KiCad WebAssembly Port

Run KiCad PCBnew in the browser using WebAssembly.

Quick Start

Full Build (KiCad + All Tests)

# 1. Initialize submodules
git submodule update --init --recursive

# 2. Build KiCad WASM (Docker, ~10 min incremental, ~1-2 hours full)
./docker/build.sh

# 3. Build wxWidgets for local testing
./scripts/build-wx-wasm.sh

# 4. Build wxWidgets test apps
./scripts/build-wasm-test.sh

# 5. Run all tests
cd tests && npm install
npm test              # wxWidgets tests (256 tests)
npm run test:kicad    # KiCad tests (2 tests)

wxWidgets Only (No Docker)

# Requires: Node.js 18+ (Emscripten SDK auto-installed on first build)
./scripts/build-wx-wasm.sh
./scripts/build-wasm-test.sh
cd tests && npm install && npm test

Project Structure

kicad-wasm/
├── kicad/                  # KiCad source (git submodule)
├── wxwidgets/              # wxWidgets source (git submodule)
├── wasm/                   # WASM compatibility layer
│   ├── bindings/           # Embind bindings for JavaScript
│   ├── cmake/              # CMake find modules
│   ├── kiplatform/         # Platform abstraction (app, UI, printing)
│   ├── libcontext/         # Coroutine/fiber implementation
│   ├── shims/              # Runtime JavaScript shims
│   └── stubs/              # Stub implementations (libgit2, curl)
├── scripts/                # Build scripts
│   ├── build-wx-wasm.sh   # Build wxWidgets for WASM
│   ├── build-wasm-test.sh          # Build wxWidgets test apps
│   ├── deps/               # Dependency build scripts
│   ├── kicad/              # KiCad build scripts
│   ├── common/             # Shared utilities
│   └── config/             # Build config wrappers
├── docker/                 # Docker build environment
├── tests/                  # Playwright E2E tests
│   ├── e2e/                # Test specs
│   └── apps/               # WASM test applications
├── tools/                  # External tools (local emsdk install)
└── output/                 # Build output (pcbnew.js, pcbnew.wasm)

Feature Branches

Curated design docs and research notes for each feature live in docs/features/<branch-name>/ (committed).

./scripts/create-feature-patches.sh [branch-name] generates per-branch patches (root.patch, kicad.patch, wxwidgets.patch) into a local features/<branch-name>/ scratch dir. That dir is gitignored — the patches are local history, not committed.

Two Build Workflows

1. KiCad Build (Docker)

Full KiCad PCBnew build using Docker:

# Build KiCad WASM
./docker/build.sh

# Copy output to test directory
./tests/scripts/setup-kicad-wasm.sh

# Run KiCad tests
cd tests && npm install && npm run test:kicad

Output: output/pcbnew.js, output/pcbnew.wasm

See docs/build.md for detailed build documentation.

Creating an isolated worktree (with submodule branches)

For an experiment or feature you can work in a disposable git worktree so the main checkout stays pristine. This repo has three submodules (kicad, wxwidgets, web/pcbjam-shared); a new worktree starts with them empty, so initialize and branch each one:

# 1. Create the worktree on a new branch (off main), at a sibling path
git worktree add -b experiment/my-thing ../kicad-wasm-my-thing main

# 2. Check out the submodules INSIDE the worktree (working trees only;
#    git objects are shared with the main checkout)
cd ../kicad-wasm-my-thing
git submodule update --init kicad wxwidgets web/pcbjam-shared

# 3. Create a matching branch in each submodule (they start at detached HEAD)
git checkout -b experiment/my-thing                 # root already on it via -b above
for sm in kicad wxwidgets web/pcbjam-shared; do
  git -C "$sm" checkout -b experiment/my-thing
done

Then build from inside the worktree. Use an isolated Docker project — do NOT set COMPOSE_PROJECT_NAME to another branch's project (e.g. kicad-wasm-main), which can collide with other workflows; docker/build.sh auto-derives an isolated project name from the worktree branch. The first build provisions deps (wxWidgets + OCC) from scratch. To keep the machine responsive, cap parallelism:

KICAD_DOCKER_CPUS=4 ./docker/build.sh pcbnew -j 4

Tear down afterward with git worktree remove ../kicad-wasm-my-thing (and docker compose -p <project> down -v to drop the isolated volumes).

Fresh worktree provisioning

Some test artifacts are gitignored and are NOT produced by the build pipeline, so they don't carry into a newly-created git worktree — without them the gal-webgl tests 404 ("Loading WASM...") and the collab specs fail with Could not resolve "@pcbjam/shared". After building (docker/build.sh + scripts/build-wx-wasm.sh) and cd tests && npm i, run once per worktree:

./scripts/setup-worktree.sh   # idempotent: sysroot headers, gal-webgl harness, web/ pnpm install, collab bundle

2. wxWidgets Test Apps (Local)

Build standalone wxWidgets test apps for feature testing:

# Build wxWidgets for WASM
./scripts/build-wx-wasm.sh

# Build test apps
./scripts/build-wasm-test.sh

# Run wxWidgets tests
cd tests && npm install && npm test

Output: tests/apps/standalone/

Prerequisites

For KiCad Build (Docker)

• Docker Desktop with 16GB+ RAM allocated
• 10+ GB disk space for build cache

For wxWidgets Build (Local)

• Node.js 18+ (for tests)
• Emscripten SDK (auto-installed on first build)

# Initialize submodules
git submodule update --init --recursive

# Install Emscripten SDK (auto-runs on first build, or run manually)
./scripts/setup-emsdk.sh

Testing

cd tests
npm install

# Run all tests
npm test

# Run specific tests
npm run test:kicad          # KiCad tests only
npx playwright test menu    # Menu tests only

See tests/README.md for test documentation.

Screenshots

CI's Linux render is the source of truth for baseline screenshots. On each main push, CI compares its render against the baselines (pinned by the R2-hosted manifest — nothing screenshot-related is committed) and posts the diff (plus the runtime-perf numbers) to Discord. To update baselines after an intended render change, promote the CI run's screenshots in the morelli review app (https://pcbjam-morelli-staging.pcbjam-staging.workers.dev) — pick the run, review the diffs, bulk-select, Promote. CI uploads every run's renders to R2 for that purpose (30-day retention).

cd tests
npm run screenshots:fetch-manifest && npm run screenshots:fetch   # materialize baselines
npm run screenshots:check                                         # local gate: current vs baselines

See tests/tools/screenshots/README.md.

Current Status

• wxWidgets WASM: Core widgets working (menus, dialogs, grids, trees, OpenGL)
• KiCad PCBnew: Builds and loads in browser, canvas rendering working
• In Progress: Testing wxWidgets features used by KiCad

Documentation

See docs/README.md for the full documentation map. Highlights:

• Build System - Docker build details
• Docker README - Container setup
• Debugging Guide - Asyncify/WASM debugging
• Tests README - Test infrastructure

Landing page / website

The marketing site and landing page live in site/ (Astro), deployed as static assets to Cloudflare R2.

On every release, bump the build SHA. site/src/components/Footer.astro has a hardcoded BUILD_SHA constant that is shown in the footer and links to the corresponding commit. Because the main-repo commit pins the KiCad and wxWidgets submodule revisions implicitly, this is our GPLv3 corresponding-source pointer (surfaced on /licenses). The site is static, so nothing sets it automatically — update BUILD_SHA by hand to the deployed pcbjam commit each time you release.

License

KiCad is GPL-3.0. This project follows the same license.

The site combines KiCad (GPLv3) with the wxWidgets fork; the wxWidgets WebAssembly port files are LGPL v2 (without the wxWindows binary exception). See the /licenses page (site/src/content/legal/licenses.md) for the full breakdown and the corresponding-source offer.