Debug FastAPI with VSCode

To debug a FastAPI app with VSCode we are going to go the debug section and create a launch.json file.

Create launch.json file on vscode

We are going to use the debug template for FastAPI, VSCode will ask for the name of our file, in my case is run.py that is located in my root folder.

Option to create a FastAPI app launch.json debug file.

It will generate a launch.json file in the .vscode folder

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python: FastAPI",
            "type": "python",
            "request": "launch",
            "module": "uvicorn",
            "args": [
                "run:app"
            ],
            "jinja": true
        }
    ]
}

JSON

launch.json

Make sure that you have your python interpreter set in VSCode and the libs fastapi and uvicorn are installed.

Setting up environments variables in VSCode

To add env vars to the debugging, we need to create env in the configuration file and set our variables there:

{
    ...
    "configurations": [
        { 
            ...,
            "env": {
                "GOOGLE_CLIENT_ID": "id_from_google",
                "SECRET_KEY": "this_is_my_secret_key"
            }
        }
    ]
}

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launch.json

Configure FastAPI port in VSCode

We may also want to run the FastAPI app in another port (default port is 8000), we can set up the port in the args section:

{
    ...
    "configurations": [
        { 
            ...,
            "args": {
                "--port",
                "7000",
                "run:app"
            }
        }
    ]
}

JSON