Sell exact or buy exact

Fix the amount you sell, or the amount you buy. Venues quote the other side.

Every quote request fixes one side of the trade with exactly one amount: sellAmount or buyAmount. Each venue quotes the other side.

You send	It is	Each quote states	Quotes are sorted by default
sellAmount	What you sell, in units of sell.asset	buy.amount, what you would buy	Most bought first, by netReceived
buyAmount	What you buy, in units of buy.asset	sell.amount, what you would sell	Least sold first

The amount is a positive decimal string in Asset units: "10" is ten USDC and "0.001" is a thousandth of an ETH, never base units. Send it as a string so no digits are lost. Send one of the two: a body with both, or with neither, is refused with 400 INVALID_REQUEST.

How amounts are read

• A venue may price a slightly smaller amount than you sent, rounded down to the precision it trades in. The quote states the amount it actually used: a request to sell "100" can come back with sell.amount of "99.99994".
• buy.amount is what lands at deliverTo after every fee the quote includes. netReceived also subtracts fees you pay separately, such as a network fee, so you can compare quotes fairly. It reads {"kind": "unavailable", "reason": ...} when a fee could not be read, never 0.
• With sort: "eta", quotes are ordered by expected time to delivery instead.

Sell exact

cURL

# Sell exactly `amount` of the sell asset. Each quote states what you would buy.
request=$(jq -nc --arg sell "$sell" --arg buy "$buy" --arg amount "$amount" '{
  sell: {asset: $sell},
  buy: {asset: $buy},
  sellAmount: $amount
}')
sell_exact=$(quote_request "$request")
jq -c '.quotes[] | {venue: .legs[0].venue.id, location: .location.kind,
  firm, sell: .sell.amount, buy: .buy.amount, expiresAt}' <<<"$sell_exact" >&2

Buy exact

cURL

# Buy exactly `buy_amount` of the buy asset. Each quote states what you would sell.
# A venue that only prices the amount you sell is listed in sources as unsupported.
request=$(jq -nc --arg sell "$sell" --arg buy "$buy" --arg amount "$buy_amount" '{
  sell: {asset: $sell},
  buy: {asset: $buy},
  buyAmount: $amount
}')
buy_exact=$(quote_request "$request")
jq -c '.quotes[] | {venue: .legs[0].venue.id, sell: .sell.amount, buy: .buy.amount}' <<<"$buy_exact" >&2
jq -c '[.sources[] | select(.status == "unsupported") | {venue: .venue.id, reason}]' <<<"$buy_exact" >&2

Not every venue can quote a fixed buy amount. A venue that only prices the amount you sell is listed in sources with the token buyAmountUnsupported, and is not asked. An on-chain protocol or bridge shows it as an unsupported row with the token in reason:

{ "status": "unsupported", "venue": { "id": "...", "modality": "bridge" }, "asked": false, "reason": "buyAmountUnsupported", "detail": null }

A venue you trade through your own exchange or OTC account can show the same limit as a filteredOut row, with the token in detail. An on-chain venue that cannot deliver an exact amount uses exactOutputDeliveryUnsupported. Check both reason and detail for these tokens.

In practice, on-chain protocols, bridges and some exchanges quote only the amount you sell, so a buy-exact search usually returns fewer quotes. When no venue can quote it, you get an empty quotes list and every venue’s reason in sources. Send sellAmount instead, sized from a price.

On GET /api/v1/prices, the same limit uses the same buyAmountUnsupported reason on an unsupported row.

What filters do to venues

Which amount you fix excludes no venue by itself: a venue that cannot serve it reads unsupported, as above. Venues your filters exclude read filteredOut and are not asked.

Refusals

Code	Why	What to do
INVALID_AMOUNT	sellAmount or buyAmount is not a positive decimal: zero, negative or not a number.	Send a positive decimal string such as "10".
INVALID_REQUEST	The body has both sellAmount and buyAmount, or neither, or the amount is not a string. message names the field.	Send exactly one amount, as a string.

In the app

On the Trade page, choose in the trade ticket whether the amount you type is the amount you sell or the amount you buy.