Claude Code Safe Mode: 5 Things Disabled + When to Use Over /clear (2026)

You upgrade to Claude Code v2.1.169. The first thing you notice is that your old /clear reflex no longer fixes everything. CLAUDE.md is stale, a plugin is shadowing a real command, your MCP server stopped responding, and a hook is silently rewriting every diff. Safe Mode is the kill switch you reach for when /clear only wipes the conversation but the problem lives in your config.

This guide covers the five things --safe-mode actually disables, exactly when to reach for it instead of /clear, and how to enable it in under 10 seconds on macOS, Windows, and WSL — with a triage workflow you can hand a teammate without explanation.

What You Can Do After Enabling Safe Mode (And What You Can’t)

Before you run the flag, know which problems it solves and which it leaves on the floor.

Decision in one sentence: if /clear does not fix it within one or two turns, reach for --safe-mode before you start uninstalling things.

Decision Frame: When to Use Safe Mode (and When NOT)

When to use

• Claude Code starts behaving differently after upgrading from v2.1.16x to 2.1.169 — the upgrade is the only variable, so cancel your customizations to confirm.
• A coworker reports “it works for me, breaks for you” — strip your CLAUDE.md and plugins, see if the bug survives.
• A plugin or MCP server installed in the last 24 hours starts blocking, throwing, or producing wrong tool output — isolate before you uninstall.
• Hooks are silently mutating tool calls and you are not sure which one — turn them all off in one shot.
• You inherit a workstation set up by someone else and want to see the “stock” CLI behavior before opting into anyone’s config.

When NOT to use

• You only need to wipe context — use /clear, do not relaunch.
• You only need to swap models — set ANTHROPIC_MODEL or use the model picker, not safe mode.
• You suspect a credential issue — safe mode does not touch ANTHROPIC_API_KEY or ANTHROPIC_BASE_URL; check those first.
• You want to disable one plugin out of five — edit your settings or the plugin directly; safe mode is all-or-nothing.
• You are mid-task with valuable conversation state — safe mode launches a fresh session, so any work-in-progress context is gone.

Stop rule

If safe mode reproduces the same bug as a normal launch, the problem is not in your customizations. Stop reading this guide, do not waste time pruning plugins, and start looking at the model, network, account, or upstream API.

What --safe-mode Disables: The Five Layers (Verbatim from v2.1.169)

The official v2.1.169 release notes describe the flag in one sentence: “start Claude Code with all customizations (CLAUDE.md, plugins, skills, hooks, MCP servers) disabled for troubleshooting.” Each of those five layers maps to a distinct failure mode.

What it does not disable: your API key, the configured base URL (so your ofox endpoint stays live), the model name in ANTHROPIC_MODEL, your conversation history file, your slash-command keybindings, or the trust dialog for the current project.

Layer 1: CLAUDE.md — the silent system prompt extender

CLAUDE.md is loaded from up to three locations on every session start: the project root, every parent directory walked toward /, and your global ~/.claude/CLAUDE.md. Whatever you write there is injected ahead of every user prompt. When safe mode is on, the model behaves as if none of those files exist. This is the first layer to suspect when “the same prompt produces different output today than yesterday” — someone (or you) likely added a new rule in CLAUDE.md that pulls behavior in an unexpected direction.

Layer 2: Plugins — the third-party extension surface

Plugins live in ~/.claude/plugins/ (or your configured plugin directory) and can register slash commands, intercept tool calls, expose new MCP servers, or modify the prompt. Safe mode skips the plugin loader entirely, which means a plugin that crashes on cold start, shadows a built-in command like /clear, or holds a Windows file lock will not appear at all. Plugin issues are the second most common “weird behavior after update” cause after CLAUDE.md.

Layer 3: Skills — both user-added and (optionally) bundled

User-added skills under ~/.claude/skills/ are disabled by safe mode automatically. Bundled skills, workflows, and built-in slash commands are not disabled by safe mode alone — they require the separate CLAUDE_CODE_DISABLE_BUNDLED_SKILLS=1 env var or disableBundledSkills: true setting (also new in v2.1.169). For most triage you want only safe mode; reach for the bundled-skills flag when you suspect a built-in skill is being chosen over your own logic.

Layer 4: Hooks — the silent tool-call mutators

Hooks fire on dozens of events — PreToolUse, PostToolUse, UserPromptSubmit, Stop, Notification, SessionStart, SessionEnd, PreCompact, SubagentStart/Stop, and more — covering tool calls, session lifecycle, and async events. A hook can rewrite the model’s tool input, block a tool from executing, swallow output, or just print extra chatter. They are the hardest layer to debug manually because their effect is silent and out-of-band. Safe mode disables every hook in one shot — usually the fastest way to confirm “is a hook eating my diffs?”

Layer 5: MCP servers — the longest-tail surface

MCP servers come from your settings file, --mcp-config flags, IDE-typed configs, and v2.1.169 enterprise-managed allowedMcpServers/deniedMcpServers policies. They can hang on cold start, collide on tool names, throw auth loops, or simply respond too slowly to be useful. Disabling all of them in one flag lets you ask “would this session work with zero MCP at all?” — a question that is otherwise expensive to answer because most users have between three and ten MCP servers configured.

System Requirements

• Claude Code ≥ v2.1.169 (June 8, 2026). Verify with claude --version. If you see 2.1.168 or below, upgrade first: npm install -g @anthropic-ai/claude-code for the npm install, or run the official installer.
• A terminal you can set env vars in: zsh, bash, fish, PowerShell, CMD, or WSL all work.
• Existing API credentials: ANTHROPIC_API_KEY (or your ofox-style key under the same name) must still be configured. Safe mode disables customizations, not auth.
• (Optional) Write access to your shell rc: if you want to persist the flag for a triage session, you will set CLAUDE_CODE_SAFE_MODE=1 in ~/.zshrc, ~/.bashrc, or PowerShell $PROFILE.

Step-by-Step: Enable Claude Code Safe Mode

Step 1: Confirm your version is v2.1.169 or newer

claude --version
# Expect: 2.1.169 (or higher)

If it returns an older version, run the upgrade matching how you installed it, then relaunch your terminal to make sure the new binary is on your PATH.

Step 2: Launch with the flag (one-shot)

macOS / Linux / WSL:

claude --safe-mode

Windows PowerShell:

claude --safe-mode

Windows CMD:

claude --safe-mode

The flag is the same everywhere; only the shell wrapping changes. The session that opens will skip every CLAUDE.md, plugin, skill, hook, and MCP server.

Step 3: (Alternative) Persist with the env var for a triage session

When you want every claude invocation in a shell to be safe — useful when you are debugging across multiple panes or repos:

macOS / Linux / WSL (bash, zsh):

export CLAUDE_CODE_SAFE_MODE=1
claude

Windows PowerShell:

$env:CLAUDE_CODE_SAFE_MODE = 1
claude

Windows CMD:

set CLAUDE_CODE_SAFE_MODE=1
claude

Verify the env var is live before you launch:

echo $CLAUDE_CODE_SAFE_MODE
# Expect: 1

Step 4: Confirm safe mode is active

Once in the session, type a prompt that should trigger a project rule from your CLAUDE.md. If the rule is ignored, safe mode is on. You can also list your loaded MCP servers — the list should be empty.

Step 5: Exit safe mode cleanly

For a one-shot launch, just /quit and start claude again without the flag.

For the env-var path, unset it before you relaunch:

# macOS / Linux / WSL
unset CLAUDE_CODE_SAFE_MODE

# PowerShell
Remove-Item Env:CLAUDE_CODE_SAFE_MODE

# CMD
set CLAUDE_CODE_SAFE_MODE=

Then check your rc files (~/.zshrc, ~/.bashrc, $PROFILE) for a stale export that would re-arm safe mode on the next shell. This is the single most common reason people report “Claude Code still ignores my CLAUDE.md” days after they thought they had turned safe mode off.

Step 6: The 3-step triage workflow

Once safe mode confirms the bug is in your customizations, narrow it down with a binary-search pattern instead of un-installing everything at once:

1. Relaunch normally, keep CLAUDE.md and plugins, manually disable hooks and MCP via settings. Reproduce? If yes, the culprit is in CLAUDE.md or a plugin — usually the larger and more recent layer.
2. Re-enable hooks, keep MCP off. Reproduce? If yes, the culprit is a hook. Disable hooks one at a time; v2.1.169 hooks are evaluated in load order, so disable the most recently added hook first.
3. Re-enable MCP servers one by one. The one that reintroduces the bug is your suspect. Restart the session between each MCP toggle — MCP servers cache their tool list at session start, so live toggling without a restart can give you a false negative.

You almost never need step 3 to finish — the bug usually surfaces by step 1 or 2. Step 3 only matters when you run many MCP servers, which is increasingly common in larger teams.

Step 7: Capture a clean repro for the bug tracker

After you have identified the offending layer, run safe mode one more time with the single offending file copied into place. This isolates the bug to one customization and gives you a tight repro to file. The repro should fit in two lines: “I added ~/.claude/plugins/foo/index.ts, with safe mode I get behavior A, with that plugin re-enabled I get behavior B.” This is the format the Claude Code maintainers respond to fastest.

Common Errors During Safe Mode Setup (and Fixes)

Team / Multi-Developer Configuration

Safe mode is the cleanest reproducibility primitive your team has when a bug report comes in. Wire it into your runbook.

Shared triage alias

Drop a one-liner into your team’s dotfiles repo so every engineer has the same entry point:

# ~/.zshrc or ~/.bashrc, committed to the team's dotfiles repo
alias claude-triage='CLAUDE_CODE_SAFE_MODE=1 claude'

When a teammate reports a Claude Code bug, the first request from the on-call is “run claude-triage, paste the repro.” That is one command, no context, no version drift.

Triage matrix

CI / scripts: don’t ship safe mode

--safe-mode is a diagnostic flag, not a deploy target. Do not add it to your CI invocations of claude -p or claude agents — you will silently lose your team’s CLAUDE.md, hooks, and any MCP integrations your CI relies on. If you suspect CI is hitting a customization bug, run safe mode locally to confirm, then patch the offending customization. A --safe-mode line in a CI YAML file is an outage waiting to happen — keep the flag where humans can see it.

Onboarding new hires

For day-one onboarding, give the new engineer a 5-minute exercise: run claude-triage, ask the same question they ask in normal mode, observe the difference. They walk away knowing what their team’s customizations actually do — instead of treating CLAUDE.md as magic that just happens.

Advanced: Pair Safe Mode with disableBundledSkills and /cd

v2.1.169 shipped three related controls, and they compose well.

--safe-mode + CLAUDE_CODE_DISABLE_BUNDLED_SKILLS=1

--safe-mode disables user-added skills under ~/.claude/skills/. To also hide the built-in / bundled skills, workflows, and built-in slash commands from the model, set CLAUDE_CODE_DISABLE_BUNDLED_SKILLS=1 (or disableBundledSkills: true in your settings). Combined, the model sees a CLI with nothing on top — useful when you want to compare “stock model behavior” against your customized behavior.

CLAUDE_CODE_SAFE_MODE=1 CLAUDE_CODE_DISABLE_BUNDLED_SKILLS=1 claude

Safe mode + /cd

v2.1.169 also added /cd to switch the session’s working directory without breaking the prompt cache mid-session. Combine the two when you triage across repos: launch with --safe-mode once, then /cd between repositories. You only pay the cold-start cost once and your triage stays on the same model context window.

Safe mode + an ofox-style upstream

If you route Claude Code through a multi-provider gateway like ofox — using ANTHROPIC_BASE_URL=https://api.ofox.ai/anthropic — safe mode keeps the routing intact while still neutralizing every local customization. That separation is the whole point: you can rule out local config without touching your upstream credentials. Safe mode is the one CLI flag that lets you ask “is it me or is it everything I added on top?” — and get an honest answer in under ten seconds.

For deeper config patterns once you are past triage, see the Claude Code ofox configuration guide, the Claude Code hooks, subagents, and skills guide, and the Claude Code safety guide for preventing accidental file deletion — all three lean on the customization layers safe mode disables.

Related Reading on Claude Code Setup

• For the broader CLI permission model, see the Claude Code token optimization guide — the customizations safe mode disables are the same ones that drive token cost.
• If you are still picking between CLIs, the Claude Code vs Codex vs Cursor vs DeepSeek TUI comparison lays out which has a comparable triage flag.
• For the “Go to Sleep” / model-stops bug that often gets confused with a customization failure, see the Claude “Go to Sleep” bug explainer — safe mode does not fix model-side issues.
• For multi-tool setups, the Cursor + Claude Code + Cline custom API setup guide shows how the same ANTHROPIC_BASE_URL pattern survives safe mode.

FAQ

See the FAQ block in the frontmatter for the eight questions and answers covered, including how --safe-mode differs from /clear, how to enable on Windows specifically, whether the flag changes which model is called, and how to exit cleanly.

Sources Checked for This Refresh

• Anthropic Claude Code v2.1.169 release notes — github.com/anthropics/claude-code/releases/tag/v2.1.169 (verified 2026-06-11)
• Claude Code official changelog — code.claude.com/docs/en/changelog (verified 2026-06-11)
• ofox.ai Anthropic-compatible endpoint reference — ofox.ai/docs (verified 2026-06-11)
• DevelopersIO v2.1.169 deep dive — dev.classmethod.jp/en/articles/20260609-cc-updates-v2-1-169/ (verified 2026-06-11)
• Anthropic engineering “How we built Claude Code auto mode” — anthropic.com/engineering/claude-code-auto-mode (verified 2026-06-11)