Phone Sessions Running Without Your Sandbox? Give claude remote-control Its Own Settings File.

At a glance

• A new --settings flag on claude remote-control applies one settings file to every session the server starts.
• Put the flag after remote-control, because a global flag before it makes the server refuse to start.
• Restart the server after you edit the file, since running sessions keep the old copy.

You start claude remote-control so you can steer Claude from your phone, and you want them sandboxed. The old --sandbox switch is gone, and --settings typed before remote-control stops the server. Hand the server one settings file instead.

Why it matters

Remote Control sessions run on your machine with your files, even when you type from a phone. Anthropic's docs say --sandbox was removed in v2.1.300 and that you turn on sandboxing in a settings file. A global --settings flag before remote-control makes the server refuse to start. The v2.1.321 changelog adds a new --settings <file> flag on claude remote-control itself. The docs flag table may still lag, so treat the changelog as the source for this new flag.

How to give every Remote Control session the same settings

We built these steps from the docs and changelog and have not run them in a live session.

1. Check your version with claude --version. You need v2.1.321 or later. On Tuesday morning npm latest was v2.1.322, and stable was still v2.1.311.
2. Create a settings file such as .claude/remote-control.json. That path is our choice, not a documented name. The sandboxing docs show sandbox.enabled set to true and allowUnsandboxedCommands set to false.
3. The docs describe sandbox.failIfUnavailable. Our read: set it to true in the same sandbox block so startup fails if the sandbox cannot start.
4. Start the server with the new flag after the subcommand: claude remote-control --settings plus the file path. Add --name for a title.
5. Open a session from your phone, run /sandbox, and ask Claude to run a harmless command to confirm the sandbox is active.
6. When you change the file, stop the server with Ctrl+C and start it again. The changelog says no new session starts until you restart.

# We have not run this script end to end on every platform. It prints and checks, and changes no files.
# Run it in a test shell. Nothing is written to your shell profile.

claude --version

# Optional file and server start, left commented so this script changes no files.
# The path .claude/remote-control.json is our choice, not a documented name.
# mkdir -p .claude
# cat > .claude/remote-control.json <<'JSON'
# {
#   "sandbox": {
#     "enabled": true,
#     "allowUnsandboxedCommands": false,
#     "failIfUnavailable": true
#   }
# }
# JSON
# Flag goes after remote-control, not before it.
# claude remote-control --settings .claude/remote-control.json --name "Sandboxed remote"

Gotchas

• Order matters. claude --settings file remote-control is the form the docs say refuses to start. Put the new --settings flag after remote-control.
• The flag is changelog only so far. The Remote Control flag table did not yet list --settings when we checked. Use the v2.1.321 changelog, and claude remote-control --help for your build.
• Edits need a restart. A changed file blocks new sessions until you restart.
• The ! prompt is different. The docs say those lines usually run outside the sandbox.
• Linux and WSL2 need dependencies. If /sandbox shows only a Dependencies tab, the sandbox cannot start, and with failIfUnavailable on, Claude Code exits.

Sources:

• Claude Code v2.1.321 release notes
• Continue local sessions from any device with Remote Control, Claude Code docs
• Sandboxing, Claude Code docs
• CLI reference, Claude Code docs

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