Schemas

Use these schemas when constructing MCP arguments. Function-specific parameters are documented in the tool pages.

Target selectors

Most tools accept any of these target forms:

"Bracket"
"obj_2a9f4c..."
"Bracket#Face3"
"Bracket#Edge2"
"sub_d8f1..."

Plain object names resolve through the document.
Snapshot uids come from take_snapshot.
Subelement refs use Object#FaceN, Object#EdgeN, Object#VertexN, Object#SolidN, or a sub_... uid.
When names collide or labels differ from internal names, prefer snapshot uid.

Vector

Accepted vector forms:

[10, 20, 0]
{"x": 10, "y": 20, "z": 0}

Two-component lists are interpreted as z=0. Use millimeter-scale coordinates unless the document explicitly uses another unit convention.

Placement

{
  "Base": {"x": 10, "y": 0, "z": 5},
  "Rotation": {
    "Axis": {"x": 0, "y": 0, "z": 1},
    "Angle": 45
  }
}

Alternate base key:

{"Position": {"x": 0, "y": 0, "z": 0}}

Alternate rotation key set:

{"Rotation": {"yaw": 0, "pitch": 0, "roll": 90}}

The axis-angle Angle is degrees in MCP property dictionaries. Native Python FreeCAD.Rotation accepts constructor forms documented in Python API.

Object spec

Used by create_objects and mirrored by create_object arguments.

{
  "Name": "Rib001",
  "Type": "Part::Box",
  "Properties": {
    "Length": 40,
    "Width": 8,
    "Height": 16,
    "Placement": {
      "Base": {"x": 0, "y": 0, "z": 0},
      "Rotation": {"Axis": {"x": 0, "y": 0, "z": 1}, "Angle": 0}
    },
    "ViewObject": {
      "ShapeColor": [0.8, 0.8, 0.8, 1.0],
      "Transparency": 0
    }
  },
  "Analysis": null
}

Property assignment rules:

If a property exists in PropertiesList, it is assigned directly.
Placement dict becomes a placement object.
Vector-valued properties accept vector dicts.
Base, Tool, Source, and Profile can reference another object by name.
References accepts a list of [object_name, subelement] pairs.
ViewObject applies visual properties such as ShapeColor, Transparency, Visibility, DisplayMode, LineColor, LineWidth, PointColor, and PointSize.

Common TypeIds

App::DocumentObjectGroup
App::Part
Part::Feature
Part::Box
Part::Cylinder
Part::Sphere
Part::Cone
Part::Torus
Part::Fuse
Part::Cut
Part::Common
PartDesign::Body
PartDesign::Pad
PartDesign::Pocket
PartDesign::Revolution
PartDesign::Fillet
PartDesign::Chamfer
Sketcher::SketchObject
Spreadsheet::Sheet
TechDraw::DrawPage
TechDraw::DrawViewPart
Fem::FemAnalysis

Check an object’s exact writable properties with get_object before assigning uncommon fields.

Sketch geometry entries

Used by edit_sketch_geometry and make_sketch_extrude.profile.

{"type": "LineSegment", "start": [0, 0], "end": [20, 0], "construction": false}
{"type": "Circle", "center": [10, 10], "radius": 5}
{"type": "ArcOfCircle", "center": [0, 0], "radius": 10, "start_angle": 0, "end_angle": 90, "angle_unit": "deg"}
{"type": "Point", "position": [0, 0]}
{"type": "Ellipse", "center": [0, 0], "major_radius": 12, "minor_radius": 6, "major_axis_direction": [1, 0, 0]}

Position ids used by constraints:

none/edge
start
end
center

Position names accepted: none, any, curve, edge, start, first, begin, end, last, center, mid, midpoint.

Sketch constraints

Each entry must include type. name is optional. Dimensional constraints accept driving: false to create a reference constraint.

{"type": "Coincident", "first": 0, "first_pos": "end", "second": 1, "second_pos": "start"}
{"type": "Horizontal", "first": 0}
{"type": "Vertical", "first": 1}
{"type": "Equal", "first": 0, "second": 2}
{"type": "Parallel", "first": 0, "second": 2}
{"type": "Perpendicular", "first": 0, "second": 1}
{"type": "Tangent", "first": 2, "second": 3}
{"type": "Distance", "first": 0, "value": 25}
{"type": "DistanceX", "first": 0, "first_pos": "start", "second": 0, "second_pos": "end", "value": 40}
{"type": "DistanceY", "first": 1, "value": 20}
{"type": "Radius", "first": 2, "value": 8}
{"type": "Diameter", "first": 2, "value": 16}
{"type": "Angle", "first": 0, "second": 1, "value": 45, "angle_unit": "deg"}
{"type": "PointOnObject", "first": 3, "first_pos": "start", "second": -1}
{"type": "Symmetric", "first": 0, "first_pos": "start", "second": 0, "second_pos": "end", "third": -2}
{"type": "Block", "first": 0}

Sketch axes use -1 for sketch X axis, -2 for sketch Y axis, and -3 for origin where supported by the constraint.

Spreadsheet cell maps

Write cells:

{
  "A1": "Length",
  "B1": "40 mm",
  "A2": "Width",
  "B2": "20 mm",
  "A3": "WallThickness",
  "B3": "2.5 mm"
}

Aliases:

{
  "B1": "Length",
  "B2": "Width",
  "B3": "WallThickness"
}

Ranges:

"A1:C10"
["A1", "B2:B8", "D4"]

Style:

{
  "targets": ["A1:B3"],
  "style": ["bold"],
  "foreground": [0.1, 0.1, 0.1],
  "background": [0.9, 0.95, 1.0],
  "alignment": ["center"],
  "display_unit": "mm",
  "style_options": "replace"
}

View call controls

Standard views:

Isometric, Front, Top, Right, Back, Left, Bottom, Dimetric, Trimetric

Display modes:

Shaded, Wireframe, Flat Lines, Hidden line, Points, As is

Camera modes:

Perspective, Orthographic

Highlight colors use RGB floats:

[1.0, 0.4, 0.0]

Measurement endpoints

measure_distance accepts object names, uids, subelement refs, or points:

{"object": "Bracket", "subelement": "Face3"}
{"x": 0, "y": 0, "z": 0}
[10, 0, 0]
"Bracket#Edge2"

Builder parameter packets

High-level builder tools expose positional arguments directly. Their internal params equivalent is:

{
  "placement": {
    "Base": {"x": 0, "y": 0, "z": 0},
    "Rotation": {"Axis": {"x": 0, "y": 0, "z": 1}, "Angle": 0}
  }
}

Shape-specific keys are documented in Geometry builder tools.

Agent Reference

MCP Tools

Target selectors

Vector

Placement

Object spec

Common TypeIds

Sketch geometry entries

Sketch constraints

Spreadsheet cell maps

View call controls

Measurement endpoints

Builder parameter packets

​Target selectors

​Vector

​Placement

​Object spec

​Common TypeIds

​Sketch geometry entries

​Sketch constraints

​Spreadsheet cell maps

​View call controls

​Measurement endpoints

​Builder parameter packets

Target selectors

Vector

Placement

Object spec

Common TypeIds

Sketch geometry entries

Sketch constraints

Spreadsheet cell maps

View call controls

Measurement endpoints

Builder parameter packets