api-designer

api-designer is a skill for Claude Code from sickn33/agentic-awesome-skills. It costs 23 tokens per session (1,679 once invoked), scanned A, original, MIT.

A REST API design assistant that turns a system description into endpoint specifications. REST APIs are web interfaces that use standard HTTP requests to access or change resources.

In plain words
What is it for?
Use it to plan endpoints, request and response details, authentication headers, and documentation for an API.
Why use it?
It gives you a structured list of routes and, when requested, their inputs, headers, responses, and other details instead of leaving the API shape undefined.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the agentic-awesome-skills plugin — 257 skills shipped together

Good fit Use it to plan endpoints, request and response details, authentication headers, and documentation for an API.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sickn33/agentic-awesome-skills/api-designer
About the project

AAS Core is a local control plane for coding agents that lets them search a large catalogue of skills, choose a stack, validate it, and create a reproducible plan. It is used to assemble and review agent workflows through its CLI, local MCP server, catalogue, plugins, and Workbench. The catalogue add-ons provide the skills, plugins, bundles, and workflows that AAS Core helps agents select and validate.

sickn33/agentic-awesome-skills · 48,503 stars · on GitHub · aaskills.tech

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add sickn33/agentic-awesome-skills --skill api-designer
Clone the repo
git clone --depth 1 https://github.com/sickn33/agentic-awesome-skills

Made for: Claude Code.

Or install agentic-awesome-skills, the plugin that ships this one along with the rest of its 257 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for api-designer

README.md
[![agentmods](https://agentmods.dev/badge/skills/sickn33/agentic-awesome-skills/api-designer/github.svg)](https://agentmods.dev/skills/sickn33/agentic-awesome-skills/api-designer)
Your own site
<a href="https://agentmods.dev/skills/sickn33/agentic-awesome-skills/api-designer"><img src="https://agentmods.dev/badge/skills/sickn33/agentic-awesome-skills/api-designer/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for api-designer

Your own site · 80×15
<a href="https://agentmods.dev/skills/sickn33/agentic-awesome-skills/api-designer"><img src="https://agentmods.dev/badge/skills/sickn33/agentic-awesome-skills/api-designer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 23 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,679 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Snyk pass 7 Sept 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00023 $0.01679
Opus 5.5 $0.00009 $0.00672
Sonnet 5.5 $0.00005 $0.00336
Haiku 4.5 $0.00002 $0.00168

Measured yesterday against content hash d85d41119664, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

api-designer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

5 near-identical copies found in the catalogue:

plugins/agentic-awesome-skills-claude/skills/api-designer/SKILL.md · 181 lines

How it starts

The opening of the file, as written. The whole thing — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Supporting material availability

This catalog copy contains the inline guidance below, but does not include the following supporting paths. They are external prerequisites, not bundled files:

  • <support-root>/references/domains.md
  • <support-root>/references/testmu_example.md

Obtain the required material from the declared upstream source, or from a user-provided installation of that source. Resolve each path relative to that installation, inspect its contents, and verify any applicable license and execution prerequisites. Do not run a command or claim a referenced procedure was followed until its required file exists. Do not fabricate the missing scripts or treat an unrelated file with the same name as equivalent. Independent steps fully documented here can proceed within the user’s authorized scope; report any dependent step as unavailable.

API Designer Skill

When to Use

Use this skill when you need generates complete, production-ready REST API endpoint specifications for any system or domain the user describes. Use this skill whenever the user asks about API design, API endpoints, REST APIs, API URLs, or says things like "what endpoints do I need for...", "design an API for...",...

You are an expert API architect.

Ask the user if they want just the endpoints or complete detailed response (Enpoints Only/Detail Design). Do not ask these options if the user has specified the details of his requirement in the input already. If the user says Endpoints Only:

  • Output only the endpoints If the user says Detail Design:
  • Output complete design as the structure described in this skill.

Output Format

First list down all the endpoints one after another as output then expand each in this exact structure for each endpoint group (resource):


RESOURCE NAME

METHOD /path/to/endpoint

Short description of what this endpoint does. Not more than two lines.

Headers

Header Value Required
Content-Type application/json Yes
Authorization Bearer <token> Yes/No
X-Api-Key <api-key> Yes/No
(add others as relevant)

Read the full file on GitHub · 181 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday Changed · +4 lines d85d41119664
  2. 11d ago Changed · +9 lines a031cfb9c658
  3. 1mo ago Changed · -39 tokens per session ba65d90c01ee
  4. 1mo ago First seen · 168 lines · 62 tokens per session scan A 61d04dca68e2

Subscribe to this mod's changes

api-designer is a skill published in the GitHub repository sickn33/agentic-awesome-skills (48,503 stars, last pushed yesterday), licensed MIT. It adds 23 tokens to every session and 1,679 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-05.