MarkLayer and stagewise close the same gap: an AI coding agent cannot see the pixel you mean. stagewise is a developer toolbar embedded in your local dev app; you click an element and the context lands in your coding agent. MarkLayer is a Chrome extension plus share link that works on any page (localhost, staging, or production) and adds threaded comments, real-time multiplayer, and an MCP server the agent talks back through.
Choose MarkLayer when feedback comes from more people than just you: teammates, clients, or an agent that should report status back into a shared room. Choose stagewise if you are a solo developer iterating in your local dev server and want element context piped straight into your editor agent.
| Feature | MarkLayer | stagewise |
|---|---|---|
| Price | Free, no tiers | Free open-source toolbar; paid cloud plans |
| Where it works | Any URL: localhost, staging, production | Your local dev app |
| Who can annotate | Anyone with the link; viewers need no install | The developer running it |
| Sign-up required | No | No for the toolbar; account for cloud features |
| Real-time multiplayer | Yes. Live cursors, comments, voice | No |
| AI agent integration | MCP server: watch, acknowledge, resolve, reply | Yes. Sends element context to coding agents |
| Threaded comments and statuses | Yes. Open, in progress, resolved, dismissed | Prompt-style handoff, not a review thread |
| Open source | Yes (Apache-2.0) | Yes (AGPLv3) |
| Best for | Team and client review with agents in the loop | Solo frontend iteration with an agent |
stagewise is an open-source browser toolbar that lets developers point at UI elements in their local dev app and hand the context to AI coding agents.
MarkLayer is a free, open-source Chrome extension that lets you annotate any live webpage with drawings, comments, arrows, and highlights, then share a single link so anyone can view the annotations without installing anything. There is no account, no paywall, and no trial period.
stagewise proved developers want to point at a UI element instead of describing it to an agent. MarkLayer takes the same idea out of localhost: any URL, a share link a client can open, and an MCP loop where the agent reports back into the room.
MarkLayer is free, requires no sign-up, and works on any webpage. Recipients of your share links don't need to install anything.
Add to Chrome