Unified sync should standardize account state and change delivery while preserving the different cursor, folder, label, and notification rules of Gmail, Microsoft Graph, and IMAP.
Expose stable account, thread, message, participant, attachment, and container resources. Keep a provider extension beside them so labels, Graph categories, IMAP flags, and native identifiers remain usable and diagnosable.
Let the product choose a time or message window, report pagination progress, and mark the account ready only after a coherent baseline is committed. A large mailbox should not block every other account.
Store Gmail history IDs, Graph delta links, and IMAP mailbox state as connector-owned cursors. Publish normalized changes only after the associated local data and next checkpoint are committed together.
Webhook and push delivery is a hint, not the database. Deduplicate by event identity, schedule reconciliation, retain tombstones long enough to propagate deletes, and rebuild from the provider when a cursor is invalid.
It means changes are normally detected soon after provider notification, with measured lag and a reconciliation fallback. It should not promise zero delay or perfect notification delivery.
Usually no. Expose a stable DewEngine checkpoint or event contract while retaining the opaque provider cursor internally for diagnostics and recovery.
Not yet. Gmail, Microsoft Graph, and IMAP/SMTP connectors are planned. This guide documents the intended architecture and the provider requirements a production release must satisfy.
DewEngine is in development. Real use cases decide what ships first.