claude-settings.md

Settings Best Practice

A comprehensive guide to all available configuration options in Claude Code's settings.json files. As of v2.1.224, Claude Code exposes 127+ settings and 311 environment variables (use the "env" field in settings.json to avoid wrapper scripts).

← Back to Claude Code Best Practice

Table of Contents

1. Settings Hierarchy
2. Core Configuration
3. Permissions
4. Hooks
5. MCP Servers
6. Sandbox
7. Plugins
8. Model Configuration
9. Display & UX
10. AWS & Cloud Credentials
11. Environment Variables
12. Useful Commands

---

Settings Hierarchy

Settings apply in order of precedence (highest to lowest):

Priority	Location	Scope	Shared?	Purpose
1	Managed settings	Organization	Yes (deployed by IT)	Security policies that cannot be overridden
2	Command line arguments	Session	N/A	Temporary single-session overrides
3	.claude/settings.local.json	Project	No (git-ignored)	Personal project-specific
4	.claude/settings.json	Project	Yes (committed)	Team-shared settings
5	~/.claude/settings.json	User	N/A	Global personal defaults

Managed settings are organization-enforced and cannot be overridden by any other level, including command line arguments. Delivery methods:

• Server-managed settings (remote delivery)
• MDM profiles — macOS plist at com.anthropic.claudecode
• Registry policies — Windows HKLM\SOFTWARE\Policies\ClaudeCode (admin) and HKCU\SOFTWARE\Policies\ClaudeCode (user-level, lowest policy priority)
• File — managed-settings.json and managed-mcp.json (macOS: /Library/Application Support/ClaudeCode/, Linux/WSL: /etc/claude-code/, Windows: C:\Program Files\ClaudeCode\)
• Drop-in directory — managed-settings.d/ alongside managed-settings.json for independent policy fragments (v2.1.83). Following the systemd convention, managed-settings.json is merged first as the base, then all *.json files in the drop-in directory are sorted alphabetically and merged on top. Later files override earlier ones for scalar values; arrays are concatenated and de-duplicated; objects are deep-merged. Hidden files starting with . are ignored. Use numeric prefixes to control merge order (e.g., 10-telemetry.json, 20-security.json)

Within the managed tier, precedence is: server-managed > MDM/OS-level policies > file-based (managed-settings.d/*.json + managed-settings.json) > HKCU registry (Windows only). Only one managed source wins for most keys; sources do not merge across tiers. Within the file-based tier, drop-in files and the base file are merged together.

Exception — admin-source union keys: The following keys are honored when any admin-controlled managed source sets them, not just the winning source: sandbox.network.allowManagedDomainsOnly, sandbox.network.allowedDomains (when allowManagedDomainsOnly is set), sandbox.filesystem.allowManagedReadPathsOnly, sandbox.filesystem.allowRead (when allowManagedReadPathsOnly is set), allowAllClaudeAiMcps, sandbox.bwrapPath, sandbox.socatPath, forceRemoteSettingsRefresh, and env (which merges per key across all admin sources rather than taking the highest-precedence source's entire object).

Note: As of v2.1.75, the deprecated Windows fallback path C:\ProgramData\ClaudeCode\managed-settings.json has been removed. Use C:\Program Files\ClaudeCode\managed-settings.json instead.

Note (v2.1.126): /config now persists changes to ~/.claude/settings.json instead of holding them in memory only. Edits made through the interactive Config UI survive restarts.

Managed-only policy keys:

Key	Type	Default	Description
parentSettingsBehavior	string	"first-wins"	Controls whether managed settings supplied programmatically by an embedding host process (SDK parent) apply when an admin-deployed managed tier is also present. "first-wins": parent-supplied settings are dropped and only the admin tier applies. "merge": parent-supplied settings apply under the admin tier and are filtered so they can tighten policy but not loosen it. Requires v2.1.133+
policyHelper	object	-	Admin-deployed executable that computes managed settings dynamically at startup. Object shape: {path: string, timeoutMs?: number, refreshIntervalMs?: number} — path points at the helper binary; timeoutMs caps the wait (omit or 0 for no timeout); refreshIntervalMs controls re-runs at session start (omit for startup-only, 0 disables, otherwise must be ≥ 60000). Only honored from MDM or a system managed-settings.json file (never from user/project settings). When configured, policyHelper output is the sole active managed source — other managed-tier sources (server-managed, MDM, file) are ignored for that run. Requires v2.1.136+
requiredMinimumVersion	string	-	(Managed only) Prevents Claude Code from starting if the installed version is below this floor. CLI exits with an error prompting the user to upgrade. Complements minimumVersion (which controls auto-update floor) — this one enforces at startup. Example: "2.1.163"
requiredMaximumVersion	string	-	(Managed only) Prevents Claude Code from starting if the installed version exceeds this ceiling. CLI exits with an error if the version is too new. Use alongside requiredMinimumVersion to pin a specific version range in managed environments. Example: "2.1.165"
browserExternalPageTools	string	-	(Managed only) Set to "disabled" to prevent Claude from using tools to read or act on external pages in the desktop app's Browser pane. Users can still navigate to external sites themselves, and local dev server previews are unaffected
disableBrowserExternalNavigation	boolean	-	(Managed only) Set to true (JSON boolean only — string "true" is silently ignored) to prevent Claude from navigating the desktop app's Browser pane to external URLs. Only JSON boolean true is honored
disableMobileSimulatorTools	boolean	-	(Managed only) Set to true (JSON boolean only — a malformed value logs a warning) to remove mobile simulator tools from Claude. Only JSON boolean true is honored

Important:

• deny rules have highest safety precedence and cannot be overridden by lower-priority allow/ask rules.
• Managed settings may lock or override local behavior even if local files specify different values.
• Array settings (e.g., permissions.allow) are concatenated and deduplicated across scopes — entries from all levels are combined, not replaced. Exceptions: fallbackModel and availableModels do not merge — the highest-precedence settings file that defines them supplies the entire value. For availableModels, a managed-source value applies as-is and lower scopes cannot extend it.

---

Core Configuration

General Settings

Key	Type	Default	Description
$schema	string	-	JSON Schema URL for IDE validation and autocompletion (e.g., "https://json.schemastore.org/claude-code-settings.json")
model	string	"default"	Override default model. Accepts aliases (sonnet, opus, haiku) or full model IDs
agent	string	-	Set the default agent for the main conversation. Value is the agent name from .claude/agents/. Also available via --agent CLI flag
language	string	"english"	Claude's preferred response language. Also sets the voice dictation language and auto-generated session titles (v2.1.121; since v2.1.176, an unset language causes titles to match the conversation language)
claudeMdExcludes	array	-	Glob patterns or absolute paths of CLAUDE.md files to skip when loading memory. Patterns match against absolute file paths. Only applies to user, project, and local memory; managed policy files cannot be excluded. Example: ["**/vendor/**/CLAUDE.md"]
claudeMd	string	-	(Managed only) CLAUDE.md-style instructions injected as organization-managed memory. Only honored when set in managed or policy settings; ignored in user, project, and local settings. Example: "Always run make lint before committing."
cleanupPeriodDays	number	30	Age cutoff for the startup cleanup sweep (minimum 1). Inactive session transcripts and orphaned subagent worktrees are deleted; as of v2.1.117 the sweep also covers ~/.claude/tasks/, ~/.claude/shell-snapshots/, and ~/.claude/backups/. Setting to 0 is rejected with a validation error. To disable transcript writes in non-interactive mode (-p), use --no-session-persistence or persistSession: false SDK option
autoUpdatesChannel	string	"latest"	Release channel: "stable" or "latest"
minimumVersion	string	-	Prevent the auto-updater from downgrading below a specific version. Automatically set when switching to the stable channel and choosing to stay on the current version until stable catches up. Used with autoUpdatesChannel
alwaysThinkingEnabled	boolean	false	Enable extended thinking by default for all sessions
thinkingBudgetTokens	number	-	Set a fixed token budget for extended thinking per response. When set, limits the number of thinking tokens to the specified value. If unset, Claude Code uses a dynamic budget based on the model and effort level. Works alongside alwaysThinkingEnabled (not in official settings page — unverified)
skipWebFetchPreflight	boolean	false	Skip the WebFetch domain safety check that sends each requested hostname to api.anthropic.com before fetching. Set to true in environments that block outbound traffic to Anthropic, such as Bedrock, Vertex AI, or Foundry deployments with restrictive egress
availableModels	array	-	Restrict which models users can select via /model, --model, Config tool, or ANTHROPIC_MODEL. Does not affect the Default option. As of v2.1.172, also constrains the model picker for subagent dispatching and the advisorModel picker. Use enforceAvailableModels: true to additionally constrain the Default model option. Example: ["sonnet", "haiku"]
enforceAvailableModels	boolean	false	(Managed only) When true, the availableModels allowlist also constrains the Default model option — users cannot select a model outside the allowlist even via the Default slot. Without this flag, availableModels leaves the Default option unrestricted. Pair with availableModels for full model lockdown (v2.1.175)
fastModePerSessionOptIn	boolean	false	Require users to opt in to fast mode each session
fastMode	boolean	false	Enable fast mode for all sessions. When true, Claude Code uses the faster model tier by default. Users can also toggle fast mode per session with /fast. Pairs with fastModePerSessionOptIn
defaultShell	string	"bash"	Default shell for input-box ! commands. Accepts "bash" (default) or "powershell". Setting "powershell" routes interactive ! commands through PowerShell on Windows. Requires CLAUDE_CODE_USE_POWERSHELL_TOOL=1 (v2.1.84). v2.1.120: When PowerShell is available, it is used as the fallback shell on Windows even without Git for Windows installed. v2.1.126: When PowerShell is enabled, it is treated as the primary shell instead of defaulting to Bash. PowerShell 7 detection now also covers Microsoft Store installs, MSI installs not on PATH, and .NET global tool installs
includeGitInstructions	boolean	true	Include built-in commit and PR workflow instructions and the git status snapshot in Claude's system prompt. The CLAUDE_CODE_DISABLE_GIT_INSTRUCTIONS environment variable takes precedence over this setting when set
voice	object	-	Voice dictation configuration. Object with three fields: enabled (boolean — push-to-talk on/off), mode (string — "hold" for hold-to-talk or "tap" for tap-to-toggle), and autoSubmit (boolean — submit transcript immediately when dictation ends). Written automatically when you run /voice. Requires a Claude.ai account (v2.1.118 expanded structure)
voiceEnabled	boolean	-	DEPRECATED — legacy alias for voice.enabled. Use the voice object instead to get mode and autoSubmit controls
showClearContextOnPlanAccept	boolean	false	Show the "clear context" option on the plan accept screen. Set to true to restore the option (hidden by default since v2.1.81)
viewMode	string	-	Default transcript view mode on startup: "default", "verbose", or "focus". Overrides the sticky /focus toggle selection when set
disableDeepLinkRegistration	string	-	Set to "disable" to prevent Claude Code from registering the claude-cli:// protocol handler with the operating system on startup. Deep links let external tools open a Claude Code session with a pre-filled prompt via claude-cli://open?q=.... The q parameter supports multi-line prompts using URL-encoded newlines (%0A). Useful in environments where protocol handler registration is restricted or managed separately
showThinkingSummaries	boolean	false	Show extended thinking summaries in interactive sessions. When unset or false (default in interactive mode), thinking blocks are redacted by the API and shown as a collapsed stub. Redaction only changes what you see, not what the model generates — to reduce thinking spend, lower the budget or disable thinking instead. Non-interactive mode (-p) and SDK callers always receive summaries regardless of this setting
disableSkillShellExecution	boolean	false	Disable inline shell execution for !`...` and ```! blocks in skills and custom commands from user, project, plugin, or additional-directory sources. Commands are replaced with [shell command execution disabled by policy] instead of being run. Bundled and managed skills are not affected (v2.1.91)
skillListingMaxDescChars	number	1536	Per-skill character cap on the combined description and when_to_use text in the skill listing Claude sees each turn. Text longer than this is truncated (v2.1.105)
skillListingBudgetFraction	number	0.01	Fraction of the model's context window reserved for the skill listing Claude sees each turn (0.01 = 1%). When the listing exceeds the budget, descriptions for the least-used skills are collapsed to bare names so Claude can still invoke them but won't see why (v2.1.105)
forceRemoteSettingsRefresh	boolean	false	(Managed only) Block CLI startup until remote managed settings are freshly fetched. If the fetch fails, the CLI exits (fail-closed). Use in enterprise environments where policy enforcement must be up-to-date before any session begins (v2.1.92)
wslInheritsWindowsSettings	boolean	false	(Windows managed settings only) When true, Claude Code on WSL reads managed settings from the Windows policy chain (HKLM registry + C:\Program Files\ClaudeCode\managed-settings.json) in addition to /etc/claude-code, with Windows sources taking priority. Only honored when set in the HKLM registry key or C:\Program Files\ClaudeCode\managed-settings.json, both of which require Windows admin to write. For HKCU policy to also apply on WSL, the flag must additionally be set in HKCU itself. Has no effect on native Windows (v2.1.118)
tui	string	"default"	Rendering mode: "fullscreen" or "default". Set via /tui fullscreen for flicker-free alt-screen rendering (v2.1.110)
awaySummaryEnabled	boolean	true	Generate an "away summary" (idle-session recap) when the user returns after being away. Set to false to opt out. Pairs with the CLAUDE_CODE_ENABLE_AWAY_SUMMARY env var (v2.1.110)
autoCompactEnabled	boolean	true	Auto-compact the conversation when context approaches the model's limit. Set to false to disable automatic compaction and manage context manually. Also disableable via the DISABLE_AUTO_COMPACT env var
autoCompactWindow	number	model-tuned	How full the context window gets before automatic compaction triggers, in tokens (100,000–1,000,000). When unset, Claude Code uses a window tuned for your model. Set it with the /autocompact command (writes to user settings) or the --autocompact CLI flag. Pairs with the CLAUDE_CODE_AUTO_COMPACT_WINDOW env var (v2.1.221+)
skillOverrides	object	-	Per-skill visibility overrides keyed by skill name. Value is "on" (full), "name-only" (visible but not auto-described), "user-invocable-only" (hidden from model discovery but still slash-invocable), or "off" (fully hidden). Example: {"legacy-context": "name-only", "deploy": "off"} (v2.1.129)
disableRemoteControl	boolean	false	Disable Remote Control: blocks claude remote-control, the --remote-control flag, auto-start, and the in-session toggle. Typically placed in managed settings for per-device MDM enforcement, but works from any scope (v2.1.128)
agentPushNotifEnabled	boolean	false	Send proactive push notifications to Remote Control when Claude decides to push (e.g., task complete). Appears in /config as Push when Claude decides
inputNeededNotifEnabled	boolean	false	Send a push notification to Remote Control when a permission prompt or question awaits user input. Appears in /config as Push when actions required
remoteControlAtStartup	boolean/null	-	Auto-connect Remote Control on startup. true always auto-connects, false never auto-connects, unset uses the organization default. Scope exception: false in project or local settings applies even against a managed true (user and project settings can opt out). Only user settings, --settings, and managed settings can set it to true (v2.1.119+)
disableAgentView	boolean	false	Set to true to turn off background agents and agent view: claude agents, --bg, /background, and the on-demand supervisor. Can be set at any scope but typically placed in managed settings. Equivalent to setting the CLAUDE_CODE_DISABLE_AGENT_VIEW env var to 1
disableWorkflows	boolean	false	Set to true to disable dynamic workflows (/workflows) and the bundled workflow slash commands. Can be set at any scope. Equivalent to the CLAUDE_CODE_DISABLE_WORKFLOWS env var. Workflows were introduced in v2.1.154
workflowKeywordTriggerEnabled	boolean	true	Whether typing the word "ultracode" in a prompt triggers a dynamic workflow. Set to false to require explicit /workflows invocation. Ultracode, /workflows, and saved workflow commands are unaffected by this setting. Appears in /config as Ultracode keyword trigger (v2.1.157; trigger keyword renamed workflow→ultracode in v2.1.160)
ultracode	boolean	-	(Session-only — not persisted) When true, the harness authors and runs a workflow for every substantive task by default, maximizing thoroughness regardless of token cost. Appears in the official "Available settings" list but is session-scoped: set via /effort ultracode, --settings, or the SDK rather than written to settings.json (v2.1.154)
dynamicWorkflowSize	string	-	Advisory guideline for the number of agents spawned in a dynamic workflow. Values: "small", "medium", "large". When set, the workflow harness uses this as the default fleet size before scaling up or down based on the task. Set via /config as Workflow size (v2.1.202; values formalized in v2.1.205) (not in official docs — unverified; superseded by workflowSizeGuideline in v2.1.219)
workflowSizeGuideline	string	"medium"	Advisory guideline for the dynamic workflow fleet size, settable from any settings file. Values: "small", "medium" (default as of v2.1.219), "large", "unrestricted". The default fleet size now renders in the running-workflow status line. Use this key instead of dynamicWorkflowSize — it propagates from managed or user settings (v2.1.219)
disableBundledSkills	boolean	false	Conceal Claude Code's built-in capabilities (bundled skills) from the model. When true, the model cannot invoke built-in skills. Paired with the CLAUDE_CODE_DISABLE_BUNDLED_SKILLS env var. Useful when strict plugin-only customization is required (v2.1.169)
disableArtifact	boolean	false	Disable the Artifact web publishing tool. When true, Claude cannot create or publish web artifacts. Can be set at any scope
enableArtifact	boolean	-	(v2.1.196+) User-level opt-in for the Artifact web publishing tool. When set to true, enables Artifact for the user even when no organization policy requires it. disableArtifact: true takes precedence and overrides this setting
feedbackSurveyRate	number	-	Probability (0–1) that the session quality survey appears when eligible. Enterprise admins can control how often the survey is shown. Example: 0.05 = 5% of eligible sessions
advisorModel	string	-	Model for the server-side advisor tool. Accepts a model alias (opus, sonnet) or a full model ID. When unset, the advisor uses the session model. Requires v2.1.98+. v2.1.210+: Setting "fable" no longer attaches an advisor — Fable 5 is temporarily unavailable in the advisor picker; use "opus" or "sonnet" instead
respondToBashCommands	boolean	true	Whether Claude automatically responds after a ! shell command completes. Set to false to disable the automatic follow-up response when a ! bash command finishes (v2.1.186)
askUserQuestionTimeout	string	"never"	How long to wait before an unanswered AskUserQuestion dialog auto-continues without the user. Values: "60s", "5m", "10m", "never" (no auto-continue — the default). Set via /config as Question auto-continue timeout. Pairs with the CLAUDE_AFK_TIMEOUT_MS env var; the env var applies only when this setting is set to a duration. Only honored from project and local settings — managed and user settings values are ignored. (v2.1.200)
theme	string	"dark"	UI color theme. Values: "auto" (follow OS), "dark", "light", "dark-daltonized", "light-daltonized", "dark-ansi", "light-ansi", "custom:<slug>", "custom:<plugin>:<slug>". Plugin-provided themes use the custom: prefix
verbose	boolean	false	Show full tool output instead of truncated summaries. Equivalent to running with --verbose; persists the verbose view across sessions
switchModelsOnFlag	boolean	true	Automatically switch to the fallback model when a safety classifier flags a request. When false, flagged requests are blocked rather than rerouted (v2.1.170)
processWrapper	string	-	Corporate launcher command used for background processes (e.g., a credential-injecting wrapper). Only honored from managed settings, user settings (~/.claude/settings.json), or --settings; ignored from project and local settings to prevent untrusted repos from hijacking background process launches (v2.1.210)
remote.defaultEnvironmentId	string	-	Default environment ID to use when launching remote sessions or background agents via --remote without an explicit environment ID. When set, Claude Code selects this environment automatically rather than prompting. Only honored from user and managed settings (v2.1.200+)

Example:

{
  "model": "opus",
  "agent": "code-reviewer",
  "language": "japanese",
  "cleanupPeriodDays": 60,
  "autoUpdatesChannel": "stable",
  "alwaysThinkingEnabled": true
}

Plans & Memory Directories

Store plan and auto-memory files in custom locations.

Key	Type	Default	Description
plansDirectory	string	~/.claude/plans	Directory where /plan outputs are stored
autoMemoryDirectory	string	-	Custom directory for auto-memory storage. Accepts ~/-expanded paths. Not accepted in project settings (.claude/settings.json) to prevent redirecting memory writes to sensitive locations; accepted from policy, local, and user settings
autoMemoryEnabled	boolean	true	Enable auto memory. When false, Claude does not read from or write to the auto-memory directory. Can also be toggled with /memory during a session, or disabled via the CLAUDE_CODE_DISABLE_AUTO_MEMORY env var
fileCheckpointingEnabled	boolean	true	Snapshot files before each edit so you can restore them with /rewind. Set to false to skip checkpointing and save disk space. Also disableable via the CLAUDE_CODE_DISABLE_FILE_CHECKPOINTING env var

Example:

{
  "plansDirectory": "./my-plans"
}

Use Case: Useful for organizing planning artifacts separately from Claude's internal files, or for keeping plans in a shared team location.

Worktree Settings

Configure how --worktree creates and manages git worktrees. Useful for reducing disk usage and startup time in large monorepos.

Key	Type	Default	Description
worktree.symlinkDirectories	array	[]	Directories to symlink from the main repository into each worktree to avoid duplicating large directories on disk
worktree.sparsePaths	array	[]	Directories to check out in each worktree via git sparse-checkout (cone mode). Only the listed paths are written to disk
worktree.baseRef	string	"fresh"	Which ref new worktrees branch from. "fresh" branches from origin/<default-branch> for a clean tree matching the remote. "head" branches from your current local HEAD, including uncommitted-but-tracked changes (v2.1.133)
worktree.bgIsolation	string	"worktree"	Isolation mode for background sessions. "worktree" (default) blocks Edit/Write in the main checkout until EnterWorktree is called; "none" lets background jobs edit the working copy directly (v2.1.143)

Example:

{
  "worktree": {
    "symlinkDirectories": ["node_modules", ".cache"],
    "sparsePaths": ["packages/my-app", "shared/utils"]
  }
}

Attribution Settings

Customize attribution messages for git commits and pull requests.

Key	Type	Default	Description
attribution.commit	string	Co-authored-by	Git commit attribution (supports trailers)
attribution.pr	string	Generated message	Pull request description attribution
attribution.sessionUrl	boolean	true	Include a link to the claude.ai session URL in commits and PRs generated in web sessions or Remote Control sessions. Set to false to omit the link. Has no effect in local CLI sessions (v2.1.183)
prUrlTemplate	string	-	URL template that controls how the "PR" badge in commit attribution links to the pull request UI. Supports placeholders for the repo host, owner, repo, and PR number. Useful for self-hosted GitLab/Bitbucket/GitHub Enterprise instances where the default https://github.com/... URL does not apply (v2.1.119)
includeCoAuthoredBy	boolean	true	DEPRECATED - Use attribution instead

Example:

{
  "attribution": {
    "commit": "Generated with AI\n\nCo-Authored-By: Claude <noreply@anthropic.com>",
    "pr": "Generated with Claude Code"
  }
}

Note: Set to empty string ("") to hide attribution entirely.

Authentication Helpers

Scripts for dynamic authentication token generation.

Key	Type	Description
apiKeyHelper	string	Shell script path that outputs auth token (sent as both X-Api-Key and Authorization: Bearer headers)
forceLoginMethod	string	Restrict login to "claudeai", "console", or "gateway" accounts. Use "gateway" for organization-managed Claude gateway deployments. (Managed only)
forceLoginOrgUUID	string | array	Require login to belong to a specific organization. Accepts a single UUID string (which also pre-selects that organization during login) or an array of UUIDs where any listed organization is accepted without pre-selection. When set in managed settings, login fails if the authenticated account does not belong to a listed organization; an empty array fails closed and blocks login with a misconfiguration message
forceLoginGatewayUrl	string	(Managed only) Pre-fill the Claude gateway URL on the login screen when forceLoginMethod is "gateway". Avoids requiring users to manually enter the gateway URL. Typically set alongside forceLoginMethod: "gateway"
gcpAuthRefresh	string	Custom script that refreshes GCP Application Default Credentials when they expire or cannot be loaded. Run by Claude Code before retrying authentication. Useful when ADC are short-lived and require an org-specific helper to renew. Example: "gcloud auth application-default login"

Example:

{
  "apiKeyHelper": "/bin/generate_temp_api_key.sh",
  "forceLoginMethod": "console",
  "forceLoginOrgUUID": ["xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "yyyyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy"]
}

Company Announcements

Display custom announcements to users at startup (cycled randomly).

Key	Type	Description
companyAnnouncements	array	Array of strings displayed at startup

Example:

{
  "companyAnnouncements": [
    "Welcome to Acme Corp!",
    "Remember to run tests before committing!",
    "Check the wiki for coding standards"
  ]
}

---

Permissions

Control what tools and operations Claude can perform.

Permission Structure

{
  "permissions": {
    "allow": [],
    "ask": [],
    "deny": [],
    "additionalDirectories": [],
    "defaultMode": "acceptEdits",
    "disableBypassPermissionsMode": "disable"
  }
}

Permission Keys

Key	Type	Description
permissions.allow	array	Rules allowing tool use without prompting
permissions.ask	array	Rules requiring user confirmation
permissions.deny	array	Rules blocking tool use (highest precedence)
permissions.additionalDirectories	array	Extra directories Claude can access
permissions.defaultMode	string	Default permission mode. Valid values: "default", "manual" (alias for "default", v2.1.200), "acceptEdits", "dontAsk", "bypassPermissions", "auto", "plan". In Remote environments, only acceptEdits and plan are honored (v2.1.70+). Note (v2.1.142): "auto" is ignored when set in project (.claude/settings.json) or local settings — a repository cannot grant itself auto mode; use ~/.claude/settings.json instead
permissions.disableBypassPermissionsMode	string	Prevent bypass mode activation
permissions.skipDangerousModePermissionPrompt	boolean	Skip the confirmation prompt shown before entering bypass permissions mode via --dangerously-skip-permissions or defaultMode: "bypassPermissions". Ignored when set in project settings (.claude/settings.json) to prevent untrusted repositories from auto-bypassing the prompt
allowManagedPermissionRulesOnly	boolean	(Managed only) Only managed permission rules apply; user/project allow, ask, deny rules are ignored
autoMode	object	Customize what the auto mode classifier blocks and allows. Contains environment (trusted infrastructure descriptions), allow (exceptions to block rules), soft_deny (block rules), and hard_deny (unconditional block rules — cannot be overridden by allow exceptions or the $defaults sentinel, v2.1.136) — all arrays of prose strings. Also accepts classifyAllShell (boolean, default false): when true, routes all Bash/PowerShell commands through the auto-mode classifier instead of only arbitrary-code-execution patterns, giving stricter coverage at the cost of more classifier calls (v2.1.193). Not read from shared project settings (.claude/settings.json) or local settings (.claude/settings.local.json) to prevent repo injection (v2.1.207 removed local-settings scope). Available in user and managed settings only; configure in ~/.claude/settings.json. Setting allow or soft_deny replaces the entire default list for that section unless you include the literal string "$defaults" in the array — the sentinel inherits the built-in rules at that position so custom entries are added alongside them (v2.1.118). Run claude auto-mode defaults to see built-in rules before customizing
disableAutoMode	string	Set to "disable" to prevent auto mode from being activated. Removes auto from the Shift+Tab cycle and rejects --permission-mode auto at startup. Can be set at any settings level; most useful in managed settings where users cannot override it
useAutoModeDuringPlan	boolean	Whether plan mode uses auto mode semantics when auto mode is available. Default: true. Not read from shared project settings (.claude/settings.json). Appears in /config as "Use auto mode during plan"

Permission Modes

Mode	Behavior
"default"	Standard permission checking with prompts
"manual"	Alias for "default" introduced in v2.1.200 — same standard permission checking with prompts. The rename improves clarity across the CLI, VS Code, and JetBrains UIs. Accepted wherever "default" is accepted
"acceptEdits"	Automatically accepts file edits and common filesystem commands (mkdir, touch, mv, cp, etc.) for paths in the working directory or additionalDirectories. v2.1.160: Always prompts before writing build-tool config files that grant code execution (.npmrc, .yarnrc*, bunfig.toml, .bazelrc, .pre-commit-config.yaml, .devcontainer/, etc.) and before writing to shell startup files (.zshenv, .zlogin, .bash_login) and ~/.config/git/
"dontAsk"	Auto-denies tools unless pre-approved via /permissions or permissions.allow rules. Tools marked requiresUserInteraction in their MCP server manifest and organization-set-to-ask connector tools are denied even if you've explicitly allowed them
"bypassPermissions"	Skip all permission checks (dangerous). All path-based prompts are skipped — writes to .git, .config/git, .claude, .vscode, .idea, .husky, .cargo, .devcontainer, .yarn, and .mvn no longer prompt (v2.1.121 exempted .claude/commands/, .claude/agents/, .claude/skills/, and .claude/worktrees/; v2.1.126 removed all remaining path-based prompts). Three classes still prompt regardless: (1) removals targeting the filesystem root or home directory (rm -rf /, rm -rf ~, including commands using $(...), backtick substitution, or <(...) process substitution), (2) tools marked requiresUserInteraction in their MCP server manifest, and (3) organization-set-to-ask connector tools. Explicit permissions.ask rules still prompt — only the built-in permission checks are bypassed
"auto"	Auto-approves tool calls with background safety checks that verify actions align with your request. Research preview. Classifier auto-approves read-only and file edits; sends everything else through a safety check. Falls back to prompting after 3 consecutive or 20 total blocks. In the default Shift+Tab permission-mode cycle since v2.1.111 (the --enable-auto-mode flag was removed in v2.1.111 — start in this mode with --permission-mode auto). Configure with the autoMode setting
"plan"	Read-only exploration mode. As of v2.1.136, file writes are blocked even when a matching Edit(...) allow rule exists — plan mode now overrides explicit allow rules to maintain its read-only guarantee

Tool Permission Syntax

Tool	Syntax	Examples
Bash	Bash(command pattern)	Bash(npm run *), Bash(* install), Bash(git * main)
PowerShell	PowerShell(cmd *)	PowerShell(Get-ChildItem *), PowerShell(git commit *) — same shape as Bash; common aliases are canonicalized (gci/ls/dir → Get-ChildItem) and the PowerShell AST is parsed so each subcommand of a `
Read	Read(path pattern)	Read(.env), Read(./secrets/**)
Edit	Edit(path pattern)	Edit(src/**), Edit(*.ts)
Write	Write(path pattern)	Write(*.md), Write(./docs/**) — valid in deny and ask rules only; accepted in allow rules at parse time but never consulted (see note below)
NotebookEdit	NotebookEdit(pattern)	NotebookEdit(*) — valid in deny and ask rules only; accepted in allow rules at parse time but never consulted (see note below)
WebFetch	WebFetch(domain:pattern)	WebFetch(domain:example.com)
WebSearch	WebSearch	Global web search
Task	Task(agent-name)	Task(Explore), Task(my-agent) — legacy alias for Agent; prefer Agent(name) in new configs
Agent	Agent(name)	Agent(researcher), Agent(*) — permission scoped to subagent spawning
Skill	Skill(skill-name) or Skill(prefix *)	Skill(weather-fetcher), Skill(weather *) matches weather-fetcher/weather-svg-creator (v2.1.139) (not in official permissions docs — unverified)
MCP	mcp__server__tool	mcp__memory__*, mcp__github__* — official docs show only the double-underscore form; MCP(server:tool) shorthand (not in official permissions docs — unverified)
Tool	Tool(param:value)	Agent(model:opus), Agent(isolation:worktree), Bash(run_in_background:true) — match deny and ask rules against a tool's input parameters; supports * wildcards in the value position. Allow rules do not use this syntax — an allow rule for one parameter value wouldn't establish overall safety, so allow rules continue to use each tool's own specifier syntax. Matching a tool's primary content field (e.g., Bash(command:rm *)) is also forbidden and triggers a startup warning (v2.1.178)
Cd	Cd(path pattern)	Cd(/home/*), Cd(~/projects/*) — controls which directories the /cd command may navigate to. Allowlist mode: adding any Cd allow rule switches /cd into allowlist mode — all paths not explicitly allowed are refused. A bare Cd deny disables /cd entirely. Wildcard semantics differ from Read/Edit: * matches exactly one path segment; ** crosses segments. A trailing /** also matches the named root itself. These rules do NOT follow gitignore-style matching

v2.1.210: Write(path), NotebookEdit(path), and Glob(path) in allow rules are accepted at parse time but never consulted — Claude Code's allow-rule evaluation only checks Edit(path) and Read(path). A startup warning flags these entries and recommends the correct alternatives. In deny and ask rules, Write(path), NotebookEdit(path), and Glob(path) continue to work as expected.

Evaluation order: Rules are evaluated in order: deny rules first, then ask, then allow. The first matching rule wins.

Deny rule glob patterns (v2.1.166): In a deny rule, using "*" in the tool-name position matches ALL tools — equivalent to a global deny. For example, "*" in the deny array blocks every tool call. This makes it possible to lock down access completely and carve out specific allow/ask exceptions.

Allow rule glob restrictions: In an allow rule, tool-name globs are only accepted after a literal mcp__<server>__ prefix — the server segment must be glob-free. An unanchored allow glob such as "*", "B*", or "mcp__*" is skipped with a startup warning and does not auto-approve anything. For example, "allow": ["mcp__github__*"] works, but "allow": ["mcp__*"] does not. Use "deny": ["*"] plus specific allow rules to allowlist instead.

Read/Edit path patterns: Permission rules for Read, Edit, and Write support gitignore-style patterns with four prefix types:

Prefix	Meaning	Example
//	Absolute path from filesystem root	Read(//Users/alice/file)
~/	Relative to home directory	Read(~/.zshrc)
/	Relative to project root	Edit(/src/**)
./ or none	Relative path (current directory)	Read(.env), Read(*.ts)

Symlink resolution: Permission rules check both the symlink path and its resolved target. Allow rules apply only when both the symlink and its target match — a symlink inside an allowed directory that points outside it still prompts. Deny rules apply when either the symlink or its target matches — a symlink to a denied file is itself denied.

Bash wildcard notes:

• * can appear at any position: prefix (Bash(* install)), suffix (Bash(npm *)), or middle (Bash(git * main))
• Word boundary: Bash(ls *) (space before *) matches ls -la but NOT lsof; Bash(ls*) (no space) matches both
• Bash(*) is treated as equivalent to Bash (matches all bash commands)
• Permission rules support output redirections: Bash(python:*) matches python script.py > output.txt
• The :* suffix syntax (e.g., Bash(npm:*)) is an equivalent way to write a trailing wildcard — it is not deprecated but only recognized at the end (e.g., Bash(git:* push) treats the colon literally). The permission dialog writes the space form
• Compound commands: shell operators (&&, ||, ;, |, |&, &, and newlines) split a command and each subcommand must match independently — Bash(safe-cmd *) does not authorize safe-cmd && other-cmd
• Process wrappers: timeout, time, nice, nohup, and stdbuf are stripped before matching (so Bash(npm test *) also matches timeout 30 npm test); bare xargs (no flags) is stripped too. Exec wrappers watch, setsid, ionice, flock, and find with -exec/-delete always prompt and cannot be approved by a prefix rule

Example:

{
  "permissions": {
    "allow": [
      "Edit(*)",
      "Bash(npm run *)",
      "Bash(git *)",
      "WebFetch(domain:*)",
      "mcp__memory__*"
    ],
    "ask": [
      "Bash(rm *)",
      "Bash(git push *)"
    ],
    "deny": [
      "Read(.env)",
      "Read(./secrets/**)",
      "Bash(curl *)"
    ],
    "additionalDirectories": ["../shared-libs/"]
  }
}

---

Hooks

Hook configuration (events, properties, matchers, exit codes, environment variables, and HTTP hooks) is maintained in a dedicated repository:

claude-code-hooks — Complete hook reference with sound notification system, all 26 hook events, HTTP hooks, matcher patterns, exit codes, and environment variables.

Hook-related settings keys (hooks, disableAllHooks (also disables any custom status line), allowManagedHooksOnly, allowedHttpHookUrls, httpHookAllowedEnvVars) are documented there.

For the official hooks reference, see the Claude Code Hooks Documentation.

---

MCP Servers

Configure Model Context Protocol servers for extended capabilities.

OAuth (v2.1.111): MCP servers that authenticate via OAuth follow RFC 9728 for protected-resource metadata discovery. Compliant servers expose authorization endpoints under /.well-known/oauth-protected-resource, and Claude Code completes the OAuth flow automatically — no manual apiKeyHelper or headersHelper script required for spec-conformant servers.

Reserved server names (v2.1.128+): workspace, Claude Browser, and Claude Preview are reserved MCP server names. User-defined servers with these names are skipped at load time with a warning logged to the session log. Rename any pre-existing servers using these names to avoid the collision.

.mcp.json hot-reload (v2.1.139): The /mcp Reconnect action now re-reads .mcp.json from disk before reconnecting, so adding or editing a server no longer requires a session restart. Claude Code also injects CLAUDE_PROJECT_DIR into stdio-launched MCP server environments (v2.1.139) so servers can resolve paths relative to the project root.

Per-server timeout floor (v2.1.162): Per-server timeout values less than 1000ms are ignored and the global MCP_TOOL_TIMEOUT default applies instead. Values ≥ 1000ms are honored as before.

MCP Settings

Key	Type	Scope	Description
enableAllProjectMcpServers	boolean	Any	Auto-approve all .mcp.json servers. Security note (v2.1.196): .mcp.json servers no longer self-approve — explicit opt-in via enableAllProjectMcpServers: true or enabledMcpjsonServers is now required
enabledMcpjsonServers	array	Any	Allowlist specific server names
disabledMcpjsonServers	array	Any	Blocklist specific server names
allowedMcpServers	array	Managed only	Allowlist with name/command/URL matching
deniedMcpServers	array	Managed only	Blocklist with matching
allowManagedMcpServersOnly	boolean	Managed only	Only allow MCP servers explicitly listed in managed allowlist
channelsEnabled	boolean	Managed only	Allow channels for Team and Enterprise users. When unset or false, channel message delivery is blocked regardless of --channels flag
allowedChannelPlugins	array	Managed only	Allowlist of channel plugins that may push messages. Replaces the default Anthropic allowlist when set. Undefined = fall back to the default, empty array = block all channel plugins. Requires channelsEnabled: true. Each entry is an object with marketplace and plugin fields (v2.1.84)
allowAllClaudeAiMcps	boolean	Managed only	Load claude.ai cloud MCP connectors alongside managed-mcp.json. When enabled, claude.ai-hosted MCP connectors are made available in addition to admin-deployed managed MCP servers
disableClaudeAiConnectors	boolean	Any	Disable auto-fetching of claude.ai MCP connectors. When true, claude.ai cloud connectors are not loaded. Restrictive-value exception: true applies from any scope, including project settings, even against a managed false — lower-priority scopes can opt out but cannot opt in (v2.1.182)

MCP Server Matching (Managed Settings)

{
  "allowedMcpServers": [
    { "serverName": "github" },
    { "serverCommand": "npx @modelcontextprotocol/*" },
    { "serverUrl": "https://mcp.company.com/*" }
  ],
  "deniedMcpServers": [
    { "serverName": "dangerous-server" }
  ]
}

${VAR} interpolation (v2.1.219): allowedMcpServers and deniedMcpServers entries may contain ${VAR} placeholders. Claude Code resolves them from the startup environment and managed-settings env block at load time. Use to reference environment-specific server names or URLs without hardcoding them in managed settings (e.g., { "serverUrl": "https://${MCP_HOST}/*" }).

Per-Server Tool Loading (alwaysLoad, v2.1.121)

By default, MCP tool definitions are deferred (loaded into context on demand via tool search). Set alwaysLoad: true on an individual MCP server entry in .mcp.json (or inline mcpServers) to exempt that server from deferral — every tool from that server then loads upfront at session start regardless of ENABLE_TOOL_SEARCH. Available on all server types; requires Claude Code v2.1.121+. Use this only for a small set of tools needed every turn — each upfront tool consumes context that would otherwise be available for conversation.

{
  "mcpServers": {
    "always-on-server": {
      "type": "http",
      "url": "https://mcp.example.com",
      "alwaysLoad": true
    }
  }
}

An MCP server can also mark individual tools as always-loaded by including "anthropic/alwaysLoad": true in the tool's _meta object — useful when only a subset of a server's tools should bypass deferral.

Example:

{
  "enableAllProjectMcpServers": true,
  "enabledMcpjsonServers": ["memory", "github", "filesystem"],
  "disabledMcpjsonServers": ["experimental-server"]
}

---

Sandbox

Configure bash command sandboxing for security.

Sandbox Settings

Key	Type	Default	Description
sandbox.enabled	boolean	false	Enable bash sandboxing
sandbox.failIfUnavailable	boolean	false	Exit with error when sandbox is enabled but cannot start, instead of running unsandboxed. Useful for enterprise policies that require strict sandboxing (v2.1.83)
sandbox.autoAllowBashIfSandboxed	boolean	true	Auto-approve bash when sandboxed. As of v2.1.139, shell-expansion forms ($VAR, $(cmd)) are correctly recognized so commands containing variable substitution no longer fall back to a prompt when sandbox auto-approval is enabled
sandbox.excludedCommands	array	[]	Commands to run outside sandbox
sandbox.allowUnsandboxedCommands	boolean	true	Allow dangerouslyDisableSandbox. When set to false, the escape hatch is completely disabled and all commands must run sandboxed (or be in excludedCommands). Useful for enterprise policies that require strict sandboxing
sandbox.filesystem.disabled	boolean	false	Skip filesystem isolation while keeping network egress control active. When true, the sandbox does not restrict file access but network egress stays confined to sandbox.network.allowedDomains. Only honored from user settings, managed settings, or --settings — ignored in .claude/settings.json and .claude/settings.local.json (v2.1.216)
sandbox.ignoreViolations	object	{}	Map of command patterns to path arrays — suppress violation warnings (in JSON schema, not on official settings page)
sandbox.enableWeakerNestedSandbox	boolean	false	(Linux and WSL2 only) Enable weaker sandbox for unprivileged Docker environments (reduces security)
sandbox.network.allowUnixSockets	array	[]	(macOS only) Specific Unix socket paths accessible in sandbox. Ignored on Linux and WSL2, where the seccomp filter cannot inspect socket paths; use allowAllUnixSockets instead
sandbox.network.allowAllUnixSockets	boolean	false	Allow all Unix sockets (overrides allowUnixSockets). On Linux and WSL2 this is the only way to permit Unix sockets, since it skips the seccomp filter that otherwise blocks socket(AF_UNIX, ...) calls
sandbox.network.allowLocalBinding	boolean	false	Allow binding to localhost ports (macOS)
sandbox.network.allowedDomains	array	[]	Network domain allowlist for sandbox
sandbox.network.strictAllowlist	boolean	false	When true, deny all network access to hosts not in allowedDomains without prompting the user. By default, unlisted hosts prompt for permission; this setting makes the allowlist a hard block. The effective allowlist also includes any WebFetch(domain:...) allow rules. Only applies to outbound connections from sandboxed bash commands — Claude Code's own API and WebFetch calls are not affected. Only honored from user settings, managed settings, or --settings — ignored in .claude/settings.json and .claude/settings.local.json (v2.1.219)
sandbox.network.deniedDomains	array	[]	Network domain denylist for bash sandbox. Takes precedence over wildcards in allowedDomains. Supports glob patterns (e.g., "*.example.com") (v2.1.113)
sandbox.network.httpProxyPort	number	-	HTTP proxy port 1-65535 (custom proxy)
sandbox.network.socksProxyPort	number	-	SOCKS5 proxy port 1-65535 (custom proxy)
sandbox.network.allowManagedDomainsOnly	boolean	false	Only allow domains in managed allowlist (managed settings)
sandbox.network.allowMachLookup	array	[]	(macOS only) Additional XPC/Mach service names the sandbox may look up. Supports a single trailing * for prefix matching. Needed for tools that communicate via XPC such as the iOS Simulator or Playwright. Example: ["com.apple.coresimulator.*"]
sandbox.filesystem.allowWrite	array	[]	Additional paths where sandboxed commands can write. Arrays are merged across all settings scopes. Also merged with paths from Edit(...) allow permission rules. Prefix: / (absolute), ~/ (home), ./ or none (project-relative in project settings, ~/.claude-relative in user settings). The older // prefix for absolute paths still works. Note: This differs from Read/Edit permission rules, which use // for absolute and / for project-relative
sandbox.filesystem.denyWrite	array	[]	Paths where sandboxed commands cannot write. Arrays are merged across all settings scopes. Also merged with paths from Edit(...) deny permission rules. Same path prefix conventions as allowWrite
sandbox.filesystem.denyRead	array	[]	Paths where sandboxed commands cannot read. Arrays are merged across all settings scopes. Also merged with paths from Read(...) deny permission rules. Same path prefix conventions as allowWrite
sandbox.filesystem.allowRead	array	[]	Paths to re-allow read access within denyRead regions. Overrides matching denyRead glob entries, but an exact-path denyRead rule still blocks exact matches — allowRead does not universally trump every denyRead pattern. Arrays are merged across all settings scopes. Same path prefix conventions as allowWrite
sandbox.filesystem.allowManagedReadPathsOnly	boolean	false	(Managed only) Only allowRead paths from managed settings are respected. allowRead entries from user, project, and local settings are ignored
sandbox.enableWeakerNetworkIsolation	boolean	false	(macOS only) Allow access to system TLS trust (com.apple.trustd.agent); reduces security
sandbox.bwrapPath	string	-	(Managed only, Linux/WSL2) Absolute path to the bubblewrap (bwrap) binary. Overrides automatic PATH detection. Only honored from managed settings, not user or project settings. Example: /opt/admin/bwrap (v2.1.133)
sandbox.socatPath	string	-	(Managed only, Linux/WSL2) Absolute path to the socat binary used for the sandbox network proxy. Overrides automatic PATH detection. Only honored from managed settings. Example: /opt/admin/socat (v2.1.133)
sandbox.allowAppleEvents	boolean	false	(macOS only) Opt-in for sandboxed commands to send Apple Events. Required for tools that use open, osascript, or browser authentication flows that depend on Apple Events IPC. Warning: Enabling this removes code-execution isolation — Apple Events can be used to execute code in other applications (v2.1.181)
sandbox.credentials	object	—	Fine-grained control over which credential files and environment variables are blocked from sandboxed subprocess environments. Object with two arrays: files (array of credential file entries — see sub-keys below) and envVars (array of {name: string, mode: string, injectHosts?: string[]} entries — mode is "deny" (default, strips the var) or "mask" (substitutes a placeholder, only honored from user settings/managed/--settings; deny takes precedence when same var appears with both modes) with injectHosts selectively exposing the value to listed hosts only). An individual invalid entry is stripped with a warning; the valid subset is enforced. (v2.1.187; per-entry object shape since v2.1.191; per-entry mode and injectHosts since v2.1.199)
sandbox.credentials.files[].path	string	—	Absolute or ~/-prefixed path to the credential file to protect
sandbox.credentials.files[].mode	string	"deny"	"deny" blocks sandboxed reads of the file; "mask" intercepts reads and substitutes placeholder values so commands can still run but cannot exfiltrate the raw credential. mask mode only honored from user settings, managed settings, or --settings (v2.1.187 deny; v2.1.221 mask)
sandbox.credentials.files[].extract	string	—	Regex with a single capture group used to locate credential values within the file for masking. Required when mode is "mask" and the file is not a well-known format. Example: "oauth_token:\\s*(\\S+)" (v2.1.221)
sandbox.credentials.files[].injectHosts	array	—	Hostnames that receive the real credential value via the TLS-termination proxy even when mode is "mask". Requires sandbox.network.tlsTerminate to be configured (v2.1.199)
sandbox.credentials.files[].onExtractNoMatch	string	"warn"	Behavior when the extract regex matches nothing: "warn" (log a warning, allow read), "deny" (block the read), or "error" (abort the sandboxed command) (v2.1.221)
sandbox.credentials.files[].maskDuplicates	boolean	false	When true, also mask occurrences of the extracted credential value that appear in other files and env vars read during the same sandboxed command (v2.1.221)
sandbox.network.tlsTerminate	object	—	TLS termination configuration for sandboxed bash commands. When set, Claude Code acts as a TLS man-in-the-middle for outbound HTTPS from the sandbox, enabling credential masking (sandbox.credentials mask mode). Set to {} to generate an ephemeral certificate authority for the session, or set caCertPath and caKeyPath to provide your own CA. Only honored from user settings, managed settings, or --settings — ignored in .claude/settings.json and .claude/settings.local.json. Experimental (v2.1.199)
sandbox.credentials.allowPlaintextInject	boolean	false	Allow mask credential substitution to also apply on plain HTTP requests (where the upstream identity is unverified and the credential travels in cleartext). When false (default), credential injection via injectHosts is restricted to TLS-terminated HTTPS connections only, preventing credentials from being sent over unencrypted channels. Use only in trusted local environments where cleartext exposure is acceptable (v2.1.199)

Example:

{
  "sandbox": {
    "enabled": true,
    "autoAllowBashIfSandboxed": true,
    "excludedCommands": ["git", "docker", "gh"],
    "allowUnsandboxedCommands": false,
    "network": {
      "allowUnixSockets": ["/var/run/docker.sock"],
      "allowLocalBinding": true
    }
  }
}

---

Plugins

Configure Claude Code plugins and marketplaces.

Plugin Settings

Key	Type	Scope	Description
enabledPlugins	object	Any	Enable/disable specific plugins
extraKnownMarketplaces	object	Project	Add custom plugin marketplaces (team sharing via .claude/settings.json)
strictKnownMarketplaces	boolean	Managed only	When true, only the official Anthropic marketplace is permitted; no additional or custom marketplaces may be installed
strictPluginOnlyCustomization	boolean | array	Managed only	Block skills, agents, hooks, and MCP servers from user and project sources, so they can only come from plugins or managed settings. true locks all four surfaces; an array such as ["skills", "hooks"] locks only the named ones
pluginSuggestionMarketplaces	array	Managed only	Allowlist of marketplace names whose plugins may appear as contextual install suggestions during a session. Restricts which marketplaces can surface "you might want this plugin" prompts (v2.1.152)
skippedMarketplaces	array	Any	Marketplaces user declined to install (in JSON schema, not on official settings page)
skippedPlugins	array	Any	Plugins user declined to install (in JSON schema, not on official settings page)
pluginConfigs	object	Managed / User / --settings	Per-plugin MCP server configs (keyed by plugin@marketplace). As of v2.1.207, no longer read from project-level .claude/settings.json or .claude/settings.local.json; only user, --settings, and managed settings are honored
blockedMarketplaces	array	Managed only	Block specific plugin marketplaces. Each entry can match by source string, hostPattern, or pathPattern — as of v2.1.119 the hostPattern and pathPattern matchers are correctly enforced before any download touches the filesystem, so blocked marketplaces never reach disk
pluginTrustMessage	string	Managed only	Custom message displayed when prompting users to trust plugins
disableSideloadFlags	boolean	Managed only	Reject the --plugin-dir, --plugin-url, --agents, and --mcp-config startup flags. When true, users cannot bypass strictKnownMarketplaces by passing sideload flags at launch. Use in managed environments to enforce marketplace-only plugin distribution (v2.1.193)

Marketplace source types: github, git, directory, settings, url, npm, file, archive. Use source: 'settings' to declare a small set of plugins inline without setting up a hosted marketplace repository. Use source: 'archive' for zip-based plugin installation with SHA-256 pinning (v2.1.224). Note: hostPattern is a matcher field for blockedMarketplaces, not a source type.

Owner wildcard entries (v2.1.223): strictKnownMarketplaces and blockedMarketplaces now accept "owner/*" wildcard entries to match all repositories from a specific organization or user.

Example:

{
  "enabledPlugins": {
    "formatter@acme-tools": true,
    "deployer@acme-tools": true,
    "experimental@acme-tools": false
  },
  "extraKnownMarketplaces": {
    "acme-tools": {
      "source": {
        "source": "github",
        "repo": "acme-corp/claude-plugins"
      }
    },
    "inline-tools": {
      "source": {
        "source": "settings",
        "name": "inline-tools",
        "plugins": [
          {
            "name": "code-formatter",
            "source": { "source": "github", "repo": "acme-corp/code-formatter" }
          }
        ]
      }
    }
  }
}

---

Model Configuration

Model Aliases

Alias	Description
"default"	Recommended for your account type
"sonnet"	Latest Sonnet model (Claude Sonnet 5 on the Anthropic API — native 1M-token context, introduced v2.1.197; Claude Sonnet 4.6 on Bedrock/Vertex/Foundry)
"opus"	Latest Opus model (Claude Opus 5 (claude-opus-5) on the Anthropic API as of v2.1.219 — 1M-token context native; Opus 4.8 on Bedrock, Vertex, and Claude Platform on AWS as of v2.1.207). Opus 5 and Opus 4.8 are the fast-mode models (Opus 4.7 removed from fast mode in v2.1.219). Opus 5 supports ultracode effort; Opus 4.8 defaults to high and supports xhigh
"haiku"	Fast Haiku model
"sonnet[1m]"	Sonnet with 1M token context
"opus[1m]"	Opus with 1M token context (default on Max, Team, and Enterprise since v2.1.75)
"opusplan"	Opus for planning, Sonnet for execution
"fable"	Claude Fable 5 — long-horizon reasoning model. Anthropic API only (v2.1.170+). Fable 5 includes 1M context by default; the [1m] suffix is auto-stripped, so fable[1m] is redundant (v2.1.173)

Example:

{
  "model": "opus"
}

Note (v2.1.144): /model changes the model for the current session only. Press d in the /model picker to also set the selection as your default. The model setting and ANTHROPIC_MODEL continue to control the persistent default.

Model Overrides

Map Anthropic model IDs to provider-specific model IDs for Bedrock, Vertex, or Foundry deployments.

Key	Type	Default	Description
effortLevel	string	-	Persist the effort level across sessions. Accepts "low", "medium", "high", "xhigh" (Fable 5, Opus 5, Sonnet 5, Opus 4.7, Opus 4.8, v2.1.111). "max" and "ultracode" are session-only and are not accepted here — set them via /effort or --settings for a single session but do not write them to settings.json. Written automatically when you run /effort <level>. The default effort is high on every model that supports effort, except Opus 4.7 which defaults to xhigh. Unsupported levels fall back to the highest supported level on the active model
fallbackModel	array	-	Up to 3 fallback model IDs tried sequentially when the primary model is unavailable (e.g., rate-limited or capacity issue). Each entry is a model ID or alias; "default" expands to the account default. Claude Code attempts the primary model first; if it fails, each fallback is tried in order. Stops at the first successful response. Unlike most array settings, this key does not merge across settings files — the highest-precedence file that defines it supplies the entire chain; entries beyond 3 (after deduplication) are silently ignored (v2.1.166)
modelOverrides	object	-	Map model picker entries to provider-specific IDs (e.g., Bedrock inference profile ARNs). Each key is a model picker entry name, each value is the provider model ID

Example:

{
  "modelOverrides": {
    "claude-opus-4-6": "arn:aws:bedrock:us-east-1:123456789:inference-profile/anthropic.claude-opus-4-6-v1:0",
    "claude-sonnet-4-6": "arn:aws:bedrock:us-east-1:123456789:inference-profile/anthropic.claude-sonnet-4-6-v1:0"
  }
}

Effort Level

The /model command exposes an effort level control that adjusts how much reasoning the model applies per response. Use the ← → arrow keys in the /model UI to cycle through effort levels.

Effort Level	Description
Ultracode	Session-only: triggers the ultracode workflow in addition to xhigh reasoning depth. Activated via /effort ultracode — not a valid effortLevel value in settings.json (v2.1.203+)
Max	Session-only: maximum reasoning depth on models that support it (Fable 5, Opus 5, Sonnet 5, Opus 4.8, Opus 4.7, Opus 4.6, Sonnet 4.6). Not a valid effortLevel value in settings.json
XHigh	Extended high reasoning depth. Available on Fable 5, Opus 5, Sonnet 5, Opus 4.7, Opus 4.8 (v2.1.111). Default on Opus 4.7 across all plans; on other supported models the default is high
High (default on all effort-supporting models except Opus 4.7)	Full reasoning depth, best for complex tasks
Medium	Balanced reasoning, good for everyday tasks
Low	Minimal reasoning, fastest responses

How to use:

1. Run /effort low, /effort medium, or /effort high to set directly (v2.1.76+)
2. Or run /model → select a model → use ← → arrow keys to adjust
3. The setting persists via the effortLevel key in settings.json

Note: Effort level is available for Opus 4.6, Sonnet 4.6, Opus 4.7, and Opus 4.8 on Max and Team plans. The default was changed from High to Medium in v2.1.68, then changed back to High for API-key, Bedrock/Vertex/Foundry, Team, and Enterprise users in v2.1.94. In v2.1.117, the default was also raised from medium to high for Pro/Max subscribers on Opus 4.6 and Sonnet 4.6, bringing all tiers into alignment on high. v2.1.111 introduced xhigh (Opus 4.7 only at the time) and made it the default effort level on Opus 4.7 across all plans. v2.1.154 added Opus 4.8 as the latest Opus on the Anthropic API; it supports xhigh but defaults to high. As of v2.1.75, 1M context window for Opus 4.6 is available by default on Max, Team, and Enterprise plans.

Effort env propagation: Inside skill files, use ${CLAUDE_EFFORT} to reference the current effort level (v2.1.120). As of v2.1.133, the same $CLAUDE_EFFORT variable is also injected into the environment of Bash tool subprocesses and hook handlers, so shell scripts and hook commands can adapt their behavior based on the active effort tier without reading a separate config file.

Model Environment Variables

Configure via env key:

{
  "env": {
    "ANTHROPIC_MODEL": "sonnet",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "custom-haiku-model",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "custom-sonnet-model",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "custom-opus-model",
    "CLAUDE_CODE_SUBAGENT_MODEL": "haiku",
    "MAX_THINKING_TOKENS": "10000"
  }
}

---

Display & UX

Display Settings

Key	Type	Default	Description
statusLine	object	-	Custom status line configuration
outputStyle	string	"default"	Output style (e.g., "Explanatory")
spinnerTipsEnabled	boolean	true	Show tips while waiting
spinnerVerbs	object	-	Custom spinner verbs with mode ("append" or "replace") and verbs array
spinnerTipsOverride	object	-	Custom spinner tips with tips (string array) and optional excludeDefault (boolean). When excludeDefault is true, only custom tips show; when false or absent, custom tips merge with built-in tips. As of v2.1.121, excludeDefault: true also suppresses time-based spinner tips
respectGitignore	boolean	true	Respect .gitignore in file picker
prefersReducedMotion	boolean	false	Reduce animations and motion effects in the UI
axScreenReader	boolean	false	Enable screen-reader-friendly output mode. When true, Claude outputs flat text without decorative box-drawing characters, color, and other terminal UI elements. Appears in /config as Screen reader mode. Only applies at the User scope — does not read from project or managed settings. Also available via the --ax-screen-reader CLI flag (v2.1.181)
syntaxHighlightingDisabled	boolean	false	Disable syntax highlighting in diffs, code blocks, and file previews. Distinct from the CLAUDE_CODE_SYNTAX_HIGHLIGHT env var, which only governs diff output
fileSuggestion	object	-	Custom file suggestion command (see File Suggestion Configuration below)
autoScrollEnabled	boolean	true	Auto-scroll the conversation in fullscreen mode. Set to false to disable automatic scrolling (v2.1.110). Versions before v2.1.119 stored this in ~/.claude.json
editorMode	string	"normal"	Key binding mode for the input prompt: "normal" or "vim". Appears in /config as Editor mode. Versions before v2.1.119 stored this in ~/.claude.json
vimInsertModeRemaps	object	-	Custom key remappings applied in vim insert mode. Object where keys are exactly two printable characters (the input sequence) and values are the replacement sequence — the only valid target value is <Esc>. Only applies when editorMode is "vim". Example: {"jk": "<Esc>", "jj": "<Esc>"} (v2.1.208)
showTurnDuration	boolean	true	Show turn duration messages after responses (e.g., "Cooked for 1m 6s"). Versions before v2.1.119 stored this in ~/.claude.json
teammateMode	string	"in-process"	How agent team teammates display: "auto" (picks split panes in tmux or iTerm2, in-process otherwise), "in-process" (default since v2.1.179), "tmux", or "iterm2" (force iTerm2 split panes regardless of auto-detection, v2.1.186). See choose a display mode. Versions before v2.1.119 stored this in ~/.claude.json
terminalProgressBarEnabled	boolean	true	Show the terminal progress bar in supported terminals (ConEmu, Ghostty 1.2.0+, and iTerm2 3.6.6+). Appears in /config as Terminal progress bar. Versions before v2.1.119 stored this in ~/.claude.json
preferredNotifChannel	string	"auto"	Method for task-complete and permission-prompt notifications. Values: "auto", "terminal_bell", "iterm2", "iterm2_with_bell", "kitty", "ghostty", "notifications_disabled". Default "auto" sends a desktop notification in iTerm2, Ghostty, and Kitty and does nothing in other terminals. Set "terminal_bell" to ring the bell character in any terminal. Appears in /config as Notifications. See Get a terminal bell or notification
wheelScrollAccelerationEnabled	boolean	true	Disable mouse-wheel scroll acceleration in fullscreen mode. Set to false to use fixed per-tick scroll steps instead of the OS-level acceleration curve (v2.1.174)
footerLinksRegexes	array	-	Array of objects matched against turn output (tool results, file contents, fetched pages, Claude's responses) to display as link badges in the footer row. Each entry is {type, pattern, url, label} where pattern is a regex with named capture groups and url/label may reference those groups. Matched patterns produce a clickable badge at the bottom of the chat UI. Capped at 5 badges per turn; URL max 2048 chars; allowed schemes: http, https, vscode, cursor, windsurf, zed, jetbrains, idea, slack, linear, notion, figma, vscode-insiders. User/--settings/managed only (v2.1.176)
emojiCompletionEnabled	boolean	true	Enable emoji shortcode autocomplete in the prompt input (e.g., :tada: → 🎉). Set to false to disable. Requires v2.1.217+

Global Config Settings (~/.claude.json)

These IDE-related preferences are stored in ~/.claude.json, not settings.json.

v2.1.119 migration note: As of v2.1.119, autoScrollEnabled, editorMode, showTurnDuration, teammateMode, and terminalProgressBarEnabled moved into settings.json and are documented in the Display Settings table above. Earlier versions stored them here.

Key	Type	Default	Description
autoConnectIde	boolean	false	Automatically connect to a running IDE when Claude Code starts from an external terminal. Appears in /config as Auto-connect to IDE (external terminal) when running outside a VS Code or JetBrains terminal
autoInstallIdeExtension	boolean	true	Automatically install the Claude Code IDE extension when running from a VS Code terminal. Appears in /config as Auto-install IDE extension. Can also be disabled via CLAUDE_CODE_IDE_SKIP_AUTO_INSTALL env var
externalEditorContext	boolean	false	Prepend Claude's previous response as #-commented context when you open the external editor with Ctrl+G. Set to true to enable
teammateDefaultModel	string	null	Default model for agent-team teammates when the lead dispatches them. null inherits the lead's model. Listed under "Global config settings" on the official settings page
diffTool	string	-	External diff tool command invoked when viewing file diffs. When set, Claude Code spawns this command with the two file paths as arguments instead of rendering the built-in diff view
permissionExplainerEnabled	boolean	true	Show an AI-generated natural-language explanation of why a permission is being requested alongside the permission prompt. Set to false to suppress the explanation and show only the raw tool call

Workspace & Teams

Key	Type	Description
sshConfigs	object[]	SSH connection definitions surfaced as a dropdown in Desktop. Each entry must include id, name, and sshHost; optionally sshPort, sshIdentityFile, and startDirectory. Only honored from managed and user settings — project settings values are ignored

Field reference:

Field	Required	Description
id	yes	Unique identifier for the SSH connection entry
name	yes	Display name shown in the Desktop dropdown
sshHost	yes	SSH host (e.g., user@dev.example.com or dev.example.com)
sshPort	no	SSH port number
sshIdentityFile	no	Path to the SSH identity file (private key)
startDirectory	no	Initial working directory after connecting

Example:

{
  "sshConfigs": [
    {
      "id": "dev-vm",
      "name": "Dev VM",
      "sshHost": "user@dev.example.com",
      "sshPort": 22,
      "sshIdentityFile": "~/.ssh/id_ed25519",
      "startDirectory": "/home/user/project"
    }
  ]
}

Status Line Configuration

{
  "statusLine": {
    "type": "command",
    "command": "~/.claude/statusline.sh",
    "padding": 2,
    "refreshInterval": 5
  }
}

Field	Description
type	Set to "command" to run a shell script
command	Shell command or script path that generates the status line output
padding	Extra horizontal spacing (in characters) added to status line content. Defaults to 0. Controls relative indentation beyond the interface's built-in spacing
refreshInterval	Re-run the command every N seconds in addition to event-driven updates. Minimum is 1. Useful when the status line shows time-based data (e.g., a clock) or when background subagents change git state while the main session is idle. Leave unset to run only on events (v2.1.97)
hideVimModeIndicator	When true, suppresses the built-in vim mode indicator from the status area so a custom status line command can render it instead. Only has effect when editorMode is "vim"

Status Line Input Fields:

The status line command receives a JSON object on stdin. For the full JSON schema and examples, see the Status Line Documentation.

Field	Description
model.id, model.display_name	Current model identifier and display name
cwd, workspace.current_dir	Current working directory (both contain the same value; workspace.current_dir preferred)
workspace.project_dir	Directory where Claude Code was launched (may differ from cwd if working directory changes)
workspace.added_dirs	Additional directories added via /add-dir or --add-dir
workspace.git_worktree	Git worktree name when inside a linked worktree created with git worktree add. Absent in the main working tree (v2.1.97)
cost.total_cost_usd	Total session cost in USD
cost.total_duration_ms	Total wall-clock time since session started, in milliseconds
cost.total_api_duration_ms	Total time spent waiting for API responses, in milliseconds
cost.total_lines_added, cost.total_lines_removed	Lines of code changed during the session
context_window.total_input_tokens, context_window.total_output_tokens	Cumulative token counts across the session
context_window.context_window_size	Maximum context window size in tokens (200000 default, 1000000 for extended context)
context_window.used_percentage	Pre-calculated percentage of context window used
context_window.remaining_percentage	Pre-calculated percentage of context window remaining
context_window.current_usage	Token counts from the last API call (input, output, cache tokens)
exceeds_200k_tokens	Whether total tokens from the most recent API response exceeds 200k (fixed threshold)
rate_limits.five_hour.used_percentage	Five-hour rate limit usage percentage (v2.1.80+)
rate_limits.five_hour.resets_at	Five-hour rate limit reset timestamp (Unix epoch seconds)
rate_limits.seven_day.used_percentage	Seven-day rate limit usage percentage
rate_limits.seven_day.resets_at	Seven-day rate limit reset timestamp (Unix epoch seconds)
session_id	Unique session identifier
session_name	Custom session name set with --name or /rename. Absent if no custom name set
transcript_path	Path to conversation transcript file
version	Claude Code version
output_style.name	Name of the current output style
vim.mode	Current vim mode (NORMAL or INSERT) when vim mode is enabled
agent.name	Agent name when running with --agent flag or agent settings
effort.level	Current reasoning effort (low, medium, high, xhigh, or max). Reflects the live session value, including mid-session /effort changes. Absent when the current model does not support the effort parameter (v2.1.121)
thinking.enabled	Whether extended thinking is enabled for the session (v2.1.121)
worktree.name	Name of the active worktree (present only during --worktree sessions)
worktree.path	Absolute path to the worktree directory
worktree.branch	Git branch name for the worktree. Absent for hook-based worktrees
worktree.original_cwd	Directory before entering the worktree
worktree.original_branch	Git branch checked out before entering the worktree. Absent for hook-based worktrees
github	GitHub repository and pull-request information for the current branch when detected — repo identity and the associated PR (v2.1.145)

File Suggestion Configuration

The file suggestion script receives a JSON object on stdin (e.g., {"query": "src/comp"}) and must output up to 15 file paths (one per line).

{
  "fileSuggestion": {
    "type": "command",
    "command": "~/.claude/file-suggestion.sh"
  },
  "respectGitignore": true
}

Example:

{
  "statusLine": {
    "type": "command",
    "command": "git branch --show-current 2>/dev/null || echo 'no-branch'"
  },
  "spinnerTipsEnabled": true,
  "spinnerVerbs": {
    "mode": "replace",
    "verbs": ["Cooking", "Brewing", "Crafting", "Conjuring"]
  },
  "spinnerTipsOverride": {
    "tips": ["Use /compact at ~50% context", "Start with plan mode for complex tasks"],
    "excludeDefault": true
  }
}

---

AWS & Cloud Credentials

AWS Settings

Key	Type	Description
awsAuthRefresh	string	Script to refresh AWS auth (modifies .aws dir)
awsCredentialExport	string	Script outputting JSON with AWS credentials

Example:

{
  "awsAuthRefresh": "aws sso login --profile myprofile",
  "awsCredentialExport": "/bin/generate_aws_grant.sh"
}

OpenTelemetry

Key	Type	Description
otelHeadersHelper	string	Script to generate dynamic OpenTelemetry headers

Example:

{
  "otelHeadersHelper": "/bin/generate_otel_headers.sh"
}

---

Environment Variables (via env)

Set environment variables for all Claude Code sessions.

{
  "env": {
    "ANTHROPIC_API_KEY": "...",
    "NODE_ENV": "development",
    "DEBUG": "true"
  }
}

Common Environment Variables

Variable	Description
ANTHROPIC_API_KEY	API key for authentication
ANTHROPIC_AUTH_TOKEN	OAuth token
CLAUDE_CODE_OAUTH_TOKEN	OAuth access token for Claude.ai authentication. Alternative to /login for SDK and automated environments. Takes precedence over keychain-stored credentials
CLAUDE_CODE_OAUTH_REFRESH_TOKEN	OAuth refresh token for Claude.ai authentication. When set, claude auth login exchanges this token directly instead of opening a browser. Requires CLAUDE_CODE_OAUTH_SCOPES
CLAUDE_CODE_OAUTH_SCOPES	Space-separated OAuth scopes the refresh token was issued with (e.g., "user:profile user:inference user:sessions:claude_code"). Required when CLAUDE_CODE_OAUTH_REFRESH_TOKEN is set
ANTHROPIC_WORKSPACE_ID	Workspace ID for workload identity federation. Set when your federation rule is scoped to more than one workspace so the token exchange knows which workspace to target (v2.1.141)
ANTHROPIC_BASE_URL	Custom API endpoint
ANTHROPIC_BEDROCK_BASE_URL	Override Bedrock endpoint URL
ANTHROPIC_BEDROCK_MANTLE_BASE_URL	Override the Bedrock Mantle endpoint URL. See Mantle endpoint
ANTHROPIC_BEDROCK_SERVICE_TIER	Bedrock service tier: default, flex, or priority. Sent as the X-Amzn-Bedrock-Service-Tier header on every request. See Amazon Bedrock service tiers (v2.1.122)
ANTHROPIC_AWS_API_KEY	Workspace API key for Claude Platform on AWS
ANTHROPIC_AWS_BASE_URL	Override Claude Platform on AWS endpoint URL
ANTHROPIC_AWS_WORKSPACE_ID	Required workspace ID for Claude Platform on AWS
CLAUDE_CODE_PROVIDER_MANAGED_BY_HOST	Set by host platforms that embed Claude Code and manage model provider routing on the user's behalf. When set, provider-selection / endpoint / authentication env vars in settings.json (e.g., CLAUDE_CODE_USE_BEDROCK, ANTHROPIC_BASE_URL, ANTHROPIC_API_KEY) are ignored so user settings cannot override the host's routing. The automatic telemetry opt-out for Bedrock/Vertex/Foundry is also skipped, so telemetry follows the standard DISABLE_TELEMETRY opt-out (v2.1.126)
ANTHROPIC_VERTEX_BASE_URL	Override Vertex AI endpoint URL
ANTHROPIC_BETAS	Comma-separated Anthropic beta header values
ANTHROPIC_VERTEX_PROJECT_ID	GCP project ID for Vertex AI
GCLOUD_PROJECT	GCP project ID for Vertex AI requests (overrides ANTHROPIC_VERTEX_PROJECT_ID)
GOOGLE_APPLICATION_CREDENTIALS	Path to GCP service account credential file for Vertex AI authentication
GOOGLE_CLOUD_PROJECT	GCP project ID for Vertex AI requests (overrides ANTHROPIC_VERTEX_PROJECT_ID)
ANTHROPIC_CUSTOM_MODEL_OPTION	Model ID to add as a custom entry in the /model picker. Use to make a non-standard or gateway-specific model selectable without replacing built-in aliases
ANTHROPIC_CUSTOM_MODEL_OPTION_NAME	Display name for the custom model entry in the /model picker. Defaults to the model ID when not set
ANTHROPIC_CUSTOM_MODEL_OPTION_DESCRIPTION	Display description for the custom model entry in the /model picker. Defaults to Custom model (<model-id>) when not set
ANTHROPIC_CUSTOM_MODEL_OPTION_SUPPORTED_CAPABILITIES	Override capability detection for the custom model entry. Comma-separated values (e.g., effort,thinking). Required when the custom model supports features the auto-detection cannot confirm. See model configuration
ANTHROPIC_MODEL	Name of the model to use. Accepts aliases (sonnet, opus, haiku) or full model IDs. Overrides the model setting
INIT_PROMPT	Custom system prompt injected at session initialization
ANTHROPIC_DEFAULT_HAIKU_MODEL	Override the Haiku model alias with a custom model ID (e.g., for third-party deployments)
ANTHROPIC_DEFAULT_HAIKU_MODEL_NAME	Customize the Haiku entry label in the /model picker when using a pinned model on Bedrock/Vertex/Foundry. Defaults to the model ID
ANTHROPIC_DEFAULT_HAIKU_MODEL_DESCRIPTION	Customize the Haiku entry description in the /model picker. Defaults to Custom model (<model-id>)
ANTHROPIC_DEFAULT_HAIKU_MODEL_SUPPORTED_CAPABILITIES	Override capability detection for a pinned Haiku model. Comma-separated values (e.g., effort,thinking). Required when the pinned model supports features the auto-detection cannot confirm
CLAUDE_PID	Read-only. Set to the PID of the Claude Code process in every subprocess it spawns (Bash tool, hooks, status line commands, MCP stdio servers). Use in scripts to signal the parent Claude Code process or to detect the Claude Code lineage. Introduced in v2.1.214
CLAUDECODE	Set to 1 in shell environments Claude Code spawns (Bash tool, tmux sessions). Not set in hooks or status line commands. Use to detect when a script is running inside a Claude Code shell
CLAUDE_CODE_CHILD_SESSION	Set to 1 in subprocesses Claude Code spawns via the Bash, PowerShell, and Monitor tools, hook commands, and status line commands. Not set for stdio MCP server subprocesses. Unlike CLAUDECODE, this is only set by Claude Code's own spawn path (not IDE extensions), so it reliably distinguishes a nested claude session from a top-level claude launched in an IDE-integrated terminal. Nested interactive TUI sessions are automatically excluded from --resume, --continue, up-arrow history, and claude agents. Non-interactive claude -p sessions still persist. Set CLAUDE_CODE_FORCE_SESSION_PERSISTENCE=1 to override this exclusion (v2.1.172)
CLAUDE_CODE_FORCE_SESSION_PERSISTENCE	Set to 1 to override the automatic exclusion of nested interactive TUI sessions from --resume, --continue, up-arrow history, and claude agents. By default, nested sessions (where CLAUDE_CODE_CHILD_SESSION=1) are excluded to prevent them from polluting history. Set this to force persistence when you want nested sessions tracked
CLAUDE_CODE_SESSION_ID	Read-only. Set automatically in Bash and PowerShell tool subprocesses to the current session ID. Matches the session_id field passed to hooks. Updated on /clear. Use to correlate scripts and external tools with the Claude Code session that launched them (v2.1.132). Also injected into stdio MCP server environments on --resume (v2.1.163 changelog) (in v2.1.163 changelog; not yet on official env-vars page — read-only)
AI_AGENT	Set automatically by Claude Code in subprocess environments (Bash tool, hooks, MCP stdio servers). Generic flag identifying the parent process as an AI agent — useful for tools that adapt behavior when invoked from any AI agent rather than checking each agent-specific variable like CLAUDECODE (in v2.1.120 changelog, not yet on official env-vars page)
CLAUDE_CODE_SKIP_FAST_MODE_NETWORK_ERRORS	Set to 1 to allow fast mode when the organization status check fails due to a network error. Useful when a corporate proxy blocks the status endpoint
CLAUDE_CODE_USE_BEDROCK	Use AWS Bedrock (1 to enable)
CLAUDE_CODE_USE_VERTEX	Use Google Vertex AI (1 to enable)
CLAUDE_CODE_USE_FOUNDRY	Use Microsoft Foundry (1 to enable)
CLAUDE_CODE_USE_MANTLE	Use the Bedrock Mantle endpoint (1 to enable)
CLAUDE_CODE_USE_POWERSHELL_TOOL	Set to 1 to enable the PowerShell tool on Windows (opt-in preview). When enabled, Claude can run PowerShell commands natively instead of routing through Git Bash. Only supported on native Windows, not WSL (v2.1.84)
CLAUDE_CODE_POWERSHELL_RESPECT_EXECUTION_POLICY	Set to 1 to stop Claude Code from passing -ExecutionPolicy Bypass when spawning PowerShell for tool calls, hooks, and status line commands, respecting the machine's effective execution policy instead. By default Claude Code bypasses execution policy at process scope so .ps1 scripts and module imports work on default-Restricted Windows. Never overrides Group Policy MachinePolicy/UserPolicy (v2.1.143)
CLAUDE_CODE_REMOTE	Read-only. Set automatically to true when Claude Code is running as a cloud session. Read this from a hook or setup script to detect whether you are in a cloud environment
CLAUDE_CODE_REMOTE_SESSION_ID	Read-only. Set automatically in cloud sessions to the current session's ID. Read this to construct a link back to the session transcript
CLAUDE_CODE_BRIDGE_SESSION_ID	Read-only. Set automatically in Bash tool and hook command subprocesses while the session has an active Remote Control connection. Value is the session ID in session_ form (same identifier in the session's claude.ai/code URL). Removed when the connection ends. Allows scripts to link back to the session that ran them. In cloud sessions, read CLAUDE_CODE_REMOTE_SESSION_ID instead (v2.1.199)
CLAUDE_REMOTE_CONTROL_SESSION_NAME_PREFIX	Prefix for auto-generated Remote Control session names. Defaults to the machine hostname
CLAUDE_CLIENT_PRESENCE_FILE	Path to a file that, when present, signals an active client and suppresses mobile push notifications from Remote Control. Useful in environments where a desktop client is always running and mobile pings are unwanted
CLAUDE_CODE_DISABLE_NOTIFICATION_PRESENCE_CHECK	Set to 1 to send push notifications even while the user is actively typing in the session. By default, notifications are suppressed when active user presence is detected (v2.1.193)
CLAUDE_CODE_ENABLE_TELEMETRY	Enable/disable telemetry (0 or 1)
DISABLE_ERROR_REPORTING	Disable error reporting (1 to disable)
DISABLE_AUTOUPDATER	Set to 1 to disable automatic update checks against the npm registry. Also configurable as a startup-only var — see CLI Startup Flags
DISABLE_UPDATES	Set to 1 to completely block all update paths — automatic checks, notifications, and manual claude update. Stricter than DISABLE_AUTOUPDATER, which only disables the background check. Use in environments where all updates must be blocked until explicitly re-enabled (in v2.1.118 changelog, not yet on official env-vars page)
CLAUDE_CODE_PACKAGE_MANAGER_AUTO_UPDATE	Set to 1 to let Claude Code run your package manager's upgrade command in the background when a new version is available. Applies to Homebrew and WinGet installations. Other package managers continue to show the upgrade command without running it. See Auto updates (v2.1.129)
CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY	Set to 1 to populate the /model picker from your gateway's /v1/models endpoint when ANTHROPIC_BASE_URL points at an Anthropic-compatible gateway such as LiteLLM, Kong, or an internal proxy. Off by default because gateways backed by a shared API key would otherwise expose every model the key can access. Discovered models are still filtered by the availableModels allowlist (v2.1.129, opt-in change from prior auto-discovery)
DISABLE_TELEMETRY	Disable telemetry (1 to disable)
DO_NOT_TRACK	Standard opt-out variable; set to 1 to opt out of telemetry collection. Respected by DISABLE_TELEMETRY
MCP_TIMEOUT	MCP startup timeout in ms
MCP_CONNECT_TIMEOUT_MS	Timeout in ms for the MCP server TCP/Unix connection phase (default: 5000). Distinct from MCP_TIMEOUT (startup) and MCP_TOOL_TIMEOUT (per-call)
MCP_SERVER_CONNECTION_BATCH_SIZE	Number of local (stdio) MCP servers to connect in parallel on startup. Use to throttle startup load on machines with many servers
MCP_REMOTE_SERVER_CONNECTION_BATCH_SIZE	Number of remote (HTTP/SSE) MCP servers to connect in parallel on startup. Separate from the local batch size to account for network latency
CLAUDE_CODE_MCP_ALLOWLIST_ENV	Spawn stdio MCP servers with a safe baseline environment only, stripping most inherited env vars to prevent credential leakage into untrusted server processes
MAX_MCP_OUTPUT_TOKENS	Max MCP output tokens (default: 25000). Warning displayed when output exceeds 10,000 tokens
API_TIMEOUT_MS	Timeout in ms for API requests (default: 600000)
API_FORCE_IDLE_TIMEOUT	Override the 5-minute idle timeout for streaming connections. Set to 0 to disable the idle timeout entirely, 1 to enforce it on all connections, or leave unset for the default (auto-enabled on slow or unreliable gateways that frequently stall). Useful for slow API gateways (v2.1.169)
CLAUDE_CODE_CONNECT_TIMEOUT_MS	REMOVED in v2.1.186. This variable is a no-op. Use API_TIMEOUT_MS instead. Previously controlled the connect, TLS, and response-header phase timeout for streaming API requests
CLAUDE_AFK_TIMEOUT_MS	How many milliseconds before an unanswered AskUserQuestion dialog auto-continues, when askUserQuestionTimeout is set to a duration. As of v2.1.200, the default is "never" (no auto-continue) controlled by askUserQuestionTimeout; this env var applies only when a timeout duration is active. Setting to 0 closes the dialog immediately. To keep questions open, prefer askUserQuestionTimeout: "never" (v2.1.198; default changed v2.1.200)
CLAUDE_AFK_COUNTDOWN_MS	How many milliseconds before auto-continue the on-screen countdown appears on an unanswered AskUserQuestion dialog (default: 20000 / 20 seconds) (v2.1.198)
BASH_MAX_TIMEOUT_MS	Bash command timeout
BASH_MAX_OUTPUT_LENGTH	Max bash output length
CLAUDE_AUTOCOMPACT_PCT_OVERRIDE	Auto-compact threshold percentage (1-100). Default is ~95%. Set lower (e.g., 50) to trigger compaction earlier. Values above 95% have no effect. Use /context to monitor current usage. Example: CLAUDE_AUTOCOMPACT_PCT_OVERRIDE=50 claude
CLAUDE_CODE_MAX_CONTEXT_TOKENS	Override the context window size Claude Code assumes for the active model. Only takes effect when DISABLE_COMPACT is also set. Use when routing to a model through ANTHROPIC_BASE_URL whose context window does not match the built-in size for its name
CLAUDE_BASH_MAINTAIN_PROJECT_WORKING_DIR	Set to 1 to return to the original working directory after each Bash or PowerShell command. By default, directory changes made inside a command persist to the next command — this variable restores the original cwd after each call
CLAUDE_CODE_DISABLE_BACKGROUND_TASKS	Disable background tasks (1 to disable)
CLAUDE_CODE_DISABLE_BG_SHELL_PRESSURE_REAP	Set to 1 to disable automatic memory-pressure reaping of idle background shell commands. When unset, Claude Code automatically reaps idle background shells under memory pressure to free resources (v2.1.193 changelog, not yet on official env-vars page)
CLAUDE_CODE_DISABLE_BG_EXIT_HANDOFF	Set to 1 to stop a background session's running background shell commands, dynamic workflows, and background subagents when the supervisor stops, restarts, or updates that session's process. By default they are handed off to the session's next process (v2.1.198)
CLAUDE_CODE_DISABLE_ADVISOR_TOOL	Set to 1 to disable the advisor tool and the /advisor command. Env-var equivalent of omitting advisor usage. Pair with advisorModel for advisor configuration (min v2.1.98)
CLAUDE_CODE_DISABLE_AGENT_VIEW	Set to 1 to turn off background agents and agent view (claude agents, --bg, /background, on-demand supervisor). Env-var equivalent of the disableAgentView setting (referenced on official settings page; not listed on the env-vars page)
CLAUDE_CODE_DISABLE_EXPLORE_PLAN_AGENTS	Set to 1 to disable the built-in Explore and Plan subagents. Claude explores with search tools or the general-purpose subagent instead. Plan mode reads files directly rather than launching Explore and Plan agents (v2.1.198)
CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS	Enable the experimental agent teams feature (1 to enable). Allows spawning coordinated teams of subagents within a session. Also configurable as a startup-only var — see CLI Startup Flags
CLAUDE_CODE_DISABLE_WORKFLOWS	Set to 1 to disable dynamic workflows (/workflows) and the bundled workflow slash commands. Env-var equivalent of the disableWorkflows setting
CLAUDE_CODE_ENABLE_AUTO_MODE	As of v2.1.207, auto mode is available on Bedrock, Vertex AI, and Foundry by default — this opt-in is no longer required. Previously (v2.1.158–v2.1.206): set to 1 to make auto mode available on those providers. Use disableAutoMode: "disable" in settings to turn auto mode off
CLAUDE_CODE_DISABLE_BUNDLED_SKILLS	Set to 1 to conceal Claude Code's built-in capabilities (bundled skills) from the model. Env-var equivalent of the disableBundledSkills setting (v2.1.169)
CLAUDE_CODE_DISABLE_ARTIFACT	Set to 1 to disable the Artifact tool, which publishes session output as a private web page on claude.ai. Equivalent to the disableArtifact setting
CLAUDE_CODE_ARTIFACT_AUTO_OPEN	Set to 0 to stop Claude Code from opening the browser automatically when a new artifact is published. Republishing an existing artifact does not open the browser regardless of this setting
ENABLE_TOOL_SEARCH	MCP tool search threshold (e.g., auto:5)
ENABLE_PROMPT_CACHING_1H	Opt into 1-hour prompt cache TTL. Replaces the deprecated ENABLE_PROMPT_CACHING_1H_BEDROCK (in v2.1.108 changelog, not yet on official env-vars page)
FORCE_PROMPT_CACHING_5M	Force 5-minute prompt cache TTL (in v2.1.108 changelog, not yet on official env-vars page)
CLAUDE_CODE_ENABLE_AWAY_SUMMARY	Opt out of away summary / idle-session recap. Set to 0 to disable. Pairs with the awaySummaryEnabled setting (v2.1.110)
DISABLE_PROMPT_CACHING	Disable all prompt caching (1 to disable)
DISABLE_PROMPT_CACHING_HAIKU	Disable Haiku prompt caching
DISABLE_PROMPT_CACHING_SONNET	Disable Sonnet prompt caching
DISABLE_PROMPT_CACHING_OPUS	Disable Opus prompt caching
ENABLE_PROMPT_CACHING_1H_BEDROCK	Request 1-hour cache TTL on Bedrock (1 to enable) (not in official docs — unverified; v2.1.108 changelog says deprecated, replaced by ENABLE_PROMPT_CACHING_1H)
CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS	Disable experimental beta features (1 to disable)
CLAUDE_CODE_SHELL	Override automatic shell detection
CLAUDE_CODE_FILE_READ_MAX_OUTPUT_TOKENS	Override default file read token limit
CLAUDE_CODE_GLOB_HIDDEN	Set to false to exclude dotfiles from results when Claude invokes the Glob tool. Included by default. Does not affect @ file autocomplete, ls, Grep, or Read
CLAUDE_CODE_GLOB_NO_IGNORE	Set to false to make the Glob tool respect .gitignore patterns. By default, Glob returns all matching files including gitignored ones. Does not affect @ file autocomplete, which has its own respectGitignore setting
CLAUDE_CODE_GLOB_TIMEOUT_SECONDS	Timeout in seconds for Glob file discovery
CLAUDE_CODE_ENABLE_TASKS	Controls whether sessions use the structured Task tools (TaskCreate, TaskUpdate, TaskGet, TaskList) or the legacy TodoWrite tool. As of v2.1.142, Task tools are the default in all modes. Set to 0 to revert to TodoWrite
CLAUDE_CODE_SIMPLE	Set to 1 to run with a minimal system prompt and only the Bash, file read, and file edit tools. Also configurable as a startup-only var — see CLI Startup Flags
CLAUDE_CODE_EXIT_AFTER_STOP_DELAY	Auto-exit SDK mode after idle duration (ms)
CLAUDE_CODE_DISABLE_ADAPTIVE_THINKING	Disable adaptive thinking (1 to disable)
CLAUDE_CODE_DISABLE_THINKING	Force-disable extended thinking (1 to disable)
DISABLE_INTERLEAVED_THINKING	Prevent interleaved-thinking beta header from being sent (1 to disable)
CLAUDE_CODE_DISABLE_1M_CONTEXT	Hold all 1M context window models to the 200K context size via auto-compaction. As of v2.1.223, this applies to all 1M models (not just one). Set to 1 to disable 1M context across your deployment
CLAUDE_CODE_ACCOUNT_UUID	Override account UUID for authentication
CLAUDE_CODE_DISABLE_GIT_INSTRUCTIONS	Disable git-related system prompt instructions
CLAUDE_CODE_ATTRIBUTION_HEADER	Set to 0 to omit the Claude Code attribution block from the system prompt
CLAUDE_CODE_NEW_INIT	Set to true to make /init run an interactive setup flow. Asks which files to generate (CLAUDE.md, skills, hooks) before exploring the codebase. Without this, /init generates a CLAUDE.md automatically
CLAUDE_CODE_PLUGIN_SEED_DIR	Path to one or more read-only plugin seed directories, separated by : on Unix or ; on Windows. Bundle pre-populated plugins into a container image. Claude Code registers marketplaces from these directories at startup and uses pre-cached plugins without re-cloning
ENABLE_CLAUDEAI_MCP_SERVERS	Enable Claude.ai MCP servers
CLAUDE_CODE_EFFORT_LEVEL	Set effort level: low, medium, high, xhigh (Opus 4.7 and 4.8, v2.1.111), max (Opus 4.6 only), or auto (use model default). Takes precedence over /effort and the effortLevel setting. Also configurable as a startup-only var — see CLI Startup Flags
CLAUDE_EFFORT	Read-only. Injected into Bash tool subprocesses and hook handlers with the active effort level so shell scripts and hooks can adapt to the current tier (companion to CLAUDE_CODE_EFFORT_LEVEL; v2.1.133). Inside skill files use ${CLAUDE_EFFORT} (in changelog, not on official env-vars page — read-only, not user-configurable)
CLAUDE_CODE_ALWAYS_ENABLE_EFFORT	Set to 1 to force-enable the effort parameter on all models, even those that do not normally support effort-level selection. Allows /effort and the effortLevel setting to take effect on models outside the standard effort-capable set (v2.1.154)
CLAUDE_CODE_MAX_TURNS	Maximum agentic turns before stopping (not in official docs — unverified)
CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC	Equivalent of setting DISABLE_AUTOUPDATER, DISABLE_FEEDBACK_COMMAND, DISABLE_ERROR_REPORTING, and DISABLE_TELEMETRY
CLAUDE_CODE_SKIP_SETTINGS_SETUP	Skip first-run settings setup flow (not in official docs — unverified)
CLAUDE_CODE_PROMPT_CACHING_ENABLED	Override prompt caching behavior (not in official docs — unverified)
CLAUDE_CODE_DISABLE_TOOLS	Comma-separated list of tools to disable (not in official docs — unverified)
CLAUDE_CODE_DISABLE_MCP	Disable all MCP servers (1 to disable) (not in official docs — unverified)
CLAUDE_CODE_MAX_OUTPUT_TOKENS	Max output tokens per response. Default: 32,000 (64,000 for Opus 4.6 as of v2.1.77). Upper bound: 64,000 (128,000 for Opus 4.6 and Sonnet 4.6 as of v2.1.77)
CLAUDE_CODE_DISABLE_FAST_MODE	Disable fast mode entirely (1 to disable)
CLAUDE_CODE_OPUS_4_6_FAST_MODE_OVERRIDE	REMOVED in v2.1.160 — the environment variable is now a no-op. Fast mode runs on the default model regardless of this variable. Previously pinned fast mode to Claude Opus 4.6 instead of the default (v2.1.142–v2.1.159)
CLAUDE_CODE_DISABLE_NONSTREAMING_FALLBACK	Set to 1 to disable the non-streaming fallback when a streaming request fails mid-stream. Streaming errors propagate to the retry layer instead. Useful when a proxy or gateway causes the fallback to produce duplicate tool execution (v2.1.83)
CLAUDE_ENABLE_STREAM_WATCHDOG	Stream idle watchdog that aborts stalled streams. Enabled by default as of v2.1.163; set to 0 to disable
CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMING	Enabled by default on the Anthropic API (v2.1.139+); set to 0 to opt out
CLAUDE_CODE_DISABLE_AUTO_MEMORY	Disable auto memory (1 to disable)
CLAUDE_CODE_DISABLE_FILE_CHECKPOINTING	Disable file checkpointing for /rewind (1 to disable)
CLAUDE_CODE_DISABLE_ATTACHMENTS	Disable attachment processing (1 to disable)
CLAUDE_CODE_DISABLE_CLAUDE_MDS	Prevent loading CLAUDE.md files (1 to disable)
CLAUDE_CODE_ADDITIONAL_DIRECTORIES_CLAUDE_MD	Load CLAUDE.md memory files from additional directories specified via --add-dir at startup (1 to enable). Also configurable as a startup-only var — see CLI Startup Flags
CLAUDE_CODE_DISABLE_POLICY_SKILLS	Skip loading skills from the system-wide managed skills directory (1 to disable)
CLAUDE_CODE_RESUME_INTERRUPTED_TURN	Auto-resume if previous session ended mid-turn (1 to enable)
CLAUDE_CODE_RESUME_INTERRUPTED_TURN_MAX_AGE_MS	Maximum age in ms of an interrupted turn that will be auto-resumed on restart. Turns older than this are skipped. Only applies when CLAUDE_CODE_RESUME_INTERRUPTED_TURN=1
CLAUDE_CODE_RESUME_PROMPT	Custom prompt injected at the start of an auto-resumed interrupted turn. Defaults to a built-in continuation message
CLAUDE_CODE_SAFE_MODE	Set to 1 to enable safe mode, which limits potentially destructive operations and enforces stricter tool guardrails
CLAUDE_CODE_SKIP_PROMPT_HISTORY	Set to 1 to skip writing prompt history and session transcripts to disk. Sessions started with this variable set do not appear in --resume, --continue, or up-arrow history. Useful for ephemeral scripted sessions
CLAUDE_CODE_USER_EMAIL	Provide user email synchronously for authentication
CLAUDE_CODE_ORGANIZATION_UUID	Provide organization UUID synchronously for authentication
CLAUDE_CONFIG_DIR	Custom config directory (overrides default ~/.claude)
CLAUDE_CODE_TMPDIR	Override the temp directory used for internal temp files. Claude Code appends /claude/ to this path. Default: /tmp on Unix/macOS, os.tmpdir() on Windows
ANTHROPIC_CUSTOM_HEADERS	Custom headers for API requests (Name: Value format, newline-separated for multiple headers)
CLAUDE_CODE_EXTRA_BODY	JSON object to merge into the top level of every API request body. Use to inject vendor-specific fields (e.g., routing hints for a custom gateway)
CLAUDE_CODE_PROPAGATE_TRACEPARENT	Set to 1 to propagate the W3C traceparent header through requests when routing through a custom proxy, linking Claude Code traces to your upstream telemetry
ANTHROPIC_FOUNDRY_API_KEY	API key for Microsoft Foundry authentication
ANTHROPIC_FOUNDRY_BASE_URL	Base URL for Foundry resource
ANTHROPIC_FOUNDRY_RESOURCE	Foundry resource name
ANTHROPIC_FOUNDRY_AUTH_TOKEN	Azure authentication token for Foundry (alternative to service principal auth, v2.1.203+)
AWS_BEARER_TOKEN_BEDROCK	Bedrock API key for authentication
ANTHROPIC_SMALL_FAST_MODEL	DEPRECATED — Use ANTHROPIC_DEFAULT_HAIKU_MODEL instead
ANTHROPIC_SMALL_FAST_MODEL_AWS_REGION	AWS region for deprecated Haiku-class model override
CLAUDE_CODE_SHELL_PREFIX	Command prefix prepended to bash commands
BASH_DEFAULT_TIMEOUT_MS	Default bash command timeout in ms
CLAUDE_CODE_SKIP_BEDROCK_AUTH	Skip AWS auth for Bedrock (1 to skip)
CLAUDE_CODE_AWS_CHAIN_RESOLVE_TIMEOUT_MS	Timeout in milliseconds for AWS credential chain resolution on Bedrock. Set lower (e.g., 5000) in environments where a credential source is absent so the chain fails fast. Default: 60000 (60 seconds) (v2.1.207)
CLAUDE_CODE_DISABLE_BEDROCK_CONTENT_TYPE_GUARD	Set to 1 to disable the Bedrock content-type guard that rejects responses with unexpected MIME types. Use when a gateway returns non-standard content types but the response body is valid (v2.1.208)
CLAUDE_CODE_SKIP_FOUNDRY_AUTH	Skip Azure auth for Foundry (1 to skip)
CLAUDE_CODE_SKIP_MANTLE_AUTH	Skip AWS authentication for Bedrock Mantle (e.g., when using an LLM gateway)
CLAUDE_CODE_SKIP_VERTEX_AUTH	Skip Google auth for Vertex (1 to skip)
CLAUDE_CODE_PROXY_RESOLVES_HOSTS	Allow proxy to perform DNS resolution
CLAUDE_CODE_API_KEY_HELPER_TTL_MS	Credential refresh interval in ms for apiKeyHelper
CLAUDE_CODE_CLIENT_CERT	Client certificate path for mTLS
CLAUDE_CODE_CLIENT_KEY	Client private key path for mTLS
CLAUDE_CODE_CLIENT_KEY_PASSPHRASE	Passphrase for encrypted mTLS key
CLAUDE_CODE_CERT_STORE	Comma-separated list of CA certificate sources for TLS connections: bundled (Mozilla CA set shipped with Claude Code) and/or system (OS trust store). Default: bundled,system. The native binary distribution is required for system store integration; on the Node.js runtime, only the bundled set is used regardless of this value (v2.1.101)
CLAUDE_CODE_PLUGIN_GIT_TIMEOUT_MS	Plugin marketplace git clone timeout in ms (default: 120000)
CLAUDE_CODE_PLUGIN_PREFER_HTTPS	Set to 1 to clone GitHub owner/repo shorthand plugin sources over HTTPS instead of SSH. Applies to plugin install/update and /plugin marketplace add/update. Useful in CI runners or containers without a configured SSH key for github.com (v2.1.141)
CLAUDE_CODE_PLUGIN_CACHE_DIR	Override the plugins root directory
CLAUDE_CODE_DISABLE_OFFICIAL_MARKETPLACE_AUTOINSTALL	Skip auto-adding the official marketplace (1 to disable)
CLAUDE_CODE_SYNC_PLUGIN_INSTALL	Wait for plugin install to complete before first query (1 to enable)
CLAUDE_CODE_SYNC_PLUGIN_INSTALL_TIMEOUT_MS	Timeout in ms for synchronous plugin install
CLAUDE_CODE_SYNC_SKILLS	Set to 1 to wait for skill sync to complete before the first query, ensuring skills are up-to-date before the session starts
CLAUDE_CODE_SYNC_SKILLS_INSTALL_TIMEOUT_MS	Timeout in ms for the skill install phase of synchronous skill sync
CLAUDE_CODE_SYNC_SKILLS_WAIT_TIMEOUT_MS	Timeout in ms to wait for all skill syncs to complete when CLAUDE_CODE_SYNC_SKILLS=1
CLAUDE_CODE_PLUGIN_KEEP_MARKETPLACE_ON_FAILURE	Set to 1 to keep the existing marketplace cache when a git pull fails instead of wiping and re-cloning. Useful in offline or airgapped environments where re-cloning would fail the same way
CLAUDE_CODE_ENABLE_BACKGROUND_PLUGIN_REFRESH	Refresh plugin state at session turn boundaries after a background install completes (1 to enable). Without this, newly installed plugins take effect on the next session
CLAUDE_CODE_HIDE_ACCOUNT_INFO	Hide email/org info from UI (not in official docs — unverified)
CLAUDE_CODE_DISABLE_CRON	Disable scheduled/cron tasks (1 to disable)
DISABLE_INSTALLATION_CHECKS	Disable installation warnings
DISABLE_FEEDBACK_COMMAND	Disable the /feedback command. The older name DISABLE_BUG_COMMAND is also accepted
DISABLE_DOCTOR_COMMAND	Hide the /doctor command (1 to disable)
DISABLE_LOGIN_COMMAND	Hide the /login command (1 to disable)
DISABLE_LOGOUT_COMMAND	Hide the /logout command (1 to disable)
DISABLE_UPGRADE_COMMAND	Hide the /upgrade command (1 to disable)
DISABLE_EXTRA_USAGE_COMMAND	Hide the /extra-usage command — renamed to /usage-credits in v2.1.144, though this env var name is unchanged (1 to disable)
DISABLE_INSTALL_GITHUB_APP_COMMAND	Hide the /install-github-app command (1 to disable)
DISABLE_NON_ESSENTIAL_MODEL_CALLS	Disable flavor text and non-essential model calls (not in official docs — unverified)
CLAUDE_CODE_DEBUG_LOGS_DIR	Override debug log file path. Despite the name, this is a file path, not a directory. Requires debug mode enabled separately via --debug, /debug, or the DEBUG env var; setting this variable alone does not enable logging. Use --debug-file to both enable debug mode and set the path at once. Default: ~/.claude/debug/<session-id>.txt
CLAUDE_CODE_DEBUG_LOG_LEVEL	Minimum debug log level
CLAUDE_AUTO_BACKGROUND_TASKS	Force auto-backgrounding of long tasks (1 to enable)
CLAUDE_CODE_DISABLE_LEGACY_MODEL_REMAP	Prevent remapping Opus 4.0/4.1 to newer models (1 to disable)
FALLBACK_FOR_ALL_PRIMARY_MODELS	Trigger fallback model for all primary models, not just default (1 to enable)
CCR_FORCE_BUNDLE	Set to 1 to force claude --remote to bundle and upload your local repository even when GitHub access is available. Also configurable as a startup-only var — see CLI Startup Flags
CLAUDE_CODE_GIT_BASH_PATH	Windows only: path to the Git Bash executable (bash.exe). Use when Git Bash is installed but not in your PATH
DISABLE_COST_WARNINGS	Disable cost warning messages
CLAUDE_CODE_SUBAGENT_MODEL	Override model for subagents (e.g., haiku, sonnet)
CLAUDE_CODE_FORWARD_SUBAGENT_TEXT	Set to 1 to forward subagent streaming text output to the parent session in real time. By default, subagent output is buffered until the subagent completes. As of v2.1.219, forwarding also works for nested subagents at depth 2+ (v2.1.211)
CLAUDE_CODE_SUBPROCESS_ENV_SCRUB	Set to 1 to strip Anthropic and cloud provider credentials from subprocess environments (Bash tool, hooks, MCP stdio servers). Use for defense-in-depth when subprocesses should not inherit API keys (v2.1.83)
CLAUDE_CODE_SCRIPT_CAPS	JSON object limiting how many times specific scripts may be invoked per session when CLAUDE_CODE_SUBPROCESS_ENV_SCRUB is set. Keys are substrings matched against the command text; values are integer call limits. For example, {"deploy.sh": 2} allows deploy.sh to be called at most twice. Matching is substring-based; runtime fan-out via xargs or find -exec is not detected — this is a defense-in-depth control
CLAUDE_CODE_PERFORCE_MODE	Set to 1 to enable Perforce-aware write protection. When set, Edit, Write, and NotebookEdit fail with a p4 edit <file> hint if the target file lacks the owner-write bit, which Perforce clears on synced files until p4 edit opens them. Prevents Claude Code from bypassing Perforce change tracking (v2.1.98)
CLAUDE_CODE_PROCESS_WRAPPER	Wrap the Claude Code process at startup. Specify the wrapper executable and arguments; Claude Code is appended as the final argument. Useful for profiling tools, sandboxes, or tracing (e.g., CLAUDE_CODE_PROCESS_WRAPPER="strace -e trace=file"). (in v2.1.208 changelog, not yet on official env-vars page)
CLAUDE_CODE_MAX_RETRIES	Override API request retry count (default: 10)
CLAUDE_CODE_RETRY_WATCHDOG	Raise the retry count for non-capacity API errors to 300. The standard retry cap (CLAUDE_CODE_MAX_RETRIES, default: 10) still applies for capacity errors (v2.1.199)
CLAUDE_CODE_MAX_TOOL_USE_CONCURRENCY	Max parallel read-only tools (default: 10)
CLAUDE_CODE_MAX_WEB_SEARCHES_PER_SESSION	Maximum web searches allowed per session (default: 200). Prevents runaway tool use in long agentic sessions (in v2.1.212 changelog, not yet on official env-vars page)
CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSION	Maximum subagents that can be spawned per session (default: 200). Prevents resource exhaustion in deeply nested agentic workflows (in v2.1.212 changelog, not yet on official env-vars page)
CLAUDE_CODE_MAX_CONCURRENT_SUBAGENTS	Maximum number of subagents that run concurrently (default: 20). Limits parallel agent fan-out; excess agents queue and run as slots free up (v2.1.217)
CLAUDE_CODE_MAX_SUBAGENT_SPAWN_DEPTH	Maximum nesting depth for subagents (default: 3 as of v2.1.219). Subagents at the depth limit cannot spawn further subagents (v2.1.217)
CLAUDE_AGENT_SDK_DISABLE_BUILTIN_AGENTS	Disable built-in subagent types in SDK mode (1 to disable)
CLAUDE_AGENT_SDK_MCP_NO_PREFIX	Skip mcp__<server>__ prefix for MCP tools in SDK mode (1 to enable)
CLAUDE_ASYNC_AGENT_STALL_TIMEOUT_MS	Stall timeout in ms for background subagents (default: 600000 / 10 minutes). The subagent is killed if it produces no output for this duration
MCP_CONNECTION_NONBLOCKING	Set to true in -p mode to skip the MCP connection wait entirely. Bounds --mcp-config server connections at 5s instead of blocking on the slowest server (in v2.1.89 changelog, not yet on official env-vars page)
CLAUDE_CODE_MCP_AUTO_BACKGROUND_MS	Duration in milliseconds after which a slow MCP tool call is automatically backgrounded (default: 120000 / 2 minutes). MCP calls that exceed this threshold continue running in the background without blocking the agent turn (in v2.1.212 changelog, not yet on official env-vars page)
CLAUDE_CODE_MCP_TOOL_IDLE_TIMEOUT	Idle timeout in ms for MCP tool calls. The tool call is cancelled if it produces no streaming response within this window. Use when a gateway or MCP server hangs silently — distinct from MCP_TOOL_TIMEOUT, which is a total wall-clock limit (v2.1.187)
CLAUDE_CODE_SESSIONEND_HOOKS_TIMEOUT_MS	SessionEnd hook timeout in ms (replaces hard 1.5s limit)
CLAUDE_CODE_STOP_HOOK_BLOCK_CAP	Maximum number of times a Stop hook can block a session from ending (default: 8). After this many blocks the session ends regardless of hook exit codes
CLAUDE_CODE_DISABLE_FEEDBACK_SURVEY	Disable feedback survey prompts (1 to disable)
CLAUDE_CODE_ENABLE_FEEDBACK_SURVEY_FOR_OTEL	Set to 1 to route the session quality survey to your own OpenTelemetry collector when Anthropic-bound nonessential traffic is blocked. Survey ratings are emitted only as OTEL events to your configured collector — no survey data is sent to Anthropic. Applies when CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC, DISABLE_TELEMETRY, or DO_NOT_TRACK is set; has no effect otherwise. CLAUDE_CODE_DISABLE_FEEDBACK_SURVEY and the organization product feedback policy take precedence (v2.1.136)
CLAUDE_CODE_DISABLE_TERMINAL_TITLE	Disable terminal title updates (1 to disable)
CLAUDE_CODE_TMUX_TRUECOLOR	Set to 1 to allow 24-bit truecolor output inside tmux. By default, Claude Code clamps to 256 colors when $TMUX is set because tmux does not pass through truecolor escape sequences unless configured to. Set this after adding set -ga terminal-overrides ',*:Tc' to your ~/.tmux.conf
CLAUDE_CODE_NO_FLICKER	Set to 1 to enable flicker-free alt-screen rendering. Eliminates visual flicker during fullscreen redraws (v2.1.88)
CLAUDE_CODE_ALT_SCREEN_FULL_REPAINT	Set to 1 to repaint the entire screen on every frame in fullscreen rendering. Use when partial redraws produce visual artifacts in unusual terminal emulators
CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN	Set to 1 to disable fullscreen rendering and use the classic main-screen renderer. The conversation stays in your terminal's native scrollback so Cmd+f and tmux copy mode work as usual. Takes precedence over CLAUDE_CODE_NO_FLICKER and the tui setting. You can also switch with /tui default (v2.1.132)
CLAUDE_CODE_FORCE_SYNC_OUTPUT	Set to 1 to force-enable DEC private mode 2026 synchronized output when your terminal supports it but is not auto-detected. Useful for emulators such as Emacs eat that implement BSU/ESU but do not reply to the capability probe. Has no effect under tmux (v2.1.129)
CLAUDE_CODE_SCROLL_SPEED	Mouse wheel scroll multiplier for fullscreen rendering. Increase for faster scrolling, decrease for finer control
CLAUDE_CODE_DISABLE_VIRTUAL_SCROLL	Set to 1 to disable virtual scrolling in fullscreen rendering and render every message in the transcript. Use if scrolling in fullscreen mode shows blank regions where messages should appear
CLAUDE_CODE_DISABLE_MOUSE	Set to 1 to disable mouse tracking in fullscreen rendering. Useful when mouse events interfere with terminal multiplexers or accessibility tools
CLAUDE_CODE_DISABLE_MOUSE_CLICKS	Set to 1 to disable mouse click interactions in fullscreen rendering while preserving wheel scroll. Distinguishes click-event suppression from full mouse tracking disable (CLAUDE_CODE_DISABLE_MOUSE). Useful when terminal selection or external accessibility tools conflict with in-app mouse clicks (in v2.1.195 changelog, not yet on official env-vars page)
CLAUDE_CODE_HIDE_CWD	Set to 1 to hide the current working directory in the Claude Code startup logo banner. Useful in screen recordings, demos, or shared sessions where the CWD path leaks information about the host or project layout (v2.1.119)
CLAUDE_CODE_ACCESSIBILITY	Set to 1 to keep native terminal cursor visible for screen readers and accessibility tools
CLAUDE_AX_SCREEN_READER	Set to 1 to render screen-reader friendly output: flat text without decorative borders or animations. Set to 0 to force screen-reader mode off even when the axScreenReader setting is true. The --ax-screen-reader CLI flag takes precedence (v2.1.181+)
CLAUDE_CODE_NATIVE_CURSOR	Set to 1 to show the terminal's own cursor at the input caret position instead of Claude Code's custom cursor character
CLAUDE_CODE_SYNTAX_HIGHLIGHT	Set to 0 to disable syntax highlighting in diff output
CLAUDE_CODE_IDE_SKIP_AUTO_INSTALL	Skip automatic IDE extension installation (1 to skip)
CLAUDE_CODE_AUTO_CONNECT_IDE	Override auto IDE connection behavior
CLAUDE_CODE_IDE_HOST_OVERRIDE	Override IDE host address for connection
CLAUDE_CODE_IDE_SKIP_VALID_CHECK	Skip IDE lockfile validation (1 to skip)
CLAUDE_CODE_OTEL_HEADERS_HELPER_DEBOUNCE_MS	Debounce interval in ms for OTel headers helper script
CLAUDE_CODE_OTEL_FLUSH_TIMEOUT_MS	Timeout in ms for OpenTelemetry flush
CLAUDE_CODE_OTEL_SHUTDOWN_TIMEOUT_MS	Timeout in ms for OpenTelemetry shutdown
CLAUDE_ENABLE_BYTE_WATCHDOG	Set to 1 to force-enable the byte-level streaming idle watchdog, or 0 to force-disable it. When unset, the watchdog is enabled by default for Anthropic API connections. The byte watchdog aborts a connection when no bytes arrive on the wire for the duration set by CLAUDE_STREAM_IDLE_TIMEOUT_MS (minimum 5 minutes), independent of the event-level watchdog
CLAUDE_ENABLE_BYTE_WATCHDOG_BEDROCK	Set to 1 to enable the byte-level streaming idle watchdog specifically for Bedrock connections. By default the byte watchdog is not active on Bedrock. Pair with CLAUDE_STREAM_IDLE_TIMEOUT_MS to configure the timeout
CLAUDE_STREAM_IDLE_TIMEOUT_MS	Timeout in ms for the streaming idle watchdog. Two watchdogs apply: byte-level (default and minimum 300000 / 5 minutes, aborts when no bytes arrive on the wire) and event-level (default 90000 / 90 seconds, no minimum, aborts when no SSE events arrive). The byte watchdog is enabled by default for Anthropic API connections; control it via CLAUDE_ENABLE_BYTE_WATCHDOG. Increase the event timeout if long-running tools or slow networks cause premature timeout errors
OTEL_LOG_TOOL_DETAILS	Set to 1 to include tool_parameters in OpenTelemetry events. Omitted by default for privacy (v2.1.85)
CLAUDE_CODE_OTEL_CONTENT_MAX_LENGTH	Maximum content length in bytes for OpenTelemetry event payloads (default: 61440 / 60 KB). Truncates large tool inputs, outputs, or message bodies before emitting them as OTel events to prevent oversized payloads (in v2.1.214 changelog, not yet on official env-vars page)
OTEL_LOG_RAW_API_BODIES	Set to 1 to emit full API request and response bodies as OpenTelemetry log events. Omitted by default for privacy and payload size. Useful for debugging at a gateway or proxy (in v2.1.111 changelog, not yet on official env-vars page)
OTEL_RESOURCE_ATTRIBUTES	Comma-separated key=value pairs added as resource attributes on all OpenTelemetry metric data points emitted by Claude Code. Use to attach environment or deployment labels (e.g., environment=production,team=platform) that appear on every metric for filtering in your collector (v2.1.162)
OTEL_LOG_USER_PROMPTS	Set to 1 to include the user_system_prompt field in OpenTelemetry LLM request spans. Omitted by default for privacy — user prompts can contain sensitive data, so opt in only when you control the OTel collector and have policies in place (in v2.1.121 changelog, not yet on official env-vars page)
OTEL_LOG_ASSISTANT_RESPONSES	Set to 1 to include model response text in OpenTelemetry log events. Omitted by default for privacy and payload size. Use only when you control the OTel collector and have policies for handling model output (in v2.1.193 changelog, not yet on official env-vars page)
OTEL_EXPORTER_OTLP_ENDPOINT	OpenTelemetry collector endpoint URL for metrics and logs. See Monitoring
OTEL_EXPORTER_OTLP_HEADERS	OpenTelemetry exporter headers (Name=Value format, comma-separated) for authenticating with your collector
OTEL_LOG_TOOL_CONTENT	Set to 1 to emit full tool inputs and outputs as OpenTelemetry log events. Omitted by default for privacy
OTEL_METRICS_EXPORTER	OpenTelemetry metrics exporter type (e.g., otlp). See Monitoring
OTEL_TRACES_EXPORTER	OpenTelemetry traces exporter type (e.g., otlp). See Monitoring
OTEL_METRICS_INCLUDE_ENTRYPOINT	Set to 1 to include the session entry-point (e.g., interactive vs -p vs SDK) as a label on all OpenTelemetry metric data points. Useful for breaking down metrics by how Claude Code was invoked (v2.1.161)
OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT	Maximum length of OpenTelemetry attribute values in bytes. Attribute values exceeding this limit are truncated. Use to cap memory and payload size when emitting spans with large attribute values
OTEL_METRICS_INCLUDE_ACCOUNT_UUID	Set to 1 to include the authenticated account UUID as a label on all OpenTelemetry metric data points
OTEL_METRICS_INCLUDE_SESSION_ID	Set to 1 to include the session ID as a label on all OpenTelemetry metric data points
OTEL_METRICS_INCLUDE_VERSION	Set to 1 to include the Claude Code version as a label on all OpenTelemetry metric data points
OTEL_METRICS_INCLUDE_RESOURCE_ATTRIBUTES	Set to 1 to promote OTEL_RESOURCE_ATTRIBUTES key/value pairs onto every metric data point as dimensions
CLAUDE_CODE_OTEL_DIAG_STDERR	Set to 1 to emit OpenTelemetry SDK diagnostic output to stderr. Use to troubleshoot collector connectivity or exporter configuration issues
CLAUDE_CODE_FORK_SUBAGENT	Set to 1 to enable forked subagents on external builds (non-Anthropic-signed distributions). Forked subagents run in an isolated child process instead of sharing the main agent's context (in v2.1.117 changelog, not yet on official env-vars page)
CLAUDE_CODE_MCP_SERVER_NAME	Name of the MCP server, passed as an environment variable to headersHelper scripts so they can generate server-specific authentication headers (in v2.1.85 changelog, not yet on official env-vars page)
CLAUDE_CODE_MCP_SERVER_URL	URL of the MCP server, passed as an environment variable to headersHelper scripts alongside CLAUDE_CODE_MCP_SERVER_NAME (in v2.1.85 changelog, not yet on official env-vars page)
ANTHROPIC_DEFAULT_OPUS_MODEL	Override Opus model alias (e.g., claude-opus-4-6[1m])
ANTHROPIC_DEFAULT_OPUS_MODEL_NAME	Customize the Opus entry label in the /model picker when using a pinned model on Bedrock/Vertex/Foundry. Defaults to the model ID
ANTHROPIC_DEFAULT_OPUS_MODEL_DESCRIPTION	Customize the Opus entry description in the /model picker. Defaults to Custom model (<model-id>)
ANTHROPIC_DEFAULT_OPUS_MODEL_SUPPORTED_CAPABILITIES	Override capability detection for a pinned Opus model. Comma-separated values (e.g., effort,thinking). Required when the pinned model supports features the auto-detection cannot confirm
ANTHROPIC_DEFAULT_SONNET_MODEL	Override Sonnet model alias (e.g., claude-sonnet-4-6)
ANTHROPIC_DEFAULT_SONNET_MODEL_NAME	Customize the Sonnet entry label in the /model picker when using a pinned model on Bedrock/Vertex/Foundry. Defaults to the model ID
ANTHROPIC_DEFAULT_SONNET_MODEL_DESCRIPTION	Customize the Sonnet entry description in the /model picker. Defaults to Custom model (<model-id>)
ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES	Override capability detection for a pinned Sonnet model. Comma-separated values (e.g., effort,thinking). Required when the pinned model supports features the auto-detection cannot confirm
ANTHROPIC_DEFAULT_FABLE_MODEL	Override Fable model alias (e.g., claude-fable-5)
ANTHROPIC_DEFAULT_FABLE_MODEL_NAME	Customize the Fable entry label in the /model picker when using a pinned model on Bedrock/Vertex/Foundry. Defaults to the model ID
ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION	Customize the Fable entry description in the /model picker. Defaults to Custom model (<model-id>)
ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES	Override capability detection for a pinned Fable model. Comma-separated values (e.g., effort,thinking). Required when the pinned model supports features the auto-detection cannot confirm
MAX_THINKING_TOKENS	Maximum extended thinking tokens per response. Set to 0 to disable extended thinking entirely on the Anthropic API (equivalent to --thinking disabled). Applies only when using a fixed thinking budget — on adaptive thinking models (Opus 4.7+), the effort level controls thinking depth instead
CLAUDE_CODE_AUTO_COMPACT_WINDOW	Set the context capacity in tokens used for auto-compaction calculations. Defaults to the model's context window (200K standard, 1M for extended context models). Use a lower value (e.g., 500000) on a 1M model to treat it as 500K for compaction. Capped at actual context window. CLAUDE_AUTOCOMPACT_PCT_OVERRIDE is applied as a percentage of this value. Setting this decouples the compaction threshold from the status line's used_percentage
DISABLE_AUTO_COMPACT	Disable automatic context compaction (1 to disable). Manual /compact still works (not in official docs — unverified)
DISABLE_COMPACT	Disable all compaction — both automatic and manual (1 to disable)
CLAUDE_CODE_ENABLE_PROMPT_SUGGESTION	Enable prompt suggestions
CLAUDE_CODE_PLAN_MODE_REQUIRED	Require plan mode for sessions
CLAUDE_CODE_TEAM_NAME	Team name for agent teams
CLAUDE_CODE_TASK_LIST_ID	Task list ID for task integration
CLAUDE_ENV_FILE	Custom environment file path
FORCE_AUTOUPDATE_PLUGINS	Force plugin auto-updates (1 to enable)
HTTP_PROXY	HTTP proxy URL for network requests
HTTPS_PROXY	HTTPS proxy URL for network requests
NO_PROXY	Comma-separated list of hosts that bypass proxy
MCP_TOOL_TIMEOUT	MCP tool execution timeout in ms
MCP_CLIENT_SECRET	MCP OAuth client secret
MCP_OAUTH_CALLBACK_PORT	MCP OAuth callback port
IS_DEMO	Enable demo mode
SLASH_COMMAND_TOOL_CHAR_BUDGET	Character budget for slash command tool output
TASK_MAX_OUTPUT_LENGTH	Maximum output length in bytes for background task results. Results exceeding this limit are truncated
MAX_STRUCTURED_OUTPUT_RETRIES	Maximum number of retries when a structured output (schema-constrained tool call) fails validation. Default: 3
DEBUG	Set to claude:* or other debug namespaces to enable verbose debug logging. Equivalent to the --debug flag for most purposes
FORCE_HYPERLINK	Set to 1 to force OSC 8 hyperlink rendering even in terminals that did not explicitly advertise support. Use when your terminal supports hyperlinks but is not auto-detected
DISABLE_GROWTHBOOK	Set to 1 to disable the GrowthBook feature-flag client, preventing outbound calls to the feature-flag CDN. Useful in air-gapped or firewall-restricted environments
DISABLE_PROMPT_CACHING_FABLE	Set to 1 to disable prompt caching specifically for Fable model requests
CLAUDE_CODE_FORCE_STRIKETHROUGH	Set to 1 to force-enable strikethrough text rendering for deleted lines in diff output even in terminals that did not confirm support
CLAUDE_DISABLE_ADOPT	Set to 1 to prevent Claude Code from adopting an existing claude process that may be running in the same terminal. Used in environments where process adoption would cause unexpected behavior
CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS	Maximum time in ms to wait for a background task to produce output before printing a waiting indicator. Controls how long Claude Code waits silently before informing the user a background task is still running
CLAUDE_CODE_TEAM_TEARDOWN_PARK_TIMEOUT_MS	Timeout in ms for agent team teardown when parking teammates. Controls how long the lead agent waits for team members to complete their teardown before proceeding
CLAUDE_CODE_SIMPLE_SYSTEM_PROMPT	Custom system prompt to inject when running in --simple / CLAUDE_CODE_SIMPLE=1 mode
CLAUDE_CODE_ENABLE_APPEND_SUBAGENT_PROMPT	Set to 1 to append the parent's system prompt to each subagent's system prompt. When unset, subagents receive their own prompt only
CLAUDE_CODE_SKIP_FAST_MODE_ORG_CHECK	Set to 1 to skip the organization-level check that determines whether fast mode is available. Use in environments where the org status endpoint is unreachable and fast mode should always be treated as available
CLAUDE_CODE_USE_ANTHROPIC_AWS	Set to 1 to use Claude Platform on AWS for API requests. Requires ANTHROPIC_AWS_API_KEY and ANTHROPIC_AWS_WORKSPACE_ID
CLAUDE_CODE_SKIP_ANTHROPIC_AWS_AUTH	Set to 1 to skip authentication when using Claude Platform on AWS. Use in environments where credentials are injected externally
CLAUDE_CODE_SKIP_AWS_CRED_CACHE	Set to 1 to disable caching of AWS credentials. Forces a fresh credential resolution on every request. Useful when credentials rotate frequently
CLAUDE_CODE_USE_NATIVE_FILE_SEARCH	Set to 1 to use native OS file search for the Glob tool on macOS (Spotlight/mdfind) and Windows (Windows Search) instead of the built-in search. May be faster on large repos with native indexing configured
VERTEX_REGION_CLAUDE_3_5_HAIKU	Vertex AI region override for Claude 3.5 Haiku
VERTEX_REGION_CLAUDE_3_5_SONNET	Vertex AI region override for Claude 3.5 Sonnet
VERTEX_REGION_CLAUDE_3_7_SONNET	Vertex AI region override for Claude 3.7 Sonnet
VERTEX_REGION_CLAUDE_4_0_OPUS	Vertex AI region override for Claude 4.0 Opus
VERTEX_REGION_CLAUDE_4_0_SONNET	Vertex AI region override for Claude 4.0 Sonnet
VERTEX_REGION_CLAUDE_4_1_OPUS	Vertex AI region override for Claude 4.1 Opus
VERTEX_REGION_CLAUDE_4_5_OPUS	Vertex AI region override for Claude 4.5 Opus
VERTEX_REGION_CLAUDE_4_5_SONNET	Vertex AI region override for Claude 4.5 Sonnet
VERTEX_REGION_CLAUDE_4_6_OPUS	Vertex AI region override for Claude 4.6 Opus
VERTEX_REGION_CLAUDE_4_6_SONNET	Vertex AI region override for Claude 4.6 Sonnet
VERTEX_REGION_CLAUDE_4_7_OPUS	Vertex AI region override for Claude 4.7 Opus
VERTEX_REGION_CLAUDE_4_8_OPUS	Vertex AI region override for Claude 4.8 Opus
VERTEX_REGION_CLAUDE_5_OPUS	Vertex AI region override for Claude 5 Opus
VERTEX_REGION_CLAUDE_5_SONNET	Vertex AI region override for Claude 5 Sonnet
VERTEX_REGION_CLAUDE_FABLE_5	Vertex AI region override for Claude Fable 5
VERTEX_REGION_CLAUDE_HAIKU_4_5	Vertex AI region override for Claude Haiku 4.5
CLAUDE_BYTE_STREAM_IDLE_TIMEOUT_MS	Timeout in milliseconds for the byte-level streaming idle watchdog before aborting a stalled connection. Applies when CLAUDE_ENABLE_BYTE_WATCHDOG is active. Minimum: 300,000 (5 minutes)
CLAUDE_CODE_DISABLE_ADMIN_ENV_UNION	Set to 1 to disable the per-key union behavior for env across multiple admin-controlled managed sources. When set, only the env block from the winning managed source is used (v2.1.223)
CLAUDE_CODE_ENABLE_OPUS_4_7_FAST_MODE	Set to 1 to enable fast mode on Opus 4.7. By default fast mode is not available on Opus 4.7 because its default effort (xhigh) differs from the fast-mode model tier
MCP_DISCOVERY_CACHE	Path to a local cache file for MCP server discovery results. When set, Claude Code reads discovery results from this file instead of querying the discovery endpoint on startup, reducing latency in environments with many MCP servers
USE_BUILTIN_RIPGREP	Set to 1 to use Claude Code's bundled ripgrep binary for the Grep tool instead of any rg found on PATH. Useful when the system rg version is incompatible or not installed. Also configurable as a startup-only var — see CLI Startup Flags
ANTHROPIC_BEDROCK_REGION_PREFIX	Region prefix for Bedrock cross-region inference profile IDs. When set, Claude Code prepends this value to Bedrock model IDs to construct cross-region inference profile ARNs automatically (v2.1.224) (in v2.1.224 changelog; not yet on official env-vars page)

---

Useful Commands

Command	Description
/model	Switch models and adjust effort level (Opus 4.7 and 4.8)
/effort	Set effort level directly: low, medium, high, xhigh (Fable 5, Opus 5, Sonnet 5, Opus 4.7, 4.8), max (session-only; available on all effort-supporting models), or ultracode (session-only; enables ultracode workflow, v2.1.203+) (v2.1.76+)
/config	Interactive configuration UI; also accepts key=value syntax for prompt-based settings: /config model=sonnet (v2.1.181)
/autocompact	Set the auto-compact window size in tokens. Writes autoCompactWindow to user settings. Use --autocompact <tokens> CLI flag for the same effect per-session (v2.1.221+)
/memory	View/edit all memory files
/agents	Manage subagents
/mcp	Manage MCP servers
/hooks	View configured hooks
/plugin	Manage plugins
claude plugin tag	Tag a plugin version in a marketplace for distribution. Run from the marketplace repo with the plugin name and version (v2.1.118)
claude plugin prune	Remove plugins whose marketplace source is no longer present (e.g., marketplace deleted or extraKnownMarketplaces entry removed). Cleans up local cache and disables orphaned plugins (v2.1.121)
claude plugin details <plugin>	Show the plugin's component inventory (commands, agents, skills, hooks) and the per-session context-token cost it adds. Useful for auditing token spend before enabling a plugin in a managed environment (v2.1.139)
/keybindings	Configure custom keyboard shortcuts
/skills	View and manage skills
/permissions	View and manage permission rules
/usage-credits	View remaining usage credits and limits. Renamed from /extra-usage in v2.1.144 (the old name still works)
claude gateway	Manage Claude Gateway connections for organization-managed deployments. Requires forceLoginMethod: "gateway" in managed settings (v2.1.195)
claude auto-mode reset	Reset auto-mode classification for the current session. Prompts for confirmation; pass --yes to skip the prompt (v2.1.212)
/fork	Fork the current session context into a new isolated subagent session (v2.1.212)
/subtask	Launch an isolated subtask in a separate context. The subtask runs independently and results are returned when it completes (v2.1.212)
--doctor	Diagnose configuration issues
--debug	Debug mode with hook execution details

---

Quick Reference: Complete Example

{
  "$schema": "https://json.schemastore.org/claude-code-settings.json",
  "model": "sonnet",
  "advisorModel": "opus",
  "agent": "code-reviewer",
  "language": "english",
  "cleanupPeriodDays": 30,
  "autoUpdatesChannel": "stable",
  "alwaysThinkingEnabled": true,
  "showThinkingSummaries": true,
  "viewMode": "default",
  "tui": "fullscreen",
  "awaySummaryEnabled": false,
  "includeGitInstructions": true,
  "defaultShell": "bash",
  "plansDirectory": "./plans",
  "claudeMdExcludes": ["**/vendor/**/CLAUDE.md"],
  "effortLevel": "high",
  "autoCompactWindow": 800000,
  "skillListingMaxDescChars": 1536,
  "skillListingBudgetFraction": 0.01,
  "disableAgentView": false,
  "disableWorkflows": false,
  "workflowKeywordTriggerEnabled": true,
  "workflowSizeGuideline": "medium",
  "syntaxHighlightingDisabled": false,
  "emojiCompletionEnabled": true,

  "worktree": {
    "symlinkDirectories": ["node_modules"],
    "sparsePaths": ["packages/my-app", "shared/utils"],
    "baseRef": "fresh",
    "bgIsolation": "worktree"
  },

  "skillOverrides": {
    "legacy-context": "name-only",
    "deploy": "off"
  },

  "modelOverrides": {
    "claude-opus-4-6": "arn:aws:bedrock:us-east-1:123456789:inference-profile/anthropic.claude-opus-4-6-v1:0"
  },

  "autoMode": {
    "classifyAllShell": false,
    "environment": [
      "Source control: github.example.com/acme-corp and all repos under it",
      "Trusted internal domains: *.internal.example.com"
    ],
    "soft_deny": ["$defaults", "Never run terraform apply"],
    "hard_deny": ["Never run rm -rf on directories outside the project"]
  },

  "permissions": {
    "allow": [
      "Edit(*)",
      "Bash(npm run *)",
      "Bash(git *)",
      "WebFetch(domain:*)",
      "mcp__memory__*",
      "Agent(*)"
    ],
    "deny": [
      "Read(.env)",
      "Read(./secrets/**)"
    ],
    "additionalDirectories": ["../shared/"],
    "defaultMode": "acceptEdits"
  },

  "enableAllProjectMcpServers": true,

  "mcpServers": {
    "always-on-server": {
      "type": "http",
      "url": "https://mcp.example.com",
      "alwaysLoad": true
    }
  },

  "sshConfigs": [
    {
      "id": "dev-vm",
      "name": "Dev VM",
      "sshHost": "user@dev.example.com"
    }
  ],

  "sandbox": {
    "enabled": true,
    "excludedCommands": ["git", "docker"],
    "filesystem": {
      "denyRead": ["./secrets/"],
      "denyWrite": ["./.env"]
    }
  },

  "attribution": {
    "commit": "Generated with Claude Code",
    "pr": ""
  },
  "prUrlTemplate": "https://gitlab.example.com/{owner}/{repo}/-/merge_requests/{number}",

  "statusLine": {
    "type": "command",
    "command": "git branch --show-current"
  },

  "spinnerTipsEnabled": true,
  "spinnerTipsOverride": {
    "tips": ["Custom tip 1", "Custom tip 2"],
    "excludeDefault": false
  },
  "prefersReducedMotion": false,
  "preferredNotifChannel": "terminal_bell",

  "env": {
    "NODE_ENV": "development",
    "CLAUDE_CODE_EFFORT_LEVEL": "medium",
    "ANTHROPIC_BEDROCK_SERVICE_TIER": "priority"
  }
}

---

Sources

• Claude Code Settings Documentation
• Claude Code CLI Reference
• Claude Code Model Configuration
• Claude Code Status Line Reference
• Claude Code Environment Variables
• Claude Code Settings JSON Schema
• Claude Code Changelog
• Claude Code GitHub Settings Examples
• Claude Code Permissions Reference
• Claude Code Sandbox Reference