STL Editor

PyPI Python Coverage Ruff

MCP server for editing STL 3D model files. Provides tools for parsing, viewing, and manipulating STL files through the Model Context Protocol.

Install

pip install mcp-stl

MCP Server

mcp-name: io.github.daedalus/mcp-stl

Tools

Reading & Writing

• read_stl_file: Read an STL file and return mesh data (vertices, normals, bounding box)
• get_mesh_info: Get summary information about an STL file without loading full geometry
• write_stl: Write mesh data to an STL file (ASCII or binary format)

Transformations

• translate_stl: Translate (move) the mesh by specified X, Y, Z offsets
• rotate_stl: Rotate the mesh around X, Y, or Z axis by a given angle in degrees
• scale_stl: Scale the mesh by specified X, Y, Z factors
• shear_stl: Apply a shear transformation (shift one axis per unit along another)
• mirror_stl: Mirror (reflect) the mesh across the plane perpendicular to a given axis
• rotate_stl_axis: Rotate the mesh around an arbitrary axis vector (Rodrigues' formula)
• combine_stl: Merge multiple STL files into one
• array_linear: Create N copies of the mesh spaced by a fixed X/Y/Z offset
• array_circular: Create N copies of the mesh at equal angular intervals around an axis

Primitives

• create_cube: Create a cube mesh
• create_box: Create a rectangular box (cuboid) with independent width/height/depth
• create_sphere: Create a sphere mesh
• create_cylinder: Create a cylinder mesh
• create_cone: Create a cone mesh
• create_torus: Create a torus (donut) mesh
• create_plane: Create a flat plane mesh
• create_capsule: Create a capsule (cylinder with hemispherical end caps)
• create_ellipsoid: Create an ellipsoid with independent radii on each axis
• create_frustum: Create a frustum (truncated cone)
• create_tube: Create a hollow cylinder (tube/pipe)
• create_pyramid: Create a regular n-sided pyramid
• create_prism: Create a regular n-sided prism (e.g. hexagonal prism)
• create_hemisphere: Create a hemisphere (dome with flat circular base)
• create_wedge: Create a right-triangular wedge (triangular prism)

Engine-Design Shapes

• create_gear: Create a spur gear mesh (configurable module, teeth, pressure angle)
• create_spring: Create a helical coil spring
• create_connecting_rod: Create a connecting rod with big/small-end bores
• create_crankshaft: Create an N-throw crankshaft
• create_valve: Create a poppet valve (stem + head disc)
• create_camshaft_lobe: Create an eccentric cam lobe with cosine nose profile

Usage

Python API

from mcp_stl import read_stl_file, create_cube, translate_stl

# Read an existing STL file
mesh = read_stl_file("model.stl")
print(f"Faces: {mesh.face_count}")

# Create a primitive
create_cube("cube.stl", size=2.0)

# Transform a mesh
translate_stl("input.stl", "output.stl", x=10.0, y=0.0, z=5.0)

MCP Server

Configure in your MCP client:

{
  "mcpServers": {
    "mcp-stl": {
      "command": "mcp-stl"
    }
  }
}

Development

git clone https://github.com/daedalus/mcp-stl.git
cd mcp-stl
pip install -e ".[test]"

# run tests
pytest

# format
ruff format src/ tests/

# lint
ruff check src/ tests/

# type check
mypy src/