OpenCut/project-management/04-cloud-sync-projects-and-assets.md

Cloud Sync for Projects and Assets

Goal

Provide reliable sync of project state and media assets across devices/accounts.

User Stories

• As a logged-in user, I want my projects available on another device.
• As a user, I want large media files to upload reliably and resume when interrupted.
• As a user, I want local edits to sync automatically without losing data.

Scope

• Sync project JSON snapshots to backend storage.
• Sync media assets to object storage.
• Add conflict handling and sync status UI.
• Keep offline-first local save as primary immediate write path.

Data Model (Proposed)

• projects table: id, user_id, name, project_json, version, timestamps.
• project_media table: project_id, asset_id, storage_key, checksum, size, mime, timestamps.

Technical Plan

1. Backend API

• GET /api/projects
• GET /api/projects/:id
• PUT /api/projects/:id (optimistic concurrency)
• POST /api/projects/:id/media/presign

2. Client Sync Service

• Hook into existing autosave flow after local save success.
• Queue sync tasks (project snapshot, then missing media uploads).
• Retry with backoff when offline/errors occur.

3. Upload Strategy

• Use presigned multipart uploads for large files.
• Track checksum to avoid re-upload unchanged assets.

4. Conflict Strategy (v1)

• Version-based conflict detect.
• If conflict, fetch latest and prompt user to choose local or remote.

Acceptance Criteria

• Logged-in user can create project on device A and open on device B.
• Media assets referenced by timeline are available after sync completes.
• Failed uploads retry automatically and expose status.
• No loss of local data when cloud is unavailable.

Risks and Mitigations

• Risk: Cost and latency for large asset storage.
• Mitigation: Incremental uploads, dedupe by checksum, optional upload limits.
• Risk: Conflict complexity.
• Mitigation: Start with simple version conflict policy before merge logic.

Deliverables

• DB schema migrations and API endpoints.
• Client cloud sync manager integrated with save lifecycle.
• Sync status indicators and error recovery UX.