Questions, answered.
The short version of everything people ask.
Is OpenPaper free?
Yes. It's MIT licensed and runs on your machine. The only costs are the model or image APIs you choose to use, billed to your own keys.
Do I need an API key?
Not to design, and not to connect an external agent like Claude Code or Cursor. The built-in agent needs an Anthropic key: paste it once, set
ANTHROPIC_API_KEY, or sign in with ant auth login. Image generation uses your own OpenAI or Gemini key.
Which agents work with it?
Any MCP client. One-click setup covers Claude Code, Claude Desktop, Cursor, VS Code, Codex, Windsurf, Gemini CLI, Antigravity, OpenCode and Copilot CLI. See Connect an agent.
Will my Paper prompts work?
They should. OpenPaper implements the same 37 tools with the same names, parameters, ID formats and response shapes, and adds
update_shader. Video export isn't implemented yet. See MCP server.
Is it affiliated with Paper?
No. OpenPaper is an independent project that reimplements Paper's public MCP behavior from scratch. It is not affiliated with or endorsed by Lost Coast Labs, Inc.
Where are my files stored?
In ~/.openpaper as plain JSON, with images in a content-addressed assets/ folder. Move it with OPENPAPER_HOME.
Exports go to ~/Downloads/OpenPaper. See Privacy & data.
Does my agent's work mess up my undo history?
No. Agents run as their own actor with their own history. Your undo only undoes your changes, and the Agents panel can undo an agent's last change.
Can I bring designs over from Figma?
Copy layers in Figma and paste them into OpenPaper. Images need a read-only Figma personal access token. Masks, noise and glass effects, and variable-font axes aren't supported yet. See Paste from Figma.
Which platforms does it run on?
Anywhere Node.js 20.19+ runs: macOS, Windows and Linux. The editor opens in your browser, and screenshots use Chrome, Edge, Brave or Chromium.
Screenshots or exports don't work. What now?
Run openpaper doctor. If no browser is found, install Chrome, Edge, Brave or Chromium, or point OPENPAPER_BROWSER at one.
Something else? Open an issue on GitHub.
Ready to try it?
Free, open source, and it runs on your machine.