A conversational transport switch must include the first outbound message

When inbound attribution depends on the latest accepted outbound record for the receiving provider, switching only the inbound webhook and reply sender creates an unreachable first-reply path. Move the initial guidance and follow-up sends through the same provider-scoped durable ledger before enabling inbound handling. Persist a submitting record before the one remote attempt, then bind provider acceptance or preserve an outcome-unknown state without automatic resend. Delivery callbacks may reconcile later, but they cannot replace the acceptance boundary.

Applies when: A bidirectional agent or campaign changes messaging providers while correlating replies from durable outbound evidence. Keywords: inbound reply attribution initial outbound provider ledger acceptance correlation