Amounts & Precision

Money is a decimal string

Every monetary value in a request or a response is a string in the asset's major units:

{"amount": "100.50", "asset": "usd"}
{"amount": "99.000000", "asset": "usdc"}

Never a float, and never a smallest-unit integer. Two consequences for your code:

• Parse into a decimal type, not a double. Decimal in Python, BigDecimal in Java, a decimal library in JavaScript. Parsing "0.1" into a float and adding it three times is how reconciliation jobs start disagreeing with the ledger.
• Send strings. A JSON number is accepted where the value is unambiguous, but a string is what round-trips exactly.

Trailing zeros in a response carry meaning: they show the asset's precision. "99.000000" is USDC at its six decimals, not a formatting accident.

Precision per asset

Decimals are the issuer's, and identical on every chain we deliver the asset on. Sending a wallet-send amount finer than the asset's decimals returns 400 invalid_amount rather than rounding it silently. That is deliberate: we would rather refuse than move a different number than the one you asked for.

Rates are basis points

Every rate on the platform is in basis points, never percent.

This applies to partner_fee_bps, corridor bps and spread_bps, and every plan-level rate. There is no percent field anywhere in the API, so a value of 1 always means 0.01%, never 1%.

Exchange rates

exchange_rate on a conversion is target per source, before fees, frozen at execution:

delivered = (source_amount - netted_fees) x exchange_rate

Only fee lines with "collection": "realtime" are netted. Lines with "collection": "monthly" are metering for your invoice and did not reduce the delivery. On the standard plan our conversion fee is monthly, so deliveries go out whole.

The rate on a quote estimate is indicative. The rate on the conversion is the fact of record.

Rounding

• Fee amounts are rounded to the source asset's precision.
• On a target-based quote estimate, the source amount needed is rounded up, so the requested delivery is always achievable.
• The combined partner fee is capped so a delivered amount can never go negative.
• Gas amounts on wallet sends are priced at the native-token rate noted when the send executed, and never re-priced. A token price move before month end is never your FX gain or loss.

Identifiers

Object ids are opaque strings with a documented prefix (cus_, va_, wop_). Do not parse them, and do not assume a length: store them as strings of at least 40 characters. The prefix is stable and is the fastest way to tell in a log which object an id refers to. See Objects & Terminology for the full list.