ifc-commit/docs/wasm.md

IFC in the Browser: WASM Options

Goal

Run ifc-commit logic (IFC extraction, modification, merge) client-side in a browser — no server, no Python install.

---

Option 1 — IfcOpenShell via Pyodide (closest drop-in)

Repo: https://github.com/IfcOpenShell/wasm-wheels Wheel index: https://ifcopenshell.github.io/wasm-wheels/

IfcOpenShell ships WASM as Pyodide wheels — Python packages compiled to wasm32 via Emscripten. The full Python API runs inside a browser through the Pyodide runtime.

Setup

<script src="https://cdn.jsdelivr.net/pyodide/v0.27/full/pyodide.js"></script>

const pyodide = await loadPyodide();
await pyodide.loadPackage("micropip");
await pyodide.runPythonAsync(`
  import micropip
  await micropip.install(
    "https://ifcopenshell.github.io/wasm-wheels/"
    "ifcopenshell-0.8.3+34a1bc6-cp313-cp313-emscripten_4_0_9_wasm32.whl"
  )
`);

Usage

# Identical to desktop ifccommit.py
import ifcopenshell
import ifcpatch

model = ifcopenshell.open("input.ifc")
result = ifcpatch.execute({
    "input": "input.ifc",
    "file": model,
    "recipe": "ExtractElements",
    "arguments": [["IfcWall", "IfcSlab"]],
})
ifcpatch.write(result, "output.ifc")

Available wheels (early 2026)

Wheel	Python	Emscripten
ifcopenshell-0.8.3+34a1bc6-cp313-cp313-emscripten_4_0_9_wasm32.whl	3.13	4.0.9
ifcopenshell-0.8.2+d50e806-cp312-cp312-emscripten_3_1_58_wasm32.whl	3.12	3.1.58

Pros / Cons

+	-
Identical API to desktop — ifcpatch recipes work as-is	Requires loading Pyodide (~10 MB) + Python interpreter overhead
ifcpatch, ifcclash, ifctester all available	Not on PyPI; must install from CDN wheel URL
Zero code changes to ifccommit.py	Slower than native due to WASM + Python layers
Models stay in browser (no server upload)	Large initial download

Best fit: A browser version that mirrors the CLI exactly — same ExtractElements, PatchIfc recipes, same Python logic.

---

Option 2 — web-ifc (C++/JS, no Python)

npm: web-ifc Repo: https://github.com/ThatOpen/engine_web-ifc (by That Open Company, formerly IFCjs)

C++ IFC parser compiled to WASM via Emscripten, with a TypeScript API. The dominant ecosystem for browser IFC tools.

npm install web-ifc

import { IfcAPI } from "web-ifc";

const api = new IfcAPI();
await api.Init();
const bytes = new Uint8Array(await file.arrayBuffer());
const modelID = api.OpenModel(bytes);
const walls = api.GetLineIDsWithType(modelID, api.IFCWALL);
api.CloseModel(modelID);

Pros / Cons

+	-
Native JS/TS — no Python runtime	No ifcpatch recipe system
Smaller footprint than Pyodide	Lower-level API — more code to replicate ifccommit logic
Actively maintained, large ecosystem	No ifcclash, ifctester, ifcdiff equivalents
Runs in Web Workers (multi-threaded)	Write support is lower-level

Best fit: A rewrite of ifc-commit as a TypeScript/JS app, or integration into a larger BIM web app (Three.js, React, etc.).

---

Option 3 — ifc-lite (Rust/WASM + WebGPU)

Repo: https://github.com/louistrue/ifc-lite npm scope: @ifc-lite/* (e.g. @ifc-lite/parser, @ifc-lite/geometry, @ifc-lite/query)

Rust-based IFC parser compiled to WASM via wasm-bindgen, with WebGPU rendering. Claims 5× faster geometry processing than alternatives. Supports IFC4, IFC4X3, and IFC5 (IFCX alpha).

npm install @ifc-lite/parser @ifc-lite/query

Pros / Cons

+	-
Fastest option (Rust + WebGPU)	Very new — alpha-stage API stability
Supports IFC5/IFCX	No ifcpatch equivalent
No Rust toolchain needed (pre-built WASM)	Requires rewriting all ifc-commit logic in TS

Best fit: Performance-critical geometry/visualization use cases.

---

Option 4 — IFCflow (inspiration, not a library)

URL: https://ifcflow.com Docs repo: https://github.com/louistrue/IfcFlow-Docs

A browser-based visual node editor for IFC pipelines. Uses the IfcOpenShell WASM wheels (Pyodide) for on-device processing. Not a reusable library — a hosted web app — but demonstrates that the Pyodide approach works end-to-end for extract/filter/export workflows similar to ifc-commit.

---

Recommended Path for ifc-commit

Phase 1 — Pyodide prototype (zero code changes)

1. Create web/index.html with Pyodide bootstrapped.
2. On file drop/upload, pass the ArrayBuffer into Python as bytes.
3. Call ifccommit.py functions directly via pyodide.runPythonAsync().
4. Offer the output .ifc as a download via a Blob URL.

This requires no changes to ifccommit.py.

Phase 2 — web-ifc rewrite (optional, for performance)

If Pyodide startup time (~3–5 s) or bundle size is a problem, rewrite the core operations using web-ifc TypeScript API. This is a significant effort — ifcpatch recipes must be re-implemented.

---

References

• IfcOpenShell WASM wheels: https://github.com/IfcOpenShell/wasm-wheels
• Wheel CDN: https://ifcopenshell.github.io/wasm-wheels/
• Pyodide: https://pyodide.org
• web-ifc: https://github.com/ThatOpen/engine_web-ifc
• ifc-lite: https://github.com/louistrue/ifc-lite
• IFCflow: https://ifcflow.com