Whiteboard
An open-source desktop app where a developer and their coding agent share a canvas: the agent draws diagrams and traces of its work, and clicking a diagram element jumps to the underlying code.
Whiteboard is a desktop app for architecting software together with a coding agent on a shared canvas. It connects to tools such as Claude Code or Codex and gives the connected agent an SDK to draw sequence diagrams, entity-relationship diagrams and quotes from its own trace onto the canvas to describe its work, and clicking a visualization jumps to the underlying code.
When navigating code inside Whiteboard, it provides VS Code's keybindings and LSP support out of the box. It also includes a semantic diff viewer as an alternative to raw diffs.
It is open source and downloadable for macOS, Windows and Linux, and is reported to work well with models such as GPT-6 Sol and Claude Opus 5.5.