Doop

Doop is an open-source alternative to Paper.design: a multiplayer design canvas for humans and AI agents. Each design lives on a shareable canvas that holds frames, which are artboards rendering real HTML in sandboxed iframes. People edit in the browser while AI agents edit through the built-in MCP server and stream their designs in live.

Everyone sees cursors, presence, frame edits, agent status and an activity feed as it happens. Clients such as Claude Code can connect once and sketch, stream and self-review designs next to your cursor, and a built-in Doop Agent can take cards or role mentions without any client. It runs on the server's Anthropic key for a few free tasks, then on a ChatGPT subscription or OpenAI key each user connects. Other features include comments pinned to elements, undo and redo, and a design memory that distills style rules agents follow.

Canvases are private by default, with access by email invitation or link sharing, and agents inherit their human's access. Doop is licensed under AGPL-3.0, written in TypeScript and built with bun. You can self-host with docker compose up, or run bun run dev with embedded Postgres and no other services.