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": "100.5", "currency": "usd"}

Never a float, and never a smallest-unit integer. Three 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 with a fractional part is refused with 422 invalid_parameter ("send amounts as strings"), because a JSON parser has already turned it into a float and lost digits. A JSON integer is exact and accepted. A request amount must be positive, with at most 38 digits and 18 decimal places.
• Amounts come back in plain notation with no trailing zeros. 7 USDC reads "7", half a dollar "0.5", zero "0". The same value reads the same in every response and webhook. Trailing zeros (or their absence) say nothing about the asset's precision: take that from the table below.
• Compare values, not strings. "10.50" in your request reads back as "10.5".

Precision per asset

Decimals are the issuer's, and identical on every chain we deliver the asset on. A wallet-send amount, or a quote estimate's target_amount, finer than the asset's decimals returns 400 invalid_amount rather than being rounded, so we never move a different number than the one you asked for.

Rates are basis points

Every rate is in basis points, never percent.

This applies to partner_fee_bps, corridor bps and spread_bps, and every plan-level rate. No fee or spread field is in percent, 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

Every rounding is explicit, and each one leans the same way for the same reason:

• Fee amounts are rounded half up to the cent.
• Delivered amounts are rounded down to the target asset's decimals, so we never deliver more than the rate and fees allow.
• exchange_rate carries 12 decimal places, rounded half up, and the delivery is priced with exactly the rate you see.
• On a target-based quote estimate, the source amount needed is rounded up, so the requested delivery is always achievable.
• total_cost_bps is a decimal string and may be fractional ("7.5").
• partner_fee_bps takes up to 3 decimal places (0 to 1000), and partner_fee_flat up to 2 (0 to 1000, in the account's currency).
• 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.