fastapi_swagger2

Swagger2 support for FastAPI

Reason behind this library:

Few API GW services like Google Cloud API GW still support only Swagger 2.0 spec. Since FastAPI only supports OAS3, it is a challenge. Converting from OAS3 to Swagger 2.0 requires some manual steps which would hinder CI/CD.

Requirements

Python 3.10+

0.4.4 - FastAPI >= 0.140.7
0.4.3 - FastAPI >= 0.140.3, < 0.140.7
0.4.2 - FastAPI >= 0.140.0, < 0.140.3
0.4.1 - FastAPI >= 0.137.2, < 0.140.0
0.4.0 - FastAPI >= 0.137.0, <= 0.137.1
0.3.5 - FastAPI >= 0.129.0, < 0.137.0
0.3.4 - FastAPI >= 0.129.0 (last tested against 0.133.1)
0.3.3 - FastAPI >= 0.128.4, <= 0.128.8 (FastAPI has dropped Python 3.9 support since 0.129.1)
0.3.2 - FastAPI >= 0.128.0, <= 0.128.3
0.3.1 - FastAPI >= 0.123.9, <= 0.127.1 + Pydantic v1/v2 (Since FastAPI 0.126.1, Pydantic v1 is deprecated)
0.3.0 - FastAPI >= 0.119.0, <= 0.123.8 + Pydantic v1/v2
0.2.7 - FastAPI >= 0.100.0, < 0.119.0 + Pydantic v1/v2
0.2.4 - FastAPI >= 0.100.0
0.1.1 - FastAPI >= 0.99.0, <= 0.99.1
0.0.3 - FastAPI >= 0.79.0, <= 0.98.0

Installation

$ pip install fastapi_swagger2

Development

$ uv sync --extra dev --extra test --extra all

Example

from typing import Union

from fastapi import FastAPI
from fastapi_swagger2 import FastAPISwagger2

app = FastAPI()
FastAPISwagger2(app)


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}

This adds following endpoints:

http://localhost:8000/swagger2.json
http://localhost:8000/swagger2/docs
http://localhost:8000/swagger2/redoc

Generate spec for CI/CD

import os

import yaml

from app.main import app

URL = os.environ["CLOUD_RUN_URL"]

app.servers.append(URL)

spec = app.swagger2()
spec['x-google-backend'] = {'address': URL}

print(yaml.dump(spec))

Development

$ uv sync --extra dev --extra test --extra all

Release files for fastapi_swagger2 0.4.4

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for fastapi_swagger2 0.4.4
File	Size	Uploaded
fastapi_swagger2-0.4.4.tar.gz	11.6 kB	Jul 30, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for fastapi_swagger2 0.4.4
File	Interpreter	ABI	Platform	Reset
fastapi_swagger2-0.4.4-py3-none-any.whl 13.1 kB Jul 30, 2026	Python 3	none	any	Details

Total release size: 24.7 kB

Release files / fastapi_swagger2-0.4.4.tar.gz

Download URL	fastapi_swagger2-0.4.4.tar.gz
Size	11.6 kB
Tags	Source
SHA-256 checksum How to use checksums	`b675d95d588b1eec27d230f22e4e133cd3cd61d55bfce61f313b243f368c7539`
BLAKE2b-256 checksum How to use checksums	`47ddfe98bb9db78171cf25531f076995942cb4561087bd1c55f0f72199a6b611`
Upload date	Jul 30, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`uv/0.11.16 {"installer":{"name":"uv","version":"0.11.16","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"macOS","version":null,"id":null,"libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":null}`

Release files / fastapi_swagger2-0.4.4-py3-none-any.whl

Download URL	fastapi_swagger2-0.4.4-py3-none-any.whl
Size	13.1 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`5a3901c0f1e04fa2686f2c5d40623cc89c96586c0c77f0c43d44def577478b6f`
BLAKE2b-256 checksum How to use checksums	`12d59bc3a581bd76766eff00c2a24b35c92568bdfffdd68fbfa38e00e3807480`
Upload date	Jul 30, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`uv/0.11.16 {"installer":{"name":"uv","version":"0.11.16","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"macOS","version":null,"id":null,"libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":null}`