Is there way to use it along with fastapi? Import fastapi inside fasthtml? Backend with fastapi and frontend with fasthtml, if yes please share examples

[saitej123]

Is there way to use it along with fastapi? Import fastapi inside fasthtml? Backend with fastapi and frontend with fasthtml !

In streamlit frontend and backend not decoupled

[jph00]

There's not much need to, since fasthtml can already create json endpoints. Just return a dict from your handler.

Having said that, we'd recommend avoiding that where possible, and instead just returning FT/HTML partials the HTMX way!

[saitej123]

Thanks for the clarification @jph00

[AartGoossens]

(I am re-using this issue as it's closely related)

I have an existing FastAPI application with a bunch of API endpoints. What would be the recommended way to serve a frontend generated by FastHTML from the same application?

1. Switch from app = fastapi.FastAPI() to app, rt = fast_app() for the entire application.
2. Use to_xml() to render FastHTML output in combination with response_class=HTMLResponse (see example 1 below)
3. Mount the FastHTML application as a sub application within the original application, as documented here. See example 2 below.
4. Another way that I haven't thought of.

What are the benefits, limitations and drawbacks of each of these options?

Example 1: using to_xml() and HTMLResponse

from fastapi import FastAPI
from fastapi.responses import HTMLResponse
from fasthtml import *
from fasthtml.core import to_xml

app = FastAPI()

@app.get("/", response_class=HTMLResponse)
def read_root():
    html = Titled("FastHTML", P("Let's do this!"))
    return to_xml(html)

Example 2: with mounting FastHTML as a sub application

from fastapi import FastAPI
from fastapi.responses import HTMLResponse
from fasthtml.fastapp import *

app = FastAPI()

@app.get("/")
def read_root():
    return {"message": "ok"}

fasthtml_app, rt = fast_app()

@rt("/")
def get():
    return Titled("FastHTML", P("Let's do this!"))

app.mount("/fasthtml", fasthtml_app)

[bennettandrews]

I'm also interested in this approach. In my case I have FastAPI applications with API endpoints for various ML tasks, but would like to also provide an admin UI to enable more control and visibility without standing up multiple apps.

[ved93]

I am also looking for the same backend with fastapi and front end with fasthtml