netOutputs

Computes net input/output token allocations per recipient based on Transfer logs. This is useful for spotting fee extractors (aggregator, app, relayer, etc.) by showing which accounts received how many tokens during a swap.

Logs can come from a TransactionReceipt or SuccessSimulationResult.

Example

import { netOutputs, type SwapParams } from "@spandex/core";
import type { TransactionReceipt } from "viem";
 
const swap: SwapParams = {} as SwapParams; // ...
const receipt: TransactionReceipt = {} as TransactionReceipt; // ...
 
const allocations = netOutputs({
  swap,
  logs: receipt.logs,
});
 
for (const [account, amount] of allocations.outputToken) {
  console.log("output recipient", account, amount.toString());
}

Params

swap

SwapParams

Swap parameters that identify the input/output tokens and swapper. This should match the swap that was used to build a quote, which was executed to produce logs. If recipientAccount is set on the swap, output attribution is evaluated against that recipient.

logs

Log[]

Event logs from a transaction receipt or simulation output.

Returns

Allocations

type Allocations = {
  inputToken: Map<Address, bigint>;
  outputToken: Map<Address, bigint>;
};

Each map is keyed by recipient address and contains the net amount of that token received by that address (base units).