The fee asset defines which asset is charged for an order fill. It is independent from order side, execution type, and sizing, although those choices determine which combinations are valid.
FeeAsset values
| Value | Behavior |
|---|---|
FEE_ASSET_UNSPECIFIED | Uses the default quote-denominated behavior |
QUOTE | Charges the fee in quote |
BASE | Deducts the fee from base received; valid only for BUY orders |
SELL fees are always quote-denominated. A SELL request with BASE is rejected rather than
rewritten.
BUY behavior
For an exact-base BUY with QUOTE, the submitted base quantity remains the gross and net base
quantity before any other adjustments. The account must fund trade notional plus the quote fee.
For an exact-base BUY with BASE, the gross base quantity is submitted for execution and the fee
reduces the net base amount received.
For a quote-budget BUY with QUOTE, the fee counts toward the maximum quote debit. For a
quote-budget BUY with BASE, the quote ceiling limits trade debit while the base fee reduces net
base received. See Order Sizing.
Decode fee values
Use the companion fee_asset field whenever a response contains fee_scaled:
| Fee asset | Scale |
|---|---|
QUOTE or FEE_ASSET_UNSPECIFIED | Pair quote_quantity_scale |
BASE | Pair base_quantity_scale |
Do not decode fee fields from the order side alone. Preserve the explicit denomination returned by the server.
Error handling
An unsupported combination returns the stable order error ERROR_CODE_FEE_ASSET_NOT_ALLOWED. Do not silently convert an invalid BASE request to QUOTE.
Preview Order validates whether the selected fee asset is allowed and whether the account currently has enough available balance. It does not return a fee estimate. Final fees are recorded per fill.
