SynapsCAD

The AI-powered 3D CAD IDE — edit code, visualize in 3D, and reshape your designs with natural language.

⚠️ Early Prototype — Not all OpenSCAD code will compile correctly yet. Start with simple models and expect rough edges. Bug reports with code snippets that cause issues are very welcome!

See SynapsCAD in Action

Overview

A desktop 3D CAD application that combines an OpenSCAD code editor, a real-time 3D viewport, and an AI assistant. Write OpenSCAD code, compile it to 3D models, visualize them interactively, and use AI to modify your designs through natural language — including context from 3D click interactions.

Download

Pre-built binaries for Linux, macOS (Apple Silicon & Intel), and Windows are available on the Releases page.

Building from Source

Prerequisites

• Rust (stable toolchain)
• An AI provider API key (e.g. ANTHROPIC_API_KEY) for the chat assistant

Quick Start

cargo run

AI Provider Setup

SynapsCAD uses the genai crate to connect to AI providers. Set the API key for your chosen provider as an environment variable:

Provider	Environment Variable
Anthropic	ANTHROPIC_API_KEY
OpenAI	OPENAI_API_KEY
Gemini	GEMINI_API_KEY
Groq	GROQ_API_KEY
DeepSeek	DEEPSEEK_API_KEY
Cohere	COHERE_API_KEY
Fireworks	FIREWORKS_API_KEY
Together	TOGETHER_API_KEY
xAI	XAI_API_KEY
ZAI	ZAI_API_KEY
Ollama	(no key needed)

export ANTHROPIC_API_KEY="sk-..."
cargo run

When an env var is set, the UI shows it as active. You can also enter or override the key in ⚙ AI Settings within the app.

This opens a window with a 3D viewport on the right and a side panel on the left containing the code editor and AI chat.

Basic Workflow

1. Write or edit OpenSCAD code in the editor panel
2. Click Compile — SynapsCAD parses and evaluates the code using scad-rs and renders CSG geometry via csgrs
3. Ask the AI assistant to modify your model — it sees your current code and part labels, and can update the code automatically

Architecture Overview

SynapsCAD is a single-binary Rust application built on three main pillars:

Runtime Stack

Layer	Technology	Role
Rendering & ECS	Bevy 0.15	3D viewport, entity management, frame loop
UI	bevy_egui (egui 0.31)	Side panel with code editor and chat interface
OpenSCAD parsing	openscad-rs	Lossless, resilient OpenSCAD parser
CSG rendering	csgrs	Constructive solid geometry — boolean ops, primitives, mesh output
Export	lib3mf	3MF export with per-part colors; STL and OBJ exported natively
AI	genai	Unified client for OpenAI / Anthropic / Gemini APIs
Async	Tokio	Background runtime for AI network calls

Key Design Decisions

• Bevy owns the main thread. The Bevy app loop drives rendering and ECS systems. A separate Tokio runtime is stored as a Bevy Resource and used only for spawning async AI tasks.

• std::sync::mpsc bridges async to sync. Background tasks (compilation, AI streaming) send results through channels. Bevy systems poll with non-blocking try_recv() each frame, keeping the viewport responsive.

• Pure-Rust compilation pipeline. OpenSCAD code is parsed by scad-syntax, evaluated by a built-in AST walker, and rendered to triangle meshes via csgrs — no external tools or WASM required.

• Built-in mesh picking. Bevy 0.15's MeshPickingPlugin provides ray-cast picking via the observer pattern — no external picking crate needed.

System Pipeline

ui_layout_system          — render egui side panel (editor + chat)
    ↓
trigger_compilation_system — if code is dirty, spawn compilation in a thread
    ↓
poll_compilation_system    — check if compilation finished, load mesh
    ↓
ai_send_system             — if chat submitted, spawn AI request on tokio
    ↓
ai_receive_system          — poll AI response, update chat + code
    ↓
adjust_camera_viewport     — resize 3D viewport to account for side panel
    ↓
orbit_camera_system        — process mouse/keyboard input for 3D navigation
    ↓
zoom_to_fit_system         — auto-frame model after compilation

3D Viewport Navigation

SynapsCAD uses Blender-style camera controls:

Action	Control
Orbit	Middle mouse button drag or Right mouse button drag
Pan	Shift + Middle mouse button drag
Zoom	Scroll wheel, +/- keys
Move focus	W/A/S/D or Arrow keys
Front view	1
Back view	2
Right view	3
Left view	4
Top view	5
Bottom view	6
Isometric	7

Contact

@boerni@chaos.social

License

GPL v3