Stl MCP server

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

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

Transformations

• translatestl**: Translate (move) the mesh by specified X, Y, Z offsets
• rotatestl**: Rotate the mesh around X, Y, or Z axis by a given angle in degrees
• scalestl**: Scale the mesh by specified X, Y, Z factors
• shearstl**: Apply a shear transformation (shift one axis per unit along another)
• mirrorstl**: Mirror (reflect) the mesh across the plane perpendicular to a given axis
• rotatestlaxis: Rotate the mesh around an arbitrary axis vector (Rodrigues' formula)
• combinestl**: Merge multiple STL files into one
• arraylinear**: Create N copies of the mesh spaced by a fixed X/Y/Z offset
• arraycircular**: Create N copies of the mesh at equal angular intervals around an axis

Primitives

• createcube**: Create a cube mesh
• createbox**: Create a rectangular box (cuboid) with independent width/height/depth
• createsphere**: Create a sphere mesh
• createcylinder**: Create a cylinder mesh
• createcone**: Create a cone mesh
• createtorus**: Create a torus (donut) mesh
• createplane**: Create a flat plane mesh
• createcapsule**: Create a capsule (cylinder with hemispherical end caps)
• createellipsoid**: Create an ellipsoid with independent radii on each axis
• createfrustum**: Create a frustum (truncated cone)
• createtube**: Create a hollow cylinder (tube/pipe)
• createpyramid**: Create a regular n-sided pyramid

Engine-Design Shapes

• creategear**: Create a spur gear mesh (configurable module, teeth, pressure angle)
• createspring**: Create a helical coil spring
• createconnectingrod: Create a connecting rod with big/small-end bores
• createcrankshaft**: Create an N-throw crankshaft
• createvalve**: Create a poppet valve (stem + head disc)
• createcamshaftlobe: 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/