You do not usually install this directly. It comes in with @moneolabs/wallet, @moneolabs/guard, or @moneolabs/trading. It is published on its own because the money type is useful without them.

Money

Amounts are integer counts of minor units in a bigint. There is no float anywhere in the arithmetic. A budget that drifts by a fraction of a cent every time it is checked is a budget that eventually lets something through.

import { parseMoney, addMoney, formatMoney, splitMoney } from "@moneolabs/core";

parseMoney("$1,234.56"); // USD, 123456 minor units
parseMoney("421.10 USDG"); // USDG, 6 decimals
parseMoney(250, "USD"); // a bare number needs an asset

formatMoney(addMoney(parseMoney("$0.10"), parseMoney("$0.20"))); // "$0.30", exactly

splitMoney(parseMoney("$100.00"), 3);
// ["$33.34", "$33.33", "$33.33"] - adds back to exactly $100.00

Precision you did not ask to lose is an error, not a rounding:

parseMoney("$0.001"); // throws: more precision than 2 decimal places allow
parseMoney("$0.1000"); // fine, trailing zeros carry no information

Scaling takes a rational, so percentages stay exact:

scaleMoney(parseMoney("$1,500.00"), 0.003); // "$4.50", via 3/1000
scaleMoney(parseMoney("$1,500.00"), 1n, 3n); // "$500.00"

Assets

USD, EUR, GBP, USDG, USDC, and ETH are built in with their real precision. Tokenized equities are not, because the list keeps changing, so register the ones you trade:

registerAsset({ symbol: "AAPL", decimals: 18 });
parseMoney("10.5 AAPL");

Clocks

Time is injected everywhere it matters, so tests do not wait for real windows.

const clock = manualClock(0);
clock.sleep(1000).then(() => console.log("woke"));
await clock.advance("2s"); // "woke"

advance() drains repeatedly rather than once. A woken task usually schedules another sleep, and with a big enough jump that new sleep can already be due.

Prices

Limits are in dollars, agents hold other things.

await valueInUsd(parseMoney("2 AAPL"), fixedPrices({ AAPL: 309.92 })); // $619.84
await valueInUsd(parseMoney("100 USDG"), peggedPrices); // $100.00, no lookup
await valueInUsd(parseMoney("1 AAPL"), peggedPrices); // throws

Refusing to guess is deliberate. A price silently assumed to be 1 is how a limit stops meaning anything.

Also here

parseDuration and formatDuration for windows like "1h30m". id() for prefixed, URL safe ids. fingerprint() and stableStringify() for content-addressing a config regardless of key order. MoneoError and friends, each carrying a stable code so agents act on codes rather than on message text.