> ## Documentation Index
> Fetch the complete documentation index at: https://docs.subtrace.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Python FastAPI + Subtrace

> Connect your FastAPI backend to Chrome DevTools using Subtrace

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:

```python theme={null}
pip install subtrace
```

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

```python theme={null}
# 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](https://subtrace.dev/dashboard)
for free to set it as an environment variable.

```bash theme={null}
# get a tracer token for free at https://subtrace.dev/dashboard
export SUBTRACE_TOKEN=
```

Start your server using the `fastapi` command:

```bash theme={null}
fastapi run main.py
```

And send some requests and see them in Chrome DevTools!

![image](https://github.com/user-attachments/assets/b2ebec37-f411-42c7-80f3-229415231266)

You can find the complete source code used in this demo [here](https://github.com/subtrace/python-fastapi-demo).