SketchForge A local-first 3D design editor that runs in your browser. Build shapes, cut holes, group parts, import STL files, and export models without accounts, cloud lock-in, or heavyweight CAD setup.

Why SketchForge

SketchForge is a lightweight CAD-style workspace for people who want to sketch, cut, and export 3D models quickly.

It is built for the satisfying loop: drop a shape, resize it, rotate it, make another shape a hole, group the result, import an STL if primitives are not enough, and export the finished model.

No login. No server project storage. No heavyweight CAD install just to make a useful part.

What It Does

• Local-first projects - designs live in browser storage with generated project thumbnails.
• Real 3D workplane - grid, camera controls, snap settings, transform handles, outlines, and inspector controls.
• Primitive shape library - boxes, cylinders, spheres, cones, pyramids, wedges, text, roofs, half spheres, torus shapes, tubes, and more.
• Solid and hole workflow - turn shapes into cutters and group them into final geometry.
• Boolean Intersection - keep only the geometry where selected solid and hole shapes overlap.
• Reversible edge tools - chamfer and fillet selected CAD edges, with history controls for removing applied edge features.
• Rotated solid edge treatment - chamfer and fillet preserve analytic box topology after one-, two-, or three-axis rotations.
• STL import - bring outside models into the same workspace as primitives.
• STL, OBJ, and STEP workflows - export selected objects or the whole scene, and round-trip exact STEP/B-Rep geometry.
• Fast browser stack - Next.js, React, TypeScript, Three.js, and Manifold/CSG geometry tooling.

Demo

Getting Started

There are two common ways to run SketchForge. If you are not sure which one to choose, use Docker.

SketchForge is local-first in both modes. The app files may be served from a computer or server, but projects stay in each user's browser storage. STL and OBJ exports download through the user's browser. SketchForge does not upload models to a SketchForge cloud service.

Download the Project

If you already know Git:

git clone https://github.com/Formsmith746/SketchForge-3D.git
cd SketchForge-3D

If you do not know Git yet:

1. Open the GitHub page for this repository.
2. Press the green Code button.
3. Press Download ZIP.
4. Extract the ZIP somewhere easy to find, such as your Desktop.
5. Open a terminal in the extracted folder.

On Windows, you can open PowerShell in the folder by opening the folder, clicking the address bar, typing powershell, and pressing Enter.

Docker / FabLab Server (Recommended)

Docker is the easiest way to run SketchForge for a classroom, workshop, or FabLab. It packages the build tools, static website, Nginx server, health check, and restart behavior together.

What You Need

• Docker Desktop on Windows or macOS, or Docker Engine on Linux
• Docker Compose, which is included with modern Docker Desktop
• This repository downloaded on the server computer

If docker is not recognized, install Docker Desktop and open it once before running the commands.

Start SketchForge

Compose (Build images locally)

From the SketchForge project folder, run:

docker compose -f deploy/docker/compose.yaml up --build -d

The first start can take a few minutes because Docker builds the app.

Compose (Prebuilt)

From the SketchForge project folder or with the downloaded deploy/docker/compose-ghcr.yaml, run:

docker compose -f deploy/docker/compose-ghcr.yaml up -d

Standalone (Prebuilt)

docker run -d --name sketchforge --restart unless-stopped -p 3000:80 ghcr.io/formsmith746/sketchforge-3d:latest

After running, open this on the same computer:

http://127.0.0.1:3000/

If that works, SketchForge is running.

Let Other Computers Join

Other computers on the same Wi-Fi or LAN need the server computer's local IP address.

On Windows PowerShell, run:

ipconfig

Look for the IPv4 Address, for example:

192.168.1.25

Then other computers can open:

http://192.168.1.25:3000/

Use your own IP address, not the example one.

Use a Different Port

If port 3000 is already being used, choose another port such as 8080.

Windows PowerShell:

$env:SKETCHFORGE_PORT = "8080"
docker compose -f deploy/docker/compose.yaml up --build -d

Linux or macOS:

SKETCHFORGE_PORT=8080 docker compose -f deploy/docker/compose.yaml up --build -d

Then open:

http://127.0.0.1:8080/

Stop SketchForge

docker compose -f deploy/docker/compose.yaml down

Update SketchForge Later

If you used Git:

git pull
docker compose -f deploy/docker/compose.yaml up --build -d

If you downloaded the ZIP, download the newest ZIP, extract it, and run:

docker compose -f deploy/docker/compose.yaml up --build -d

Docker Troubleshooting

• docker is not recognized: install Docker Desktop, open it, and try again.
• Docker says the daemon is not running: Docker Desktop is closed or still starting.
• Port already in use: use another port, for example 8080.
• Other computers cannot connect: check that they are on the same network and that the server firewall allows the chosen port.
• The page opens but old files appear: stop and rebuild with docker compose -f deploy/docker/compose.yaml down, then docker compose -f deploy/docker/compose.yaml up --build -d.

If you already have Node.js installed, the repository also includes shortcuts:

npm run docker:up
npm run docker:down

Local Development

Use this path if you want to edit SketchForge's code.

What You Need

• Node.js 20 or newer
• npm, included with Node.js

Check your versions:

node -v
npm -v

If those commands do not work, install Node.js from the official Node.js website and reopen your terminal.

Install and Run

From the SketchForge project folder:

npm install
npm run dev

Open:

http://127.0.0.1:3000/

Leave the terminal open while you use the app. To stop the development server, press Ctrl+C in the terminal.

Useful Developer Commands

Run TypeScript checks:

npm run typecheck

Run tests:

npm run test

Start the local SketchForge MCP bridge for editor automation:

npm run mcp:sketchforge

Create a production build:

npm run build

Build a static export:

npm run export

Contributing

Contributions are welcome. Good places to help:

• editor bug fixes
• geometry and boolean test cases
• STL import/export edge cases
• UI polish
• documentation screenshots and videos
• accessibility and performance improvements

Read .github/CONTRIBUTING.md before opening a pull request.

Security

Please do not open public issues for security-sensitive reports. Read .github/SECURITY.md for the reporting process.

License

MIT. See LICENSE.

SketchForge MCP Skill

SketchForge includes a local MCP server for AI clients that support MCP tools. It lets an agent inspect and control a live local editor tab: list open editors, read the scene, create/update/select objects, group/cut/separate parts, list CAD edge ids, apply chamfer or fillet, inspect errors, and capture viewport images.

This is for local development only. Run SketchForge with npm run dev; the MCP route is disabled in production builds and Docker/static hosting.

Start SketchForge for MCP

From the SketchForge project folder:

npm install
npm run dev

Open an editor tab:

http://127.0.0.1:3000/?editor=1

The AI client starts the MCP server with:

node scripts/sketchforge-mcp-server.mjs

Codex

The Codex skill is included at:

docs/skills/sketchforge-mcp-skill

Install it into your Codex skills folder.

Windows PowerShell:

New-Item -ItemType Directory -Force "$env:USERPROFILE\.codex\skills" | Out-Null
Copy-Item -Recurse -Force "docs\skills\sketchforge-mcp-skill" "$env:USERPROFILE\.codex\skills\sketchforge-mcp-skill"

macOS or Linux:

mkdir -p ~/.codex/skills
cp -R docs/skills/sketchforge-mcp-skill ~/.codex/skills/

Then add an MCP server entry to your Codex config. Use docs/mcp/codex-config.example.toml as the template and replace the script path with the absolute path on your machine. Restart Codex after changing the config.

Once installed, ask Codex:

Use $sketchforge-mcp-skill to list my open SketchForge editors and inspect the current scene.

Claude

Claude does not use Codex SKILL.md files, but it can use the same SketchForge MCP server. Add the server to Claude Desktop's MCP config using docs/mcp/claude-desktop-config.example.json as the template, replacing the script path with the absolute path on your machine.

After restarting Claude Desktop, ask:

Use the SketchForge MCP tools to list open editors, inspect the scene, and modify the selected object.

The main tool names are sketchforge_list_editors, sketchforge_read_scene, sketchforge_list_objects, sketchforge_create_shape, sketchforge_update_object, sketchforge_list_edges, sketchforge_apply_edge_treatment, and sketchforge_capture_image.