Openapi Spec Generation

---
triggers:
  - "openapi spec generation"
name: openapi-spec-generation
description: 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.
---

# 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 |

## Note
Skill content truncated for token efficiency. Full version available in the source repository.