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CADDesigner-Code/workspace/skills/simplecad-self-evolve/references/docs/api/stack.md

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+# stack
+
+## API Definition
+
+```python
+def stack(assembly: Assembly, parts: Sequence[Union[str, PartHandle]], axis: str = 'z', gap: float = 0.0, align: Literal['center', 'start', 'end'] = 'center', justify: Literal['start', 'center', 'end', 'space-between'] = 'start', bounds: Optional[Tuple[PointAnchor, PointAnchor]] = None) -> Assembly
+```
+
+*Source: constraints.py*
+
+## Description
+
+Declaratively stack multiple parts along the specified axis.
+
+Semantics:
+- sequential stacking: part i is placed after part i-1 with the given gap
+- cross-axis alignment: the other two axes are aligned according to `align`
+- main-axis distribution: `justify` controls how the whole stack is placed
+within the bounds
+
+BBox-first note:
+- This function uses axis-aligned bounding-box (AABB) anchors such as
+`bbox.top` and `bbox.bottom` to approximate Flexbox-like box semantics.
+- For parts with large rotations, the AABB changes with pose, so the layout
+result changes as well. This is expected in the current MVP stage.
+
+Note:
+- This is container-level sugar that compiles into a set of `offset(...)`
+constraints internally.