# Openapi Spec Generation

> Generate and maintain OpenAPI 3.1 specifications from code, design-first specs, and validation patterns. Use when creating API documentation, generating SDKs, or ensuring API contract compliance.

Source: https://skillsagentes.com/skills/wshobson/agents/openapi-spec-generation
Repository: https://github.com/wshobson/agents
Author: wshobson
License: MIT
Updated: hace 2 meses
Context cost: 49 tok installed, 511 tok once triggered, 6.4k tok with every bundled file
Bundle: 3 files, 25 KB
Permissions requested: none declared

## Install

```bash
npx -y skills add wshobson/agents --skill openapi-spec-generation --agent claude-code
```

## What it does

- Genera y mantiene especificaciones OpenAPI 3.1 a partir de código existente
- Aplica un enfoque design-first para escribir contratos de API antes de codificar
- Valida implementaciones de API contra su especificación
- Aporta plantillas y ejemplos detallados en references/details.md

## Use it when

- Crear documentación de API desde cero
- Generar specs OpenAPI a partir de código existente
- Diseñar contratos de API con enfoque design-first
- Generar SDKs de cliente a partir de specs o montar portales de documentación

## What triggers it

- "Genera la especificación OpenAPI 3.1 para esta API REST"
- "Crea el contrato de API antes de implementar el código"
- "Valida que mi implementación cumple con el spec OpenAPI"

## Files

- SKILL.md — 2 KB
- references/code-first-and-tooling.md — 11 KB
- references/details.md — 12 KB

## SKILL.md

Reproduced verbatim from wshobson/agents under MIT. This section is the upstream document and is in English.

# OpenAPI Spec Generation

Comprehensive patterns for creating, maintaining, and validating OpenAPI 3.1 specifications for RESTful APIs.

## When to Use This Skill

- Creating API documentation from scratch
- Generating OpenAPI specs from existing code
- Designing API contracts (design-first approach)
- Validating API implementations against specs
- Generating client SDKs from specs
- Setting up API documentation portals

## Core Concepts

### 1. OpenAPI 3.1 Structure

```yaml
openapi: 3.1.0
info:
  title: API Title
  version: 1.0.0
servers:
  - url: https://api.example.com/v1
paths:
  /resources:
    get: ...
components:
  schemas: ...
  securitySchemes: ...
```

### 2. Design Approaches

| Approach         | Description                  | Best For            |
| ---------------- | ---------------------------- | ------------------- |
| **Design-First** | Write spec before code       | New APIs, contracts |
| **Code-First**   | Generate spec from code      | Existing APIs       |
| **Hybrid**       | Annotate code, generate spec | Evolving APIs       |

## Templates and detailed worked examples

Full template library and detailed worked examples live in `references/details.md`. Read that file when you need the concrete templates.

## Best Practices

### Do's

- **Use $ref** - Reuse schemas, parameters, responses
- **Add examples** - Real-world values help consumers
- **Document errors** - All possible error codes
- **Version your API** - In URL or header
- **Use semantic versioning** - For spec changes

### Don'ts

- **Don't use generic descriptions** - Be specific
- **Don't skip security** - Define all schemes
- **Don't forget nullable** - Be explicit about null
- **Don't mix styles** - Consistent naming throughout
- **Don't hardcode URLs** - Use server variables

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Skills Agentes — https://skillsagentes.com/skills/wshobson/agents/openapi-spec-generation