Introducing Gradio Clients


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See the Release History




Mount a gradio.Blocks to an existing FastAPI application.

Example Usage

from fastapi import FastAPI
import gradio as gr
app = FastAPI()
def read_main():
    return {"message": "This is your main app"}
io = gr.Interface(lambda x: "Hello, " + x + "!", "textbox", "textbox")
app = gr.mount_gradio_app(app, io, path="/gradio")
Then run uvicorn run:app from the terminal and navigate to http://localhost:8000/gradio.


Parameter Description



The parent FastAPI application.




The blocks object we want to mount to the parent app.




The path at which the gradio application will be mounted.


dict[str, Any] | None

default: None

Additional keyword arguments to pass to the underlying FastAPI app as a dictionary of parameter keys and argument values. For example, "docs_url": "/docs"


Callable | tuple[str, str] | list[tuple[str, str]] | None

default: None

If provided, username and password (or list of username-password tuples) required to access the gradio app. Can also provide function that takes username and password and returns True if valid login.


str | None

default: None

If provided, HTML message provided on login page for this gradio app.


Callable[[fastapi.Request], str | None] | None

default: None

A function that takes a FastAPI request and returns a string user ID or None. If the function returns None for a specific request, that user is not authorized to access the gradio app (they will see a 401 Unauthorized response). To be used with external authentication systems like OAuth. Cannot be used with auth.


str | None

default: None

The subpath corresponding to the public deployment of this FastAPI application. For example, if the application is served at "", the root_path should be set to "/myapp". A full URL beginning with http:// or https:// can be provided, which will be used in its entirety. Normally, this does not need to provided (even if you are using a custom path). However, if you are serving the FastAPI app behind a proxy, the proxy may not provide the full path to the Gradio app in the request headers. In which case, you can provide the root path here.


list[str] | None

default: None

List of complete filepaths or parent directories that this gradio app is allowed to serve. Must be absolute paths. Warning: if you provide directories, any files in these directories or their subdirectories are accessible to all users of your app.


list[str] | None

default: None

List of complete filepaths or parent directories that this gradio app is not allowed to serve (i.e. users of your app are not allowed to access). Must be absolute paths. Warning: takes precedence over allowed_paths and all other directories exposed by Gradio by default.


str | None

default: None

If a path to a file (.png, .gif, or .ico) is provided, it will be used as the favicon for this gradio app's page.



default: True

If True, any errors in the gradio app will be displayed in an alert modal and printed in the browser console log. Otherwise, errors will only be visible in the terminal session running the Gradio app.


str | int | None

default: None

The maximum file size in bytes that can be uploaded. Can be a string of the form "<value><unit>", where value is any positive integer and unit is one of "b", "kb", "mb", "gb", "tb". If None, no limit is set.