Overview & pitch

§A Overview · §B Product · §C Architecture · §D Rationale →

The medium got richer. The loop didn't.

Today

Claude writes a spec — first markdown, then HTML for diagrams, tables, mockups.
To change anything you alt-tab to the terminal and re-describe what you're looking at.
It regenerates; you re-read, find the next thing, alt-tab again. Linear, lossy, one thread.

With Sandpaper

Read the rich document exactly as now.
Point at the section and say the change — or edit it in place.
It stays one durable file — the canonical spec your team builds from.

The bet

If people can read the rich document and change it in place — while their explicitly selected Claude Code or Codex provider rewrites the file as the single source of truth and shows its live status — then design collaboration collapses from a terminal monologue into a fast, non-linear conversation on the page, and the artifact stays canonical enough to drive what gets built. spec →

Who it's for — and where it stops

A product-minded founder who designs and conceptualizes with Claude Code or Codex and consumes the output as rich HTML. It is a refinement loop for documents — not an IDE, not a Figma. Knowing where it stops is the discipline. scope →

On the name

Sandpaper — sand a rough draft into a finished spec. It's subtractive by nature, so the product has to keep earning the “make it richer,” not only the “smooth it.” why →