defspec

Create the OpenAPI spec and document from dataclass, attrs, msgspec, etc.

Why not ...

[!NOTE] There are also lots of other projects can generate the OpenAPI document or even validate the data. This project is not intended to replace them.

This project is a legacy of a private initiative. During the development, I discovered that using msgspec could elegantly define and generate the API schema. The OpenAPI component can be utilized to generate the API documentation for various projects. As a result, I made the decision to extract it and transform it into a public project.

You can use this project as a low-level component or a drop-in module when you don't want to introduce too many other dependencies.

Installation

pip install defspec

Examples

• flask: examples/flask
• falcon: examples/falcon

You can run the above examples and open the OpenAPI document in your browser:

• swagger: http://127.0.0.1:8000/openapi/swagger
• redoc: http://127.0.0.1:8000/openapi/redoc
• scalar: http://127.0.0.1:8000/openapi/scalar

Usage

from dataclasses import dataclass
from typing import List

from defspec import OpenAPI


@dataclass
class User:
    name: str
    age: int


openapi = OpenAPI()
openapi.register_route("/", method="get", summary="Hello World")
openapi.register_route(
    "/users", method="post", summary="Get all the user info", response_type=List[User]
)

# get the OpenAPI spec
print(openapi.to_dict())
# get the OpenAPI spec bytes
with open("openapi.json", "wb") as f:
    f.write(openapi.to_json())

# serve as a HTTP server
openapi.serve_as_http_daemon(port=8000, run_in_background=True)