CLAUDE_CODE_CHILD_SESSION

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_CHILD_SESSION is a Claude Code environment variable. Added between v2.1.143 and v2.1.212 and still present in v2.1.294. It is listed in the official reference.

Status	Present in v2.1.294
Added	Added between v2.1.143 and v2.1.212
Category	Sessions
Official docs	Listed

How to set it

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

export CLAUDE_CODE_CHILD_SESSION=<value>
claude

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

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

Related variables

CLAUDE_BRIDGE_REATTACH_SESSION: Session identity used during bridge reconnection.
CLAUDE_CODE_BRIDGE_SESSION_ID
CLAUDE_CODE_EMIT_SESSION_STATE_EVENTS: Controls whether Claude Code emits session state change events.
CLAUDE_CODE_FORCE_SESSION_PERSISTENCE
CLAUDE_CODE_POST_FOR_SESSION_INGRESS_V2: Use POST-based session ingress v2.
CLAUDE_CODE_REMOTE_SESSION_ID: Remote session identifier.
CLAUDE_CODE_REMOTE_SESSION_ORIGIN: Provenance tag for cloud/remote sessions, checked against the value "review".
CLAUDE_CODE_RESUME_FROM_SESSION: Instructs Claude Code to bootstrap a new session's context from an existing session ID.

Frequently asked questions

Which Claude Code version has CLAUDE_CODE_CHILD_SESSION?

Added between v2.1.143 and v2.1.212 and still present in v2.1.294.

How do I set CLAUDE_CODE_CHILD_SESSION?

Export it before starting Claude Code (export CLAUDE_CODE_CHILD_SESSION=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.