Whiteboard by /dev/fast

Whiteboard by /dev/fast is an open-source canvas for software development that allows users to review interactive visualizations, diffs, and agent trajectories in one interface.

Whiteboard is an open-source, MIT-licensed canvas designed for software development review and architectural planning. It allows developers to critique interactive visualizations, agent trajectories, and code diffs from a single interface. The software uses an AST-based diffing library written in Rust to validate hit text against pinned Git blobs and generate full file comparisons. Users can navigate session history, expand pseudocode summaries into full source code, and maintain control flow by folding code blocks. Data persists via a SQLite backend, which manages session history and resume states within atomic transactions.

Whiteboard by /dev/fast at a glance

Best for: Software engineer, Designer
Runs on: macOS, Windows, Linux
Pricing: Free
Released: August 2026
Category: AI coding tool
Website: dev.fast

Key features

AST-based diffing library written in Rust
SQLite-backed storage for session history
Interactive visualization of agent trajectories
Code folding and pseudocode summarization
Git blob validation for file comparisons
Atomic transaction writes for resume state

Use it for

Reviewing proposed API changes
Analyzing coding agent interaction trajectories
Navigating complex control flow diagrams
Comparing source code against pinned Git commits

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