---
id: kfactory
version: "3.0.4"
license: unclear
license_treatment: unclear
maintenance: active
---

# kfactory — KLayout API implementation of gdsfactory

License: unclear · Maintenance: active · Downloads: 242.9K/mo

## What it is and what it does

KFactory is a Python framework for designing photonic and electronic chip layouts, built on KLayout's C++ geometry engine. It abstracts chip design into parametric cells that can be cached and reused, provides routing algorithms for optical and electrical paths, and supports cross-section definitions for waveguide profiles. The framework integrates schematic-driven workflows with netlist extraction and layout-vs-schematic verification, allowing designers to move between logical schematics and physical layouts.

The package works with both integer (DBU) and floating-point (µm) coordinate systems, includes Jupyter integration for live preview in KLayout, and bundles a PDK system for packaging technology definitions. It requires Python 3.12 or later and depends on 18 runtime packages spanning geometry (scipy, rectangle-packer), configuration (pydantic, ruamel-yaml), and version management (semver). No known security vulnerabilities are reported.

Use it for:

- Design parametric photonic circuits with automatic cell deduplication and caching
- Route optical waveguides and electrical traces with Manhattan and all-angle primitives
- Define reusable cross-sections and automatically generate cladding layers via Minkowski sums
- Extract netlists from physical layouts and verify consistency with schematics
- Develop technology PDKs that bundle layers, factories, and design rules for reuse
- Interactively preview and edit chip layouts in Jupyter notebooks with KLive integration

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

KFactory is a Python framework for designing photonic and electronic chip layouts, providing parametric cells, routing primitives, cross-section definitions, and schematic-driven design with layout verification on top of KLayout's geometry engine.

Yes, if you are designing photonic or electronic chips and want a Python-native parametric layout framework. The active maintenance, low install friction, and rich feature set (routing, schematics, verification) make it a solid choice for chip design workflows. Verify the license treatment before use in proprietary contexts, and confirm klayout system dependencies match your environment.

## Install

pip install kfactory
uv add kfactory
poetry add kfactory

## Installing kfactory

Before you install: Low friction; pure Python wheel with 18 runtime dependencies including well-maintained packages like pydantic, loguru, and scipy. Active maintenance with a release 18 days ago. Requires Python 3.12 or later.

License in practice: License treatment is unclear in the fact sheet; the description excerpt mentions MIT licensing, but the metadata does not confirm this. Verify the actual license before adopting in a commercial or restricted context.

Quickstart:

pip install kfactory

import kfactory as kf

@kf.cell
def my_waveguide() -> kf.KCell:
    return kf.KCell(name="waveguide")

Requires Python 3.12 or later; klayout system dependency may need separate installation depending on your platform.

Verify before relying:

- Whether the MIT license mentioned in the description excerpt is the authoritative license for this version
- Whether klayout requires system-level installation or is bundled with the package
- Performance characteristics and scalability limits for large chip designs
- Compatibility guarantees with specific KLayout versions

## Package facts

- License: not declared (unclear)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 242.9K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

photonic chip layout design, parametric cell generation, optical waveguide routing, GDS layout framework, schematic-driven chip design, KLayout Python API, electronic circuit layout, netlist extraction verification, chip-design, photonics, parametric-layout

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