CLAUDE_CODE_COLD_COMPACT

Updated October 23, 2026 by Alex Sorokoletov

CLAUDE_CODE_COLD_COMPACT is a Claude Code environment variable. Added between v2.1.123 and v2.1.126 and still present in v2.1.310. 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_COLD_COMPACT=<value>
claude

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

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

Release notes that mention it

• Claude Code v2.1.126 — `project purge`, Gateway Model Picker, and What's Actually New
• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models

Related variables

• CLAUDE_AFTER_LAST_COMPACT: Request only conversation logs after last compaction.
• CLAUDE_CODE_AUTO_COMPACT_WINDOW: Controls the token window threshold at which automatic context compaction kicks in.
• CLAUDE_CODE_IDLE_COMPACT_MIN_TOKENS: Sets the minimum conversation size, in tokens, before idle compaction runs.
• DISABLE_AUTO_COMPACT: Disable automatic compaction only (manual /compact still works).
• DISABLE_CLAUDE_CODE_SM_COMPACT: Disable session memory compaction.
• DISABLE_COMPACT: Disable all compaction (manual + auto).
• ENABLE_CLAUDE_CODE_SM_COMPACT: Force enable session memory compaction.
• CLAUDE_CODE_AUTO_MODE_COMPACT_THREAD_RULE

Frequently asked questions

All variables, searchable: Claude Code environment variables.