VentForge

Design vent and perforation patterns for 3D printing, laser cutting and CNC, then export them as ready-to-use files. Use the desktop editor, let an AI assistant such as Claude do the designing through the built-in MCP server, or put the pattern straight onto your part in Autodesk Fusion. All of them work on the same design file.

Features

• 10 layouts: grid (square, diamond, hexagon), random, path, spiral, concentric, fibonacci, crosslines, voronoi stone cracks, flow lines, and custom points.
• Hole shapes: circle, rounded rectangle, hexagon, polygon, star, or your own outline.
• Gradients: vary size, spacing, angle or shape across the plate. Drive them with points, lines or curves, with noise, or with a grayscale image.
• Boundary: none, circle, rounded rectangle, or a drawn outline, with margin and clipping.
• Fan grilles: one click for a 40–140 mm fan: holes only over the blades, 4 screw holes, and the share of the fan opening left open (airflow).
• Keep-outs: circles, rectangles or any outline that stay free of holes (bosses, logos, screws), optionally cut as holes. Draw them on the canvas with the Keep-out tool (K; Shift for a circle, right-click to remove).
• Machining: CNC tool radius (rounds inside corners, drops holes the cutter cannot reach) and laser kerf compensation for SVG/DXF. Set a minimum feature (about 2× nozzle for 3D printing) to flag holes that would close up.
• Textures: instead of cutting through, sink the pattern into the top (deboss) or raise it (emboss) by a set depth, for grips, decorative panels and labels (Plate → Making it).
• Export: PNG, SVG, DXF, STEP, STL. You can also wrap the pattern onto a tube or cut it into an existing STEP part.
• Checks: hole count, open area, the thinnest wall in mm (marked on the canvas), and warnings where walls get thinner than your minimum.
• Airflow estimate: pressure loss of the grille (Idelchik thin perforated plate) at 2 m/s, so two designs can be compared by airflow. A rough figure, not a flow simulation.
• Autodesk Fusion add-in: put the pattern on a face of your part as one timeline feature, with the face's holes and bosses as keep-outs, and a live link to the editor (see below).
• Undo/redo, presets, and a personal library (also from the AI assistant: save_to_library).

Install

You need Python 3.11 or newer. Install the full app with uv (recommended) or pipx:

uv tool install "ventforge[all]"

pipx install "ventforge[all]"

Pick a smaller install if you don't need everything:

Use the desktop editor

ventforge

To open a saved design, pass its file: ventforge my_vent.vent.json.

1. Pick a design from the Library, or a layout under Pattern → Layout.
2. Drag the sliders. The preview updates as you go.
3. Pick a file type from the green Export button.

The panel only shows settings that change something for the current design. Pick Star holes and the star settings appear; pick Cracks or Slots and the hole settings go away, because those layouts make their own shapes. Hover over a setting for a short explanation.

Changing a setting in a Variation tab switches that variation on (the tab then shows a ●). Picking a Drawn outline or hole shape, or the Your points layout, starts drawing on the canvas right away.

Canvas controls

Your design saves itself shortly after each change.

Use it with an AI assistant (MCP)

You don't need to install anything first, because uv downloads VentForge on demand.

Claude Code:

claude mcp add ventforge -- uvx --from "ventforge[all]" ventforge --mcp

Claude Desktop: add this to claude_desktop_config.json, then restart the app:

{
  "mcpServers": {
    "ventforge": {
      "command": "uvx",
      "args": ["--from", "ventforge[all]", "ventforge", "--mcp"]
    }
  }
}

Then ask, for example: "Make a 120 × 80 mm hexagon vent with 4 mm holes that get smaller toward the edges, and export it as STEP."

The assistant works on ~/Documents/VentForge/current.vent.json. If you open that file in the editor (or ask the assistant to "open it in the GUI"), you can watch the design change live.

Tools the server offers: new_design, open_design, list_presets, save_to_library, get_design, describe_parameters (every setting with its editor name and what it does), set_params (also tells the assistant which of its settings do nothing for this design), add_control, clear_controls, fan_grille, fit_open_area (solve a parameter for a target open area), preview, export, wrap_cylinder, cut_into_part, apply_to_fusion (update the Fusion parts that use this design), open_in_gui. The library is the same folder the editor uses.

Use it in Autodesk Fusion

VentForge comes with a Fusion add-in. It puts a pattern on any flat face of your part as one Combine feature on the timeline, instead of a sketch pattern with thousands of copies. The pattern stays linked to its VentForge design, so you can keep editing it.

Set it up (once)

1. Install VentForge with the CAD extra (or ventforge[all]):

   uv tool install "ventforge[all]"
   

2. Copy the add-in into Fusion:

   ventforge install-fusion
   

3. In Fusion, open Utilities → Add-Ins, pick VentForge and click Run. Tick Run on Startup so it loads with Fusion from now on.

Run ventforge install-fusion again after you update VentForge or move its environment, then Stop and Run the add-in in Fusion. The add-in calls your VentForge installation, because Fusion's own Python has no geometry libraries.

Put a pattern on a part

Open Solid → Create → VentForge pattern.

1. Pick a flat face of your part.
2. Choose a design, or leave Design empty for a new one:
   • Empty: VentForge makes a design shaped like the face, saved in ~/Documents/VentForge/Fusion. Holes in the face and anything standing on it (bosses, ribs, standoffs) become keep-outs, so you see them in the editor and no hole lands on them.
   • Choose design… takes any saved design, for example one from your library or the AI assistant's current.vent.json.
3. Set a rotation if you want one and press OK.

The pattern goes onto the part right away and the VentForge editor opens next to Fusion.

Edit it live

Change the pattern in the editor and press Ctrl+S. Fusion rebuilds the pattern in place, in the same timeline feature. You don't need to close the editor or run the command again. Slider moves on their own don't update Fusion, so you can try things out without waiting for a rebuild after each one.

• Placement: the pattern centre sits on the face centre, with x along the world X axis (turned by your rotation).
• Cut or raise: Plate → Making it → Pattern is decides what happens. Cut through cuts through the body, Sunk in cuts the pattern in by the depth, Raised adds it on top. Switching between them while linked switches the Combine between cut and join.
• How long the link lasts: until you close Fusion or stop the add-in. To link again later, run the command on the face once more.
• The live link needs a parametric design (with a timeline). In direct modelling the pattern is placed once.
• Each manual save also writes a small <design>.vent.json.saved file next to the design. That is how the add-in tells a real save from the editor's automatic saves. You can delete these files.

If something goes wrong

• An error box after a save: the update was skipped, and your part keeps the last good pattern. Fix the design (for example a relief depth thicker than the plate) and save again.
• A document briefly opens and closes on each update: some Fusion builds cannot read STEP files directly, so the add-in imports through a scratch document. This is expected.
• The command is missing from Solid → Create: check that VentForge is running under Utilities → Add-Ins.

Project layout

ventforge/
├── model.py         design file format: every parameter and its default
├── params.py        what each parameter is called, does, and when it matters (editor + MCP)
├── pattern.py       geometry: places and shapes the holes
├── export.py        PNG, SVG, DXF, STEP and STL output, tube wrap, cut into part
├── gui.py           desktop editor
├── mcp_server.py    MCP tools for AI assistants
├── __main__.py      `ventforge` command (editor, --mcp server, tool, install-fusion)
├── fusion/          Autodesk Fusion add-in, installed by `ventforge install-fusion`
└── presets/         example designs shipped with the package
tests/               pytest suite, including a real MCP client/server run
.github/workflows/   CI on Windows, macOS and Linux; publishes to PyPI on version tags

Licence

GPL-3.0-or-later, see LICENSE. You may use, change and sell VentForge. Versions you distribute must stay open source under the same licence.