CLAUDE_CODE_SAVE_HOOK_ADDITIONAL_CONTEXT

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_SAVE_HOOK_ADDITIONAL_CONTEXT is a Claude Code environment variable: Extra context passed to save hooks. Removed between v2.1.96 and v2.1.100, 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_SAVE_HOOK_ADDITIONAL_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_SAVE_HOOK_ADDITIONAL_CONTEXT": "<value>"
  }
}

Release notes that mention it

• Claude Code v2.1.100 — 3 New Environment Variables: Context Token Limits, Perforce VCS, and Script Capability Controls

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_MODE_SIBLING_CONTEXT: Includes sibling files (or sessions) when classifying.
• CLAUDE_CODE_DISABLE_1M_CONTEXT: Disable extended 1M token context window.
• CLAUDE_CONTEXT_COLLAPSE: Collapses context on the fly, with a dedicated model to do it.
• CLAUDE_CODE_RESUME_TOLERATES_CONTEXT_APPENDS
• CLAUDE_CODE_RESUME_TOLERATES_CONTEXT_SEEDS
• CLAUDE_CONTEXT_COLLAPSE_MODEL
• CLAUDE_AFTER_LAST_COMPACT: Request only conversation logs after last compaction.

Frequently asked questions

All variables, searchable: Claude Code environment variables.