How to Set Up Auto-Running Scripts in QGIS

Some of the scripts sold on this site run automatically every time QGIS opens — applying styles, detecting layer types, generating indices. This guide explains how to set that up. You only need to do this once, and no coding is required.

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What you need

• QGIS 3.28 or newer
• The startup scripts you have downloaded (each is a .py file)
• startup_script.py — the entry point that tells QGIS which scripts to load (included with your purchase or downloadable below)

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Step 1 — Create a scripts folder

Make a folder anywhere on your machine to hold all your QGIS scripts. A good location:

Documents/QGIS_scripts/Startup_scripts/

Inside that folder, place two things:

1. An empty file named __init__.py — this tells Python to treat the folder as a package. Just create a blank file with that exact name.
2. startup_script.py — the entry point (see below).

Your downloaded scripts (e.g. auto_style_geojson.py) go in the same folder alongside them.

Startup_scripts/
├── __init__.py              ← empty file, required
├── startup_script.py        ← the entry point
├── auto_style_geojson.py    ← a downloaded startup script
├── auto_generate_ndvi.py    ← another downloaded startup script
└── ...

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Step 2 — Tell QGIS where the entry point is

1. Open QGIS
2. Go to Settings → Options → System → Environment
3. Tick Use custom variables
4. Add a new row:

Apply	Variable	Value
Overwrite	PYQGIS_STARTUP	full path to your startup_script.py

The value should be the full path — for example:

/Users/yourname/Documents/QGIS_scripts/Startup_scripts/startup_script.py

5. Click OK and restart QGIS.

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Step 3 — Register each script in startup_script.py

startup_script.py is the file that decides which scripts run on launch. Open it and you will see a delayed_start function with a block like this — one pair of lines per script:

def delayed_start():

    import Startup_scripts.auto_style_geojson as auto_style_geojson
    auto_style_geojson.run()

    import Startup_scripts.auto_generate_ndvi as auto_generate_ndvi
    auto_generate_ndvi.run()

    # add more scripts below in the same pattern ...

When you download a new startup script, copy it into the Startup_scripts/ folder and add the same two lines for it — using the script’s filename (without .py) as the name:

    import Startup_scripts.your_script_name as your_script_name
    your_script_name.run()

Restart QGIS and it will run automatically from that point on.

To turn a script off without deleting it, put a # in front of both lines:

    # import Startup_scripts.auto_generate_ndvi as auto_generate_ndvi
    # auto_generate_ndvi.run()

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What a startup script looks like

Each script you download follows this pattern — a single run() function that QGIS calls at launch. Here is auto_style_geojson.py as an example:

# auto_style_geojson.py
# Automatically styles any GeoJSON boundary layer with a transparent
# fill and black border whenever it is loaded into QGIS.

from qgis.core import QgsProject, QgsFillSymbol

def apply_transparent_border_style(layer):
    symbol = QgsFillSymbol.createSimple({
        'color': '255,255,255,0',
        'outline_color': '0,0,0,255',
        'outline_width': '1.0'
    })
    layer.renderer().setSymbol(symbol)
    layer.triggerRepaint()

def on_layer_added(layer):
    if layer.source().lower().endswith('.geojson'):
        apply_transparent_border_style(layer)

def run():
    QgsProject.instance().layersAdded.connect(
        lambda layers: [on_layer_added(l) for l in layers]
    )

You never need to edit these files. Just drop them in the folder and register them in startup_script.py.

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Adding a new script

Each time you download a new startup script:

1. Copy the .py file into your Startup_scripts/ folder
2. Open startup_script.py and add the two import lines inside delayed_start
3. Restart QGIS

That’s the full process — no other configuration needed.