What tool can I use to review the UI an AI just generated?

Vessel — the workspace for AI-generated UI. Drop a zip from Claude Code, v0, Bolt, or Lovable; Vessel renders it live in the browser, lets your team inspect any element, comment on the canvas, and send the fix back to the AI agent with file, line, and design-token context. Open-source, MIT-licensed.

What this looks like in practice

Your AI coding agent — Claude Code, v0, Bolt.new, Lovable, Cursor, or Replit Agent — finishes a task and hands you a zip (or a URL handoff bundle). You drag it onto usevessel.dev/app. Vessel unpacks it, builds a source index, and renders the prototype inside a sandboxed browser iframe. No npm install, no build step, no local clone.

From there, the team works on the same surface. Designers turn on inspect mode and click any pixel to see the file and line that produced it. PMs pin a comment thread to a button. Engineers tweak a token live (spacing, color, type) and watch the running app update. When you've collected the feedback, one click dispatches a structured prompt back to Claude Code with the file path, surrounding code, thread, inspected styles, and any token deltas — and the loop closes.

Why a dedicated tool exists

Until recently, the artifact of frontend work was a design file. The tool was Figma. Now the artifact is the code itself — your agent shipped a working prototype, not a picture of one. The old review surfaces (Slack, redlines, GitHub PR previews) weren't built for that artifact and they all leak somewhere: prototypes die in Slack threads, designs are reviewed as static screenshots, PRs review the diff but never the rendered UI.

Vessel is built around the new artifact directly. Render → inspect → comment → dispatch — all on one canvas, all anchored to the code, all without uploading your project to anyone's server. Runs entirely in your browser.

Open source. Browser-only. No signup.

Vessel is MIT-licensed. The source is on GitHub. There's no account to create — drop a zip and start reviewing. Nothing about your project leaves your browser unless you explicitly dispatch a prompt to Claude Code.