worktree-data-sync

name	worktree-data-sync
description	Sync non-git data between existing git worktrees. Supports seed, diff, and apply modes using explicit --from/--to endpoints. Does not create/remove worktrees or manage sandbox settings.
user-invocable	true

Worktree Data Sync Skill

Sync non-git files between existing git worktrees.

When to Use

Activate this skill when the request is about:

• comparing non-git files across worktrees
• copying managed data from one worktree into another
• reconciling non-git differences after parallel work

Do not use this skill for:

• creating/removing worktrees
• branch checkout/merge/switch logic
• sandbox permission setup

Command Surface

Single CLI entrypoint:

python3 <skill-dir>/scripts/sync_worktree_data.py --to <worktree-path> --mode <seed|diff|apply> [OPTIONS]

Replace <skill-dir> with the directory that contains this SKILL.md.

Endpoints

• --to is required (destination worktree)
• --from is optional (source worktree)
• when --from is omitted, source defaults to the main worktree
• both endpoints must be existing worktrees in the same repository

Modes

--mode seed

Materialize missing managed files in destination from source.

Rules:

• copies only missing files
• never overwrites existing destination files
• applies stateless managed-path discovery

Optional: --seed-sync-mode <auto|force-symlink|force-cow> (default: auto)

• auto: preserve current per-path behavior (symlink-only roots get symlinks, others get copies)
• force-symlink: create top-level symlinks for all managed roots when the destination path does not already exist; conflicting paths are skipped
• force-cow: copy/COW all managed roots, including symlink-only annotated paths

--seed-sync-mode is only valid with --mode seed; the CLI rejects it for other modes.

--mode diff

Report source-to-destination differences for managed files.

Statuses:

• new: exists in source but missing in destination
• modified: exists in both but differs
• unchanged: identical (only shown with --include-unmodified)

Output options:

• human-readable report (default)
• JSON report (--json), compatible with apply mode

--mode apply

Execute sync actions for selected changes.

Actions:

• --action overwrite: copy source file to destination path
• --action rename: copy source file to destination with suffix

Selection options:

• --from-json <file> from prior diff output
• --files <path...> for explicit relative paths
• omit both to auto-process current diff (new + modified)

No delete/discard action is provided.

Managed Path Discovery

Discovery is stateless and source-driven. Managed roots come from:

• gitignored paths via git ls-files --others --ignored --exclude-standard --directory
• tracked symlinks that resolve outside the repo
• top-level symlink safety net
• .gitignore symlink-only annotations

Annotate a path as symlink-only by adding a duplicate line with the tag comment:

Data/
Data/  # data-sync:symlink

The first line is the actual gitignore rule; the second is the annotation the discovery script parses. Legacy tag # worktree:symlink is also supported.

Symlink-only roots are symlinked in seed auto mode and excluded from diff/apply actions.

Examples

# Seed from main worktree into destination
python3 <skill-dir>/scripts/sync_worktree_data.py \
  --to ../MyRepo-feature \
  --mode seed

# Seed using top-level symlinks for all managed roots
python3 <skill-dir>/scripts/sync_worktree_data.py \
  --to ../MyRepo-feature \
  --mode seed \
  --seed-sync-mode force-symlink

# Seed using copy/COW for all managed roots (including symlink-only)
python3 <skill-dir>/scripts/sync_worktree_data.py \
  --to ../MyRepo-feature \
  --mode seed \
  --seed-sync-mode force-cow

# Diff explicit source -> destination
python3 <skill-dir>/scripts/sync_worktree_data.py \
  --from ../MyRepo-expA \
  --to ../MyRepo-expB \
  --mode diff --json

# Apply overwrite using diff json
python3 <skill-dir>/scripts/sync_worktree_data.py \
  --to ../MyRepo-expB \
  --mode apply \
  --from-json /tmp/changes.json \
  --action overwrite

# Apply rename for explicit files
python3 <skill-dir>/scripts/sync_worktree_data.py \
  --from ../MyRepo-expA \
  --to ../MyRepo-expB \
  --mode apply \
  --files output/result.csv notes/draft.md \
  --action rename \
  --suffix _from_expA