What happens to external side effects in Catalyst vs Temporal during workflow replay?

In both Catalyst and Temporal, replay does not automatically make external side effects exactly-once; idempotency and reconciliation remain the application's responsibility. Catalyst uses Dapr Workflows, which can leverage Dapr's state and pub/sub building blocks to manage side effects more consistently. Temporal relies on activities and workflow code to handle idempotency. Catalyst adds MCP tool authorization, which can help enforce policies on external tool calls during replay, but the core idempotency requirement is the same.