Double-entry posting engine¶
| ID | MOD-001 |
| System | SD01 |
| Repo | bank-core |
| Build status | Deployed |
| Deployed | Yes |
| Last commit | e2f9f6d2d84040afc886c30d86c606f440072543 |
Enforces balanced debit/credit pairs on every transaction. Rejects any posting that does not balance to zero. Atomically posts both legs in a single Postgres transaction.
See Architecture Epic for acceptance criteria.
Module dependencies¶
Depends on¶
| Module | Title | Required? | Contract | Reason |
|---|---|---|---|---|
| MOD-104 | AWS shared infrastructure bootstrap | Required | — | AWS shared infrastructure provisioned by MOD-104 (EventBridge buses, S3, KMS, Kinesis, Cognito) is required before this module can be deployed. |
| MOD-103 | Neon database platform bootstrap | Required | — | Neon database and schema provisioned by MOD-103 must exist before this module can read or write Postgres. |
Required by¶
| Module | Title | As | Contract |
|---|---|---|---|
| MOD-002 | Immutable transaction log | Hard dependency | — |
| MOD-003 | Real-time balance engine | Hard dependency | — |
| MOD-004 | Multi-currency ledger (NZD/AUD) | Hard dependency | — |
| MOD-005 | Daily accrual calculator | Hard dependency | — |
| MOD-007 | Account state machine | Hard dependency | — |
| MOD-008 | Dormancy & escheatment engine | Hard dependency | — |
| MOD-022 | Payment audit trail | Hard dependency | — |
| MOD-031 | ECL calculation & GL posting | Hard dependency | — |
| MOD-038 | Data quality & reconciliation monitor | Hard dependency | — |
| MOD-051 | Financial automation rules engine | Hard dependency | — |
| MOD-065 | Credit servicing & collections | Hard dependency | — |
| MOD-067 | Trade finance operations | Hard dependency | — |
| MOD-080 | Statutory financial reporting & ERP integration | Hard dependency | — |
| MOD-081 | Payment reconciliation engine | Optional enhancement | — |
| MOD-087 | Transaction enrichment engine | Hard dependency | — |
| MOD-101 | Wealth intelligence engine | Hard dependency | — |
| MOD-110 | Fee engine | Hard dependency | — |
| MOD-111 | Term deposit maturity engine | Hard dependency | — |
| MOD-112 | Amortisation schedule engine | Hard dependency | — |
| MOD-114 | Direct debit mandate management | Hard dependency | — |
| MOD-115 | Property security and LVR management | Hard dependency | — |
| MOD-116 | Mortgage servicing engine | Hard dependency | — |
| MOD-117 | Overdraft management engine | Hard dependency | — |
| MOD-118 | Member equity and share registry | Hard dependency | — |
| MOD-119 | BPAY payment integration | Hard dependency | — |
| MOD-120 | PayID and Osko integration | Hard dependency | — |
| MOD-121 | Construction loan drawdown engine | Hard dependency | — |
| MOD-122 | NZ faster payments and A2A integration | Hard dependency | — |
| MOD-123 | ATM network integration | Hard dependency | — |
| MOD-125 | Joint account management | Hard dependency | — |
| MOD-129 | Teller operations and branch cash management | Hard dependency | — |
| MOD-130 | Notice account management | Hard dependency | — |
| MOD-133 | Trust account management | Hard dependency | — |
| MOD-134 | Community account management | Hard dependency | — |
| MOD-135 | Batch payment and payroll file processing | Hard dependency | — |
| MOD-136 | BPAY biller registration and inbound BPAY | Hard dependency | — |
| MOD-137 | Agency banking adapter | Hard dependency | — |
| MOD-140 | Chart of accounts and GL configuration | Hard dependency | — |
| MOD-141 | Intra-bank transfer engine | Hard dependency | — |
| MOD-143 | Open Bank Resolution pre-positioning | Hard dependency | — |
| MOD-147 | Related party exposure monitor | Hard dependency | — |
| MOD-149 | Scam intelligence reporting & reimbursement | Hard dependency | — |
| MOD-152 | Climate risk assessment | Hard dependency | — |
| MOD-159 | Synthetic transaction engine | Hard dependency | — |
| MOD-160 | Cross-module acceptance suite | Optional enhancement | — |
| MOD-166 | Transaction category corrections | Hard dependency | — |
| MOD-167 | Credit card facility engine | Hard dependency | — |
Policies satisfied¶
| Policy | Title | Mode | How |
|---|---|---|---|
| CLQ-006 | Capital Disclosure & Reporting Policy | AUTO |
Every capital position is derived from posted ledger entries — no manual override path exists |
| REP-004 | Financial Statements Policy | AUTO |
Statutory P&L and balance sheet sourced directly from ledger — no manual restatement |
| PAY-001 | Payment Operations Policy | GATE |
Payment posting enforces settlement finality — entry is atomic and irreversible |
| CLQ-002 | Liquidity Risk Management Policy | CALC |
Intraday liquidity position calculated from real-time ledger balances |
| PAY-007 | Ledger Posting & Account Integrity Policy | LOG |
Every payment posting is recorded in the immutable ledger — provides the transaction record required for payment obligations and dispute resolution. |
| OPS-007 | Financial Processing Resilience & Idempotency Policy | LOG |
Double-entry ledger creates an immutable audit trail for every financial transaction — provides the primary evidence base for operational risk event reconstruction. |
Capabilities satisfied¶
(No capabilities mapped)
Part of SD01 — Core Banking Platform
Compiled 2026-05-22 from source/entities/modules/MOD-001.yaml