# Prerequisites

## Python

kfactory requires **Python 3.10+**. Familiarity with Python basics — functions, classes, type hints, and virtual environments — will help you follow the tutorials.

A good starting point: [learnpython.org](<https://www.learnpython.org/>)

## Python environment

We strongly recommend using a dedicated virtual environment per project. Popular choices:

| Tool | Notes |
| --- | --- |
| [uv](<https://docs.astral.sh/uv/>) | Fast, modern, Rust-backed. Recommended. |
| [venv](<https://docs.python.org/3/library/venv.html>) | Built into Python, minimal setup. |
| [conda / miniconda](<https://docs.conda.io/en/latest/miniconda.html>) | Good when non-Python dependencies are involved. |

## KLayout

[KLayout](<https://www.klayout.de/intro.html>) is the open-source GDS/OASIS viewer that kfactory builds on. kfactory uses the `klayout` Python package internally, but having the **desktop application** installed lets you open `.gds` files and use the `kf.show()` live preview feature.

Download: [klayout.de/build.html](<https://www.klayout.de/build.html>)

## klive (optional)

[klive](<https://github.com/gdsfactory/klive>) is a KLayout plug-in that streams GDS files directly from Python into the running KLayout window. It is not required to run kfactory, but it makes the interactive design loop much faster.

See [KLive Setup](<https://gdsfactory.github.io/kfactory/3.5.0/getting_started/klive_setup/index.md>) for installation instructions.

## See Also

| Topic | Where |
| --- | --- |
| Installing kfactory | [Getting Started: Installation](<https://gdsfactory.github.io/kfactory/3.5.0/getting_started/installation/index.md>) |
| KLive streaming setup | [Getting Started: KLive Setup](<https://gdsfactory.github.io/kfactory/3.5.0/getting_started/klive_setup/index.md>) |
| 5-minute quickstart | [Getting Started: Quickstart](<https://gdsfactory.github.io/kfactory/3.5.0/getting_started/quickstart/index.md>) |