magic/npm

magic-vlsi-wasm

Magic VLSI layout tool, compiled to WebAssembly as a headless library. Runs in Node.js, browsers, and Web Workers — no X11, no Tk, no native dependencies.

Use it to programmatically read and write .mag, .gds, .cif, .ext, and SPICE netlists; run DRC; extract parasitics — anywhere JavaScript runs.

Install

npm install magic-vlsi-wasm

Requires Node.js 18 or newer.

Quick start

import createMagic from 'magic-vlsi-wasm';

const { runCommand, FS } = await createMagic();

// Write a layout into Magic's virtual filesystem
FS.writeFile('/work/inv.mag', layoutBytes);

// Run Magic commands
runCommand('tech load minimum');
runCommand('load /work/inv');
runCommand('gds write /work/inv');

// Read the result back out
const gdsBytes = FS.readFile('/work/inv.gds');

The scmos technology family (scmos, minimum, nmos, ...) is embedded in the WASM binary and available out of the box. Custom tech files can be written into the VFS at /magic/sys/current/<name>.tech.

API

createMagic(options?): Promise<MagicInstance>

options is forwarded to the underlying Emscripten module. Useful keys:

Key	Default	Purpose
wasmBinary	fetched lazily	Pre-fetched ArrayBuffer of magic.wasm (skips a network round-trip in browsers)
print	console.log	Callback for each stdout line
printErr	console.error	Callback for each stderr line

The returned MagicInstance exposes:

Method	Description
runCommand(cmd: string)	Dispatch a single Magic command. Returns 0 on success.
sourceFile(path: string)	Execute a script from the virtual filesystem.
init()	Force initialization. Idempotent — runCommand and sourceFile call it for you.
update()	Drive a display-update cycle. No-op in this headless build.
FS	Emscripten virtual filesystem. See the Emscripten docs.

Full TypeScript types ship in index.d.ts.

Examples

The package ships runnable examples for the most common workflows. After installing, run one directly:

node node_modules/magic-vlsi-wasm/examples/extract.js
node node_modules/magic-vlsi-wasm/examples/gds.js
node node_modules/magic-vlsi-wasm/examples/drc.js
node node_modules/magic-vlsi-wasm/examples/cif.js

Or, when developing inside this repo:

npm test           # full suite (extract, gds, drc, cif)
npm run test:gds   # GDS write only
npm run test:drc   # DRC check only
npm run test:cif   # CIF write only

Each example is self-contained and reads examples/siliwiz.{mag,tech} by default. See examples/ for the source.

Build from source

If you want to rebuild the WASM module yourself, see toolchains/emscripten/README.md. The short version:

bash npm/build.sh           # debug build, copies magic.js + magic.wasm into npm/
bash npm/build.sh --release # optimized
bash npm/build.sh --test    # build + run tests
bash npm/build.sh --pack    # build + produce magic-vlsi-wasm-<version>.tgz

You will need an activated emsdk checkout (Magic pins emsdk 3.1.56 — see the comment in npm/build.sh).

Limitations

• Headless only. There is no display driver, so commands that draw to a window (view, findbox, interactive macros) are no-ops.
• WASM memory starts at 32 MB and grows as needed. Very large GDS imports may need INITIAL_MEMORY bumped (rebuild required).
• Single-threaded. WASM modules are not thread-safe — create one instance per worker.

License

HPND — Copyright (C) 1985, 1990 Regents of the University of California.

Bundled test technology

The example layout (examples/siliwiz.mag) and technology file (examples/siliwiz.tech) are derived from the SiliWiz educational silicon design tool. They are bundled here only as a runnable smoke test for the WASM build. The technology file is © R. Timothy Edwards, Open Circuit Design, 2023, marked by the author as containing no proprietary information.