Run a live session
A checklist run or an interview round goes off and comes back with a report. A live session is the opposite: you sit beside the actor while it works. The browser is on the left, the chat on the right, and underneath it the steps the actor took and the captures it kept. Ask it to try something, watch what it does, change the task halfway through, or take the browser and drive it yourself.
Start a session
Open Live sessions
Open a project and choose Live sessions under Discover. The page lists the project's sessions, newest first, so you can go back to any earlier one and read what happened.
Click New session
The dialog asks only what cannot change once the session is running:
- Actor: who uses the product.
- Start on: the address the browser opens first.
- Session: Interview or Task (see below).
- Browser: This Mac or Cloud browser.
Replies, tools and sign-ins are all changed from inside the session.
Click Start session
The browser opens on the start address and the actor is ready for its first message.
Interview or task
- Interview (the default): the actor stays in character and thinks aloud while you moderate. Ask it what it expects a page to do, what it would click next, or what would stop it signing up. This is a moderated usability session without recruiting anyone.
- Task: the actor does what you ask and reports back. Use it to reproduce a bug, walk a flow end to end, or check something quickly before a release.
Choose a browser
- Cloud browser works from anywhere, on public sites.
- This Mac is offered when you are in the desktop app and your plan includes devices. The actor drives a Chrome on your Mac, so it can open local dev servers, staging behind your VPN and anything else this Mac can reach. When a session can run on this Mac, it is the default.
You do not need to set your Mac up as a device first. If it is not one yet, starting the session pairs it for you in the background, and that pairing is removed again when its last session ends. A Mac that already belongs to someone else in the workspace, or to another workspace, is never moved: the dialog says so and offers the cloud browser instead.
Steer the actor
Type in the chat to give the actor a task or ask it a question. While it is working, a new message is queued for when it finishes. Choose Send now to steer the current task instead of waiting.
Each step it takes appears in the journey under the browser, grouped by task, so you can see exactly what it clicked, typed and read.
Replies
The actor keeps replies short by default: the result first, no recap of the task and no commentary on each click, since you can see the browser yourself. Open Replies to change that from its next reply:
- Detail: from a sentence to a thorough account with evidence.
- Narration: from results only to thinking aloud at every step. An interview starts with more narration than a task.
Take control
Click Take control in the header, or click or type in the browser itself. If the actor is in the middle of a step, it stops first. Now the browser is yours: sign in, fill a form, dismiss a banner or get the page into the state you want.
Click Return control when you are done. The actor is told you drove the browser in the meantime, so its next step starts from the page as you left it.
Keep what it finds
- Findings are recorded by the actor as it works, with a severity and the screenshot that shows the problem.
- Capture saves a screenshot of the browser as it is now. It is off while the actor is driving.
- Notes are your own, added from the captures tray.
Captures stay with the session after it ends.
Tools and sign-ins
Open Tools during a session to see what the actor can use beyond the browser.
- Project and actor MCP servers you have already connected in Stunt Double.
- On this Mac: MCP servers that run on your own Mac, in sessions using the desktop app. Turn them on for the session, then import servers from Claude Desktop or Cursor, or add them in the app. The app asks you to approve each server, showing the exact command, before it ever runs, and the chat asks you before each tool call. Switch on Run read-only tools without asking to skip that question for tools their server marks read-only.
What a tool returns is kept in the session's transcript, which everyone in the workspace can read, so only turn on servers whose output you are happy to share.
Browser sign-ins (sessions on This Mac) controls where the browser keeps its cookies and sign-ins:
- Per actor: each actor keeps its own sign-ins, the way two real people would. This is the default.
- Shared in this workspace: sign in once and every actor in the workspace starts signed in.
Sign-ins stay on your Mac, in a browser profile kept apart from your own Chrome, so an actor never sees your personal sessions. The same section lists the profiles stored on this Mac with their size, and can clear one.
A Mac MCP server that starts with npx or uvx needs Node or uv. If it is
missing, the server's row links to Set up this Mac,
which installs it.
End the session
Click End session and confirm. The browser closes and the transcript, journey and captures stay where they are.
Once a session ends, a summary takes the browser's place: how long it ran, the pages visited, the findings by severity and your notes, with a short account of what happened and suggested next steps.
A session left idle closes its browser on its own after a while. When that is close, Keep session open appears in the header with the time it closes.
Who can see a session
Only the person who started a session can chat with the actor or drive the browser. Everyone else in the workspace can open it and follow along: the journey, the captures and the transcript update live, and the browser pane shows the latest screenshot.
Next steps
- Set up the desktop app to run sessions on your Mac
- Run an interview across a whole panel of actors
- Write effective checklists to keep checking what a session found