How can I run the fast-api server using Pycharm?

Question

I have a simple API function as below,

from fastapi import FastAPI

app = FastAPI()


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

I am starting the server using uvicorn command as,

uvicorn main:app

Since we are not calling any python file directly, it is not possible to call uvicorn command from Pycharm.

So, How can I run the fast-api server using Pycharm?

JPG · Accepted Answer · 2021-05-12T13:40:50.537

180

Method-1: Run FastAPI by calling `uvicorn.run(...)`

In this case, your minimal code will be as follows,

# main.py

import uvicorn
from fastapi import FastAPI

app = FastAPI()


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


if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8000)

Normally, you'll start the server by running the following command,

python main.py

Pycharm Setup

For this setup, and now, you can set the script path in Pycharm's config

Notes

Script Path: path to the FastAPI script
Python Interpreter: Choose your interpreter/virtual environment
Working Directory: Your FastAPI project root

Method-2: Run FastAPI by calling `uvicorn` command

In this case, your minimal code will be as follows,

# main.py

from fastapi import FastAPI

app = FastAPI()


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

Normally, you'll start the server by running the following command,

uvicorn main:app --reload

Pycharm Setup

For this setup, and now, you can set the script path in Pycharm's config

Notes

Module name: set to uvicorn
[Optional] Script: Path to uvicorn binary. You will get the path by executing the command, which uvicorn , inside your environment. (See this image)
Parameters: The actual parameters of uvicorn command
Python Interpreter: Choose your interpreter/virtual environment
Working Directory: Your FastAPI project root

edited May 12 '21 at 13:40

answered Jul 12 '20 at 03:44

JPG

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The problem is that you can't deploy to production this way because you can't really pass other parameters to uvicorn...say "workers", etc. At least I can't get it to work. – GregH Sep 22 '20 at 06:19
Also, this is *not for production*. Suppose if you want to update the number of workers, you need to update your code, which is of course not a good idea. That's why unicorn supports the commandline setup. – JPG Sep 22 '20 at 06:22
BTW, the `uvicorn.run(...)` supports all the args supported by the commandline – JPG Sep 22 '20 at 06:23
You can pass in args via pycharm and dynamically configure uvicorn all args supported via config = Config(app, **kwargs) – Timothy Mugayi Oct 12 '20 at 03:08
Could you explain why that matter here? Sorry that I didn't get your point @TimothyMugayi – JPG Oct 12 '20 at 03:14
I was looking for this solution for the past 2 (two) years now :) – Borko Rastović Jul 23 '21 at 06:57
Is running on `0.0.0.0` safe? I'm a novice but someone might have told me at some point, "don't do that". I changed it to `localhost` and it works. – mLstudent33 Sep 06 '21 at 01:45

score 43 · Answer 2 · edited Nov 18 '21 at 08:52

43

You can do it without adding code to main.py

In target to run instead of Script path choose Module name
In Module name type uvicorn
In parameters app.main:app --reload --port 5000

edited Nov 18 '21 at 08:52

Rui Peres

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answered Mar 24 '21 at 18:48

Max

1,634
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2

Awesome, couln't find an answer anywhere else on how to debug AND reload at the same time – Tobias Feil Apr 09 '21 at 13:03
2

This is the best answer in my opinion as it is the only one that lets you use `--reload` – James Apr 16 '21 at 15:06
Ensure to check working directory if you get 'app' module not found. – Natacha Oct 08 '22 at 16:20
Server log output is better using this method, it should be the best answer. – TASC Solutions Feb 11 '23 at 17:44

score 12 · Answer 3 · answered Jul 12 '20 at 03:43

Try to call uvicorn inside your code. e.g:

from fastapi import FastAPI
import uvicorn

app = FastAPI()


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

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=5000, log_level="info")

Reference

Suyog Shimpi · Answer 4 · 2021-09-20T03:14:32.330

3

Another example, this might be helpful to someone.

# fastapi_demo.py

import uvicorn
from fastapi import FastAPI, Response

app = FastAPI()

@app.route('/', methods=['POST'])
def demo(request):
    try:
        print(request)
    except Exception as e:
        print(e)
    return Response(content='OK')


if __name__ == '__main__':
    uvicorn.run(app='fastapi_demo:app')

edited Sep 20 '21 at 03:14

answered Aug 20 '21 at 09:48

Suyog Shimpi

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1
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this results in the fastapi_demo to be run twice. If you have a (for example) global variable it will be initialized – jaecktec Sep 19 '21 at 09:19
Thanks, @Coco to identify my mistake. It was running twice just because of misconfiguration. Actually, I have added `reload=True` and it leads to double initialization. To avaid that you must add `reload_dirs=['/app_dir_name',]`. But, this approach is not wrong to run app by PyCharm. [Check this](https://www.uvicorn.org/#running-programmatically) FYI – Suyog Shimpi Sep 20 '21 at 06:43
you would need to run `uvicorn.run(app)` instead, that'd not start the app twice – jaecktec Oct 24 '21 at 19:37

How can I run the fast-api server using Pycharm?

4 Answers4

Method-1: Run FastAPI by calling `uvicorn.run(...)`

Pycharm Setup

Notes

Method-2: Run FastAPI by calling `uvicorn` command

Pycharm Setup

Notes

Linked

How can I run the fast-api server using Pycharm?

4 Answers4

Method-1: Run FastAPI by calling uvicorn.run(...)

Pycharm Setup

Notes

Method-2: Run FastAPI by calling uvicorn command

Pycharm Setup

Notes

Linked

Method-1: Run FastAPI by calling `uvicorn.run(...)`

Method-2: Run FastAPI by calling `uvicorn` command