CLAUDE_CODE_AUTO_MODE_SIBLING_CONTEXT

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_AUTO_MODE_SIBLING_CONTEXT is a Claude Code environment variable: Includes sibling files (or sessions) when classifying. Lets the gate reason about consistency across related files instead of judging each change in isolation. Removed between v2.1.219 and v2.1.221, so current releases ignore it. 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_AUTO_MODE_SIBLING_CONTEXT=<value>
claude

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

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

Release notes that mention it

• Claude Code v2.1.209 — Auto Mode Grows Up

Related variables

• CLAUDE_CODE_AUTO_MODE_PRIOR_ASSISTANT_CONTEXT: Feeds prior assistant turns into the decision, so the classifier can see the reasoning behind an edit.
• CLAUDE_CODE_AUTO_COMPACT_WINDOW: Controls the token window threshold at which automatic context compaction kicks in.
• CLAUDE_CODE_DISABLE_1M_CONTEXT: Disable extended 1M token context window.
• CLAUDE_CODE_SAVE_HOOK_ADDITIONAL_CONTEXT: Extra context passed to save hooks.
• CLAUDE_CONTEXT_COLLAPSE: Collapses context on the fly, with a dedicated model to do it.
• DISABLE_AUTO_COMPACT: Disable automatic compaction only (manual /compact still works).
• CLAUDE_CODE_RESUME_TOLERATES_CONTEXT_APPENDS
• CLAUDE_CODE_RESUME_TOLERATES_CONTEXT_SEEDS

Frequently asked questions

All variables, searchable: Claude Code environment variables.