CLAUDE_ENABLE_BYTE_WATCHDOG

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_ENABLE_BYTE_WATCHDOG is a Claude Code environment variable: Activates a byte-level watchdog on API response streams. The v2.1.105 changelog describes a fix for stalled API streams: "streams now abort after 5 minutes of no data and retry non-streaming instead of hanging indefinitely." This variable likely gates that behavior — when enabled, the runtime monitors incoming byte…. Added between v2.1.104 and v2.1.107 and still present in v2.1.294. It is listed in the official reference.

How to set it

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

export CLAUDE_ENABLE_BYTE_WATCHDOG=<value>
claude

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

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

Release notes that mention it

• Claude Code v2.1.107 — 6 New Environment Variables: Worktrees, Away Mode, and Stream Resilience
• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models

Related variables

• CLAUDE_ENABLE_STREAM_WATCHDOG: Enable stream health monitoring.
• CLAUDE_BYTE_STREAM_IDLE_TIMEOUT_MS
• CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMING: Enable fine-grained (eager) input streaming for tools.
• CLAUDE_CODE_RETRY_WATCHDOG: Tunes the retry watchdog that detects API calls silently looping without progress.
• CLAUDE_CODE_RETRY_WATCHDOG_MAX_WAIT_MS
• CLAUDE_STREAM_FIRST_BYTE_TIMEOUT_MS
• ANTHROPIC_BASE_URL: Custom endpoint for Anthropic services.
• API_FORCE_IDLE_TIMEOUT

Frequently asked questions

All variables, searchable: Claude Code environment variables.