DESIGN:OS Studio (design-os-studio)
Native GPU-accelerated interface design studio in Rust. It opens and writes .fig files with no Figma app installed, runs your own coding agent CLI in an Agents panel on the open file, and ships a Model Context Protocol server (designos-mcp) so agents can edit a .fig headless.
Open a .fig, edit it, and write it back — in the Studio window, or without a window through designos FILE --inspect-json, --export-fig, --scan-design-system and --codegen, or through designos-mcp. Studio draws the canvas on the GPU with wgpu (Metal, DirectX 12 or Vulkan). The Agents panel runs Claude Code, Codex, Grok, Antigravity or Gemini CLI as a live session on the open file with your own sign-in, so Studio needs no API key. Work with variables and modes, select matching layers with Multi-Edit (Q), and read Dev Mode code in eight languages (CSS, Tailwind, React, SwiftUI, UIKit, Compose, Android XML and HTML). Saving a .fig has known issue #834.
Studio, designed in Studio
Studio's own interface is kept as a design system in a Studio file, design/studio-ui.designos: foundations, component sets, Studio surfaces and editor screens on six pages. These captures open that file in the 0.7.7 release build with designos-studio --screenshot (2x); click an image for full size.
Why this exists
Why DESIGN:OS Studio?
Browser-based design tools keep your files on a vendor's servers and give coding agents little more than a REST export. design-os-studio is a local-first studio written in Rust. It reads and writes .fig files on your disk, runs your own agent CLI in an Agents panel, and serves the open file to agents through a local MCP server.
| Dimension | DESIGN:OS Studio | How to check |
|---|
| Rendering | Native Rust canvas: wgpu on Metal, DirectX 12 or Vulkan, with a tiny-skia CPU renderer for headless captures. It requests no repaint while the view is idle (FrameKey frame reuse). | Open a file, leave it still, and read the process CPU time twice with ps -o time= -p <pid>. |
| Large files | A spatial index of 2048-unit grid cells (SceneIndex) limits work to the viewport, and repeated shapes share one mesh (GeomCache). The 336 MB Untitled UI PRO kit opens as one document of 207,601 nodes. | designos <file> --inspect-json prints the node count. |
.fig files | Reads .fig containers (fig-kiwi, DEFLATE or Zstd) and writes container version 106, in a ZIP with meta.json and images/. Known issue in 0.6.0: saving a .fig drops numbered-list formatting and writes inherited or variable-bound paints on instances as fixed values. | Export a file, then read the version from the canvas.fig header (see below). |
| Agents | The Agents panel starts your own agent CLI (Claude Code, Codex, Grok, Antigravity or Gemini CLI) as a live session on the open file, and keeps a file's sessions across restarts. Each CLI uses its own sign-in, so Studio needs no API key. | designos-studio <file> --panel agents |
| MCP server | designos-mcp serves its tools over stdio: see the design, read its design system, write in one step (designos_apply_batch) and lint the result (designos_lint). | Send tools/list to designos-mcp --workspace <dir>. The tool table below is generated from that list. |
| Variables |
To read the container version of an exported file, run unzip -p out.fig canvas.fig | head -c 12 | xxd. The header starts with fig-kiwi and ends with 6a00 0000, which is 106 in little-endian.
Where hosted tools win, and it is not close: real-time multiplayer with live cursors, enterprise cloud administration with SSO and SCIM, and hosted comment notifications by email or Slack. Studio has none of these. If your workflow needs real-time cloud multiplayer without local file ownership, use Figma (paired with our live bridge design-os-figma-plugin) or a hosted Penpot instance instead.
Facts Register
This is the beginning of the README. Read the rest at the original. Read the full README ↗
