CLAUDE_CODE_CCR_EARLY_HYDRATE_PREFETCH

Updated October 14, 2026 by Alex Sorokoletov

CLAUDE_CODE_CCR_EARLY_HYDRATE_PREFETCH is a Claude Code environment variable. Added between v2.1.252 and v2.1.266 and still present in v2.1.295. 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_CCR_EARLY_HYDRATE_PREFETCH=<value>
claude

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

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

Related variables

• CLAUDE_CODE_MANAGED_CONFIG_PREFETCH: Turns on a hedged prefetch of the organization's managed settings during startup, so the first managed-settings fetch runs earlier in the launch sequence.
• CLAUDE_CODE_USE_CCR_V2: Use Claude Code Router v2 for cowork sessions.
• CLAUDE_CODE_ARTIFACT_OPENING_PREFETCH
• CLAUDE_CODE_CCR_FOLD_FIRST_TURN_RESCAN
• CLAUDE_CODE_CCR_SURFACE
• ANTHROPIC_BETAS: Comma-separated beta feature headers.
• ANTHROPIC_CUSTOM_HEADERS: Custom HTTP headers (newline-separated Key: Value).
• ANTHROPIC_FEDERATION_RULE_ID

Frequently asked questions

All variables, searchable: Claude Code environment variables.