> ## Documentation Index
> Fetch the complete documentation index at: https://docs.opengeometry.io/llms.txt
> Use this file to discover all available pages before exploring further.

# IFC export (experimental)

> Export scenes to IFC4 text with optional semantics mapping

<Warning>
  IFC export is experimental and may change. If you hit an exporter limitation or confusing output,
  reach out on [Discord](https://discord.gg/cZY2Vm6E).
</Warning>

## Overview

OpenGeometry can export B-Reps and scenes to **IFC4** (text / Part 21 style). You can export a
single B-Rep payload or export a whole scene through `OGSceneManager`. IFC export supports an
optional semantics mapping that lets you control which IFC classes to emit and attach properties.

## Initialization

Initialize the WASM module once before using `OGSceneManager`:

```ts theme={null}
import { OpenGeometry } from "opengeometry";

await OpenGeometry.create({ wasmURL: "/opengeometry_bg.wasm" });
```

## Export APIs

### exportBrepToIfc

```ts theme={null}
import { OGSceneManager } from "opengeometry";

const manager = new OGSceneManager();
const result = manager.exportBrepToIfc(brepSerialized);
```

### exportSceneToIfc / exportCurrentSceneToIfc

```ts theme={null}
import { OGSceneManager } from "opengeometry";

const manager = new OGSceneManager();
const sceneId = manager.createScene("ifc export");

const result = manager.exportSceneToIfc(sceneId);
// or:
const result2 = manager.exportCurrentSceneToIfc();
```

## Result type

`export*ToIfc(...)` returns an `OGIfcExportResult`:

<ResponseField name="text" type="string">
  IFC text output.
</ResponseField>

<ResponseField name="reportJson" type="string">
  A JSON string containing export statistics (elements written, semantics applied, fallbacks, and more).
</ResponseField>

## Config JSON

All IFC exports accept an optional `config_json` string. If it is `null`, `undefined`, or an empty
string, OpenGeometry uses defaults. If you provide `config_json`, it must deserialize into the full
`IfcExportConfig` shape (required fields must be present).

Example JSON payload:

```json theme={null}
{
  "schema": "Ifc4Add2",
  "project_name": "OpenGeometry Project",
  "site_name": "OpenGeometry Site",
  "building_name": "OpenGeometry Building",
  "storey_name": "OpenGeometry Storey",
  "scale": 1.0,
  "error_policy": "BestEffort",
  "validate_topology": true,
  "require_closed_shell": true,
  "semantics": {
    "wall-1": {
      "ifc_class": "IFCWALL",
      "name": "Exterior wall",
      "description": "Demo export wall",
      "tag": "W1",
      "property_sets": {
        "Pset_WallCommon": {
          "Reference": "W1"
        }
      },
      "quantity_sets": {
        "BaseQuantities": {
          "Length": 6.0
        }
      }
    }
  }
}
```

### Semantics mapping

The `semantics` map is keyed by your `entity_id` values in the scene. When you specify
`ifc_class`, OpenGeometry validates it against the allowed list and:

* Uses the requested class when it is supported
* Falls back to `IFCBUILDINGELEMENTPROXY` in best-effort mode
* Errors in strict mode

Supported classes:

* `IFCBUILDINGELEMENTPROXY`
* `IFCWALL`
* `IFCSLAB`
* `IFCCOLUMN`
* `IFCBEAM`
* `IFCMEMBER`
* `IFCDOOR`
* `IFCWINDOW`
* `IFCROOF`
* `IFCSTAIR`
* `IFCRAILING`
* `IFCFOOTING`

## Examples

### Export and download IFC in the browser

```ts theme={null}
const result = manager.exportCurrentSceneToIfc();

const blob = new Blob([result.text], { type: "text/plain" });
const url = URL.createObjectURL(blob);

const link = document.createElement("a");
link.href = url;
link.download = "model.ifc";
link.click();

URL.revokeObjectURL(url);
```

### Native-only file export

<Note>
  Native-only builds also expose `exportSceneToIfcFile(...)` (not available in browser/WASM builds).
</Note>

## Related

* [Exports](/OpenGeometry/concepts/exports) for an overview of available exporters and runtime constraints
* [STL export](/OpenGeometry/api/export/stl)
* [STEP export](/OpenGeometry/api/export/step) (experimental)
* [Scene Management](/OpenGeometry/api/scene/scene-management) - Organizing geometry entities

## Live demo

There is no dedicated IFC export demo page yet. Start from the demo index:
[OpenGeometry demos](https://demo.opengeometry.io/).