CLAUDE_CODE_STREAM_TIMER_SLACK_MS

Updated November 3, 2026 by Alex Sorokoletov

CLAUDE_CODE_STREAM_TIMER_SLACK_MS is a Claude Code environment variable: Sets the stream timer slack in milliseconds as an integer from 0 to 1000; values outside that range become 0, and when unset the default comes from a server-side setting. Added in v2.1.318 and still present in v2.1.318. 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_STREAM_TIMER_SLACK_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_STREAM_TIMER_SLACK_MS": "<value>"
  }
}

Related variables

• CLAUDE_BYTE_STREAM_IDLE_TIMEOUT_MS
• CLAUDE_CODE_DISABLE_MEMORY_STREAM_LIST: Turns off the incremental metadata-streaming path inside multi-store memory sync.
• CLAUDE_ENABLE_STREAM_WATCHDOG: Enable stream health monitoring.
• CLAUDE_STREAM_FIRST_BYTE_TIMEOUT_MS: Overrides the first-byte deadline for a dispatched API request.
• CLAUDE_STREAM_IDLE_TIMEOUT_MS: Configures the streaming idle watchdog threshold — the maximum time Claude Code waits for data on an open SSE connection before treating it as stalled.
• CLAUDE_CODE_DIR_SYNC_STREAM
• CLAUDE_CODE_STREAM_EVENT_HOLD_MS
• CLAUDE_CODE_STREAM_EVENT_MAX_LINE_BYTES

Frequently asked questions

All variables, searchable: Claude Code environment variables.