CLAUDE_CODE_ARG_KEY_SHAPE

Updated October 14, 2026 by Alex Sorokoletov

CLAUDE_CODE_ARG_KEY_SHAPE is a Claude Code environment variable. Added between v2.1.247 and v2.1.252 and still present in v2.1.295. It is not in the official reference.

Status	Present in v2.1.295
Added	Added between v2.1.247 and v2.1.252
Category	Other
Official docs	Not listed

How to set it

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

export CLAUDE_CODE_ARG_KEY_SHAPE=<value>
claude

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

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

Related variables

CLAUDE_AI_IMPORT_SHAPE
CLAUDE_CHROME_TAB_GROUP_KEY
ANTHROPIC_BETAS: Comma-separated beta feature headers.
ANTHROPIC_CUSTOM_HEADERS: Custom HTTP headers (newline-separated Key: Value).
ANTHROPIC_FEDERATION_RULE_ID
ANTHROPIC_ORGANIZATION_ID
ANTHROPIC_WORKSPACE_ID
BETA_TRACING_ENDPOINT: Custom endpoint for beta tracing.

Frequently asked questions

Which Claude Code version has CLAUDE_CODE_ARG_KEY_SHAPE?

Added between v2.1.247 and v2.1.252 and still present in v2.1.295.

How do I set CLAUDE_CODE_ARG_KEY_SHAPE?

Export it before starting Claude Code (export CLAUDE_CODE_ARG_KEY_SHAPE=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.