freecad-scripts | SkillBundle

FreeCAD Scripts

Expert skill for generating production-quality Python scripts for the FreeCAD CAD application. Interprets shorthand, quasi-code, and natural language descriptions of 3D modeling tasks and translates them into correct FreeCAD Python API calls.

When to Use This Skill

Writing Python scripts for FreeCAD's built-in console or macro system
Creating or manipulating 3D geometry (Part, Mesh, Sketcher, Path, FEM)
Building parametric FeaturePython objects with custom properties
Developing GUI tools using PySide/Qt within FreeCAD
Manipulating the Coin3D scenegraph via Pivy
Creating custom workbenches or Gui Commands
Automating repetitive CAD operations with macros
Converting between mesh and solid representations
Scripting FEM analyses, raytracing, or drawing exports

Prerequisites

FreeCAD installed (0.19+ recommended; 0.21+/1.0+ for latest API)
Python 3.x (bundled with FreeCAD)
For GUI work: PySide2 (bundled with FreeCAD)
For scenegraph: Pivy (bundled with FreeCAD)

FreeCAD Python Environment

FreeCAD embeds a Python interpreter. Scripts run in an environment where these key modules are available:

import FreeCAD          # Core module (also aliased as 'App')
import FreeCADGui       # GUI module (also aliased as 'Gui') — only in GUI mode
import Part             # Part workbench — BRep/OpenCASCADE shapes
import Mesh             # Mesh workbench — triangulated meshes
import Sketcher         # Sketcher workbench — 2D constrained sketches
import

The FreeCAD Document Model

Core Concepts

Vectors and Placements

Creating and Manipulating Geometry (Part Module)

The Part module wraps OpenCASCADE and provides BRep solid modeling:

Topological Exploration

Mesh Module

Sketcher Module

Create a sketch on XY plane

sketch = doc.addObject("Sketcher::SketchObject", "MySketch") sketch.Placement = FreeCAD.Placement( FreeCAD.Vector(0, 0, 0), FreeCAD.Rotation(0, 0, 0, 1) )

Add geometry (returns geometry index)

idx_line = sketch.addGeometry(Part.LineSegment( FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(10, 0, 0))) idx_circle = sketch.addGeometry(Part.Circle( FreeCAD.Vector(5, 5, 0), FreeCAD.Vector(0, 0, 1), 3))

Add constraints

sketch.addConstraint(Sketcher.Constraint("Coincident", 0, 2, 1, 1)) sketch.addConstraint(Sketcher.Constraint("Horizontal", 0)) sketch.addConstraint(Sketcher.Constraint("DistanceX", 0, 1, 0, 2, 10.0)) sketch.addConstraint(Sketcher.Constraint("Radius", 1, 3.0)) sketch.addConstraint(Sketcher.Constraint("Fixed", 0, 1))

Constraint types: Coincident, Horizontal, Vertical, Parallel, Perpendicular,

Tangent, Equal, Symmetric, Distance, DistanceX, DistanceY, Radius, Angle,

Fixed (Block), InternalAlignment

doc.recompute()

 
### Draft Module
 
```python
import Draft
import FreeCAD
 
# 2D shapes
line = Draft.makeLine(FreeCAD.Vector(0,0,0), FreeCAD.Vector(10,0,0))
circle = Draft.makeCircle(5)
rect = Draft.makeRectangle(10, 5)
poly = Draft.makePolygon(6, radius=5)   # hexagon
 
# Operations
moved = Draft.move(obj, FreeCAD.Vector(10, 0, 0), copy=True)
rotated = Draft.rotate(obj, 45, FreeCAD.Vector(0,0,0),
                        axis=FreeCAD.Vector(0,0,1), copy=True)
scaled = Draft.scale(obj, FreeCAD.Vector(2,2,2), center=FreeCAD.Vector(0,0,0),
                      copy=True)
offset = Draft.offset(obj, FreeCAD.Vector(1,0,0))
array = Draft.makeArray(obj, FreeCAD.Vector(15,0,0),
                         FreeCAD.Vector(0,15,0), 3, 3)

Creating Parametric Objects (FeaturePython)

FeaturePython objects are custom parametric objects with properties that trigger recomputation:

import FreeCAD
import Part
 
class MyBox:
    """A custom parametric box."""
 
    def __init__(self, obj):
        obj.Proxy = self
        obj.addProperty("App::PropertyLength", "Length", "Dimensions",
                         "Box length").Length = 10.0
        obj.addProperty("App::PropertyLength", "Width", "Dimensions",
                         "Box width").Width = 10.0
        obj.addProperty("App::PropertyLength", "Height", "Dimensions",
                         "Box height").Height = 10.0
 
    def execute(self, obj):
        """Called on document recompute."""
        obj.Shape = Part.makeBox(obj.Length, obj.Width, obj.Height)
 
    def onChanged(self, obj, prop):
        """Called when a property changes."""
        pass
 
    def __getstate__(self):
        return None
 
    def __setstate__(self, state):
        return None
 
 
class ViewProviderMyBox:
    """View provider for custom icon and display settings."""
 
    def __init__(self, vobj):
        vobj.Proxy = self
 
    def getIcon(self):
        return ":/icons/Part_Box.svg"
 
    def attach(self, vobj):
        self.Object = vobj.Object
 
    def updateData(self, obj, prop):
        pass
 
    def onChanged(self, vobj, prop):
        pass
 
    def __getstate__(self):
        return None
 
    def __setstate__(self, state):
        return None
 
 
# --- Usage ---
doc = FreeCAD.ActiveDocument or FreeCAD.newDocument("Test")
obj = doc.addObject("Part::FeaturePython", "CustomBox")
MyBox(obj)
ViewProviderMyBox(obj.ViewObject)
doc.recompute()

Common Property Types

Property Type	Python Type	Description
`App::PropertyBool`	`bool`	Boolean
`App::PropertyInteger`	`int`	Integer
`App::PropertyFloat`	`float`	Float
`App::PropertyString`	`str`	String
`App::PropertyLength`	`float` (units)	Length with units
`App::PropertyAngle`	`float` (deg)	Angle in degrees
`App::PropertyVector`	`FreeCAD.Vector`	3D vector
`App::PropertyPlacement`	`FreeCAD.Placement`	Position + rotation
`App::PropertyLink`	object ref	Link to another object
`App::PropertyLinkList`	list of refs	Links to multiple objects
`App::PropertyEnumeration`	`list`/`str`	Dropdown selection
`App::PropertyFile`	`str`	File path
`App::PropertyColor`	`tuple`	RGB color (0.0-1.0)
`App::PropertyPythonObject`	any	Serializable Python object

Creating GUI Tools

Gui Commands

import FreeCAD
import FreeCADGui
 
class MyCommand:
    """A custom toolbar/menu command."""
 
    def GetResources(self):
        return {
            "Pixmap": ":/icons/Part_Box.svg",
            "MenuText": "My Custom Command",
            "ToolTip": "Creates a custom box",
            "Accel": "Ctrl+Shift+B"
        }
 
    def IsActive(self):
        return FreeCAD.ActiveDocument is not None
 
    def Activated(self):
        # Command logic here
        FreeCAD.Console.PrintMessage("Command activated\n")
 
FreeCADGui.addCommand("My_CustomCommand", MyCommand())

PySide Dialogs

from PySide2 import QtWidgets, QtCore, QtGui
 
class MyDialog(QtWidgets.QDialog):
    def __init__(self, parent=None):
        super().__init__(parent or FreeCADGui.getMainWindow())
        self.setWindowTitle("My Tool")
        self.setMinimumWidth(300)
 
        layout = QtWidgets.QVBoxLayout(self)
 
        # Input fields
        self.label = QtWidgets.QLabel("Length:")
        self.spinbox = QtWidgets.QDoubleSpinBox()
        self.spinbox.setRange(0.1, 1000.0)
        self.spinbox.setValue(10.0)
        self.spinbox.setSuffix(" mm")
 
        form = QtWidgets.QFormLayout()
        form.addRow(self.label, self.spinbox)
        layout.addLayout(form)
 
        # Buttons
        btn_layout = QtWidgets.QHBoxLayout()
        self.btn_ok = QtWidgets.QPushButton("OK")
        self.btn_cancel = QtWidgets.QPushButton("Cancel")
        btn_layout.addWidget(self.btn_ok)
        btn_layout.addWidget(self.btn_cancel)
        layout.addLayout(btn_layout)
 
        self.btn_ok.clicked.connect(self.accept)
        self.btn_cancel.clicked.connect(self.reject)
 
# Usage
dialog = MyDialog()
if dialog.exec_() == QtWidgets.QDialog.Accepted:
    length = dialog.spinbox.value()
    FreeCAD.Console.PrintMessage(f"Length: {length}\n")

Task Panel (Recommended for FreeCAD integration)

class MyTaskPanel:
    """Task panel shown in the left sidebar."""
 
    def __init__(self):
        self.form = QtWidgets.QWidget()
        layout = QtWidgets.QVBoxLayout(self.form)
        self.spinbox = QtWidgets.QDoubleSpinBox()
        self.spinbox.setValue(10.0)
        layout.addWidget(QtWidgets.QLabel("Length:"))
        layout.addWidget(self.spinbox)
 
    def accept(self):
        # Called when user clicks OK
        length = self.spinbox.value()
        FreeCAD.Console.PrintMessage(f"Accepted: {length}\n")
        FreeCADGui.Control.closeDialog()
        return True
 
    def reject(self):
        FreeCADGui.Control.closeDialog()
        return True
 
    def getStandardButtons(self):
        return int(QtWidgets.QDialogButtonBox.Ok |
                   QtWidgets.QDialogButtonBox.Cancel)
 
# Show the panel
panel = MyTaskPanel()
FreeCADGui.Control.showDialog(panel)

Coin3D Scenegraph (Pivy)

from pivy import coin
import FreeCADGui
 
# Access the scenegraph root
sg = FreeCADGui.ActiveDocument.ActiveView.getSceneGraph()
 
# Add a custom separator with a sphere
sep = coin.SoSeparator()
mat = coin.SoMaterial()
mat.diffuseColor.setValue(1.0, 0.0, 0.0)  # Red
trans = coin.SoTranslation()
trans.translation.setValue(10, 10, 10)
sphere = coin.SoSphere()
sphere.radius.setValue(2.0)
sep.addChild(mat)
sep.addChild(trans)
sep.addChild(sphere)
sg.addChild(sep)
 
# Remove later
sg.removeChild(sep)

Custom Workbench Creation

import FreeCADGui
 
class MyWorkbench(FreeCADGui.Workbench):
    MenuText = "My Workbench"
    ToolTip = "A custom workbench"
    Icon = ":/icons/freecad.svg"
 
    def Initialize(self):
        """Called at workbench activation."""
        import MyCommands  # Import your command module
        self.appendToolbar("My Tools", ["My_CustomCommand"])
        self.appendMenu("My Menu", ["My_CustomCommand"])
 
    def Activated(self):
        pass
 
    def Deactivated(self):
        pass
 
    def GetClassName(self):
        return "Gui::PythonWorkbench"
 
FreeCADGui.addWorkbench(MyWorkbench)

Macro Best Practices

# Standard macro header
# -*- coding: utf-8 -*-
# FreeCAD Macro: MyMacro
# Description: Brief description of what the macro does
# Author: YourName
# Version: 1.0
# Date: 2026-04-07
 
import FreeCAD
import Part
from FreeCAD import Base
 
# Guard for GUI availability
if FreeCAD.GuiUp:
    import FreeCADGui
    from PySide2 import QtWidgets, QtCore
 
def main():
    doc = FreeCAD.ActiveDocument
    if doc is None:
        FreeCAD.Console.PrintError("No active document\n")
        return
 
    if FreeCAD.GuiUp:
        sel = FreeCADGui.Selection.getSelection()
        if not sel:
            FreeCAD.Console.PrintWarning("No objects selected\n")
 
    # ... macro logic ...
 
    doc.recompute()
    FreeCAD.Console.PrintMessage("Macro completed\n")
 
if __name__ == "__main__":
    main()

Selection Handling

# Get selected objects
sel = FreeCADGui.Selection.getSelection()           # List of objects
sel_ex = FreeCADGui.Selection.getSelectionEx()       # Extended (sub-elements)
 
for selobj in sel_ex:
    obj = selobj.Object
    for sub in selobj.SubElementNames:
        print(f"{obj.Name}.{sub}")
        shape = obj.getSubObject(sub)  # Get sub-shape
 
# Select programmatically
FreeCADGui.Selection.addSelection(doc.MyBox)
FreeCADGui.Selection.addSelection(doc.MyBox, "Face1")
FreeCADGui.Selection.clearSelection()

Console Output

FreeCAD.Console.PrintMessage("Info message\n")
FreeCAD.Console.PrintWarning("Warning message\n")
FreeCAD.Console.PrintError("Error message\n")
FreeCAD.Console.PrintLog("Debug/log message\n")

Common Patterns

Parametric Pad from Sketch

doc = FreeCAD.ActiveDocument
 
# Create sketch
sketch = doc.addObject("Sketcher::SketchObject", "Sketch")
sketch.addGeometry(Part.LineSegment(FreeCAD.Vector(0,0,0), FreeCAD.Vector(10,0,0)))
sketch.addGeometry(Part.LineSegment(FreeCAD.Vector(10,0,0), FreeCAD.Vector(10,10,0)))
sketch.addGeometry(Part.LineSegment(FreeCAD.Vector(10,10,0), FreeCAD.Vector(0,10,0)))
sketch.addGeometry(Part.LineSegment(FreeCAD.Vector(0,10,0), FreeCAD.Vector(0,0,0)))
# Close with coincident constraints
for i in range(3):
    sketch.addConstraint(Sketcher.Constraint("Coincident", i, 2, i+1, 1))
sketch.addConstraint(Sketcher.Constraint("Coincident", 3, 2, 0, 1))
 
# Pad (PartDesign)
pad = doc.addObject("PartDesign::Pad", "Pad")
pad.Profile = sketch
pad.Length = 5.0
sketch.Visibility = False
doc.recompute()

Export Shapes

# STEP export
Part.export([doc.MyBox], "/path/to/output.step")
 
# STL export (mesh)
import Mesh
Mesh.export([doc.MyBox], "/path/to/output.stl")
 
# IGES export
Part.export([doc.MyBox], "/path/to/output.iges")
 
# Multiple formats via importlib
import importlib
importlib.import_module("importOBJ").export([doc.MyBox], "/path/to/output.obj")

Units and Quantities

# FreeCAD uses mm internally
q = FreeCAD.Units.Quantity("10 mm")
q_inch = FreeCAD.Units.Quantity("1 in")
print(q_inch.getValueAs("mm"))  # 25.4
 
# Parse user input with units
q = FreeCAD.Units.parseQuantity("2.5 in")
value_mm = float(q)  # Value in mm (internal unit)

Compensation Rules (Quasi-Coder Integration)

When interpreting shorthand or quasi-code for FreeCAD scripts:

Terminology mapping: "box" → Part.makeBox(), "cylinder" → Part.makeCylinder(), "sphere" → Part.makeSphere(), "merge/combine/join" → .fuse(), "subtract/cut/remove" → .cut(), "intersect" → .common(), "round edges/fillet" → .makeFillet(), "bevel/chamfer" → .makeChamfer()
Implicit document: If no document handling is mentioned, wrap in standard doc = FreeCAD.ActiveDocument or FreeCAD.newDocument()
Units assumption: Default to millimeters unless stated otherwise
Recompute: Always call doc.recompute() after modifications
GUI guard: Wrap GUI-dependent code in if FreeCAD.GuiUp: when the script may run headless
Part.show(): Use Part.show(shape, "Name") for quick display, or doc.addObject("Part::Feature", "Name") for named persistent objects

References

Primary Links

Bundled Reference Documents

See the references/ directory for topic-organized guides:

scripting-fundamentals.md — Core scripting, document model, console
geometry-and-shapes.md — Part, Mesh, Sketcher, topology
parametric-objects.md — FeaturePython, properties, scripted objects
gui-and-interface.md — PySide, dialogs, task panels, Coin3D
workbenches-and-advanced.md — Workbenches, macros, FEM, Path, recipes_

FreeCAD Scripts

When to Use This Skill

Writing Python scripts for FreeCAD's built-in console or macro system
Creating or manipulating 3D geometry (Part, Mesh, Sketcher, Path, FEM)
Building parametric FeaturePython objects with custom properties
Developing GUI tools using PySide/Qt within FreeCAD
Manipulating the Coin3D scenegraph via Pivy
Creating custom workbenches or Gui Commands
Automating repetitive CAD operations with macros
Converting between mesh and solid representations
Scripting FEM analyses, raytracing, or drawing exports

Prerequisites

FreeCAD installed (0.19+ recommended; 0.21+/1.0+ for latest API)
Python 3.x (bundled with FreeCAD)
For GUI work: PySide2 (bundled with FreeCAD)
For scenegraph: Pivy (bundled with FreeCAD)

FreeCAD Python Environment

FreeCAD embeds a Python interpreter. Scripts run in an environment where these key modules are available:

import FreeCAD          # Core module (also aliased as 'App')
import FreeCADGui       # GUI module (also aliased as 'Gui') — only in GUI mode
import Part             # Part workbench — BRep/OpenCASCADE shapes
import Mesh             # Mesh workbench — triangulated meshes
import Sketcher         # Sketcher workbench — 2D constrained sketches
import

The FreeCAD Document Model

Core Concepts

Vectors and Placements

Creating and Manipulating Geometry (Part Module)

The Part module wraps OpenCASCADE and provides BRep solid modeling:

Topological Exploration

Mesh Module

Sketcher Module

Create a sketch on XY plane

sketch = doc.addObject("Sketcher::SketchObject", "MySketch") sketch.Placement = FreeCAD.Placement( FreeCAD.Vector(0, 0, 0), FreeCAD.Rotation(0, 0, 0, 1) )

Add geometry (returns geometry index)

idx_line = sketch.addGeometry(Part.LineSegment( FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(10, 0, 0))) idx_circle = sketch.addGeometry(Part.Circle( FreeCAD.Vector(5, 5, 0), FreeCAD.Vector(0, 0, 1), 3))

Add constraints

Constraint types: Coincident, Horizontal, Vertical, Parallel, Perpendicular,

Tangent, Equal, Symmetric, Distance, DistanceX, DistanceY, Radius, Angle,

Fixed (Block), InternalAlignment

doc.recompute()

 
### Draft Module
 
```python
import Draft
import FreeCAD
 
# 2D shapes
line = Draft.makeLine(FreeCAD.Vector(0,0,0), FreeCAD.Vector(10,0,0))
circle = Draft.makeCircle(5)
rect = Draft.makeRectangle(10, 5)
poly = Draft.makePolygon(6, radius=5)   # hexagon
 
# Operations
moved = Draft.move(obj, FreeCAD.Vector(10, 0, 0), copy=True)
rotated = Draft.rotate(obj, 45, FreeCAD.Vector(0,0,0),
                        axis=FreeCAD.Vector(0,0,1), copy=True)
scaled = Draft.scale(obj, FreeCAD.Vector(2,2,2), center=FreeCAD.Vector(0,0,0),
                      copy=True)
offset = Draft.offset(obj, FreeCAD.Vector(1,0,0))
array = Draft.makeArray(obj, FreeCAD.Vector(15,0,0),
                         FreeCAD.Vector(0,15,0), 3, 3)

Creating Parametric Objects (FeaturePython)

FeaturePython objects are custom parametric objects with properties that trigger recomputation:

import FreeCAD
import Part
 
class MyBox:
    """A custom parametric box."""
 
    def __init__(self, obj):
        obj.Proxy = self
        obj.addProperty("App::PropertyLength", "Length", "Dimensions",
                         "Box length").Length = 10.0
        obj.addProperty("App::PropertyLength", "Width", "Dimensions",
                         "Box width").Width = 10.0
        obj.addProperty("App::PropertyLength", "Height", "Dimensions",
                         "Box height").Height = 10.0
 
    def execute(self, obj):
        """Called on document recompute."""
        obj.Shape = Part.makeBox(obj.Length, obj.Width, obj.Height)
 
    def onChanged(self, obj, prop):
        """Called when a property changes."""
        pass
 
    def __getstate__(self):
        return None
 
    def __setstate__(self, state):
        return None
 
 
class ViewProviderMyBox:
    """View provider for custom icon and display settings."""
 
    def __init__(self, vobj):
        vobj.Proxy = self
 
    def getIcon(self):
        return ":/icons/Part_Box.svg"
 
    def attach(self, vobj):
        self.Object = vobj.Object
 
    def updateData(self, obj, prop):
        pass
 
    def onChanged(self, vobj, prop):
        pass
 
    def __getstate__(self):
        return None
 
    def __setstate__(self, state):
        return None
 
 
# --- Usage ---
doc = FreeCAD.ActiveDocument or FreeCAD.newDocument("Test")
obj = doc.addObject("Part::FeaturePython", "CustomBox")
MyBox(obj)
ViewProviderMyBox(obj.ViewObject)
doc.recompute()

Common Property Types

Property Type	Python Type	Description
`App::PropertyBool`	`bool`	Boolean
`App::PropertyInteger`	`int`	Integer
`App::PropertyFloat`	`float`	Float
`App::PropertyString`	`str`	String
`App::PropertyLength`	`float` (units)	Length with units
`App::PropertyAngle`	`float` (deg)	Angle in degrees
`App::PropertyVector`	`FreeCAD.Vector`	3D vector
`App::PropertyPlacement`	`FreeCAD.Placement`	Position + rotation
`App::PropertyLink`	object ref	Link to another object
`App::PropertyLinkList`	list of refs	Links to multiple objects
`App::PropertyEnumeration`	`list`/`str`	Dropdown selection
`App::PropertyFile`	`str`	File path
`App::PropertyColor`	`tuple`	RGB color (0.0-1.0)
`App::PropertyPythonObject`	any	Serializable Python object

Creating GUI Tools

Gui Commands

import FreeCAD
import FreeCADGui
 
class MyCommand:
    """A custom toolbar/menu command."""
 
    def GetResources(self):
        return {
            "Pixmap": ":/icons/Part_Box.svg",
            "MenuText": "My Custom Command",
            "ToolTip": "Creates a custom box",
            "Accel": "Ctrl+Shift+B"
        }
 
    def IsActive(self):
        return FreeCAD.ActiveDocument is not None
 
    def Activated(self):
        # Command logic here
        FreeCAD.Console.PrintMessage("Command activated\n")
 
FreeCADGui.addCommand("My_CustomCommand", MyCommand())

PySide Dialogs

from PySide2 import QtWidgets, QtCore, QtGui
 
class MyDialog(QtWidgets.QDialog):
    def __init__(self, parent=None):
        super().__init__(parent or FreeCADGui.getMainWindow())
        self.setWindowTitle("My Tool")
        self.setMinimumWidth(300)
 
        layout = QtWidgets.QVBoxLayout(self)
 
        # Input fields
        self.label = QtWidgets.QLabel("Length:")
        self.spinbox = QtWidgets.QDoubleSpinBox()
        self.spinbox.setRange(0.1, 1000.0)
        self.spinbox.setValue(10.0)
        self.spinbox.setSuffix(" mm")
 
        form = QtWidgets.QFormLayout()
        form.addRow(self.label, self.spinbox)
        layout.addLayout(form)
 
        # Buttons
        btn_layout = QtWidgets.QHBoxLayout()
        self.btn_ok = QtWidgets.QPushButton("OK")
        self.btn_cancel = QtWidgets.QPushButton("Cancel")
        btn_layout.addWidget(self.btn_ok)
        btn_layout.addWidget(self.btn_cancel)
        layout.addLayout(btn_layout)
 
        self.btn_ok.clicked.connect(self.accept)
        self.btn_cancel.clicked.connect(self.reject)
 
# Usage
dialog = MyDialog()
if dialog.exec_() == QtWidgets.QDialog.Accepted:
    length = dialog.spinbox.value()
    FreeCAD.Console.PrintMessage(f"Length: {length}\n")

Task Panel (Recommended for FreeCAD integration)

class MyTaskPanel:
    """Task panel shown in the left sidebar."""
 
    def __init__(self):
        self.form = QtWidgets.QWidget()
        layout = QtWidgets.QVBoxLayout(self.form)
        self.spinbox = QtWidgets.QDoubleSpinBox()
        self.spinbox.setValue(10.0)
        layout.addWidget(QtWidgets.QLabel("Length:"))
        layout.addWidget(self.spinbox)
 
    def accept(self):
        # Called when user clicks OK
        length = self.spinbox.value()
        FreeCAD.Console.PrintMessage(f"Accepted: {length}\n")
        FreeCADGui.Control.closeDialog()
        return True
 
    def reject(self):
        FreeCADGui.Control.closeDialog()
        return True
 
    def getStandardButtons(self):
        return int(QtWidgets.QDialogButtonBox.Ok |
                   QtWidgets.QDialogButtonBox.Cancel)
 
# Show the panel
panel = MyTaskPanel()
FreeCADGui.Control.showDialog(panel)

Coin3D Scenegraph (Pivy)

from pivy import coin
import FreeCADGui
 
# Access the scenegraph root
sg = FreeCADGui.ActiveDocument.ActiveView.getSceneGraph()
 
# Add a custom separator with a sphere
sep = coin.SoSeparator()
mat = coin.SoMaterial()
mat.diffuseColor.setValue(1.0, 0.0, 0.0)  # Red
trans = coin.SoTranslation()
trans.translation.setValue(10, 10, 10)
sphere = coin.SoSphere()
sphere.radius.setValue(2.0)
sep.addChild(mat)
sep.addChild(trans)
sep.addChild(sphere)
sg.addChild(sep)
 
# Remove later
sg.removeChild(sep)

Custom Workbench Creation

import FreeCADGui
 
class MyWorkbench(FreeCADGui.Workbench):
    MenuText = "My Workbench"
    ToolTip = "A custom workbench"
    Icon = ":/icons/freecad.svg"
 
    def Initialize(self):
        """Called at workbench activation."""
        import MyCommands  # Import your command module
        self.appendToolbar("My Tools", ["My_CustomCommand"])
        self.appendMenu("My Menu", ["My_CustomCommand"])
 
    def Activated(self):
        pass
 
    def Deactivated(self):
        pass
 
    def GetClassName(self):
        return "Gui::PythonWorkbench"
 
FreeCADGui.addWorkbench(MyWorkbench)

Macro Best Practices

# Standard macro header
# -*- coding: utf-8 -*-
# FreeCAD Macro: MyMacro
# Description: Brief description of what the macro does
# Author: YourName
# Version: 1.0
# Date: 2026-04-07
 
import FreeCAD
import Part
from FreeCAD import Base
 
# Guard for GUI availability
if FreeCAD.GuiUp:
    import FreeCADGui
    from PySide2 import QtWidgets, QtCore
 
def main():
    doc = FreeCAD.ActiveDocument
    if doc is None:
        FreeCAD.Console.PrintError("No active document\n")
        return
 
    if FreeCAD.GuiUp:
        sel = FreeCADGui.Selection.getSelection()
        if not sel:
            FreeCAD.Console.PrintWarning("No objects selected\n")
 
    # ... macro logic ...
 
    doc.recompute()
    FreeCAD.Console.PrintMessage("Macro completed\n")
 
if __name__ == "__main__":
    main()

Selection Handling

# Get selected objects
sel = FreeCADGui.Selection.getSelection()           # List of objects
sel_ex = FreeCADGui.Selection.getSelectionEx()       # Extended (sub-elements)
 
for selobj in sel_ex:
    obj = selobj.Object
    for sub in selobj.SubElementNames:
        print(f"{obj.Name}.{sub}")
        shape = obj.getSubObject(sub)  # Get sub-shape
 
# Select programmatically
FreeCADGui.Selection.addSelection(doc.MyBox)
FreeCADGui.Selection.addSelection(doc.MyBox, "Face1")
FreeCADGui.Selection.clearSelection()

Console Output

FreeCAD.Console.PrintMessage("Info message\n")
FreeCAD.Console.PrintWarning("Warning message\n")
FreeCAD.Console.PrintError("Error message\n")
FreeCAD.Console.PrintLog("Debug/log message\n")

Common Patterns

Parametric Pad from Sketch

doc = FreeCAD.ActiveDocument
 
# Create sketch
sketch = doc.addObject("Sketcher::SketchObject", "Sketch")
sketch.addGeometry(Part.LineSegment(FreeCAD.Vector(0,0,0), FreeCAD.Vector(10,0,0)))
sketch.addGeometry(Part.LineSegment(FreeCAD.Vector(10,0,0), FreeCAD.Vector(10,10,0)))
sketch.addGeometry(Part.LineSegment(FreeCAD.Vector(10,10,0), FreeCAD.Vector(0,10,0)))
sketch.addGeometry(Part.LineSegment(FreeCAD.Vector(0,10,0), FreeCAD.Vector(0,0,0)))
# Close with coincident constraints
for i in range(3):
    sketch.addConstraint(Sketcher.Constraint("Coincident", i, 2, i+1, 1))
sketch.addConstraint(Sketcher.Constraint("Coincident", 3, 2, 0, 1))
 
# Pad (PartDesign)
pad = doc.addObject("PartDesign::Pad", "Pad")
pad.Profile = sketch
pad.Length = 5.0
sketch.Visibility = False
doc.recompute()

Export Shapes

# STEP export
Part.export([doc.MyBox], "/path/to/output.step")
 
# STL export (mesh)
import Mesh
Mesh.export([doc.MyBox], "/path/to/output.stl")
 
# IGES export
Part.export([doc.MyBox], "/path/to/output.iges")
 
# Multiple formats via importlib
import importlib
importlib.import_module("importOBJ").export([doc.MyBox], "/path/to/output.obj")

Units and Quantities

# FreeCAD uses mm internally
q = FreeCAD.Units.Quantity("10 mm")
q_inch = FreeCAD.Units.Quantity("1 in")
print(q_inch.getValueAs("mm"))  # 25.4
 
# Parse user input with units
q = FreeCAD.Units.parseQuantity("2.5 in")
value_mm = float(q)  # Value in mm (internal unit)

Compensation Rules (Quasi-Coder Integration)

When interpreting shorthand or quasi-code for FreeCAD scripts:

Terminology mapping: "box" → Part.makeBox(), "cylinder" → Part.makeCylinder(), "sphere" → Part.makeSphere(), "merge/combine/join" → .fuse(), "subtract/cut/remove" → .cut(), "intersect" → .common(), "round edges/fillet" → .makeFillet(), "bevel/chamfer" → .makeChamfer()
Implicit document: If no document handling is mentioned, wrap in standard doc = FreeCAD.ActiveDocument or FreeCAD.newDocument()
Units assumption: Default to millimeters unless stated otherwise
Recompute: Always call doc.recompute() after modifications
GUI guard: Wrap GUI-dependent code in if FreeCAD.GuiUp: when the script may run headless
Part.show(): Use Part.show(shape, "Name") for quick display, or doc.addObject("Part::Feature", "Name") for named persistent objects

References

Primary Links

Bundled Reference Documents

See the references/ directory for topic-organized guides:

scripting-fundamentals.md — Core scripting, document model, console
geometry-and-shapes.md — Part, Mesh, Sketcher, topology
parametric-objects.md — FeaturePython, properties, scripted objects
gui-and-interface.md — PySide, dialogs, task panels, Coin3D
workbenches-and-advanced.md — Workbenches, macros, FEM, Path, recipes_

import FreeCAD import Part # --- Primitive Shapes --- box = Part.makeBox(10, 10, 10) # length, width, height cyl = Part.makeCylinder(5, 20) # radius, height sphere = Part.makeSphere(10) # radius cone = Part.makeCone(5, 2, 10) # r1, r2, height torus = Part.makeTorus(10, 2) # major_r, minor_r # --- Wires and Edges --- edge1 = Part.makeLine((0, 0, 0), (10, 0, 0)) edge2 = Part.makeLine((10, 0, 0), (10, 10, 0)) edge3 = Part.makeLine((10, 10, 0), (0, 0, 0)) wire = Part.Wire([edge1, edge2, edge3]) # Circles and arcs circle = Part.makeCircle(5) # radius arc = Part.makeCircle(5, FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(0, 0, 1), 0, 180) # start/end angle # --- Faces --- face = Part.Face(wire) # From a closed wire # --- Solids from Faces/Wires --- extrusion = face.extrude(FreeCAD.Vector(0, 0, 10)) # Extrude revolved = face.revolve(FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(0, 0, 1), 360) # Revolve # --- Boolean Operations --- fused = box.fuse(cyl) # Union cut = box.cut(cyl) # Subtraction common = box.common(cyl) # Intersection fused_clean = fused.removeSplitter() # Clean up seams # --- Fillets and Chamfers --- filleted = box.makeFillet(1.0, box.Edges) # radius, edges chamfered = box.makeChamfer(1.0, box.Edges) # dist, edges # --- Loft and Sweep --- loft = Part.makeLoft([wire1, wire2], True) # wires, solid swept = Part.Wire([path_edge]).makePipeShell([profile_wire], True, False) # solid, frenet # --- BSpline Curves --- from FreeCAD import Vector points = [Vector(0,0,0), Vector(1,2,0), Vector(3,1,0), Vector(4,3,0)] bspline = Part.BSplineCurve() bspline.interpolate(points) edge = bspline.toShape() # --- Show in document --- Part.show(box, "MyBox") # Quick display (adds to active doc) # Or explicitly: doc = FreeCAD.ActiveDocument or FreeCAD.newDocument() obj = doc.addObject("Part::Feature", "MyShape") obj.Shape = box doc.recompute()