Computer
The Computer tab is where the agent does work that needs a working environment. Code, files, commands, builds, browsers, anything that needs to actually run instead of just be described. You watch it happen live and step in when you want.
Overview
- Where
- Computer tab in the right panel
- Panes
- Shell, files with editor, live preview
- Activation
- Opens automatically when the agent needs to run something
- Control
- You can take the keyboard at any moment
- Persistence
- Files and state stay across turns within a session
- Restart
- One click; resets the environment to a clean state
Most chat replies do not need the Computer. The Computer matters the moment a request stops being description and starts being execution. Build me this. Run this script. Try this fix and prove it works. Open this site and check the rendering. That is when the Computer comes alive.
What the Computer is
A working environment scoped to your session.
The Computer is a clean working environment the agent uses to perform tasks. It can read and write files, run commands, install packages, start servers, render previews, and do anything you would normally do in a terminal. It is isolated from your local machine so the agent cannot touch your laptop. It is scoped to your session so the work you do today is still here tomorrow.
Watching work happen
Three panes, all live.
| Pane | What it shows |
|---|---|
| Shell | Every command the agent runs and the streaming output of that command |
| Files | The file tree, with badges for created, modified, and deleted files; clicking a file opens it in the editor |
| Preview | Live HTTP preview if the agent is running a server, image preview if it generated an image, video preview if it rendered one |
All three update in real time. You do not have to refresh. Long-running work scrolls in the shell while the file tree updates and the preview reloads.
The shell view
The conversation between the agent and the working environment.
Every command the agent runs shows up here with its full output. Stdout and stderr stream live. You can scroll back through the session to see everything that happened.
| Thing you can do | How |
|---|---|
| Read along | Just keep the tab open. The shell scrolls automatically when new output arrives |
| Search the shell history | Cmd or Ctrl plus F in the pane to search within the visible output |
| Type a command yourself | Click into the input row at the bottom; the agent can see anything you type |
| Interrupt a running command | The stop button at the right of the command row sends an interrupt |
| Copy output | Select text and copy as you would in any terminal |
The files view
Tree on the left, editor on the right.
The file tree shows the structure of the working directory. Files the agent created have a green dot. Modified files have a yellow dot. Deleted files cross out. Click any file to open it in the editor pane.
| Thing you can do | How |
|---|---|
| Open a file | Click in the tree |
| Edit a file directly | Click into the editor and type; saves on blur |
| Create a new file | Right-click in the tree for the new file action |
| Rename a file | Right-click on the file in the tree |
| Drag a file in from your laptop | Drop onto the tree to upload it into the working directory |
| Download a file | Right-click the file for the download action |
The live preview
Whatever the agent is rendering, shown live.
If the agent runs a dev server, the preview pane shows it. If the agent generates an image or a video, the preview pane shows that. If the agent builds a deck, the preview pane shows the deck. The preview reloads whenever the underlying artifact changes.
| Preview kind | Refresh behaviour |
|---|---|
| HTTP server | Auto-reload on file save (when the dev server supports it) |
| Static HTML | Reload on the file tree change |
| Image | Replaces when the file changes |
| Video | Replaces when the file changes; click play to view |
| Console-only | If nothing renders, the preview pane stays empty and you watch the shell |
Intervening
You can take over at any moment.
- 01Tell the agent to stopHit the stop button on the running command, or send a chat message asking the agent to pause.
- 02Make your changeEdit a file directly, run a command yourself, or upload something new.
- 03Hand backSend a chat message describing what you did and what you want the agent to do next.
What persists
The Computer is scoped to your session.
| Thing | Stays until |
|---|---|
| Files in the working directory | You delete them or you reset the Computer |
| Installed packages | Reset of the Computer |
| Running processes (servers, watchers) | You stop them, you reset, or the session ends |
| Shell history | Always available within the session; cleared on reset |
| The preview URL | Stable for the lifetime of the session |
Use cases
Five things people actually do in the Computer.
Build a small app from scratch
Tell Sentinel what you want. The agent scaffolds the project, installs dependencies, writes the code, starts the dev server, and the preview comes up. You iterate by chatting: change the colour, add a button, hook it to this API. Every change you see live.
Fix a bug in your existing repo
Paste a public repository URL or upload your folder. The agent pulls it into the Computer, reads the code, locates the bug, writes the fix, runs the tests, iterates until green. You read the diff in the editor and copy what you need.
Generate a one-off script and run it
Ask for a script that does a thing (parses a log, processes a CSV, hits an API and writes a report). The agent writes it in the files pane, runs it in the shell, shows you the output. Download the output if you want it locally.
Build a slide deck or carousel and watch it render
For visual content the Computer runs the renderer and the preview pane shows the result. You scroll through slides, ask for changes, the renderer reruns, the preview refreshes.
Try an idea fast
The Computer is the lowest-cost way to prototype. Ask for a working version of an idea, watch it come together, decide if it has legs. If it does, push the code somewhere durable. If not, close the tab.