Cloud Sync uploads your Nessie library to Nessie Cloud so it can be used outside the Mac where the data was first imported.
Nessie is local-first by default: your synced conversations, contexts, profile, and chats live on your Mac. Cloud Sync is the opt-in layer that makes that same library available to networked surfaces.
For the surface-by-surface mental model, see Local machines and Cloud Sync.
Cloud Sync enables:
- MCP — Claude, ChatGPT, and other MCP clients read from the cloud copy because they cannot access your Mac's local database directly
- Teams — shared sources are pulled into each teammate's library through Cloud Sync
- Managed skills — the Skills library lives in Cloud Sync so you can create, share, and install the same packages on every device. See Why manage skills on Nessie?
- Multi-device sync — your Nessie data can follow you across Macs and supported agent devices
- Headless agent access — API-key devices can sync and read the sources assigned to them
What gets synced:
- Contexts and folders
- Managed skills and skill bundles
- Synced conversation transcripts
- Profile sections
- Nessie chats
- Source graph metadata, including integration roots and team-shared resources
What does not get synced:
- Provider login credentials
- Browser session cookies
- Local app settings that only apply to one Mac
Security and privacy: Cloud Sync data is encrypted in transit and at rest using industry-standard infrastructure controls. Your provider credentials and browser sessions stay local to your Mac; Cloud Sync stores the Nessie data needed to make your library available from MCP, Teams, agents, and your other devices.
Cloud Sync is separate from Privacy Mode. Privacy Mode controls whether conversation content is shared with Nessie for product improvement. Cloud Sync controls whether your library is stored in Nessie Cloud so you can access it outside the original Mac. You can use Cloud Sync while staying in Privacy Mode; synced data is used to provide sync, MCP, Teams, and agent access, not to improve Nessie's systems.
