AI & developer tools
TurtlePen
A drawing language that gives AI a ruler, a canvas, and a way to check its work.
The question
AI-generated diagrams often look plausible until a label escapes its box or a connector crosses the wrong thing. A convincing picture is not the same as a correct diagram.
The approach
TurtlePen measures text before placement and builds on an integer-exact lattice. Drawing, layout, semantic timelines, validation, and export share the same document model. Findings explain the conflict instead of quietly resizing the work.
Where it stands
The site hosts the canonical 87-tool engine. Public source includes the pen language, measurement and rendering core, a viewer, and MCP transports. The browser companion offers a smaller shared canvas for a person and an agent. The spatial layer adds physical primitives, curved sweeps, lofts, transforms, bounded box booleans, and TPF/STL/GLB export. The complete engine check passes 758 tests; exported model topology and dimensions are independently checked.
The current boundary
The six-tool browser companion and the full remote MCP have different capabilities and separate document state. Structural validation does not replace visual judgment. The 3D layer is available through the remote MCP; the page-local canvas remains 2D. Slicer acceptance, manufacturability, and physical printing remain unverified.