kwasm 0.2.6

Standalone web-based layout viewer using KLayout

kwasm

Standalone wasm-based client-only layout viewer for semiconductor designs, powered by KLayout.

kwasm compiles KLayout's layout rendering engine to WebAssembly via Emscripten, wrapped in a Rust FFI layer. The result is an interactive GDS2/OASIS viewer that runs entirely in the browser — no install required.

Features

• View GDS2 and OASIS layout files in the browser
• Pan, zoom, select, measure, and draw annotations
• Layer panel with per-layer visibility toggling and color display
• Toolbar with switchable interaction modes
• Dark and light theme
• Load layouts via drag & drop or ?url= query parameter
• Configurable toolbar via ?tools= query parameter
• Python package with embeddable Jupyter viewer
• CLI for bundling layouts into self-contained HTML files

Quick Start

# Build all WASM artifacts
just build

# Build docs site and serve at http://localhost:8080
just serve

Available Commands

Command	Description
just build [mode]	Build WASM artifacts (all by default)
just dev [mode]	Copy bundled HTML from dist/ into the Python package
just wheel	Build Python wheel
just dist	Build everything (WASM + wheel)
just check [mode]	Check WASM compilation (no link)
just docs [mode]	Build versioned documentation pages in site/
just serve [mode] [port]	Build docs and serve
just clean	Clean build artifacts

Query Parameters

Parameter	Description
?url=	Load a layout file from a URL (e.g. ?url=https://example.com/chip.gds)
?tools=	Comma-separated list of toolbar tools to show. All tools are shown by default.
?lyp=	Load a .lyp layer properties file from a URL (e.g. ?lyp=layers.lyp)
?drop=	Enable/disable drag & drop (true/false). Default: true.
?layers=	Show/hide the layer panel (true/false). Default: true.

Available tool names for ?tools=:

Name	Description
select	Pointer/select mode
move	Pan mode
ruler	Ruler/measure mode
draw-polyline	Draw polyline annotations
draw-manhattan	Draw manhattan route
draw-freehand	Draw freehand annotations
clear-all	Erase all annotations
fit-all	Zoom to fit layout
reload	Reload layout
top-ports	Toggle top-level port markers
instance-ports	Toggle instance port markers
dangling-ports	Toggle dangling port markers
text	Toggle text labels
theme	Light/dark mode toggle

Example: ?tools=ruler,top-ports,instance-ports shows only the ruler, top-level ports, and instance ports buttons.

Python Package

kwasm is available as a Python package that bundles the WASM viewer:

pip install kwasm

Jupyter Notebook

import kwasm

kwasm.show("my_chip.gds")
kwasm.show("my_chip.gds", lyp="layers.lyp", tools=("ruler", "fit-all"))

When used with gdsfactory, you can pass components directly:

import gdsfactory as gf
import kwasm

c = gf.components.mzi()
kwasm.show(c)

CLI

# Bundle a GDS into a self-contained HTML file
kwasm bundle my_chip.gds --output viewer.html --lyp layers.lyp

# Bundle and open in the default browser
kwasm view my_chip.gds

License

GPL-3.0