Typically, VSCode is used to develop a FastAPI app. However, you can get a FastAPI app up and running on a Linux system.

On a Debian distribution (Mint, Ubuntu), apt-get can be used to install python-virtualenv. On a Red Hat Distribution (CentOS, Fedora, Red Hat), dnf install or yum install can be used.

dnf install python-virtualenv

If using version 2 of Python, the python -m virtualenv <something unique> command can be used to create a virtual environment. In this example, a virtual environment named demo is created.

python -m virtualenv demo

If using version 3 of Python, the python3 -m venv <something unique> command can be used to create a virtual environment.

python3 -m venv demo

The source command to activate the virtual environment.

source demo/bin/activate

pip install can be used to install FastAPI in the virtual environment. The fastapi[standard] package is used so you can run your FastAPI app on the command line using the fastapi CLI. The uvicorn package is used so that you can run your FastAPI app on the command line using the uvicorn CLI.

(demo) [john.doe@localhost ~]$ pip install fastapi
(demo) [john.doe@localhost ~]$ pip install "fastapi[standard]"
(demo) [john.doe@localhost ~]$ pip install uvicorn

The pip list command should return something like this.

~]$ pip list
Package           Version
----------------- ----------
annotated-types   0.7.0
anyio             4.8.0
certifi           2024.12.14
click             8.1.8
dnspython         2.7.0
email_validator   2.2.0
fastapi           0.115.6
fastapi-cli       0.0.7
h11               0.14.0
httpcore          1.0.7
httptools         0.6.4
httpx             0.28.1
idna              3.10
Jinja2            3.1.5
markdown-it-py    3.0.0
MarkupSafe        3.0.2
mdurl             0.1.2
pip               23.2.1
pydantic          2.10.5
pydantic_core     2.27.2
Pygments          2.19.1
python-dotenv     1.0.1
python-multipart  0.0.20
PyYAML            6.0.2
rich              13.9.4
rich-toolkit      0.12.0
shellingham       1.5.4
sniffio           1.3.1
starlette         0.41.3
typer             0.15.1
typing_extensions 4.12.2
uvicorn           0.34.0
uvloop            0.21.0
watchfiles        1.0.3
websockets        14.1

Create a file named app.py that contains something like this.

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def home():
    return {"Hello": "World"}

Run the app.

(demo) [john.doe@localhost ~]$ fastapi run app.py

Something like this should be displayed.

   FastAPI   Starting production server 🚀

             Searching for package file structure from directories with __init__.py files
             Importing from /home/john.doe

    module   🐍 app.py

      code   Importing the FastAPI app object from the module with the following code:

             from app import app

       app   Using import string: app:app

    server   Server started at http://0.0.0.0:8000
    server   Documentation at http://0.0.0.0:8000/docs

             Logs:

      INFO   Started server process [2667570]
      INFO   Waiting for application startup.
      INFO   Application startup complete.
      INFO   Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)

In another Terminal on the same Linux system, the curl command can be used to see if you can get a response from your FastAPI app.

~]$ curl http://127.0.0.1:8000/
{"Hello":"World"}

Optionally, you can use import uvicorn and then use uvicorn.run to pass in additional options, such as host and port.

from fastapi import FastAPI
import uvicorn

app = FastAPI()

@app.get("/")
def home():
    return {"Hello": "World"}

if __name__ == "__main__":
    uvicorn.run(app, host='0.0.0.0', port=12345)

And then you can run the FastAPI app using the Python CLI instead of the fastapi CLI.

(demo) [john.doe@localhost ~]$ python3 app.py
INFO:     Started server process [2681853]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
INFO:     Uvicorn running on http://0.0.0.0:12345 (Press CTRL+C to quit)