Agent Browser Google Chrome Linux

# Controlling a User's Authenticated Chrome via agent-browser (Linux)

## agent-browser

Install once if not present:

```bash
npm i -g agent-browser
```

Do **not** run `agent-browser install` — that downloads a testing Chromium with no user session, which defeats the purpose of this skill.

Before running any agent-browser commands, load the actual workflow content from the CLI:

```bash
agent-browser skills get core             # workflows, common patterns, troubleshooting
agent-browser skills get core --full      # include full command reference and templates
```

The CLI serves skill content that always matches the installed version, so instructions never go stale.

## The Core Constraint

Chrome refuses remote debugging on the default user-data-dir (`~/.config/google-chrome`) for security. You'll see this error in `/tmp/chrome.log`:

```
DevTools remote debugging requires a non-default data directory. Specify this using --user-data-dir.
```

**The fix:** copy the user's profile to a non-default dir, kill all Chrome, launch from the copy with the debug port, connect agent-browser via CDP.

## Step 0: Find the Right DISPLAY

Everyone's Linux setup is different. Before launching Chrome, find the X display where the user's desktop session is running:

```bash
# Option A: check what the user's shell already has
echo $DISPLAY

# Option B: scan running processes for an X display
ps aux | grep -oP 'DISPLAY=\S+' | sort -u

# Option C: list /tmp/.X11-unix sockets (each one is a display)
ls /tmp/.X11-unix/
# X0 → :0, X1 → :1, etc.

# Option D: look at who's logged into the X session
who | grep '(:[0-9]'
```

Common values are `:0`, `:1`, or `:10`. Use whatever you find — substitute it for `DISPLAY=:1` in the recipe below. If you're in a Kasm/VNC environment, `:1` is typical, but verify first.

If `echo $DISPLAY` returns something, that's the right one. If it's empty, you're likely in an SSH session without X forwarding — look at the X11-unix sockets or check with the user.

## The Recipe (run in order, every time)

Before going through the full setup, check if Chrome is already running with the debug port — if so, you can skip straight to connecting:

```bash
# Quick check: is port 9222 already listening?
curl -s -m 2 http://127.0.0.1:9222/json/version | head -2
```

If that returns a `{"Browser": "Chrome/...` response, Chrome is already up with remote debugging enabled. Run the verification one-liner from the Verification section below — if you land on the target site (not a sign-in page), you're done, skip the rest of the recipe.

If the port is not listening, or you land on a sign-in page, proceed with the full recipe:

```bash
# 1. Kill ALL Chrome processes (any leftover holds the SingletonLock)
pkill -9 -f 'google-chrome\|/opt/google/chrome/chrome'
sleep 3
pgrep -af chrome | grep -v 'crashpad\|chrome-devtools\|grep'  # confirm empty

# 2. Verify the user's session is fresh in their profile
ls -la ~/.config/google-chrome/Default/Cookies   # check mtime is recent

# 3. Copy profile to a non-default location, strip the lock files
rm -rf /tmp/chrome-debug-profile
cp -a ~/.config/google-chrome /tmp/chrome-debug-profile
rm -f /t