A developer working under the handle devdotfast released Whiteboard, an open-source, MIT-licensed IDE that gives developers and coding agents a shared design canvas, according to its GitHub repository. The tool integrates with agents including Claude Code and Codex, and it reached the top of Hacker News with more than 300 points.
Whiteboard's diff viewer parses code with a Rust-based, AST-aware engine so it highlights only the parts of a change that matter semantically, rather than a raw line-by-line diff, the repository says. A decision log records the reasoning behind an agent's autonomous choices, and diagrams link directly to the underlying code through language server support.
The project vendors Microsoft's open-source Code OSS rather than maintaining patches against it, because the developer found coding agents struggle to manage patches over time, according to the repository. It runs locally, with optional telemetry that excludes code and prompts, and the developer says it performs best with high-capability models such as GPT-6 Sol and Claude Opus 5.5.
The project has drawn 876 stars and 33 forks since launch. Current limitations include no in-app file editing and limited support for projects spanning multiple repositories, according to the repository. A hosted team product is planned.
The tool is a bet that the bottleneck in agent-assisted development is no longer generating code, it is understanding why an agent changed what it changed. A canvas that tracks decisions instead of just diffs is a direct answer to that, for teams willing to run another IDE alongside their existing one.