Two-Way Sync
Paired triggers and actions with loop prevention and last-write-wins semantics.
Two-way sync keeps records in step across two systems — a contact in HubSpot ↔ a contact in Salesforce, an order in Shopify ↔ an invoice in QuickBooks. A change on either side propagates to the other, without ping-ponging into an infinite loop.
When to ask for it
You ask Claude for a two-way sync when:
- You're keeping the same record in step across two systems, and either side can be the source of an update
- A one-way pipe wouldn't work because both sides change
You don't want it when:
- The flow is one-way (A pushes to B, B never pushes back)
- The two sides are different kinds of records (a contact on one side, a task on the other) — that's a one-way pipeline, not a sync
What you ask for
- "Build a two-way sync of contacts between HubSpot and Salesforce."
- "Two-way sync orders between Shopify and our internal database, picking webhooks where available."
Claude handles the constraints — picking trigger styles per side, preventing the infinite loop, deciding which side wins on simultaneous updates — without you having to specify any of it.
Hard constraint
Both sides must expose a "last modified" timestamp on the synced record. Without it, there's no way to tell which change came first when both sides update at once. If the vendor doesn't expose this, Claude will tell you a two-way sync isn't possible and offer one-way alternatives.