You can connect your FastAPI backend to Chrome DevTools using Subtrace with just one line of code. With Subtrace, you can inspect the status, headers, payload, and latency of all API requests so you can debug way faster.

To begin, install Subtrace using the pip command:

pip install subtrace

For this guide, we’ll use the following Python FastAPI app as an example:

# Add this line to install Subtrace on your FastAPI server
import subtrace

from fastapi import FastAPI
import requests

app = FastAPI()

counter = 0

@app.get("/counter")
def get_counter():
    return {"counter": counter}

@app.post("/uuid")
def new_uuid():
    global counter
    counter += 1
    return requests.get("https://httpbin.org/uuid").json()

Get a SUBTRACE_TOKEN from the Subtrace dashboard for free to set it as an environment variable.

# get a tracer token for free at https://subtrace.dev/dashboard
export SUBTRACE_TOKEN=

Start your server using the fastapi command:

fastapi run main.py

And send some requests and see them in Chrome DevTools!

You can find the complete source code used in this demo here.

SvelteKitGunicorn