• ZDR uses 1 bridge account for all transfers
• ZDR initiates BOTH ACH legs
• Redis locks funds during transfer
• If Tx2 fails → ZDR refunds Tx1
• Net: ZDR bridge holds <1ms, money moved in <5 seconds
Why ZDR works
• Atomic Settlement: All‑or‑nothing state change in Redis (debit A, credit B or nothing). Pending locks hold value during bridge legs.
• Atomic Movement: Movement fires during settlement; if Leg 2 fails before FINAL, ZDR atomically refunds Leg 1 and releases the lock.
Why it's new
• Rail, not middleware: Verification (Plaid) + atomic state (Redis) + programmatic ACH legs → one finality contract.
• Zero dead float: FINAL or REJECTED with audit trail.
• Composable legs: Swap ACH for RTP/wire/SEPA; atomic semantics unchanged.
Fees
• Preset: Per‑leg/rail fees (flat/bps) debited atomically alongside the move.
• Manual: Post‑assess/waive via adjustment tied to FINAL tx.
Savings on float
• Float eliminated: Hours–days of float collapse to a <1ms in‑memory lock and deterministic refund.
• Millions per year: Less funding cost, reserves, overdrafts, write‑offs.