IFCX - Open Building Data Exchange

An open-source IFC5 extension for building data: 2D drawings, 3D models, GIS, and annotations in one format.

Key advantages:

94% smaller than DXF -- IFCXB binary rivals DWG file sizes
IFC5-compatible -- every valid IFC5 file is a valid IFCX file
Drawing + Model in one file -- explicit separation via ifcx::purpose
Built-in versioning -- GitDiff: semantic diffs, branching, merging inside the file
6 languages -- Python, TypeScript, Rust, C++, C#, JavaScript
From-scratch parsers -- DXF, DWG, DGN without external libraries
5 integrations -- Revit, FreeCAD, Blender, Web Viewer, CLI
MIT licensed -- no patents, no vendor lock-in

What is IFCX?

IFCX extends IFC5 (buildingSMART) with full 2D CAD capabilities. It stores drawings, 3D models, annotations, and GIS data in a single JSON-based format:

.ifcx -- JSON, human-readable, git-diffable, IFC5-compatible
.ifcxb -- compact binary (CBOR + Zstandard), 94% smaller than DXF

One file can hold 50+ drawing views, a BIM model, and revision history -- all with shared geometry and styles.

Why IFCX?

Problem	IFCX Solution
DWG is proprietary -- controlled by Autodesk, reverse-engineered at best	Fully open schema, MIT licensed, community-governed
DXF is verbose -- text-based group codes, no formal schema	JSON with strict JSON Schema, easy to parse in any language
IFC lacks 2D -- no dimensions, no hatching, no paper space	Extends IFC to cover the full DWG/DXF entity set
No compact open binary -- DXF files are huge	IFCXB rivals DWG in file size (tested: 94% smaller than DXF)
No versioning in CAD files -- changes require external VCS	Built-in GitDiff: revision tracking, branching, merging inside the file
Drawing vs Model confusion -- IFC is model-only, DWG is drawing-only	Explicit `purpose` separation: drawing, model, annotation, sheet

Schema Versions

IFCX supports two schema versions:

Version	Schema File	Architecture	Description
v1	`schema/ifcx.schema.json`	Entity-based	DWG/DXF-style flat entity list. Direct mapping to CAD entities.
v2	`schema/ifcx-v2.schema.json`	IFC5 node-based	Composition-based architecture with `path`, `children`, `attributes`, `inherits`. IFC5-compatible.

v2 Schema (IFC5 Architecture)

The v2 schema adopts the IFC5 node/composition model from buildingSMART. Instead of flat entity lists, data is organized as composable nodes with namespaced attributes:

{
  "header": {
    "ifcxVersion": "2.0",
    "id": "project-001"
  },
  "imports": [
    {"uri": "https://ifcx.dev/@standards.buildingsmart.org/ifc/core/ifc@v5a.ifcx"},
    {"uri": "https://ifcx.openaec.org/schemas/geom@v1.ifcx"}
  ],
  "data": [
    {
      "path": "wall-line-001",
      "attributes": {
        "ifcx::purpose": "drawing",
        "ifcx::geom::line": {"points": [[0, 0], [5000, 0]]},
        "ifcx::style::curveStyle": {"colour": {"r":0,"g":0,"b":0}, "width": 0.35},
        "ifcx::layer::assignment": {"name": "Walls"}
      }
    }
  ]
}

Key v2 concepts:

Nodes with paths -- each element has a unique path identifier
Namespaced attributes -- ifcx::geom::*, ifcx::annotation::*, bsi::ifc::*, etc.
Composition -- children and inherits enable hierarchy and reuse
IFC5 compatibility -- every valid IFC5 file is a valid IFCX file
Drawing vs Model -- explicit ifcx::purpose attribute separates drawing geometry from BIM model data

See docs/ifc5-compatibility.md and docs/drawing-vs-model.md for details.

v1-to-v2 Conversion

Convert existing v1 files to v2 format:

from ifcx.converters import V2Converter

# Convert v1 document to v2 node-based format
v2_doc = V2Converter.from_v1(v1_doc)

# Each v1 entity becomes a node with namespaced attributes
# LINE -> ifcx::geom::line, CIRCLE -> ifcx::geom::circle, etc.

Supported Formats

IFCX reads and writes all major CAD formats:

Format	Read	Write	Description
`.ifcx` (v1)	All languages	All languages	IFCX JSON -- entity-based schema
`.ifcx` (v2)	All languages	All languages	IFCX JSON -- IFC5 node-based schema
`.ifcxb`	All languages	All languages	IFCX Binary (CBOR + Zstandard)
`.dxf`	All languages	All languages	AutoCAD DXF (R12-R2024)
`.dwg`	All languages	--	AutoCAD DWG (R2000/AC1015)
`.dgn`	All languages	--	MicroStation DGN V7 (ISFF)
`.geojson`	Planned	Planned	GeoJSON geographic features
`.gml`	Planned	Planned	OGC Geography Markup Language

All parsers are built from scratch -- no external DXF/DWG/DGN libraries.

Libraries

First-class libraries in 6 languages:

Language	Package	DXF	DWG	DGN	IFCXB
Python	`libraries/python/`	Full parser + writer	R2000 parser	V7 parser	CBOR + Zstandard
TypeScript	`libraries/typescript/`	Full parser + writer	R2000 parser	V7 parser	CBOR + fzstd
Rust	`libraries/rust/`	Full parser + writer	R2000 parser	V7 parser	ciborium + zstd
C++	`libraries/cpp/`	Full parser + writer	R2000 parser	V7 parser	Custom
C#	`libraries/csharp/`	Full parser + writer	R2000 parser	V7 parser	Brotli/GZip
JavaScript	`viewer/`	Built-in converter	--	--	--

Package Publishing (Planned)

Registry	Package Name	Language
PyPI	`pip install ifcx`	Python
npm	`npm install @ifcx/core`	TypeScript/JS
crates.io	`cargo add ifcx`	Rust
NuGet	`dotnet add package Ifcx`	C#
vcpkg	`vcpkg install ifcx`	C++
Shared lib	`ifcx.dll` / `libifcx.so`	C/C++ FFI

Quick Start

Python

from ifcx.document import IfcxDocument
from ifcx.converters import DxfImporter, DxfExporter
from ifcx.binary import IfcxbEncoder

# Import a DXF file
doc = DxfImporter.from_file("drawing.dxf")
print(f"Entities: {len(doc.entities)}, Layers: {list(doc.tables['layers'].keys())}")

# Add geometry
doc.add_entity({"type": "LINE", "start": [0, 0, 0], "end": [100, 50, 0], "layer": "Walls"})
doc.add_entity({"type": "CIRCLE", "center": [50, 50, 0], "radius": 25})

# Export to IFCX JSON
with open("output.ifcx", "w") as f:
    f.write(doc.to_json())

# Export to IFCXB binary (94% smaller than DXF)
IfcxbEncoder.to_file(doc, "output.ifcxb")

# Export back to DXF
DxfExporter.to_file(doc, "output.dxf")

Python (v2 Format)

from ifcx.converters import DxfImporter, V2Converter

# Import DXF and convert to v2 node-based format
v1_doc = DxfImporter.from_file("drawing.dxf")
v2_doc = V2Converter.from_v1(v1_doc)

# v2 uses IFC5-style nodes with namespaced attributes
for node in v2_doc.data:
    print(f"  {node['path']}: {list(node['attributes'].keys())}")

# Save as v2 IFCX
with open("output-v2.ifcx", "w") as f:
    f.write(v2_doc.to_json())

CLI

python cli/ifcx_cli.py convert drawing.dxf output.ifcx     # DXF -> IFCX
python cli/ifcx_cli.py convert drawing.dwg output.ifcxb    # DWG -> IFCXB binary
python cli/ifcx_cli.py convert model.dgn output.dxf        # DGN -> DXF
python cli/ifcx_cli.py info drawing.ifcx                   # Show file info
python cli/ifcx_cli.py diff original.dxf roundtrip.dxf     # Compare files
python cli/ifcx_cli.py stats drawing.ifcxb                 # Compression stats

TypeScript

import { DxfImporter, IfcxWriter } from '@ifcx/core';

const doc = DxfImporter.fromString(dxfContent);
const json = IfcxWriter.toString(doc);

Rust

use ifcx::{DxfImporter, IfcxWriter};

let doc = DxfImporter::from_file("drawing.dxf")?;
IfcxWriter::to_file(&doc, "output.ifcx")?;

Schema Overview

v1 Schema (`schema/ifcx.schema.json`)

Covers all DWG/DXF entity types:

Category	Entity Types
Geometry	LINE, POINT, CIRCLE, ARC, ELLIPSE, SPLINE, RAY, XLINE, HELIX
Polylines	LWPOLYLINE, POLYLINE2D, POLYLINE3D, MLINE
Text	TEXT, MTEXT (with rich text formatting)
Dimensions	LINEAR, ALIGNED, ANGULAR, RADIUS, DIAMETER, ORDINATE, ARC
Annotations	LEADER, MULTILEADER, TOLERANCE (GD&T), TABLE
Hatching	HATCH (patterns, solid fills, gradients, all boundary types)
Blocks	BlockDefinition, INSERT, ATTDEF, ATTRIB (with dynamic blocks)
Layouts	VIEWPORT, LAYOUT, PLOTSETTINGS (paper space / model space)
3D	3DSOLID, BODY, REGION, SURFACE, MESH, 3DFACE
Images	IMAGE, WIPEOUT, UNDERLAY (PDF/DWF/DGN)
Other	LIGHT, CAMERA, SECTION, GEOPOSITIONMARKER, PROXY

v2 Schema (`schema/ifcx-v2.schema.json`)

IFC5-compatible node-based architecture with namespaced attributes:

Namespace	Purpose
`ifcx::geom::*`	2D geometry (line, polyline, circle, arc, ellipse, bspline, mesh)
`ifcx::annotation::*`	Text, dimensions, leaders, tolerances, tables, tags
`ifcx::sheet::*`	Paper layouts, viewports, title blocks, plot settings
`ifcx::hatch::*`	Hatching (pattern, solid, gradient, SVG, material-based)
`ifcx::style::*`	Curve styles, fill styles, text styles
`ifcx::svg::*`	SVG/CSS properties (Bonsai/BlenderBIM compatibility)
`ifcx::layer::*`	Layer assignments and properties
`ifcx::component::*`	Block definitions and reusable components
`ifcx::image::*`	Raster images and embedded media
`ifcx::geo::*`	GIS / CRS (EPSG, GeoJSON, map conversion)
`ifcx::revision::*`	Built-in versioning (GitDiff)
`ifcx::purpose`	Drawing / model / annotation / sheet separation
`bsi::ifc::*`	IFC5 classification, materials, properties (pass-through)
`usd::*`	USD geometry and transforms (IFC5 pass-through)

Versioning (GitDiff)

IFCX v2 includes optional built-in version tracking -- no external VCS required:

Revision metadata -- author, timestamp, message, tags per revision
Semantic diffs -- track changes per node and attribute (not text lines)
Branching and merging -- parallel development with conflict resolution
Undo support -- optional previous values for rollback
Compact storage -- only changed attributes are stored per revision (~5-15 KB per 100 revisions)
Visual diff -- viewer can show added (green), modified (orange), deleted (red) overlays

See docs/versioning.md for the full specification.

Drawing vs Model Separation

IFCX v2 introduces explicit separation between drawing and model data via the ifcx::purpose attribute:

Purpose	Description	Source
`"drawing"`	Pure 2D/3D geometry -- lines, arcs, text. No semantic meaning.	DWG/DXF import
`"model"`	BIM objects with IFC classes, materials, properties.	IFC import
`"annotation"`	Dimensions, labels, tags that reference model objects.	Bonsai/Revit
`"sheet"`	Paper layouts with viewports and title blocks.	Paper space

A single IFCX file can contain both drawing and model data. Viewers can filter by purpose.

See docs/drawing-vs-model.md for details.

Integrations

Tool	Type	Location
Web Viewer	HTML5 Canvas 2D viewer	`viewer/`
PyRevit	Revit view export/import	`integrations/pyrevit/`
FreeCAD	Workbench (import/export)	`integrations/freecad/`
Blender	Addon with Bonsai bridge	`integrations/blender/`
CLI	Command-line converter	`cli/`
Schema Helper	Interactive schema browser	`tools/schema-helper.html`
QGIS	GIS integration (planned)	--

Web Viewer

Open viewer/index.html in a browser. Drag-and-drop .ifcx or .dxf files. Supports pan, zoom, layer visibility, and entity inspection. No build step needed.

PyRevit (Revit)

Copy integrations/pyrevit/IFCX.extension/ to your PyRevit extensions directory. Adds toolbar buttons to export the active view to IFCXB or DXF, and import IFCX files as detail lines.

FreeCAD

Copy integrations/freecad/ to ~/.FreeCAD/Mod/IFCX/. Registers as a workbench with import/export for .ifcx, .ifcxb, .dxf, and .dgn. Also available via FreeCAD Addon Manager.

Blender

Install integrations/blender/ifcx_addon/ as a Blender addon. Adds File > Import/Export menus for IFCX. Includes a Bonsai (BlenderBIM) bridge for IFC annotation export.

Schema Helper

Open tools/schema-helper.html in a browser. Interactive tool for exploring the IFCX v1 and v2 schemas, browsing entity types, attribute namespaces, and generating example JSON.

Round-Trip Verification

Tested with 15 real-world DXF files:

Name           Entities  DXF RT  IFCXB RT  DXF KB  IFCXB KB  Compression
polylines      83        PASS    PASS      94      3.6       96% smaller
3dface         71        PASS    PASS      146     4.0       97% smaller
text           224       PASS    PASS      227     12.0      95% smaller
hatches        32        PASS    PASS      143     3.1       98% smaller
dimensions     4         PASS    PASS      99      2.3       98% smaller
world (2875)   2875      PASS    PASS      546     56.6      90% smaller
─────────────────────────────────────────────────────────────────────────
Total                                      2516    138       94% smaller

DWG parser tested with 223 entities from example_2000.dwg. DGN parser tested with 896 elements from tag.dgn.

Project Structure

Ifc-Factory/
├── schema/                    # IFCX JSON Schema definitions
│   ├── ifcx.schema.json       # v1 schema (entity-based, all DWG/DXF types)
│   ├── ifcx-v2.schema.json    # v2 schema (IFC5 node-based architecture)
│   ├── ifcxb.spec.md          # Binary format specification
│   └── attributes.md          # v2 attribute namespace reference
├── libraries/
│   ├── python/                # Python library (pip installable)
│   ├── typescript/            # TypeScript/JS library (npm)
│   ├── rust/                  # Rust library (crates.io)
│   ├── cpp/                   # C++ library (CMake)
│   └── csharp/                # C# library (.NET 8)
├── viewer/                    # HTML5 2D viewer
├── cli/                       # Command-line converter tool
├── tools/
│   └── schema-helper.html     # Interactive schema browser
├── integrations/
│   ├── pyrevit/               # Autodesk Revit integration
│   ├── freecad/               # FreeCAD workbench
│   └── blender/               # Blender addon + Bonsai bridge
├── docs/                      # Documentation
│   ├── ifc5-compatibility.md  # IFC5 extension architecture
│   ├── drawing-vs-model.md    # Drawing vs model separation
│   ├── versioning.md          # GitDiff / revision tracking
│   ├── connections-and-views.md
│   ├── schema-overview.html   # Visual schema overview
│   ├── schema-graph.html      # Schema relationship graph
│   └── ifcx-report.html       # 2-page project report
├── testdata/                  # Verification test suite
├── examples/                  # Example IFCX files
├── archives/                  # Previous Ifc-Factory code
├── ROADMAP.md                 # Development roadmap
└── README.md

Roadmap

See ROADMAP.md for the full development plan. Current status:

Phase	Description	Status
1	Foundation (schema, skeletons)	Done
2	Core libraries (6 languages)	Done
3	DXF conversion	Done
4	DWG conversion	Done (R2000)
5	Verification test suite	Done
6	2D Viewer	Done
7	FreeCAD integration	Done
8	Blender/Bonsai integration	Done
9	Advanced features	Planned
10	Ecosystem (CLI, publishing)	In progress
11	v2 schema migration (all languages)	In progress
12	Package publishing (pip, npm, crates.io, NuGet, vcpkg)	Planned
13	QGIS integration	Planned
14	GeoJSON/GML import/export	Planned

Design Principles

Full DWG/DXF fidelity -- every entity, style, and property has an IFCX representation
IFC5 compatible -- v2 schema is a superset of IFC5; every valid IFC5 file is valid IFCX
Open and human-readable -- JSON format, version-controllable, diffable
Compact binary -- IFCXB achieves DWG-comparable file sizes
Lossless round-trip -- IFCX <-> IFCXB is always lossless
Multi-language -- first-class libraries in Python, TypeScript, Rust, C++, C#
Drawing + Model -- explicit separation of drawing geometry and BIM model data
Built-in versioning -- optional GitDiff for revision tracking without external VCS
No external dependencies -- all parsers built from scratch
No vendor lock-in -- MIT licensed, no patents

Contributing

Contributions welcome. Key areas:

v2 schema migration for TypeScript, Rust, C++, C# libraries
Additional DWG version support (R2004, R2007, R2010+)
DGN V8 parser
GeoJSON/GML import and export
QGIS integration plugin
Additional entity types and edge cases
Package publishing (npm, PyPI, crates.io, NuGet, vcpkg)
Documentation and examples

Trademarks

This project is not affiliated with, endorsed by, or sponsored by Autodesk, Inc., Bentley Systems, Incorporated, or buildingSMART International Limited.

AutoCAD, Revit, DWG, and DXF are registered trademarks or trademarks of Autodesk, Inc. MicroStation is a registered trademark of Bentley Systems, Incorporated. IFC and buildingSMART are trademarks of buildingSMART International Limited. All other trademarks are the property of their respective owners.

This software reads and writes files in these formats for interoperability purposes only. See NOTICE for the full trademark attribution.

License

MIT License. See LICENSE for details.

Name		Name	Last commit message	Last commit date
Latest commit History 39 Commits
.github		.github
archives		archives
cli		cli
docs		docs
examples		examples
integrations		integrations
libraries		libraries
schema		schema
testdata		testdata
tools		tools
viewer		viewer
.gitignore		.gitignore
CLEAN-ROOM.md		CLEAN-ROOM.md
LICENSE		LICENSE
NOTICE		NOTICE
README.md		README.md
ROADMAP.md		ROADMAP.md

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IFCX - Open Building Data Exchange

What is IFCX?

Why IFCX?

Schema Versions

v2 Schema (IFC5 Architecture)

v1-to-v2 Conversion

Supported Formats

Libraries

Package Publishing (Planned)

Quick Start

Python

Python (v2 Format)

CLI

TypeScript

Rust

Schema Overview

v1 Schema (schema/ifcx.schema.json)

v2 Schema (schema/ifcx-v2.schema.json)

Versioning (GitDiff)

Drawing vs Model Separation

Integrations

Web Viewer

PyRevit (Revit)

FreeCAD

Blender

Schema Helper

Round-Trip Verification

Project Structure

Roadmap

Design Principles

Contributing

Trademarks

License

About

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v1 Schema (`schema/ifcx.schema.json`)

v2 Schema (`schema/ifcx-v2.schema.json`)

Packages