Agent skill

Openapi Generator

by majiayu000 in majiayu000/claude-skill-registry

Specialized skill for generating and validating OpenAPI 3.0/3.1 specifications.

MITAuto-check: notesBackend & APIs

Install Openapi Generator

skills CLI
$ npx skills add majiayu000/claude-skill-registry --skill openapi-generator -a claude-code

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

GitHub CLI
$ gh skill install majiayu000/claude-skill-registry openapi-generator --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/majiayu000/claude-skill-registry.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/api/openapi-generator-a5c-ai-babysitter .claude/skills/openapi-generator && 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/

Facts

Skill name
openapi-generator
GitHub stars
666
Used in
1 other repo
Token cost
~2.4k tokens
SKILL.md length
334 words
Files
2
Skills in repo
971
Repo updated
First seen
Licence
MIT

At a glance

Specialized skill for generating and validating OpenAPI 3.0/3.1 specifications.

  • Works in 6 steps: OpenAPI Specification Generation → Specification Validation → Schema Inference → …
  • Tasks that involve OpenAPI specifications
  • SKILL.md covers Overview, Prerequisites, Capabilities and MCP Server Integration, plus 5 more sections
  • Reaches opensource.org

What it does

Openapi Generator is an agent skill from majiayu000/claude-skill-registry. Specialized skill for generating and validating OpenAPI 3.0/3.1 specifications. Supports code-first and spec-first approaches, schema inference, validation, and mock server generation.

Its SKILL.md is about 2.4k tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file (for example `metadata.json`).

It sits in Backend & APIs, covering OpenAPI specifications. It works with OpenAPI and Model Context Protocol. The repository describes itself as: Searchable Claude Code skills catalog with source-linked guides and generated registry artifacts. The licence is MIT.

When your agent uses it

  • Tasks that involve OpenAPI specifications

Example prompts

  • “/openapi-generator”

Requirements

  • Python 3
  • Node.js
  • Pre-approved tools (allowed-tools): Bash(*), Read, Write, Edit, Glob, Grep, WebFetch

Workflow steps

6 steps, taken from the step headings in SKILL.md.

  1. OpenAPI Specification Generation
  2. Specification Validation
  3. Schema Inference
  4. Breaking Change Detection
  5. Mock Server Generation
  6. Code Generation

What it can do on your machine

Read from SKILL.md and the folder at commit 000116a. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves these tools, so the agent can use them without asking each time:

    • Bash(*)
    • Read
    • Write
    • Edit
    • Glob
    • Grep
    • WebFetch

    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 bash, yaml, javascript and json).

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Hosts in commands or code, which the agent is likely to contact:

    • opensource.org

    Also links to:

    • github.com
    • apidog.com

    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

Openapi Generator loads about 2.4k tokens when it runs. Until then it costs about 51 tokens; SKILL.md has 334 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~51
When it runs · the whole SKILL.md, loaded when a task matches
~2.4k

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: notes

The automated check noted patterns worth knowing about, such as sudo or a known installer.

  • NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
    allowed-tools: Bash(*), Read, Write, Edit, Glob, Grep, WebFetch

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 majiayu000/claude-skill-registry at commit 000116a, republished under its MIT licence (© majiayu000). 334 words, ~2,382 tokens.

Download SKILL.mdSave it as .claude/skills/openapi-generator/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.
name
openapi-generator
description
Specialized skill for generating and validating OpenAPI 3.0/3.1 specifications. Supports code-first and spec-first approaches, schema inference, validation, and mock server generation.
allowed-tools
Bash(*), Read, Write, Edit, Glob, Grep, WebFetch
metadata.author
babysitter-sdk
metadata.version
1.0.0
metadata.category
api-design
metadata.backlog-id
SK-SA-002

openapi-generator

You are openapi-generator - a specialized skill for generating and validating OpenAPI specifications. This skill enables AI-powered API design with best practices for REST API documentation.

Overview

This skill enables comprehensive OpenAPI specification management including:

  • Generate OpenAPI 3.0/3.1 specifications from requirements
  • Validate existing specifications against OpenAPI standards
  • Infer schemas from code annotations or examples
  • Generate client/server code from specifications
  • Create mock servers for API testing
  • Detect breaking changes between spec versions

Prerequisites

  • Node.js (v18+) for tooling
  • Optional: spectral, redocly, swagger-cli
  • Optional: Prism for mock servers

Capabilities

1. OpenAPI Specification Generation

Generate complete OpenAPI specifications:

yaml
openapi: 3.1.0
info:
  title: Payment API
  description: API for processing payments
  version: 1.0.0
  contact:
    name: API Support
    email: api@example.com
  license:
    name: MIT
    url: https://opensource.org/licenses/MIT

servers:
  - url: https://api.example.com/v1
    description: Production server
  - url: https://staging-api.example.com/v1
    description: Staging server

tags:
  - name: payments
    description: Payment operations
  - name: refunds
    description: Refund operations

paths:
  /payments:
    post:
      operationId: createPayment
      summary: Create a new payment
      tags: [payments]
      security:
        - bearerAuth: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/PaymentRequest'
            examples:
              creditCard:
                summary: Credit card payment
                value:
                  amount: 9999
                  currency: USD
                  paymentMethod:
                    type: card
                    cardNumber: "4111111111111111"
      responses:
        '201':
          description: Payment created successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Payment'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'

components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT

  schemas:
    PaymentRequest:
      type: object
      required:
        - amount
        - currency
        - paymentMethod
      properties:
        amount:
          type: integer
          minimum: 1
          description: Amount in smallest currency unit (cents)
        currency:
          type: string
          enum: [USD, EUR, GBP]
          description: ISO 4217 currency code
        paymentMethod:
          $ref: '#/components/schemas/PaymentMethod'
        metadata:
          type: object
          additionalProperties:
            type: string

    Payment:
      type: object
      properties:
        id:
          type: string
          format: uuid
        status:
          type: string
          enum: [pending, processing, completed, failed]
        amount:
          type: integer
        currency:
          type: string
        createdAt:
          type: string
          format: date-time

  responses:
    BadRequest:
      description: Invalid request
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'

    Unauthorized:
      description: Authentication required
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'

    Error:
      type: object
      properties:
        code:
          type: string
        message:
          type: string
        details:
          type: array
          items:
            type: object
2. Specification Validation

Validate OpenAPI specifications using multiple tools:

bash
# Using Spectral (Stoplight)
spectral lint openapi.yaml --ruleset .spectral.yaml

# Using Redocly CLI
redocly lint openapi.yaml

# Using swagger-cli
swagger-cli validate openapi.yaml

# Using openapi-generator-cli
openapi-generator-cli validate -i openapi.yaml
3. Schema Inference

Infer OpenAPI schemas from examples:

javascript
// Input: JSON examples
const examples = [
  { id: 1, name: "Product A", price: 29.99, inStock: true },
  { id: 2, name: "Product B", price: 49.99, inStock: false }
];

// Generated schema
const schema = {
  type: 'object',
  required: ['id', 'name', 'price', 'inStock'],
  properties: {
    id: { type: 'integer' },
    name: { type: 'string' },
    price: { type: 'number', format: 'double' },
    inStock: { type: 'boolean' }
  }
};
4. Breaking Change Detection

Detect breaking changes between API versions:

bash
# Using openapi-diff
openapi-diff v1/openapi.yaml v2/openapi.yaml --format json

# Breaking changes include:
# - Removed endpoints
# - Required parameter added
# - Response schema changes
# - Security requirement changes
5. Mock Server Generation

Generate mock servers from specifications:

bash
# Using Prism
prism mock openapi.yaml

# Using Mockoon
mockoon-cli start --data openapi.yaml

# Using openapi-mock-generator
openapi-mock-generator -i openapi.yaml -o ./mocks
6. Code Generation

Generate client and server code:

bash
# Generate TypeScript client
openapi-generator-cli generate \
  -i openapi.yaml \
  -g typescript-axios \
  -o ./generated/client

# Generate Node.js server stubs
openapi-generator-cli generate \
  -i openapi.yaml \
  -g nodejs-express-server \
  -o ./generated/server

# Generate Python client
openapi-generator-cli generate \
  -i openapi.yaml \
  -g python \
  -o ./generated/python-client

MCP Server Integration

This skill can leverage the following MCP servers:

ServerDescriptionInstallation
mcp-openapi-schemaOpenAPI schema exploration for LLMsGitHub
Apidog MCP ServerAPI documentation and code generationapidog.com

Best Practices

API Design Principles
  1. Use semantic versioning - Include version in URL or header
  2. Consistent naming - Use camelCase for JSON, kebab-case for URLs
  3. Proper HTTP methods - GET (read), POST (create), PUT (replace), PATCH (update), DELETE (remove)
  4. Meaningful status codes - 2xx success, 4xx client errors, 5xx server errors
  5. Pagination - Use cursor-based or offset pagination for lists
Schema Design
yaml
# Good: Reusable components
components:
  schemas:
    PaginatedResponse:
      type: object
      properties:
        data:
          type: array
        pagination:
          $ref: '#/components/schemas/Pagination'

    Pagination:
      type: object
      properties:
        total: { type: integer }
        limit: { type: integer }
        offset: { type: integer }
        hasMore: { type: boolean }
Security Definitions
yaml
# Multiple security options
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
    apiKeyAuth:
      type: apiKey
      in: header
      name: X-API-Key
    oauth2:
      type: oauth2
      flows:
        authorizationCode:
          authorizationUrl: https://auth.example.com/authorize
          tokenUrl: https://auth.example.com/token
          scopes:
            read: Read access
            write: Write access

Process Integration

This skill integrates with the following processes:

  • api-design-specification.js - Primary API design workflow
  • microservices-decomposition.js - Service interface definition
  • system-design-review.js - API review and validation

Output Format

When generating specifications, provide structured output:

json
{
  "operation": "generate",
  "version": "3.1.0",
  "status": "success",
  "specification": {
    "path": "./api/openapi.yaml",
    "format": "yaml",
    "endpoints": 15,
    "schemas": 23
  },
  "validation": {
    "errors": 0,
    "warnings": 2,
    "details": [
      { "level": "warning", "path": "/paths/users", "message": "Missing description" }
    ]
  },
  "artifacts": ["openapi.yaml", "openapi.json"],
  "mockServer": {
    "url": "http://localhost:4010",
    "tool": "prism"
  }
}

Error Handling

Common Errors
ErrorCauseResolution
Invalid schema reference$ref points to undefinedDefine all referenced schemas
Duplicate operationIdNon-unique operation IDsEnsure unique operationIds
Invalid response codeInvalid HTTP status codeUse standard status codes
Missing required fieldSchema validation failureAdd all required fields

Constraints

  • Follow OpenAPI specification standards
  • Use semantic versioning for APIs
  • Document all endpoints with descriptions
  • Include examples for complex schemas
  • Validate specifications before publishing

© majiayu000, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file in skills/api/openapi-generator-a5c-ai-babysitter of majiayu000/claude-skill-registry.

  • SKILL.md
  • metadata.json

Open the folder on GitHubat commit 000116a

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in majiayu000/claude-skill-registry, which our catalogue first saw on October 7, 2026.

Compare with similar skills

Openapi Generator 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.

Openapi Generator compared with similar skills
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Openapi Generator this skillmajiayu000/claude-skill-registry6661 repos~2.4kAutomated safety check: NotesMIT
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API Endpoint Contracttrycompai/comp2k—~2.7kAutomated safety check: PassAGPL-3.0
SpikardGoldziher/spikard123—~799Automated safety check: PassMIT
Executor Usagejeremyosih/pi-executor104—~1.4kAutomated safety check: PassMIT
Catalog Sample Datakubeflow/hub186—~1.1kAutomated safety check: PassApache-2.0

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Categories

Questions about Openapi Generator

What does Openapi Generator do?

Specialized skill for generating and validating OpenAPI 3.0/3.1 specifications. Openapi Generator is an agent skill from majiayu000/claude-skill-registry.1 specifications.

When should I use Openapi Generator?

Openapi Generator fits situations like: tasks that involve OpenAPI specifications.

How do I install Openapi Generator in Claude Code?

Run `npx skills add majiayu000/claude-skill-registry --skill openapi-generator -a claude-code`. Or copy the skill folder (skills/api/openapi-generator-a5c-ai-babysitter in majiayu000/claude-skill-registry) into .claude/skills/openapi-generator in your project. Claude Code loads it when a task matches its description.

How do I install Openapi Generator in Codex?

Run `npx skills add majiayu000/claude-skill-registry --skill openapi-generator -a codex`. Or copy the skill folder (skills/api/openapi-generator-a5c-ai-babysitter in majiayu000/claude-skill-registry) into .agents/skills/openapi-generator in your project. Codex loads it when a task matches its description.

Can I use Openapi Generator 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 majiayu000/claude-skill-registry --skill openapi-generator -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/openapi-generator, .gemini/skills/openapi-generator, .github/skills/openapi-generator and .opencode/skills/openapi-generator in your project.

What does Openapi Generator need to run?

SKILL.md names no scripts, command-line tools or credentials: Openapi Generator is instructions for the agent only. Our summary lists: Python 3; Node.js. Its frontmatter pre-approves these tools: Bash(*), Read, Write, Edit, Glob, Grep, WebFetch.

Does Openapi Generator access the network?

SKILL.md names 3 domains. In commands or code: opensource.org; the agent is likely to contact it when it follows the instructions. As links in the text: github.com and apidog.com. This is read from the text; nothing was executed.

Is Openapi Generator safe to install?

Our automated static check of SKILL.md found notes only (pre-approves every shell command (allowed-tools: bash)), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.

What licence does Openapi Generator use?

Openapi Generator 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 Openapi Generator use?

About 2.4k tokens (SKILL.md is roughly 9.5k 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 Openapi Generator?

Skills that share tags, products or a category with Openapi Generator: OpenAPI to MCP Server (mcp-use/mcp-use, 11k stars), API Endpoint Contract (trycompai/comp, 2k stars), Spikard (Goldziher/spikard, 123 stars) and Executor Usage (jeremyosih/pi-executor, 104 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Openapi Generator?

majiayu000 (a GitHub user) maintains it in majiayu000/claude-skill-registry, which has 666 GitHub stars. The repository holds 971 skills in this directory. The repository was last updated on October 7, 2026.

Source: majiayu000/claude-skill-registry on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.