use-finance

RustUse is "Composable sets of primitive Rust utility crates for fellow crustaceans."

use-finance is a practical financial primitive set. It provides small, composable Rust primitives for money, currencies, amounts, ledgers, transactions, payments, receipts, invoices, bank accounts, routing numbers, IBANs, BICs, ACH metadata, reconciliation, and BAI2 banking file records.

use-finance is not a bank integration, payment processor, tax engine, accounting platform, financial advisor, exchange-rate service, market data provider, trading system, or database layer.

Boundary

Use use-finance for practical finance and accounting primitives: money, invoices, payments, receipts, ledgers, bank accounts, routing numbers, IBANs, BICs, conservative ACH metadata, reconciliation, and BAI2 banking files.

Use use-quant for quantitative finance and market-analysis primitives: bars, ticks, market prices, price series, returns, drawdowns, volatility, risk, factors, portfolio weights, and signals.

This workspace is intentionally offline and deterministic. It does not fetch exchange rates, connect to banks, call external APIs, run async runtimes, query databases, or model market trades.

Crates

Crate	Purpose
use-finance	Thin facade over the focused practical finance crates.
use-currency	Uppercase 3-letter currency code primitives.
use-amount	Decimal-safe scaled integer amounts without floating point.
use-money	Amounts paired with currencies and same-currency arithmetic.
use-ledger	Debit, credit, posting, journal entry, ledger entry, and balance primitives.
use-transaction	Generic financial transaction identifiers, dates, statuses, and directions.
use-payment	Payment references, methods, statuses, directions, and amounts.
use-receipt	Receipt numbers, receipt statuses, received timestamps, and applied amounts.
use-invoice	Invoice numbers, lines, statuses, due dates, totals, and balances due.
use-bank-account	Bank account numbers, masks, account types, and holder names.
use-routing-number	ABA routing number validation and formatting.
use-iban	IBAN validation, compact normalization, and grouped formatting.
use-bic	SWIFT/BIC-style bank identifier code validation.
use-ach	Conservative ACH/NACHA-oriented enums, identifiers, and entry metadata.
use-reconciliation	Deterministic reconciliation candidates, scores, results, and exceptions.
use-bai2	Initial BAI2 record parsing, validation, continuation handling, and normalized transactions.

Example

use use_finance::{ach, amount, bai2, bic, currency, iban, money, reconciliation, routing_number};

let usd = currency::CurrencyCode::new("USD")?;
let cents = amount::Amount::from_minor_units(12_345, 2)?;
let invoice_total = money::Money::new(cents, usd.clone());

let routing = routing_number::RoutingNumber::new("021000021")?;
assert_eq!(routing.as_str(), "021000021");

let iban = iban::Iban::new("GB82 WEST 1234 5698 7654 32")?;
let bic = bic::Bic::new("DEUTDEFF500")?;
let ach_entry = ach::AchEntry::new(
    ach::AchStandardEntryClass::Ppd,
    ach::AchTransactionCode::CheckingCredit,
    ach::AchTraceNumber::new("123456780000001")?,
    ach::AchCompanyId::new("1234567890")?,
    ach::AchIndividualId::new("EMPLOYEE001")?,
);

let records = bai2::parse_logical_records("16,475,12345,Z,bank-ref,customer-ref,invoice payment/\n")?;
let detail = bai2::TransactionDetailRecord::try_from(&records[0])?;
let normalized = bai2::NormalizedTransaction::from_detail(&detail)?;

let candidate = reconciliation::ReconciliationCandidate::new(
    "bank-ref",
    "invoice-1001",
    amount::Amount::zero(2)?,
    reconciliation::MatchScore::exact(),
)?;

assert_eq!(invoice_total.currency().as_str(), "USD");
assert_eq!(iban.country_code(), "GB");
assert_eq!(bic.country_code(), "DE");
assert_eq!(ach_entry.transaction_code().direction(), ach::AchEntryDirection::Credit);
assert_eq!(normalized.amount().minor_units(), 12_345);
assert_eq!(candidate.score(), reconciliation::MatchScore::exact());
# Ok::<(), Box<dyn std::error::Error>>(())

The example composes primitives that downstream crates can store, compare, serialize, or transform. It does not perform live reconciliation, fetch bank data, call payment APIs, or infer matches with machine learning.

License

Licensed under either of the following, at your option:

• Apache License, Version 2.0, in LICENSE-APACHE
• MIT license, in LICENSE-MIT