CLAUDE_BRIDGE_REATTACH_SESSION

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_BRIDGE_REATTACH_SESSION is a Claude Code environment variable: Session identity used during bridge reconnection. Pairs with CLAUDE_BRIDGE_REATTACH_SEQ — the bridge presents both to resume exactly where it disconnected. Added in v2.1.118 and still present in v2.1.294. 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_BRIDGE_REATTACH_SESSION=<value>
claude

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

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

Release notes that mention it

• Claude Code v2.1.126 — `project purge`, Gateway Model Picker, and What's Actually New
• Claude Code v2.1.123 — Background Daemons, Agent Fleets, and CoWork Memory
• Claude Code v2.1.118 — 10 New Environment Variables: Forked Subagents Ship, Subscription Tiering Takes Shape
• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models

Related variables

• CLAUDE_BRIDGE_REATTACH_SEQ: Sequence number for the bridge reconnection protocol.
• CLAUDE_CODE_BRIDGE_SESSION_ID
• CLAUDE_BRIDGE_REATTACH_GROUPING
• CLAUDE_BRIDGE_REATTACH_NO_BACKFILL
• CLAUDE_BRIDGE_REATTACH_OUTBOUND_ONLY
• CLAUDE_BRIDGE_REATTACH_OWNER_ACCT
• CLAUDE_BRIDGE_REATTACH_OWNER_ORG
• CLAUDE_BRIDGE_USE_CCR_V2: Toggle for CCR v2 bridge protocol — companion to the existing CLAUDE_CODE_USE_CCR_V2 introduced in v2.1.69.

Frequently asked questions

All variables, searchable: Claude Code environment variables.