CLAUDE_GATEWAY_LOG_FORMAT

Updated November 6, 2026 by Alex Sorokoletov

CLAUDE_GATEWAY_LOG_FORMAT is a Claude Code environment variable: Set to json to write gateway logs as JSON; any other value keeps the plain text format. Added in v2.1.319 and still present in v2.1.319. It is not in the official reference.

Status	Present in v2.1.319
Added	Added in v2.1.319
Category	Debugging
Official docs	Not listed

How to set it

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

export CLAUDE_GATEWAY_LOG_FORMAT=<value>
claude

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

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

Release notes that mention it

Related variables

CLAUDE_GATEWAY_LOG_LEVEL: Set the gateway log threshold to debug, info, warn or error; messages below the level were dropped and it defaulted to info.
ANTHROPIC_LOG: SDK internal logging level.
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_RUNNER_DEBUG_LOG_PATH
ANTHROPIC_PROFILE
CLAUDE_CODE_DEBUG_LOGS_DIR: Custom directory for debug logs.

Frequently asked questions

What does CLAUDE_GATEWAY_LOG_FORMAT do?

Set to json to write gateway logs as JSON; any other value keeps the plain text format.

Which Claude Code version has CLAUDE_GATEWAY_LOG_FORMAT?

Added in v2.1.319 and still present in v2.1.319.

How do I set CLAUDE_GATEWAY_LOG_FORMAT?

Export it before starting Claude Code (export CLAUDE_GATEWAY_LOG_FORMAT=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.