Wanted to comment on AKX answer, but I can't. rep too low. This is how i did mine.

docs_url=None if APP_MODE == "production" else "/docs" #disables docs
redoc_url=None if APP_MODE == "production" else "/redoc" #disables redoc
openapi_url=None if APP_MODE == "production" else "/openapi.json" #disables openapi.json suggested by tobias comment.
app = FastAPI(docs_url=docs_url, redoc_url=redoc_url, openapi_url=openapi_url)

where APP_MODE is os.environ.get("APP_MODE", "production")