interface Interaction {
  target: string;       // Smart contract address
  value: BigNumberish;  // ETH value to send
  callData: string;     // Encoded function call data
}

interface InteractionLike {
  target: string;
  value?: BigNumberish;  // Defaults to 0
  callData?: string;     // Defaults to "0x"
}

enum InteractionStage {
  PRE = 0,   // Before token transfers
  INTRA = 1, // During trading (after sells, before buys)
  POST = 2,  // After all trading
}

encoder.encodeInteraction({
  target: tokenAddress,
  callData: token.interface.encodeFunctionData("permit", [
    owner, spender, value, deadline, v, r, s
  ]),
}, InteractionStage.PRE);

// Uniswap swap for liquidity sourcing
encoder.encodeInteraction({
  target: uniswapRouter,
  callData: router.interface.encodeFunctionData("exactInputSingle", [params]),
}, InteractionStage.INTRA);

// WETH unwrapping
encoder.encodeInteraction({
  target: wethAddress,
  callData: weth.interface.encodeFunctionData("withdraw", [amount]),
}, InteractionStage.POST);

import { normalizeInteraction } from "@cowprotocol/contracts";

const interaction = normalizeInteraction({
  target: contractAddress,
  // value defaults to 0
  // callData defaults to "0x"
});

import { normalizeInteractions } from "@cowprotocol/contracts";

const interactions = normalizeInteractions([
  { target: addr1, callData: data1 },
  { target: addr2, callData: data2 },
]);

const encoder = new SettlementEncoder(domain);

// Pre-settlement permit
encoder.encodeInteraction(permitInteraction, InteractionStage.PRE);

// Intra-settlement swap (default stage)
encoder.encodeInteraction(swapInteraction);

// Post-settlement cleanup
encoder.encodeInteraction(unwrapInteraction, InteractionStage.POST);