FX rate lock & conversion¶

Locks a customer rate for 30–60 seconds. On confirmation, posts both legs atomically through the FX nostro. See ADR-015.

Module dependencies¶

Module	Title	Required?	Contract	Reason
MOD-004	Multi-currency ledger (NZD/AUD)	Required	—	Posts FX conversion entries through the multi-currency ledger to maintain accurate per-currency balances.
MOD-085	Market rates ingestion & normalisation	Required	—	Requires live FX spot rates from the market rates ingestion module to price and lock conversions.
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-144	Confirmation of payee — account name verification	Hard dependency	—
MOD-145	Payment hold & friction engine	Hard dependency	—

Policy	Title	Mode	How
PAY-004	Cross-Border Payments & FX Policy	`LOG`	FX rate applied to each conversion is locked and recorded — no post-hoc rate adjustment possible
CON-005	Fee & Pricing Transparency Policy	`GATE`	Spread disclosed to customer before confirmation — system enforces pre-disclosure not post-disclosure
CLQ-004	Interest Rate Risk in the Banking Book (IRRBB) Policy	`CALC`	FX position updated on each conversion — IRRBB and FX risk exposure current at all times

Capability	Title	Mode	How
CAP-003	Multi-currency wallet (USD, EUR, GBP, SGD, JPY)	`AUTO`	Converts between wallet currencies at live rates, maintaining accurate sub-balances per currency in the multi-currency wallet.
CAP-006	Foreign exchange — live rates, rate lock	`AUTO`	Locks the exchange rate for up to 24 hours so the customer knows the exact settlement amount before confirming.
CAP-043	Transparent FX markup display	`AUTO`	Exposes the FX margin applied to each conversion so customers can see the full cost before accepting a rate.

Part of SD04 — Payments Processing Platform Compiled 2026-05-22 from source/entities/modules/MOD-025.yaml