

This is for the design stage of an API, REST or GraphQL: modeling resources, planning the overall architecture, and writing OpenAPI specifications.

It covers the decisions that repeat across every endpoint - versioning strategies, pagination patterns, and standards for how errors are returned.

## What's inside

- SKILL.md - instructions
- references/error-handling.md - reference
- references/openapi.md - reference
- references/pagination.md - reference
- references/rest-patterns.md - reference
- references/versioning.md - reference

## Questions

### Is API Designer safe to install?

AIR scanned this exact version of API Designer and recorded 0 findings and 2 flagged items. AIR's verdict: safe. The verdict is named by the content that was read, at commit 5e8b6b8ff400, so it cannot drift onto a version nobody scanned. The full report is at https://airmarket.ai/security/api-designer.

### How do I install API Designer?

Open https://airmarket.ai/app/api-designer on Air Market and use the install action: Air Market hands Claude a prompt naming this exact skill, and Claude sets it up. Source, pinned to the exact commit this listing describes: https://github.com/Jeffallan/claude-skills/tree/5e8b6b8ff4007414f91f980771047b6136600c34/skills/api-designer. Install from that link, not the branch.

## Related on Air Market

- [More Developer Tools listings](/category/devtools)
- [Everything by Jeffallan](/@jeffallan)

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Canonical URL: <https://airmarket.ai/app/api-designer>