Fees

BopAMM router fees let integrators take a share of successful BopAMM output. They are optional: pass 0 when you do not want a fee. Fees apply only when the BopAMM leg succeeds. Fallback output from swapWithFallback is not fee-charged by the BopAMM router.

How fees work

The requested fee is the total fee on gross BopAMM output, in basis points, capped at 1,000 bps. The router applies its configured protocol share to that total fee, sends the remainder to your fee_recipient, and delivers the remaining output to the swap recipient. For example, if the gross BopAMM output is 1,000 units and fee = 25, the total router fee is 2.5 units. A configured protocol share applies to that 2.5, and the rest goes to your fee recipient. The router checks minAmountOut after fees. If you set a fee yourself, calculate your minimum from the post-fee amount.

amount_after_fee = amount_out * (10_000 - FEE_BPS) // 10_000
min_amount_out = amount_after_fee * (10_000 - SLIPPAGE_BPS) // 10_000

Pack the router fee

BopAmmRouter takes a single packed uint256 fee argument.

Bits	Value
Low 160 bits	Integrator fee recipient address.
High bits	Fee bps of gross BopAMM output.

from web3 import Web3


def pack_router_fee(fee_bps: int, fee_recipient: str | None) -> int:
    if fee_bps == 0:
        return 0
    if fee_recipient is None:
        raise ValueError("fee_recipient is required when fee_bps is non-zero")
    return (fee_bps << 160) | int(Web3.to_checksum_address(fee_recipient), 16)


FEE_BPS = 25  # 0.25% of gross BopAMM output
FEE_RECIPIENT = "0x0000000000000000000000000000000000000005"
FEE = pack_router_fee(FEE_BPS, FEE_RECIPIENT)

Add a fee to router calldata

When you build swapWithAllowance calldata yourself, pass the packed fee as the final argument.

amount_out = core.functions.quote(USDC, WETH, amount_in).call(
    block_identifier=state["stateBlock"],
    state_override=state_override,
)
amount_after_fee = amount_out * (10_000 - FEE_BPS) // 10_000
min_amount_out = amount_after_fee * (10_000 - SLIPPAGE_BPS) // 10_000

swap = router.functions.swapWithAllowance(
    USDC,
    WETH,
    amount_in,
    min_amount_out,
    account.address,
    deadline,
    FEE,
)

The same packed FEE argument is used when composing swapWithFallback manually.

Add a fee through `/quote`

For /quote-generated swapWithFallback calldata, pass fee and fee_recipient as query parameters. The endpoint packs them into tx.data for you.

quote = httpx.get(
    f"{API_BASE}/quote",
    params={
        "sell_tokens": USDC,
        "buy_tokens": WETH,
        "sell_amounts": str(amount_in),
        "taker_address": account.address,
        "slippage": "0.005",
        "approval_type": "Standard",
        "gasless": "false",
        "fee": "25",
        "fee_recipient": FEE_RECIPIENT,
    },
    headers={"Authorization": f"Bearer {API_KEY}"},
)
quote.raise_for_status()
quote = quote.json()

Quote response buy amounts are net of the total router fee. buyTokens[].minimumAmount already reflects fee plus slippage, and the returned tx.data carries the packed router fee.

Introduction

Core Concepts

RFQ API

BopAMM

Aggregation API

Price API

Trade History API

How fees work

Pack the router fee

Add a fee to router calldata

Add a fee through `/quote`

​How fees work

​Pack the router fee

​Add a fee to router calldata

​Add a fee through /quote

How fees work

Pack the router fee

Add a fee to router calldata

Add a fee through `/quote`