OpenAPI Code Generator
Build an OpenAPI 3.0 specification visually. Define your API info, add endpoints with methods and parameters, then copy the YAML for Swagger UI, Redoc, or code generation tools.
API Info
Add Endpoint
Body fields (one per line: fieldName:type e.g. name:string, age:integer)
Frequently Asked Questions
What is OpenAPI / Swagger?▼
OpenAPI (formerly Swagger) is a standard specification for describing RESTful APIs. It allows you to document endpoints, parameters, request bodies, and responses in a machine-readable format (YAML or JSON) that tools can use to generate docs, client SDKs, and server stubs.
What is the difference between OpenAPI 3.0 and Swagger 2.0?▼
Swagger 2.0 is the older spec. OpenAPI 3.0 introduced components/schemas (replacing definitions), requestBody (replacing body parameters), and better support for multiple servers. OpenAPI 3.1 aligns fully with JSON Schema.
Can I use this YAML with Swagger UI?▼
Yes. The generated YAML is valid OpenAPI 3.0 and works directly with Swagger UI, Redoc, Stoplight, and any OpenAPI-compatible tool. You can paste it into editor.swagger.io to preview it.
What are path parameters vs query parameters?▼
Path parameters are part of the URL path (e.g., /users/{id}). Query parameters are appended after ? (e.g., /users?role=admin). Path parameters are typically required; query parameters are often optional filters.
What is a requestBody in OpenAPI?▼
A requestBody describes the payload sent in POST/PUT/PATCH requests. It typically contains a JSON schema describing the expected fields. In OpenAPI 3.0, requestBody is defined separately from parameters.
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