ANTHROPIC_LOG

Updated October 13, 2026 by Alex Sorokoletov

ANTHROPIC_LOG is a Claude Code environment variable: SDK internal logging level. Its release history is not tracked here. It is not in the official reference.

Status	Present in v2.1.294
Category	Debugging
Official docs	Not listed

How to set it

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

export ANTHROPIC_LOG=<value>
claude

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

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

Related variables

ANTHROPIC_PROFILE
CLAUDE_CODE_COMMIT_LOG: Likely controls whether or where Claude Code logs commit operations.
CLAUDE_CODE_DEBUG_LOG_LEVEL: Set debug logging verbosity level.
CLAUDE_CODE_FRAME_TIMING_LOG: Enable per-frame render timing logs in the terminal UI.
CLAUDE_GATEWAY_LOG_LEVEL
CLAUDE_RUNNER_DEBUG_LOG_PATH
CLAUDE_CODE_DEBUG_LOGS_DIR: Custom directory for debug logs.
CLAUDE_CODE_DEBUG_REPAINTS: Enables debug logging for terminal repaint operations.

Frequently asked questions

What does ANTHROPIC_LOG do?

SDK internal logging level

Which Claude Code version has ANTHROPIC_LOG?

Its release history is not tracked here.

How do I set ANTHROPIC_LOG?

Export it before starting Claude Code (export ANTHROPIC_LOG=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.