Miscellaneous & Internal

Type: String (module filter)
Default: Unspecified
Description: Enable debug output for various modules. Wildcard filtering supported (e.g., claude:* for all Claude-prefixed modules).
Example: export DEBUG=claude:*

Type: Boolean (1, true, 0, false)
Default: false
Description: Enable debug output for authentication. Traces auth flow for troubleshooting.
Example: export DEBUG_AUTH=1

Type: Boolean (1, true, 0, false)
Default: false
Description: Enable debug output for the Anthropic SDK. Traces SDK behavior.
Example: export DEBUG_SDK=1

Type: Boolean (1, true, 0, false)
Default: true
Description: Control the attribution header in API requests. Set to ‘0’ to disable.
Example: export CLAUDE_CODE_ATTRIBUTION_HEADER=0

Type: Boolean (1, true, 0, false)
Default: false
Description: Scrub environment variables from subprocesses. Removes sensitive vars before spawning subprocesses.
Example: export CLAUDE_CODE_SUBPROCESS_ENV_SCRUB=1

Type: Boolean (1, true, 0, false)
Default: false
Description: Force display of the user survey. Useful for testing the survey UI.
Example: export CLAUDE_FORCE_DISPLAY_SURVEY=1

Type: Boolean (1, true, 0, false)
Default: false
Description: Force code terminal mode. Enables a minimal terminal environment.
Example: export FORCE_CODE_TERMINAL=1

Type: Integer (milliseconds)
Default: 100
Description: Polling interval for Chokidar file watcher in milliseconds. Only used when polling is active.
Example: export CHOKIDAR_INTERVAL=200

Type: Boolean (1, true, 0, false)
Default: false
Description: Force Chokidar to use polling instead of native file watching. Useful on systems with unreliable inotify.
Example: export CHOKIDAR_USEPOLLING=1

Type: URL
Default: Unspecified
Description: Endpoint URL for beta tracing. Used together with ENABLE_BETA_TRACING_DETAILED.
Example: export BETA_TRACING_ENDPOINT=https://tracing.company.com

Type: String (base64-encoded data)
Default: Unspecified
Description: Base64-encoded development bundle passed to the bughunter agent subprocess.
Example: export BUGHUNTER_DEV_BUNDLE_B64=SGVsbG8gV29ybGQ=

Type: Boolean (truthy values activate)
Default: unset
Description: Activates coordinator mode — Claude Code’s multi-agent orchestration layer. Gated at compile time by COORDINATOR_MODE flag. Session resume auto-flips this env var to match the mode the session was created in. See Coordinator/.
Example: export CLAUDE_CODE_COORDINATOR_MODE=1
Related: CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS, CLAUDE_CODE_TASK_LIST_ID

Type: Enum (string)
Default: auto
Allowed values: auto, iterm2, iterm2_with_bell, kitty, osascript, notify-send, command, bell
Description: Selects the desktop notification mechanism. auto picks the best available for the terminal. osascript is macOS-only; notify-send is Linux-only; iterm2* and kitty require those specific terminals. command runs a configured shell command. bell writes \a to the terminal.
Example: export CLAUDE_NOTIFICATION_CHANNEL=kitty

Type: Boolean (truthy values activate)
Default: unset
Description: Enables a Unix Domain Socket inbox for inter-process messaging between concurrent Claude Code sessions. When set (and not in --bare mode), Claude Code spawns a UDS listener at startup. Socket path exported to child processes via CLAUDE_CODE_MESSAGING_SOCKET. Internal infrastructure — primarily ant-only.
Example: export UDS_INBOX=1
Related: CLAUDE_CODE_MESSAGING_SOCKET

Type: String (filesystem path)
Default: set by Claude Code when UDS_INBOX is active
Description: Path to the UDS inbox socket, populated by the parent Claude Code process when UDS_INBOX is set. Child processes read this env var to connect back to the parent’s messaging server. Users should NOT set this directly.
Example: /tmp/claude-code-messaging-<pid>.sock (auto-generated)
Related: UDS_INBOX

Type: String ("ant" is the only load-bearing value)
Default: unset
Description: Build-time/runtime flag identifying Anthropic-internal builds. When set to "ant", the binary enables ANT-ONLY features — additional slash commands (e.g. /bughunter, /ctx_viz, /good-claude), extra flags (--afk, --agent-teams, --tasks, --delegate-permissions, --dangerously-skip-permissions-with-classifiers), and extended enum values (e.g. effortLevel: "max"). This is not a user-configurable setting — setting it in a public build does not unlock those features, because the surrounding code paths are compiled out or guarded by additional gates. Referenced across the codebase as process.env.USER_TYPE === 'ant'.
Example: (N/A — not user-configurable)