Official agent skill

API Design

Guide for designing and documenting RESTful APIs. An agent skill from microsoft/haste.

OfficialMITAuto-check passedBackend & APIs

Install API Design

skills CLI

$ npx skills add microsoft/haste --skill api-design -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install microsoft/haste api-design --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.github/skills/api-design .claude/skills/api-design && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "api-design" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/api-design into .claude/skills/api-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-design", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/microsoft/haste/tree/main/.github/skills/api-design

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add microsoft/haste --skill api-design -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install microsoft/haste api-design --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.github/skills/api-design .agents/skills/api-design && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "api-design" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/api-design into .agents/skills/api-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-design", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add microsoft/haste --skill api-design -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install microsoft/haste api-design --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.github/skills/api-design .cursor/skills/api-design && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "api-design" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/api-design into .cursor/skills/api-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-design", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/microsoft/haste.git --path .github/skills/api-design

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add microsoft/haste --skill api-design -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install microsoft/haste api-design --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.github/skills/api-design .gemini/skills/api-design && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "api-design" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/api-design into .gemini/skills/api-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-design", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install microsoft/haste api-design

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add microsoft/haste --skill api-design -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .github/skills && cp -r skills-src/.github/skills/api-design .github/skills/api-design && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "api-design" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/api-design into .github/skills/api-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-design", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add microsoft/haste --skill api-design -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install microsoft/haste api-design --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/haste.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.github/skills/api-design .opencode/skills/api-design && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "api-design" agent skill from https://github.com/microsoft/haste/tree/main/.github/skills/api-design into .opencode/skills/api-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-design", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: api-design
GitHub stars: 106
Token cost: ~663 tokens
SKILL.md length: 237 words
Files: 1
Skills in repo: 9
Repo updated: Oct 2, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Guide for designing and documenting RESTful APIs. An agent skill from microsoft/haste.

Works in 6 steps: HTTP method and path → Description → Request parameters (path, query, body)… → …
Asked to design an API
SKILL.md covers Overview, Key Concepts, Decision Framework and Documentation Requirements, plus 1 more section
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

API Design is an agent skill from microsoft/haste, published by the product's own GitHub organization. Guide for designing and documenting RESTful APIs. Use when asked to design an API, create endpoints, or document an API.

Its SKILL.md is about 660 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Backend & APIs, covering API design and REST APIs. The repository describes itself as: High Speed Assessment and Satellite Tracking for Emergencies. The licence is MIT.

When your agent uses it

Asked to design an API
Create endpoints
Document an API

Example prompts

“/api-design”

Workflow steps

6 steps, taken from the first numbered list in SKILL.md.

HTTP method and path
Description
Request parameters (path, query, body) with types
Response schema with examples
Error codes and descriptions
Authentication requirements

What it can do on your machine

Read from SKILL.md and the folder at commit 079bd89. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are json).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

API Design loads about 663 tokens when it runs. Until then it costs about 33 tokens; SKILL.md has 237 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~33
When it runs · the whole SKILL.md, loaded when a task matches: ~663

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from microsoft/haste at commit 079bd89, republished under its MIT licence (© microsoft). 237 words, ~663 tokens.

Download SKILL.mdSave it as .claude/skills/api-design/SKILL.md (or your agent's skills folder).

name: api-design
description: Guide for designing and documenting RESTful APIs. Use when asked to design an API, create endpoints, or document an API.
source: Internal engineering practices, REST API conventions
domain: architecture
level: intermediate
agents: backend-dev, gis
created_date: 2026-04-27
status: draft

API Design

Overview

Standards and patterns for designing consistent, well-documented RESTful APIs. Covers naming, HTTP methods, error handling, status codes, and documentation requirements.

Key Concepts

Naming Conventions

Plural nouns for resources: /users, /orders, /products
Kebab-case for multi-word: /user-profiles
Nest related resources: /users/{id}/orders
Query params for filtering: /users?role=admin&active=true

HTTP Methods

Method	Purpose	Idempotent	Response
GET	Read	Yes	200 + body
POST	Create	No	201 + body + Location
PUT	Replace	Yes	200 + body
PATCH	Partial update	No	200 + body
DELETE	Remove	Yes	204 (no body)

Error Response Format

json

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Human-readable description",
    "details": [
      {"field": "email", "message": "Invalid email format"}
    ]
  }
}

Status Codes

200: Success — 201: Created — 204: No content
400: Bad request — 401: Unauthorized — 403: Forbidden
404: Not found — 409: Conflict — 422: Unprocessable
429: Rate limited — 500: Internal error

Decision Framework

Scenario	Method	Path	Status
List items	GET	/items	200
Get one item	GET	/items/{id}	200 / 404
Create item	POST	/items	201
Full update	PUT	/items/{id}	200 / 404
Partial update	PATCH	/items/{id}	200 / 404
Delete item	DELETE	/items/{id}	204 / 404
Search	GET	/items?q=term	200
Bulk action	POST	/items/batch	200 / 207

Documentation Requirements

Every endpoint must document:

HTTP method and path
Description
Request parameters (path, query, body) with types
Response schema with examples
Error codes and descriptions
Authentication requirements

Common Pitfalls

Using verbs in URLs — Use nouns: /users not /getUsers
Inconsistent error format — Use the same error schema everywhere
Missing pagination — Any list endpoint that can grow needs pagination
No versioning strategy — Decide early: URL (/v1/) or header-based

Files

Just SKILL.md in .github/skills/api-design of microsoft/haste.

Open the folder on GitHubat commit 079bd89

Compare with similar skills

API Design next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

API Design compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
API Design this skillmicrosoft/haste	106	—	~663	Automated safety check: Pass	MIT	5 days ago
API DesignerJeffallan/claude-skills	12k	2 repos	~2k	Automated safety check: Pass	MIT	4 days ago
Nodejs Backend Patternsever-works/ever-works	158	17 repos	~4k	Automated safety check: Pass	AGPL-3.0	2 days ago
Pangolin CRUD Endpointsfosrl/pangolin	23k	—	~461	Automated safety check: Pass	Custom licence	today
Old Coder API DesignAmazingAng/old-coder	749	1 repos	~3.4k	Automated safety check: Pass	MIT	1 mo ago
REST API Contract Reviewdecebals/claude-code-java	750	1 repos	~2.8k	Automated safety check: Pass	MIT	1 mo ago

Similar skills

API Designer
Jeffallan/claude-skills
Designs REST and GraphQL APIs from resource modeling to an OpenAPI 3.1 contract, with versioning, pagination and RFC 7807 error handling.
12k GitHub starsUsed in 2 repos~2k tokens
Backend & APIsAuto-check passed
Nodejs Backend Patterns
ever-works/ever-works
Build production-ready Node.js backend services with Express/Fastify, implementing middleware patterns, error handling, authentication, database integration, and API design best practices.
158 GitHub starsUsed in 17 repos~4k tokens
Backend & APIsAuto-check passed
Pangolin CRUD Endpoints
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Use whenever asked to add, create, or scaffold a CRUD endpoint, router, or entity in this repo's server (create/list/get/update/delete handlers, new…
23k GitHub stars~461 tokensUpdated today
Backend & APIsAuto-check passed
Old Coder API Design
AmazingAng/old-coder
Reviews or designs an HTTP/JSON API's endpoints, auth, pagination, versioning and deprecations, guarding against inventing a bespoke interface or silently breaking consumers.
749 GitHub starsUsed in 1 repo~3.4k tokens
Backend & APIsAuto-check passed
REST API Contract Review
decebals/claude-code-java
Reviews REST API design for correct HTTP verbs, versioning, DTO use, consistent responses and backward compatibility before an API change ships.
750 GitHub starsUsed in 1 repo~2.8k tokens
Backend & APIsAuto-check passed
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Questions about API Design

What does API Design do?

Guide for designing and documenting RESTful APIs. An agent skill from microsoft/haste. API Design is an agent skill from microsoft/haste, published by the product's own GitHub organization. Guide for designing and documenting RESTful APIs.

When should I use API Design?

API Design fits situations like: asked to design an API; create endpoints; document an API.

How do I install API Design in Claude Code?

Run `npx skills add microsoft/haste --skill api-design -a claude-code`. Or copy the skill folder (.github/skills/api-design in microsoft/haste) into .claude/skills/api-design in your project. Claude Code loads it when a task matches its description.

How do I install API Design in Codex?

Run `npx skills add microsoft/haste --skill api-design -a codex`. Or copy the skill folder (.github/skills/api-design in microsoft/haste) into .agents/skills/api-design in your project. Codex loads it when a task matches its description.

Can I use API Design in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add microsoft/haste --skill api-design -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/api-design, .gemini/skills/api-design, .github/skills/api-design and .opencode/skills/api-design in your project.

What does API Design need to run?

SKILL.md names no scripts, command-line tools or credentials: API Design is instructions for the agent only.

Does API Design access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is API Design safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does API Design use?

API Design is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does API Design use?

About 663 tokens (SKILL.md is roughly 2.7k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to API Design?

Skills that share tags, products or a category with API Design: API Designer (Jeffallan/claude-skills, 12k stars), Nodejs Backend Patterns (ever-works/ever-works, 158 stars), Pangolin CRUD Endpoints (fosrl/pangolin, 23k stars) and Old Coder API Design (AmazingAng/old-coder, 749 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains API Design?

microsoft (a GitHub organization, an official publisher) maintains it in microsoft/haste, which has 106 GitHub stars. The repository holds 9 skills in this directory. The repository was last updated on October 2, 2026.

Source: microsoft/haste on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install API Design

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

API Design

Overview

Key Concepts

Naming Conventions

HTTP Methods

Error Response Format

Status Codes

Decision Framework

Documentation Requirements

Common Pitfalls

Files

Compare with similar skills

Similar skills

More from microsoft/haste

Related

Questions about API Design