CLAUDE_BG_ISOLATION

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_BG_ISOLATION is a Claude Code environment variable: Isolation mode for background agent processes — controls how separated the daemon's process space is from the foreground session. Values likely span a native-to-sandboxed spectrum, letting enterprise deployments enforce stricter boundaries than personal setups. Added between v2.1.118 and v2.1.123 and still present in v2.1.294. It is not in the official reference.

Status	Present in v2.1.294
Added	Added between v2.1.118 and v2.1.123
Category	Sessions
Official docs	Not listed

How to set it

For one session, export it in the shell that starts Claude Code:

export CLAUDE_BG_ISOLATION=<value>
claude

To apply it to every session, add it to the env object of a settings file:

// ~/.claude/settings.json
{
  "env": {
    "CLAUDE_BG_ISOLATION": "<value>"
  }
}

Release notes that mention it

Related variables

CLAUDE_AUTO_BACKGROUND_TASKS: Enable automatic background task execution.
CLAUDE_BG_BACKEND: Set to "daemon" to route background work through a daemon backend.
CLAUDE_BG_RENDEZVOUS_SOCK: Socket path for the IPC channel between a foreground Claude session and the background daemon.
CLAUDE_BG_SOURCE: Tags where a background job originated: CLI, SDK, Remote Control, another agent.
CLAUDE_BG_STARTUP_WEDGE_MS: Startup jitter for background sessions.
CLAUDE_BG_TCC_DISCLAIMED: macOS TCC (Transparency, Consent, and Control) permission disclaimer state for background sessions.
CLAUDE_BRIDGE_REATTACH_SEQ: Sequence number for the bridge reconnection protocol.
CLAUDE_BRIDGE_REATTACH_SESSION: Session identity used during bridge reconnection.

Frequently asked questions

What does CLAUDE_BG_ISOLATION do?

Isolation mode for background agent processes — controls how separated the daemon's process space is from the foreground session. Values likely span a native-to-sandboxed spectrum, letting enterprise deployments enforce stricter boundaries than personal setups.

Which Claude Code version has CLAUDE_BG_ISOLATION?

Added between v2.1.118 and v2.1.123 and still present in v2.1.294.

How do I set CLAUDE_BG_ISOLATION?

Export it before starting Claude Code (export CLAUDE_BG_ISOLATION=value), or add it to the "env" object in ~/.claude/settings.json to apply it to every session.

All variables, searchable: Claude Code environment variables.