OpenAPI to application code skill for Claude: generate an app from a spec

Makes Claude read an OpenAPI spec and generate a complete application in your framework, with models, handlers, services and tests.

Installs: 9.5K; on skills.sh
Stars: 40.7K; on GitHub
Updated: Oct 2026; last repo commit

You give Claude an OpenAPI spec as a URL, a file path or pasted text, plus the framework and naming you want. Claude checks the spec, plans the architecture, then writes the project: models, controllers or handlers, a service layer, validation, logging and error handling.

It adds supporting files too: unit tests, a README, a .gitignore, a .env.example and API docs. SKILL.md is a generic prompt that follows 'the active framework's conventions', so name the framework yourself. The folder is one file with no scripts.

Good for

Backend developers who start from an OpenAPI or Swagger spec
Developers who name their own framework and want a first version of the service
Developers who want a README and .env example generated with the code

Install openapi-to-application-code

Claude Code

Copy this prompt.

Install the openapi-to-application-code skill in Claude Code. Run this command:

npx skills add https://github.com/github/awesome-copilot --skill openapi-to-application-code

Then check that it loaded and tell me how to use it.

2
Paste it into Claude Code. It shows the change and asks before running it.

Requires Node.js.

Pick one route. Each Copilot CLI plugin route installs a plugin that lists this skill and one agent in its plugin.json (no hooks or MCP config files in the plugin folder). Choose the one that matches your framework. The skills CLI and folder routes install only this skill, which is generic: name your framework in the prompt.

Built from the package data we hold. Not yet tested by us.

What's in the skill

When it loads

Generate a complete, production-ready application from an OpenAPI specification

Sections in SKILL.md

Input Requirements
Generation Process
Step 1: Analyze the OpenAPI Specification
Step 2: Design Application Architecture
Step 3: Generate Application Code
Step 4: Add Supporting Files
Output Structure
Best Practices Applied
Next Steps
Questions to Ask if Needed

Key facts

Author: Listed in github/awesome-copilot (community-contributed; the SKILL.md names no author)
License: MIT
Installs on skills.sh: 9,476 (Nov 2, 2026)
GitHub stars: 40,666 for the whole github/awesome-copilot repo (Nov 2, 2026)
Last repo commit: Oct 30, 2026
Audits on skills.sh: Gen Agent Trust Hub: pass, Socket: pass, Snyk: warn
What it includes: 1 file: SKILL.md (bundles no scripts)
Part of: Five framework plugins (FastAPI, NestJS, Spring Boot, Go, .NET), each listing this skill and one agent in its plugin.json

What it includes

Takes a URL, a file path or pasted OpenAPI text
SKILL.md accepts a URL to the spec, a local file path or the full text. It also asks for project name, framework and version, package naming and the auth method if the spec does not say.
Try: “Generate a FastAPI app from ./openapi.yaml, with JWT auth and PostgreSQL.”
Network · Input: the spec
Validates it and lists endpoints, schemas and security
Claude checks the spec for completeness, lists endpoints and schemas, notes auth requirements and flags ambiguities.
Read · Step 1: Analyze the spec
Plans folders, layers and configuration
Claude plans the directory structure, controller grouping, service layer, data models and startup configuration for the chosen framework.
Read · Step 2: Design the architecture
Writes models, controllers, services and repositories
Creates the build files, models and DTOs from the schemas, route handlers, services, a data layer if needed, plus validation, logging and error handling.
Write · Step 3: Generate the code
Writes tests, README, .gitignore and .env.example
Adds unit tests for services and controllers, setup instructions, environment templates, API docs and example requests.
Write · Step 4: Add supporting files
Asks about database, Docker, auth type and tests
SKILL.md lists questions on ORM or in-memory data, Docker, JWT vs OAuth2 vs API keys vs basic auth, test scope, database choice and pagination.
Read · Questions to ask if needed

From the official docs

Permissions

Medium risk

What it can do

Read your data
Create and change things
Delete things
Read-only mode

Watch out for

It writes a whole project into your folder
The output tree includes source, tests, a .gitignore, a .env.example and optionally docker-compose.yml. Generate into an empty folder or a branch so you can review the diff. github.com
Specs from URLs are untrusted input
Claude reads the spec text and builds code from it. Use a spec you trust, and read the generated auth and config code. github.com
The plugin routes add an agent
Each of the five plugins lists this skill and one agent in its plugin.json. The skills CLI route installs only the skill. github.com

Security advisories

No published security advisories as of Nov 2, 2026.

Technical details

Turning on read-only	No read-only mode. Use version control.
Sign-in and keys	No key. SKILL.md asks for the auth method your API uses and tells you to configure environment variables and database connections.
Scopes	Writes a new application project, with tests and config files May fetch the spec from a URL you give SKILL.md tells you to install dependencies, configure environment variables and run the tests and dev server after generation

Questions

What does this skill do?

It makes Claude generate a working application from an OpenAPI spec: models, controllers or handlers, a service layer, validation, error handling, logging, tests and setup files.

Which frameworks does it support?

SKILL.md does not name one. It says to follow the active framework's conventions and asks you for the target framework and version. The repo also has five plugins that pair this skill with an agent for FastAPI, NestJS, Spring Boot, Go and .NET.

How do I install it?

Use the install box at the top of this page. The Copilot CLI tab lists the five framework plugins; the other tabs install only this skill.

Can I paste the spec instead of giving a link?

Yes. SKILL.md accepts a URL, a local file path or the full spec pasted into the chat.

Is it safe?

The skill is one text file that asks Claude to write a new project and its tests. It writes many files, so generate into an empty folder or a branch and read the diff before you run anything. Run the tests and the dev server only after you have reviewed the code.

Does it add a database?

Only if you want one. SKILL.md lists a question about ORM and database setup versus in-memory or mock data, and a repository layer is generated "if applicable".

Information

updated Nov 2, 2026

Repository: github/awesome-copilot
Folder: skills/openapi-to-application-code

github/awesome-copilot skills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 7

openapi-to-application-code SKILL.md · github.com
openapi-to-application-python-fastapi plugin.json · github.com
awesome-copilot README · github.com
openapi-to-application-nodejs-nestjs plugin.json · github.com
openapi-to-application-java-spring-boot plugin.json · github.com
openapi-to-application-go plugin.json · github.com
openapi-to-application-csharp-dotnet plugin.json · github.com