CLAUDE_CODE_MAIN_REPLY_HOLD_MS

Updated November 3, 2026 by Alex Sorokoletov

CLAUDE_CODE_MAIN_REPLY_HOLD_MS is a Claude Code environment variable: Number of milliseconds to hold back the main reply stream before handing pieces on; applies only when the relevant transport is active and defaults to 0. Added in v2.1.318 and still present in v2.1.318. It is not in the official reference.

Status	Present in v2.1.318
Added	Added in v2.1.318
Category	Other
Official docs	Not listed

How to set it

For one session, export it in the shell that starts Claude Code:

export CLAUDE_CODE_MAIN_REPLY_HOLD_MS=<value>
claude

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

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

Related variables

CLAUDE_CODE_UNWATCHED_REPLY_HOLD_MS: Number of milliseconds to hold streamed replies for unwatched contexts (subagent, auxiliary, compaction); defaults to 0, meaning no hold.
CLAUDE_CODE_HOLD_REPORT_PARK_AT_INIT: Reported a parked turn at initialization, but only when CLAUDE_CODE_RESUME_INTERRUPTED_TURN was also set; read until v2.1.309.
CLAUDE_CODE_REPLY_GATE_POLICY: Carries a reply-gate policy into agent-loop sessions: a list of terminal tools and caps on how many times Claude asks after a person's message, after its own task or a server event, and otherwise.
ANTHROPIC_BETAS: Comma-separated beta feature headers.
ANTHROPIC_CUSTOM_HEADERS: Custom HTTP headers (newline-separated Key: Value).
ANTHROPIC_FEDERATION_RULE_ID
ANTHROPIC_ORGANIZATION_ID
ANTHROPIC_WORKSPACE_ID

Frequently asked questions

What does CLAUDE_CODE_MAIN_REPLY_HOLD_MS do?

Number of milliseconds to hold back the main reply stream before handing pieces on; applies only when the relevant transport is active and defaults to 0.

Which Claude Code version has CLAUDE_CODE_MAIN_REPLY_HOLD_MS?

Added in v2.1.318 and still present in v2.1.318.

How do I set CLAUDE_CODE_MAIN_REPLY_HOLD_MS?

Export it before starting Claude Code (export CLAUDE_CODE_MAIN_REPLY_HOLD_MS=value), or add it to the "env" object in ~/.claude/settings.json to apply it to every session.

All variables, searchable: Claude Code environment variables.