Multi-currency ledger (NZD/AUD)¶

Maintains separate currency ledgers per account and per nostro. FX conversion entries routed through internal FX nostro pair. See ADR-015.

Module dependencies¶

Module	Title	Required?	Contract	Reason
MOD-001	Double-entry posting engine	Required	—	Extends the posting engine to handle matched currency-pair entries and FX nostro postings.
MOD-002	Immutable transaction log	Required	—	Persists multi-currency ledger entries to the immutable transaction log.
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.

Module	Title	As	Contract
MOD-025	FX rate lock & conversion	Hard dependency	—
MOD-082	Nostro & FX treasury management	Hard dependency	—

Policy	Title	Mode	How
PAY-004	Cross-Border Payments & FX Policy	`LOG`	Every NZD/AUD conversion recorded as matched pair through FX nostro — full audit trail
CLQ-001	Capital Adequacy Policy	`CALC`	Capital ratios calculated against currency-adjusted RWA — multi-currency positions visible
AML-008	Cross-Border Transfer Reporting Policy	`AUTO`	Cross-border transfer flag applied automatically on NZD↔AUD conversions for CMIR/IFTI reporting
REP-002	Prudential Reporting Policy	`CALC`	Prudential returns include currency-split balance sheet sourced from ledger

(No capabilities mapped)

Part of SD01 — Core Banking Platform Compiled 2026-05-22 from source/entities/modules/MOD-004.yaml