# Installing FastAPI on unmanaged servers

> Install FastAPI and run it with an ASGI server on an unmanaged server, where you control the full software stack.

Source: https://helpcenter.ruachost.com/developers/programming-languages/installing-fastapi-on-unmanaged-servers/

**Installing FastAPI on unmanaged servers**\
Learn how to install and run FastAPI on an unmanaged server using the command line. FastAPI is a Python-based framework for building APIs (Application Programming Interfaces).

This article provides step-by-step instructions for installing and running FastAPI on an unmanaged server.

**Important:** FastAPI is asynchronous and requires the Asynchronous Server Gateway Interface (ASGI), not WSGI. Managed hosting environments using Passenger and WSGI cannot run FastAPI, so this setup is only for unmanaged hosting accounts.

**Installing FastAPI**\
To install FastAPI, create a Python virtual environment, activate it, and then use `pip` to install FastAPI. Follow these steps:

1. Log in to your server using SSH.
2. **Ubuntu users (as root)**: install `curl` and Python 3 virtual environment support:

```
apt install curl python3.8-venv
```

**Note:** Other Linux distributions may already have these packages installed. Consult your distribution’s documentation if not.

3. As a regular (non-root) user, create and activate a virtual environment:

```
cd ~
python3 -m venv fastapi-test
cd fastapi-test
source bin/activate
```

4. Update pip:

```
pip install --upgrade pip
```

5. Install FastAPI and Uvicorn:

```
pip install fastapi
pip install "uvicorn[standard]"
```

6. Verify the installation and version:

```
pip show fastapi
```

**Running an example application**\
Now that FastAPI is installed, you can create a basic application:

1. Create a file named `main.py` using a text editor.
2. Copy the following code into `main.py`:

```
from typing import Union
from fastapi import FastAPI

app = FastAPI()

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

@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

3. Start the development server:

```
uvicorn main:app --reload
```

4. In another terminal, test the API using curl:

```
curl localhost:8000/items/5?q=my_query
```

Expected JSON response:

```
{"item_id":5,"q":"my_query"}
```

You now have a basic working API built with FastAPI.

**More information**\
For further details and documentation, visit [FastAPI Official Site](https://fastapi.tiangolo.com/).