Add to Chrome
SafariHow they compare
Vex and Design Mode agree that edits should be structured data, not prose. They part ways on how much to own. Vex is a platform: Chrome extension, FastAPI orchestrator with SQLite, Electron desktop app, NATS for streaming, Claude Agent SDK adapters, execution traces with token cost per batch, and framework detection that generates idiomatic React, Vue, Svelte, Django or Rails code. Design Mode is an extension plus an optional relay: it records the change and speaks MCP to the agent you already have.
Feature-by-feature
| Feature | Design Mode | Vex |
|---|---|---|
| Visual editing on a scriptable webpage | Yes — typography, colour, layout, spacing, motion and effects on localhost, staging or production pages the extension can script. Browser-protected pages are excluded. | Yes — resize, restyle, swap images and AI-generate sections on live pages in Chrome 116+ |
| MCP (Model Context Protocol) handoff to AI agents | Yes — Cloud, Local, and Self-hosted modes; eight common session tools, plus Local feedback rounds | No — REST batch submit to its own Agent Orchestrator, which runs Claude via the Agent SDK |
| Persistent change history (Changes tab) | Yes — searchable, filterable, exportable | Batches and per-batch execution traces stored in SQLite |
| Open source | Yes (MIT) | Source is public on GitHub but licensed 'All rights reserved' — not open source |
| Price | Free MIT-licensed extension | Free to run; you supply the Claude credentials |
| Markdown / JSON export of the diff | Yes | Not documented |
| Best fit for | Designers, developers, QA, PMs, content, indie hackers, agencies, vibe coders | Developers who want a self-hosted end-to-end visual-edit-to-code pipeline |
When to pick Design Mode
- You already run Claude Code, Cursor, Codex, Windsurf or any MCP client and don't want a second agent runtime.
- You want to install from a store and be editing in a minute — Vex needs Node 20+, Python 3.11+, uv, an orchestrator and a desktop app.
- You need Firefox or Safari.
- You want an MIT licence; Vex's repository is 'All rights reserved'.
When to pick Vex
- You want the tool to run the agent for you and show full execution traces, tool calls and cost per batch.
- You want AI section generation and framework-aware code output built into the editor.
- You're comfortable self-hosting a Python service and prefer an all-in-one pipeline.
Honest take
Vex is ambitious and its execution-trace view (steps, tool calls, tokens, cost) is something Design Mode does not offer. It is also early — version 0.1.5 at the time of checking, a handful of stars, and a non-open licence despite the public repository. Design Mode's case is that most people already have an agent; they need a clean, portable way to hand it a change, not another orchestrator.
Sources and scope
Sources checked 11 October 2026. Review of the Vex GitHub README (features, architecture, quick start, API reference, licence section) and repository metadata via the GitHub API. The extension, orchestrator and desktop app were not installed or run. Capability claims are as documented by the author, not independently runtime-verified.