CLAUDE_CODE_STREAM_EVENT_NO_SUBSCRIBER_HOLD_MS

Updated November 6, 2026 by Alex Sorokoletov

CLAUDE_CODE_STREAM_EVENT_NO_SUBSCRIBER_HOLD_MS is a Claude Code environment variable: Milliseconds to hold a stream event when nothing is subscribed; used only when CLAUDE_CODE_STREAM_EVENT_HOLD_MS is also set. Added in v2.1.319 and still present in v2.1.319. 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_EVENT_NO_SUBSCRIBER_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_STREAM_EVENT_NO_SUBSCRIBER_HOLD_MS": "<value>"
  }
}

Related variables

• CLAUDE_CODE_STREAM_EVENT_HOLD_MS
• CLAUDE_CODE_STREAM_EVENT_MAX_LINE_BYTES
• 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_CODE_HOME_SEED_HOLD_TIMEOUT_MS: Maximum time in milliseconds to hold for the home settings seed; capped at the built-in default, so it can only shorten the wait.
• CLAUDE_CODE_STREAM_TIMER_SLACK_MS: 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.
• CLAUDE_ENABLE_STREAM_WATCHDOG: Enable stream health monitoring.
• CLAUDE_STREAM_FIRST_BYTE_TIMEOUT_MS: Overrides the first-byte deadline for a dispatched API request.

Frequently asked questions

All variables, searchable: Claude Code environment variables.