Features and Toggles

These variables flip one feature each. Some turn off a feature that is on by default. Others force on a feature that a server flag controls. A row with the Gated badge only works when a feature flag or server gate allows it, unless the variable overrides the gate.

This page lists 66 variables. Most take 1 to turn on and 0 to turn off.

Example

export CLAUDE_CODE_SIMPLE=1
claude

Claude Code starts in its minimal mode. This is the same mode that the --bare flag turns on.

Variables

The table is sorted by name. The Gated badge tells you a flag or gate is involved. See Environment Variables for the columns.

Variable	Status	What it does	Values and default	Notes
AI_AGENT	Undocumented	Carries an agent id for child tools. Claude Code fills it when it is unset or starts with claude-code_ or claude-code/.	On or off	All sessions. Not set from project env before trust
BUN_CHROME_PATH	Undocumented Gated	Sets the Chrome binary for the artifact preview browser. It replaces the search for Playwright and system Chrome.	Text. Preview needs CLAUDE_CODE_ARTIFACT_PREVIEW or a feature flag and a build that includes it	Artifact preview (feature gated)
CLAUDE_CODE_ARTIFACT	Undocumented Gated	Turns artifacts on or off. A falsy value turns them off.	On or off. First-party only. A truthy value overrides the SDK default-off	First-party provider. gated by a feature flag flag. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_ASSETS	Undocumented	Turns artifact asset uploads on or off.	On, off, or unset. Without it the agent mode or the host capabilities decide. The value also sets the reported source to env	Artifacts. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_COMMENT_FAST_ACK	Undocumented Gated	Turns on a quick acknowledgement reply to artifact comments before the full reply.	On, off, or unset, false by default. Else a feature flag decides with default false. The ack text starts I'm on it	Artifacts with comment auto-react. gated by a feature flag flag. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_COMMENT_RESPONDER	Undocumented Gated	Turns on responder dispatch for artifact comment threads. A classifier picks the lane act or pipeline.	On, off, or unset, false by default. Else a feature flag decides with default false	Artifacts with comment auto-react. gated by a feature flag flag. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_COMMENTS	Documented Differs Gated	Turns the reading of artifact comments on or off.	On, off, or unset, false by default. Docs only mention 0 to stop it	Artifacts. gated by a feature flag flag. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_COMMENTS_AUTOREACT	Documented Differs Gated	Lets Claude reply on its own to comments sent to it.	On, off, or unset, false by default. Docs only mention 0 to stop it	Artifacts. gated by a feature flag flag. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_DB	Undocumented	Turns the artifact database feature on or off.	On, off, or unset, on by default. A falsy value turns it off. The calls go to /api/frame/db/agent	Artifacts. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_DB_STR_REPLACE	Undocumented Gated	Turns on the str_replace edit operation for artifact database documents.	On, off, or unset, false by default. Needs CLAUDE_CODE_ARTIFACT_DB on. Else a feature flag decides with default false	Artifacts. gated by a feature flag flag. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_DELETE	Undocumented Gated	Turns on artifact delete.	On, off, or unset, false by default. Else a feature flag decides with default false. Remote sessions may disable it by another check	Artifacts. gated by a feature flag flag. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_FRESH_READ	Undocumented	Lets artifact reads fetch fresh data from the docs store. Set to 0 to turn this off.	On, off, or unset, on by default. Only the value false turns it off	Artifacts with the docs store. Not set from project env before trust
CLAUDE_CODE_ARTIFACT_HOT	Undocumented Gated	Overrides a gate for artifact hot updates. No visible effect in a print-mode probe (Probes).	On, off, or unset, off by default. A session value frozenHotUpdate wins first	Artifacts, gated by a feature flag
CLAUDE_CODE_ARTIFACT_INHERITED_TYPE_GRANT	Undocumented Gated	Overrides the artifact inherited-type-grant gate. Claude Code logs the result as a feature flag.	Off by default. Env read	Artifacts, gated by a feature flag
CLAUDE_CODE_ARTIFACT_MULTI_FILE	Undocumented Gated	Forces the artifact multi-file gate on or off. No visible effect in a print-mode probe (Probes).	On, off, or unset, off by default	Artifacts, gated by a feature flag
CLAUDE_CODE_ARTIFACT_OPEN_ACTION	Undocumented Gated	Forces the artifact open-action gate on or off. No visible effect in a print-mode probe (Probes).	On, off, or unset, off by default	Artifacts, gated by a feature flag
CLAUDE_CODE_ARTIFACT_OPENING_PREFETCH	Undocumented	Set to false to turn off the artifact prefetch at session start.	On, off, or unset. Only false has an effect. Otherwise the result follows the artifact REPL tool and quickstart checks	Artifacts, when the base check passes
CLAUDE_CODE_ARTIFACT_PATH_PIN	Undocumented	Turns the artifact path-pin check on or off. The check makes Claude read published files before it replaces or removes them.	On, off, or unset, true by default. A session value frozenPathPin wins first	Artifacts
CLAUDE_CODE_ARTIFACT_PIN	Undocumented	Turns artifact pinning on or off. Pinning is also off in some cloud sessions.	On, off, or unset, true by default. Returns off in a CLAUDE_CODE_REMOTE session that is not a bound cloud session	Artifacts, local and cloud sessions
CLAUDE_CODE_ARTIFACT_PRESENCE	Undocumented Gated	Forces the artifact presence connection on or off. Presence keeps one live connection for each artifact slug.	On, off, or unset, off by default	Artifacts, gated by a feature flag
CLAUDE_CODE_ARTIFACT_PREVIEW	Undocumented	Set to false to turn off artifact preview. Set to true to force it on.	On, off, or unset. Unset means preview follows a browser check. In a CLAUDE_CODE_REMOTE session it may pick the emulator engine, else local Chrome	Artifacts, local and cloud sessions
CLAUDE_CODE_ARTIFACT_PREVIEW_EMULATOR	Undocumented Gated	Pins the artifact preview emulator off or on.	On, off, or unset. false pins it off. true pins it on if the emulator skill files pass a check	Cloud sessions, gated by a feature flag
CLAUDE_CODE_ARTIFACT_PUBLISH_EDITS	Documented	Lets the artifact publish tool apply small edits to a file in the same call. Set to 0 to turn that off.	On, off, or unset, true by default	Artifacts
CLAUDE_CODE_ARTIFACT_SHARE	Undocumented	Turns on artifact sharing when set to true in a cloud or desktop session.	On, off, or unset. Sharing needs true and a cloud or desktop surface. Presence of any value also marks the host contract	Cloud and desktop sessions
CLAUDE_CODE_ARTIFACT_START_KIT	Undocumented Gated	Forces the artifact start kit gate on or off. No visible effect in a print-mode probe (Probes).	On, off, or unset, off by default	Artifacts, gated by a feature flag
CLAUDE_CODE_ARTIFACT_TOOLSET	Undocumented Gated	Picks the artifact tool set. When on, Claude loads the artifact tool through tool search.	On, off, or unset, off by default	Artifacts, gated by a feature flag
CLAUDE_CODE_ARTIFACT_TYPE_CATALOG	Undocumented Gated	Forces the artifact type catalog gate on or off.	On, off, or unset, off by default	Artifacts, gated by a feature flag
CLAUDE_CODE_ARTIFACT_TYPE_CLOUD_CREATE	Undocumented Gated	Forces on or off the creation of a new artifact from a type in cloud sessions.	On, off, or unset, off by default	Cloud sessions, gated by a feature flag
CLAUDE_CODE_ARTIFACT_TYPES	Undocumented Gated	Forces the artifact types gate on or off. It works with the /api/frame/types endpoints.	On, off, or unset, off by default	Artifacts, gated by a feature flag
CLAUDE_CODE_ARTIFACT_VERIFY	Undocumented Gated	Turns on artifact verify reads from /api/frame/diag. It is always off in CLAUDE_CODE_REMOTE sessions.	On, off, or unset, off by default	Local sessions, gated by a feature flag
CLAUDE_CODE_ATTACHMENTS_BY_PATH	Undocumented	Sends attachments by path. It sets the upload mode to none and keeps the file delivery tool on without the first-party check.	On or off, off by default. Also keeps tool results in subagents	All sessions
CLAUDE_CODE_ATTRIBUTION_ANNOUNCEMENT	Undocumented Gated	Forces the attribution announcement on or off.	On, off, or unset, on by default. Cached per session	All sessions, gated by a feature flag
CLAUDE_CODE_BASALT_COVE	Undocumented	Forces the basalt_cove client-data feature on. Probe: Adds a "Communicating with the user" section and a code-comment rule to the system prompt. See Probes.	On or off. Else the basalt_cove client-data entry decides	All sessions
CLAUDE_CODE_DISABLE_ARTIFACT	Documented	Turns off the Artifact tool. No settings file can turn it back on.	On or off. Used as the envDisableVar next to the enableArtifact setting	All sessions. Project env can set it before trust
CLAUDE_CODE_DISABLE_PROACTIVITY	Undocumented	Turns off the proactivity selector, which is on by default through a feature flag.	On or off. Claude Code passes 1 to background sessions it starts when set	All sessions
CLAUDE_CODE_FLAG_FETCH_WAIT_MS	Undocumented	Sets how long a non-interactive start waits for the GrowthBook flag fetch.	A number of milliseconds, 3000 by default. Whole number of at least 0	Non-interactive and remote startup
CLAUDE_CODE_GROWTHBOOK_KICK_FROM_INIT	Undocumented	Starts the GrowthBook flag fetch during init.	On or off, off by default. Also recorded in the startup flag fetch event	Startup
CLAUDE_CODE_GROWTHBOOK_KICK_ON_WARM_CACHE	Undocumented	Starts the GrowthBook flag fetch even when the disk cache is warm, for remote non-interactive starts.	On or off, off by default. Recorded in the startup flag fetch event	Remote non-interactive startup
CLAUDE_CODE_INCLUDE_PARTIAL_MESSAGES	Undocumented	Turns on partial message streaming in print or SDK mode, as an OR with the matching CLI option.	On or off. Combined with a local flag value	Print and SDK modes
CLAUDE_CODE_MANAGED_CONFIG_PREFETCH	Undocumented Gated	Forces the prefetch of managed config on or off.	On, off, or unset. Unset gives false unless a first-party login exists and a feature flag is not on	First-party logins
CLAUDE_CODE_PARSED_WILLOW	Undocumented Gated	Overrides a feature flag, which defaults to on. No visible effect in a print-mode probe (Probes).	On, off, or unset. Wins over the flag when set	All sessions
CLAUDE_CODE_PER_TURN_TIMING	Undocumented Gated	Gates a per-turn timing feature for the model request. No visible effect in a print-mode probe (Probes).	Needs a model check and a per_turn_timing setting, else it falls back to per_turn_effort	All sessions
CLAUDE_CODE_PEWTER_OWL	Undocumented Gated	Forces the pewter_owl_tool and pewter_owl_brief features on or off. It wins over a feature flag and a feature flags.	On, off, or unset. Without it the code checks non-interactive mode, a model allowlist (a feature flag), then the flag or client data	All sessions, gated by a feature flag
CLAUDE_CODE_PEWTER_OWL_TOOL	Undocumented Gated	Forces only the pewter_owl_tool feature on or off. When true it also changes the turn-end check that uses a feature flag.	On, off, or unset. Wins over CLAUDE_CODE_PEWTER_OWL for this one feature	All sessions, gated by a feature flag
CLAUDE_CODE_POLISHED_DEWDROP	Undocumented Gated	Overrides a feature flag. drop maps to drop_block and block maps to error. No visible effect in a print-mode probe (Probes).	enum of drop, block, off. Order is env, then client data, then the flag	All sessions
CLAUDE_CODE_PROJECTS_SESSION	Undocumented	When true it turns on a URL cache state for the web fetch tool. It also joins an entrypoint check. No visible effect in a print-mode probe (Probes).	On or off	All sessions
CLAUDE_CODE_SAFE_MODE	Documented	Starts safe mode. Config such as CLAUDE.md, skills, plugins, hooks, and MCP servers does not load. Managed policy still applies.	On or off. Boolean 1 or true. The --safe-mode flag sets it to 1 and also sets CLAUDE_CODE_DISABLE_CLAUDE_MDS to 1	All sessions. The --desktop command refuses to run in safe mode
CLAUDE_CODE_SIMPLE	Documented	Runs a minimal mode with Bash, read, and edit tools only. Hooks, skills, plugins, MCP discovery, auto memory, and CLAUDE.md do not load.	On or off. Boolean. The --bare flag sets it to 1	All sessions. Set by Claude Code for --bare
CLAUDE_CODE_SLEEPY_SNOWFLAKE	Undocumented Gated	Sets the scope of a feature flag feature. No visible effect in a print-mode probe (Probes).	Text. Else a recorded value or the flag client data with threads, all, or off is used	All sessions, behind a feature flag
CLAUDE_CODE_SUPPRESS_SESSION_ATTRIBUTION	Undocumented	Leaves the session URL out of attribution text such as commit and PR footers.	On or off. The attribution.sessionUrl setting set to false has the same effect	All sessions
CLAUDE_CODE_TODO_REMINDER_MODE	Undocumented	Selects the todo reminder mode. Env wins over the feature flag.	One of a fixed set of values, baseline by default. Enum baseline or off	All sessions
CLAUDE_WORKFLOW_NAME_ONLY	Undocumented	When on, workflow discovery returns only the built-in workflow list and scans no files.	-	-
CLAUDE_WORKSHOP_PROGRESS	Undocumented	Turns the workshop authoring-progress hook off when set to a false value.	-	-
DISABLE_BRIEF_MODE_STOP_HOOK	Undocumented	Stops the brief-mode check at the end of a turn. That check adds a reminder when the turn used no brief tool. No visible effect in a print-mode probe (Probes).	On or off	-
DISABLE_BUG_COMMAND	Documented	Disables the bug report command. The message names this var.	On or off	-
DISABLE_DOCTOR_COMMAND	Documented	Hides the /doctor command and its /checkup alias.	On or off	-
DISABLE_EXTRA_USAGE_COMMAND	Documented	Hides the /usage-credits command.	On or off	-
DISABLE_FEEDBACK_COMMAND	Documented	Disables the feedback command.	On or off	-
DISABLE_GROWTHBOOK	Documented	Turns off GrowthBook flag fetching. Code defaults apply.	On or off	-
DISABLE_INSTALL_GITHUB_APP_COMMAND	Documented	Hides the /install-github-app command.	On or off	-
DS_CHROMIUM_PATH	Undocumented	Gives the Chromium path to Playwright in a bundled script that renders Storybook stories.	Text, browser by default. Unset means the Playwright default browser	Bundled design-system script only
OneDrive	Undocumented Gated	Adds the OneDrive Documents folder to the Windows profile folders that Claude Code checks for PowerShell profiles.	Text. Used only if the path exists	Windows only. Not set from project env before trust
OneDriveCommercial	Undocumented Gated	Adds the OneDrive for Business Documents folder to the Windows profile folders that Claude Code checks.	Text. Used only if the path exists. The docs for the managed path setting also list %OneDriveCommercial%	Windows only. Not set from project env before trust
OneDriveConsumer	Undocumented Gated	Adds the personal OneDrive Documents folder to the Windows profile folders that Claude Code checks.	Text. Used only if the path exists. The managed path setting text also lists %OneDriveConsumer%	Windows only. Not set from project env before trust
P4PORT	Undocumented	Marks the repo as Perforce when set, and reports hasP4Port in diagnostics.	Text	All platforms. Not set from project env before trust
SAFEUSER	Undocumented	Is shown as SAFEUSER in the context block of the commit and PR commands.	Text, empty by default	Commit and PR slash commands. Not set from project env before trust

How It Works

Claude Code asks a server for feature flags at startup. A flag turns a feature on or off for an account. Some variables override a flag. Others only work when the flag is already on. Turning telemetry off also stops flag fetching, which turns off the features that need it.

Related Pages

• Environment Variables: how Claude Code reads variables and which value wins.
• Telemetry and Debug
• Undocumented Items: every item that only the program shows.

Source: the program (variable names found in the 2.1.304 binary) and the Environment Variables page of the official docs.