GradioでSEO / Vary: Accept-Languageの付与

...

def main():
    from starlette.middleware import Middleware
    from starlette.middleware.base import BaseHTTPMiddleware

    class VaryHeaderMiddleware(BaseHTTPMiddleware):
        async def dispatch(self, request, call_next):
            response = await call_next(request)
            response.headers["Vary"] = "Accept-Language"
            return response

    demo = create_interface()

    demo.launch(
        server_name="0.0.0.0",
        server_port=8080,
        ssr_mode=False,  # True だとResponseヘッダーが付与されない
        i18n=i18n,
        app_kwargs={"middleware": [Middleware(VaryHeaderMiddleware)]},
    )


if __name__ == "__main__":
    main()