Agent skill · writing content · wshobson
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.
Why this skill is useful
Provides detailed patterns and templates for generating and maintaining OpenAPI 3.1 specifications that the AI wouldn't reliably generate on its own.
What it needs
About 1k tokens when loaded. Last updated 2026-08-05. 38,570 stars on the source repository.
What this skill does
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 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
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills wshobson/openapi-spec-generation