# export_model_json

## API Definition

```python
def export_model_json(
    session: 'GraphSession',
    indent: int = 2,
    *,
    result_node_ids: Optional[Sequence[str]] = None,
) -> str
```

*Source: serializer.py*

## Import Surface

- top-level: `from simplecadapi import export_model_json`

## Description

Export the canonical 2.0 model seed JSON.

Current Phase 1 scope uses the active session as the container of:
- operation graph
- expression graph
- capabilities/schema metadata

When `result_node_ids` is omitted, explicitly captured session results are used
when available; otherwise export falls back to graph leaves. New top-level model
code normally reads `ModelResult.model_json` instead of calling this function
directly.