garrytan/gstack/freeze

/freeze — Restrict Edits to a Directory

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

GSTACK_STATE_ROOT=$(~/.claude/skills/gstack/bin/gstack-paths --get GSTACK_STATE_ROOT); : "${GSTACK_STATE_ROOT:?gstack-paths failed; reinstall with ./setup or /gstack-upgrade}"
mkdir -p "$GSTACK_STATE_ROOT"/analytics
echo '{"skill":"freeze","ts":"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'","repo":"'$(basename "$(git rev-parse --show-toplevel 2>/dev/null)" 2>/dev/null || echo "unknown")'"}'  >> "$GSTACK_STATE_ROOT"/analytics/skill-usage.jsonl 2>/dev/null || true

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:

Set the user-selected boundary with the shared state writer. It resolves the physical absolute path and serializes replacement with investigation cleanup:

bash "$HOME/.claude/skills/gstack/freeze/bin/freeze-state.sh" set "<user-provided-path>"

Only report success if the helper succeeds. On FREEZE_BUSY or unexpected state, preserve it and ask the user to inspect recovery after any active writer finishes; never write or delete the state file directly.

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

How it works

The hook reads file_path from the Edit/Write tool input JSON, or notebook_path from a NotebookEdit (Jupyter notebook) call (shared real-JSON extractor with /careful — one copy, sourced by both hooks), then checks whether the path starts with the freeze directory. If not, it returns a hookSpecificOutput payload with permissionDecision: "deny" to block the operation (nested under hookSpecificOutput — Claude Code ignores a top-level permissionDecision).

Polarity is fail-closed: a tool payload the hook cannot parse is DENIED, not allowed — a boundary that fails open is not a boundary. A payload that parses but has neither path field (a non-file tool) is allowed. A deny names the tool, the path field, the boundary and /unfreeze. The path is resolved before the check: ~, .. and relative paths, and symlinks at every depth, even through folders that do not exist yet. A path the hook cannot place (a symlink loop, a line break, a Windows drive-relative path, over 4096 characters) is denied.

The freeze boundary persists until explicitly removed via the state file. The hook script reads it on every Edit/Write/NotebookEdit invocation. Boundaries containing spaces are supported.

Notes

• The trailing / on the freeze directory prevents /src from matching /src-old
• Freeze applies to Edit, Write and NotebookEdit only — Read, Bash, PowerShell, Glob, Grep are unaffected
• This prevents accidental edits, not a security boundary — Bash or PowerShell commands like sed or Set-Content can still modify files outside the boundary
• To deactivate, run /unfreeze; ending or killing a conversation does not remove persisted state