# Settings Best Practice

![Last Updated](https://img.shields.io/badge/Last_Updated-May%2012%2C%202026%2011%3A40%20PM%20PKT-white?style=flat&labelColor=555) ![Version](https://img.shields.io/badge/Claude_Code-v2.1.139-blue?style=flat&labelColor=555)<br>
[![Implemented](https://img.shields.io/badge/Implemented-2ea44f?style=flat)](../.claude/settings.json)

A comprehensive guide to all available configuration options in Claude Code's `settings.json` files. As of v2.1.139, Claude Code exposes **60+ settings** and **180+ environment variables** (use the `"env"` field in `settings.json` to avoid wrapper scripts).

<table width="100%">
<tr>
<td><a href="../">← Back to Claude Code Best Practice</a></td>
<td align="right"><img src="../!/claude-jumping.svg" alt="Claude" width="60" /></td>
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</table>

## Table of Contents

1. [Settings Hierarchy](#settings-hierarchy)
2. [Core Configuration](#core-configuration)
3. [Permissions](#permissions)
4. [Hooks](#hooks)
5. [MCP Servers](#mcp-servers)
6. [Sandbox](#sandbox)
7. [Plugins](#plugins)
8. [Model Configuration](#model-configuration)
9. [Display & UX](#display--ux)
10. [AWS & Cloud Credentials](#aws--cloud-credentials)
11. [Environment Variables](#environment-variables-via-env)
12. [Useful Commands](#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 is used; sources do not merge across tiers. Within the file-based tier, drop-in files and the base file are merged together.

> **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}` pointing at the helper binary. Only honored from MDM or a system `managed-settings.json` file (never from user/project settings). Helper output is merged into the managed tier on every startup. Requires v2.1.136+ |

**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.

---

## 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 the terminal tab title (v2.1.121) |
| `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 |
| `skipWebFetchPreflight` | boolean | `false` | Skip WebFetch blocklist check before fetching URLs *(in JSON schema, not on official settings page)* |
| `availableModels` | array | - | Restrict which models users can select via `/model`, `--model`, Config tool, or `ANTHROPIC_MODEL`. Does not affect the Default option. Example: `["sonnet", "haiku"]` |
| `fastModePerSessionOptIn` | boolean | `false` | Require users to opt in to fast mode each session |
| `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 Ctrl+O 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) |
| `skillOverrides` | string | - | Control automatic skill invocation behavior. Values: `"off"` (skills are not invoked at all), `"user-invocable-only"` (only skills the user explicitly invokes via `/skill-name` run; auto-discovery via skill descriptions is disabled), `"name-only"` (skills are matched by exact name only; description-based auto-discovery is disabled). Use to keep a tighter rein on which skills the model loads or runs (v2.1.129) |
| `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) |
| `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](https://code.claude.com/docs/en/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) |
| `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 |

**Example:**
```json
{
  "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 |

**Example:**
```json
{
  "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) |

**Example:**
```json
{
  "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 |
| `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:**
```json
{
  "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 `X-Api-Key` header) |
| `forceLoginMethod` | string | Restrict login to `"claudeai"` or `"console"` accounts |
| `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 |
| `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:**
```json
{
  "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:**
```json
{
  "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

```json
{
  "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. In Remote environments, only `acceptEdits` and `plan` are honored (v2.1.70+) |
| `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](https://code.claude.com/docs/en/permission-modes#eliminate-prompts-with-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 `$defaults` sentinel, v2.1.136) — all arrays of prose strings. **Not read from shared project settings** (`.claude/settings.json`) to prevent repo injection. Available in user, local, and managed settings. Setting `allow` or `soft_deny` **replaces** the entire default list for that section unless you include the literal string `"$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](https://code.claude.com/docs/en/permission-modes#eliminate-prompts-with-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 |
| `"acceptEdits"` | Auto-accept file edits without asking |
| `"dontAsk"` | Auto-denies tools unless pre-approved via `/permissions` or `permissions.allow` rules |
| `"bypassPermissions"` | Skip all permission checks (dangerous). Writes to protected paths (`.git`, `.claude`, `.vscode`, `.idea`, `.husky`) still prompt. As of v2.1.121, writes to `.claude/commands/`, `.claude/agents/`, `.claude/skills/`, and `.claude/worktrees/` are explicitly exempt from the protected-paths prompt because Claude routinely writes there when creating skills, subagents, and commands. **v2.1.126** further extends the exemption: writes to `.claude/`, `.git/`, `.vscode/`, and shell config files (e.g., `.bashrc`, `.zshrc`) no longer prompt under `--dangerously-skip-permissions`. Catastrophic removal commands still prompt as a safety net |
| `"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)` |
| `Read` | `Read(path pattern)` | `Read(.env)`, `Read(./secrets/**)` |
| `Edit` | `Edit(path pattern)` | `Edit(src/**)`, `Edit(*.ts)` |
| `Write` | `Write(path pattern)` | `Write(*.md)`, `Write(./docs/**)` |
| `NotebookEdit` | `NotebookEdit(pattern)` | `NotebookEdit(*)` |
| `WebFetch` | `WebFetch(domain:pattern)` | `WebFetch(domain:example.com)` |
| `WebSearch` | `WebSearch` | Global web search |
| `Task` | `Task(agent-name)` | `Task(Explore)`, `Task(my-agent)` |
| `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) |
| `MCP` | `mcp__server__tool` or `MCP(server:tool)` | `mcp__memory__*`, `MCP(github:*)` |

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

**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)` |

**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 legacy `:*` suffix syntax (e.g., `Bash(npm:*)`) is equivalent to ` *` but is deprecated

**Example:**
```json
{
  "permissions": {
    "allow": [
      "Edit(*)",
      "Write(*)",
      "Bash(npm run *)",
      "Bash(git *)",
      "WebFetch(domain:*)",
      "mcp__*"
    ],
    "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](https://github.com/shanraisshan/claude-code-hooks)** — Complete hook reference with sound notification system, all 25 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](https://code.claude.com/docs/en/hooks).

---

## MCP Servers

Configure Model Context Protocol servers for extended capabilities.

> **OAuth (v2.1.111):** MCP servers that authenticate via OAuth follow [RFC 9728](https://datatracker.ietf.org/doc/rfc9728/) 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 name (v2.1.128):** `workspace` is a reserved MCP server name. User-defined servers with this name are skipped at load time with a warning logged to the session log. Rename any pre-existing `workspace` server 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.

### MCP Settings

| Key | Type | Scope | Description |
|-----|------|-------|-------------|
| `enableAllProjectMcpServers` | boolean | Any | Auto-approve all `.mcp.json` servers |
| `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](https://code.claude.com/docs/en/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) |

### MCP Server Matching (Managed Settings)

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

### 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.

```json
{
  "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:**
```json
{
  "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.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.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](#tool-permission-syntax), 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. Takes precedence over `denyRead`. 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) |

**Example:**
```json
{
  "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` | array | Managed only | Allowlist of permitted marketplaces |
| `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 | Any | Per-plugin MCP server configs (keyed by `plugin@marketplace`) *(in JSON schema, not on official settings page)* |
| `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 |

**Marketplace source types:** `github`, `git`, `directory`, `hostPattern`, `settings`, `url`, `npm`, `file`. Use `source: 'settings'` to declare a small set of plugins inline without setting up a hosted marketplace repository.

**Example:**
```json
{
  "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 4.6) |
| `"opus"` | Latest Opus model (Claude Opus 4.6) |
| `"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 |

**Example:**
```json
{
  "model": "opus"
}
```

### 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"`, or `"xhigh"` (Opus 4.7 only, v2.1.111). Written automatically when you run `/effort low`, `/effort medium`, `/effort high`, or `/effort xhigh`. Supported on Opus 4.6, Sonnet 4.6, and Opus 4.7. Unsupported levels fall back to the highest supported level on the active model |
| `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:**
```json
{
  "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 |
|-------------|-------------|
| Max | Maximum reasoning depth, Opus 4.6 only |
| XHigh | Extended high reasoning depth, Opus 4.7 only (default on Opus 4.7 across all plans, v2.1.111) |
| High (default on Opus 4.6/Sonnet 4.6) | 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, and Opus 4.7 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) and made it the default effort level on Opus 4.7 across all plans. 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:

```json
{
  "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 |
| `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` |
| `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 | `"auto"` | How [agent team](https://code.claude.com/docs/en/agent-teams) teammates display: `"auto"` (picks split panes in tmux or iTerm2, in-process otherwise), `"in-process"`, or `"tmux"`. See [choose a display mode](https://code.claude.com/docs/en/agent-teams#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](https://code.claude.com/docs/en/terminal-config#get-a-terminal-bell-or-notification) |

### 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 | `true` | Include additional context about the external editor when available. Set to `false` to disable |

### 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` |

**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:**
```json
{
  "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

```json
{
  "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) |

**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](https://code.claude.com/docs/en/statusline).

| 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 |

### 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).

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

**Example:**
```json
{
  "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:**
```json
{
  "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:**
```json
{
  "otelHeadersHelper": "/bin/generate_otel_headers.sh"
}
```

---

## Environment Variables (via `env`)

Set environment variables for all Claude Code sessions.

```json
{
  "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_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](https://code.claude.com/docs/en/amazon-bedrock#use-the-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](https://code.claude.com/docs/en/amazon-bedrock#service-tiers) (v2.1.122) |
| `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 |
| `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](https://code.claude.com/docs/en/model-config#customize-pinned-model-display-and-capabilities) |
| `ANTHROPIC_MODEL` | Name of the model to use. Accepts aliases (`sonnet`, `opus`, `haiku`) or full model IDs. Overrides the `model` setting |
| `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 |
| `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_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) |
| `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](https://code.claude.com/docs/en/amazon-bedrock#use-the-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_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_REMOTE_CONTROL_SESSION_NAME_PREFIX` | Prefix for auto-generated Remote Control session names. Defaults to the machine hostname |
| `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](./claude-cli-startup-flags.md#environment-variables) |
| `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](https://code.claude.com/docs/en/setup#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) |
| `MCP_TIMEOUT` | MCP startup timeout in ms |
| `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) |
| `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` | Keep cwd between bash calls (`1` to enable) |
| `CLAUDE_CODE_DISABLE_BACKGROUND_TASKS` | Disable background tasks (`1` to disable) |
| `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` | Set to `true` to enable task tracking in non-interactive mode (`-p` flag). Tasks are on by default in interactive mode |
| `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-cli-startup-flags.md#environment-variables) |
| `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` | Disable 1M token context window (`1` to disable) |
| `CLAUDE_CODE_ACCOUNT_UUID` | Override account UUID for authentication |
| `CLAUDE_CODE_DISABLE_GIT_INSTRUCTIONS` | Disable git-related system prompt instructions |
| `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 only, 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-cli-startup-flags.md#environment-variables) |
| `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_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` | Abort stalled streams (`1` to enable) |
| `CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMING` | Enable fine-grained tool streaming (`1` to enable) |
| `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_RESUME_INTERRUPTED_TURN` | Auto-resume if previous session ended mid-turn (`1` to enable) |
| `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) |
| `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 |
| `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_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_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_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_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 (`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 directory path |
| `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-cli-startup-flags.md#environment-variables) |
| `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_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_MAX_RETRIES` | Override API request retry count (default: 10) |
| `CLAUDE_CODE_MAX_TOOL_USE_CONCURRENCY` | Max parallel read-only tools (default: 10) |
| `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) |
| `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_SESSIONEND_HOOKS_TIMEOUT_MS` | SessionEnd hook timeout in ms (replaces hard 1.5s limit) |
| `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_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_ALTERNATE_SCREEN` | Set to `1` to opt out of the alternate-screen (fullscreen) renderer entirely and use the classic scrollback renderer. Useful when terminal multiplexers, recording tools, or accessibility tooling do not handle the alt-screen buffer cleanly (v2.1.132) |
| `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_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_FORCE_SYNC_OUTPUT` | Set to `1` to force synchronous output flushing for Claude Code's writes to the terminal. Defaults to async/buffered output for performance. Use as a debugging aid when terminal output appears interleaved or out-of-order with subprocess output (v2.1.129) |
| `CLAUDE_CODE_PACKAGE_MANAGER_AUTO_UPDATE` | Control background package-manager-based auto-update checking for Claude Code. Set to `0` to disable the background check (Claude Code will not poll the package manager for newer versions); set to `1` (default) to keep the background check enabled. Independent of `DISABLE_AUTOUPDATER`, which gates the npm-registry auto-updater (v2.1.129) |
| `CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY` | Set to `1` to opt into fetching the available-models list from the configured LLM gateway (e.g., a corporate proxy in front of Bedrock/Vertex). When enabled, the `/model` picker is populated from the gateway's discovery endpoint instead of the built-in alias list. Use when your gateway exposes a curated subset of models the user should choose from (v2.1.129) |
| `CLAUDE_CODE_ENABLE_FEEDBACK_SURVEY_FOR_OTEL` | Set to `1` to re-enable the in-session quality survey for OpenTelemetry-enabled enterprises. The survey is suppressed by default when `OTEL_*` env vars or `feedbackSurveyRate` are configured to avoid leaking survey traffic into enterprise telemetry pipelines. Use when admins want sampled survey data despite an OTel deployment (v2.1.136) |
| `CLAUDE_CODE_ACCESSIBILITY` | Set to `1` to keep native terminal cursor visible for screen readers and accessibility tools |
| `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_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 *(in v2.1.85 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_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)* |
| `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 |
| `MAX_THINKING_TOKENS` | Maximum extended thinking tokens per response |
| `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 |
| `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 |
| `VERTEX_REGION_CLAUDE_3_5_HAIKU` | Vertex AI region override for Claude 3.5 Haiku |
| `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 |

---

## Useful Commands

| Command | Description |
|---------|-------------|
| `/model` | Switch models and adjust Opus 4.6 effort level |
| `/effort` | Set effort level directly: `low`, `medium`, `high`, `xhigh` (Opus 4.7 only, v2.1.111), or `max` (Opus 4.6 only) (v2.1.76+) |
| `/config` | Interactive configuration UI |
| `/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 |
| `--doctor` | Diagnose configuration issues |
| `--debug` | Debug mode with hook execution details |

---

## Quick Reference: Complete Example

```json
{
  "$schema": "https://json.schemastore.org/claude-code-settings.json",
  "model": "sonnet",
  "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",
  "effortLevel": "xhigh",

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

  "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": {
    "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(*)",
      "Write(*)",
      "Bash(npm run *)",
      "Bash(git *)",
      "WebFetch(domain:*)",
      "mcp__*",
      "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](https://code.claude.com/docs/en/settings)
- [Claude Code Settings JSON Schema](https://json.schemastore.org/claude-code-settings.json)
- [Claude Code Changelog](https://github.com/anthropics/claude-code/blob/main/CHANGELOG.md)
- [Claude Code GitHub Settings Examples](https://github.com/feiskyer/claude-code-settings)
- [Shipyard - Claude Code CLI Cheatsheet](https://shipyard.build/blog/claude-code-cheat-sheet/)
- [Claude Code Environment Variables Reference](https://code.claude.com/docs/en/env-vars)
- [Claude Code Permissions Reference](https://code.claude.com/docs/en/permissions)
