Cloud Sync

Synchronize ARC configuration across machines using a configurable storage backend. Cloud sync pushes and pulls config.json, shared layer content, and task data.

Quick Start

arc sync configure --provider filesystem --path /mnt/nas/arc-sync
arc sync push
arc sync pull
arc sync status

Sync Providers

ARC uses a SyncProvider interface with pluggable backends. The filesystem provider ships built-in; additional providers (S3, etc.) are planned.

Filesystem Provider

Works with any mounted path — NAS, Dropbox folder, USB drive, or a network share.

arc sync configure --provider filesystem --path ~/Dropbox/arc-sync
arc sync configure --provider filesystem --path /mnt/nas/arc-config

The filesystem provider uses:

• Atomic writes — temp file + rename to prevent corruption
• Mtime change detection — only syncs files that have actually changed
• Cursor tracking — remembers the last sync point for efficient deltas

What Gets Synced

Data	Synced
config.json	Profile registry, active profile, settings
shared/	Shared layer content (MCP servers, commands, CLAUDE.md)
tasks/	Task store
memory/	Persistent memory (if shared memory enabled)
Credentials	Never synced — stays local

WARNING

Credentials and API keys are never included in sync. Each machine maintains its own authentication state.

Conflict Resolution

Sync uses last-write-wins conflict resolution. When a conflict is detected, the newer version wins and the older version is logged to ~/.arc/sync-conflicts.json for manual review.

# Check for drift between local and remote
arc sync status

# View conflict log
cat ~/.arc/sync-conflicts.json

Shared Layer

The shared layer (~/.arc/shared/) is the primary mechanism for sharing configuration across profiles on the same machine. Cloud sync extends this to work across machines.

# Enable shared layer for a profile
arc shared enable work --memory --claude-md

# Sync shared content to all enabled profiles
arc shared sync

# Check what's shared and which profiles are enabled
arc shared status

How Shared Syncing Works

• MCP servers — shared keys merged into profile's settings.json, profile-specific keys win on conflict
• Commands — files from shared/commands/ copied into profile, existing files preserved
• CLAUDE.md — shared content wrapped in sentinel markers and prepended
• Memory/Projects — directories linked via Windows junction or Unix symlink

A manifest file (.arc-shared.json) tracks what was synced, enabling clean reversal and re-sync.

TUI Sync View

The TUI Sync view displays real shared layer state with keyboard-driven sync actions.

Key	Action
p	Pull — sync remote changes to local
P	Push — sync local changes to remote

The view shows the current sync status, last sync time, which profiles have the shared layer enabled, and any pending changes. Sync progress is displayed inline during pull and push operations.

Web Dashboard Sync Management

The Web Dashboard Sync view provides sync management through a browser interface:

• Status — real-time sync state, last sync time, and drift detection
• Pull — pull remote changes to the local machine
• Push — push local changes to the remote sync target
• Conflict log — view any sync conflicts pending resolution

All sync operations broadcast progress updates over WebSocket. Connected clients see pull/push status in real time.

TIP

Sync is fully managed from all three interfaces — CLI, TUI, and Web Dashboard. The TUI and Web views show the same real-time shared layer state.

SyncManager

The SyncManager wraps any SyncProvider with cursor tracking and status reporting:

interface SyncProvider {
  push(data: SyncDelta): Promise<void>;
  pull(cursor: string): Promise<SyncDelta>;
  status(): Promise<SyncStatus>;
}

Use arc sync status to see the last sync time and detect drift between local and remote state.