How to export Swagger to Yaml when accessed with docs.

Hello.

As the title says, I always want to have the Swagger documentation that opens when I access / docs as a yaml file, but I don’t know how to do it.

I want to generate type information to be used in the front end from the output yaml file.

[insomnes]

@satodaiki as @falkben mentioned you can get openapi data in app, so you can run startup function like this:

import json

from fastapi import FastAPI


app = FastAPI()


@app.on_event("startup")
def save_openapi_json():
    openapi_data = app.openapi()
    # Change "openapi.json" to desired filename
    with open("openapi.json", "w") as file:
        json.dump(openapi_data, file)

But there is catch if you run uvicorn as: uvicorn app.main: app --reload It would reload permanently, cause file would be overwritten in this simple example. You can check for changes before writing or remove --reload option

[falkben]

app.openapi() will return the openapi schema as a dictionary.

you could convert this to yaml file, and serve it on /docs if you wanted…