openapi-spec-generation

Generate and validate OpenAPI 3.1 specifications from design or code sources.

1|Updated Dec 23, 2025
One-click install
npx skills add https://github.com/ccf/claude-code-ccf-marketplace --skill openapi-spec-generation
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: openapi-spec-generation
Source: https://github.com/ccf/claude-code-ccf-marketplace/tree/main/plugins/documentation/skills/openapi-spec-generation
Command: npx skills add https://github.com/ccf/claude-code-ccf-marketplace --skill openapi-spec-generation

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This skill automates the creation, validation, and maintenance of OpenAPI 3.1 specifications, bridging design-first concepts with code-first reality to ensure consistent API contracts.

Core Features & Use Cases

  • Design-first to generate specs from API design
  • Code-first to derive specs from existing codebases and validate against standards
  • Validate specs with tools like spectral and openapi-generator
  • Generate SDKs for multiple languages from a single spec
  • Use-case: teams iterating API design, documentation, and client integration

Quick Start

Run openapi-spec-generation with your API project to produce an initial OpenAPI 3.1 spec and a validation plan. For example, map your codebase to a YAML spec, then run validations and generator commands to produce client SDKs.

Frequently Asked Questions about openapi-spec-generation

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I generate OpenAPI 3.1 specifications from an existing codebase?▼

To generate OpenAPI 3.1 specifications from a code-first source, this skill maps your existing codebase structures to a YAML spec and validates them against API standards using spectral.

How does design-first API validation work with OpenAPI specs?▼

Design-first API validation takes your initial API design, produces an OpenAPI 3.1 specification, and runs validations using spectral and openapi-generator to ensure consistent API contracts.

What is the best way to generate client SDKs across multiple languages from an OpenAPI spec?▼

The best way to generate client SDKs is to use openapi-generator commands on your validated OpenAPI 3.1 spec, producing client libraries suitable for multiple programming languages.

Do I need openapi-generator and spectral installed to validate OpenAPI specs?▼

Yes, you need openapi-generator and spectral installed in a compatible development environment, as these tools are required to run the validation and generation commands for your OpenAPI specs.

Can I derive OpenAPI specs from both design-first and code-first sources?▼

Yes, you can derive OpenAPI specs from both approaches, bridging design-first concepts with code-first reality to automate creation, validation, and maintenance of consistent API contracts.

Why does my OpenAPI spec validation fail during code-first generation?▼

OpenAPI spec validation may fail if the derived spec does not meet OpenAPI 3.1 standards, requiring you to run spectral validations to identify and fix contract inconsistencies before generating SDKs.