freeze

name	freeze
version	0.1.0
description	Restrict file edits to a specific directory for the session. Blocks Edit and Write outside the allowed path. Use when debugging to prevent accidentally "fixing" unrelated code, or when you want to scope changes to one module. Use when asked to "freeze", "restrict edits", "only edit this folder", or "lock down edits". (Nexus)
allowed-tools	["Bash","Read","AskUserQuestion"]
hooks	{"PreToolUse":[{"matcher":"Edit","hooks":[{"type":"command","command":"bash ${CLAUDE_SKILL_DIR}/../../../runtimes/hooks/freeze/bin/check-freeze.sh","statusMessage":"Checking freeze boundary..."}]},{"matcher":"Write","hooks":[{"type":"command","command":"bash ${CLAUDE_SKILL_DIR}/../../../runtimes/hooks/freeze/bin/check-freeze.sh","statusMessage":"Checking freeze boundary..."}]}]}

/freeze — Restrict Edits to a Directory

Overview

This skill creates a session edit boundary. It is a safety tool for reducing accidental scope creep, not a replacement for code review or shell discipline.

Lock file edits to a specific directory. Any Edit or Write operation targeting a file outside the allowed path will be blocked (not just warned).

Setup

Ask the user which directory to restrict edits to. Use AskUserQuestion:

• Question: "Which directory should I restrict edits to? Files outside this path will be blocked from editing."
• Text input (not multiple choice) — the user types a path.

Once the user provides a directory path:

1. Resolve it to an absolute path:

FREEZE_DIR=$(cd "<user-provided-path>" 2>/dev/null && pwd)
echo "$FREEZE_DIR"

2. Ensure trailing slash and save to the freeze state file:

FREEZE_DIR="${FREEZE_DIR%/}/"
STATE_DIR="${CLAUDE_PLUGIN_DATA:-$HOME/.nexus}"
mkdir -p "$STATE_DIR"
echo "$FREEZE_DIR" > "$STATE_DIR/freeze-dir.txt"
echo "Freeze boundary set: $FREEZE_DIR"

Tell the user: "Edits are now restricted to <path>/. Any Edit or Write outside this directory will be blocked. To change the boundary, run /freeze again. To remove it, run /unfreeze or end the session."

How it works

The hook reads file_path from the Edit/Write tool input JSON, then checks whether the path starts with the freeze directory. If not, it returns permissionDecision: "deny" to block the operation.

The freeze boundary persists for the session via the state file. The hook script reads it on every Edit/Write invocation.

Notes

• The trailing / on the freeze directory prevents /src from matching /src-old
• Freeze applies to Edit and Write tools only — Read, Bash, Glob, Grep are unaffected
• This prevents accidental edits, not a security boundary — Bash commands like sed can still modify files outside the boundary
• To deactivate, run /unfreeze or end the conversation

Output Contract

Report the absolute freeze boundary path and the active enforcement behavior:

• Edit and Write outside the boundary are blocked.
• Read/search/shell tools are not blocked by this skill.
• /unfreeze clears the boundary.

Do not claim freeze is active unless freeze-dir.txt was written successfully.

Verification Evidence

Verify by reading or echoing the saved state file after setup:

STATE_DIR="${CLAUDE_PLUGIN_DATA:-$HOME/.nexus}"
cat "$STATE_DIR/freeze-dir.txt"

The reported path must exactly match the absolute directory boundary with a trailing slash.