CLAUDE_CODE_DISABLE_NESTED_SESSION_ID

Updated November 2, 2026 by Alex Sorokoletov

CLAUDE_CODE_DISABLE_NESTED_SESSION_ID is a Claude Code environment variable: Set to a truthy value to stop the session-id getter from returning null and have it return the resolved id instead. Added between v2.1.315 and v2.1.317 and still present in v2.1.317. It is not in the official reference.

How to set it

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

export CLAUDE_CODE_DISABLE_NESTED_SESSION_ID=<value>
claude

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

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

Release notes that mention it

• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models
• claude-code-env-vars-v2-1-317

Related variables

• CLAUDE_BRIDGE_REATTACH_SESSION: Session identity used during bridge reconnection.
• CLAUDE_CODE_BRIDGE_SESSION_ID
• CLAUDE_CODE_CHILD_SESSION
• CLAUDE_CODE_DISABLE_BACKGROUND_TASKS: Disable background tasks entirely.
• CLAUDE_CODE_DISABLE_BG_EXIT_HANDOFF
• CLAUDE_CODE_DISABLE_BG_STABLE_PATH: On macOS, skips resolving a stable executable path for the background process and re-execs using the current executable path instead.
• CLAUDE_CODE_DISABLE_QUIET_BACKGROUND_WAIT: When set, disables the quiet long background wait, so the session returns instead of entering a long sleep while background work is idle.
• CLAUDE_CODE_EMIT_SESSION_STATE_EVENTS: Controls whether Claude Code emits session state change events.

Frequently asked questions

All variables, searchable: Claude Code environment variables.