Pen

Tom Krcha demonstrates Pencil, a visual design tool that lets AI agents create and edit designs on a canvas. Its swarm mode assigns agents to separate screens, while visible cursors show their work and make parallel activity easier to follow. Pencil stores designs in the agent-oriented, JSON-based Pen format, which can be edited with coding agents and converted into platform-specific code. Krcha frames Pencil as a visual planning space for exploring design options before choosing what to build, and describes its origins, adoption, and his earlier work in design tools.