mcp-stl

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/