App Kit FAQs

import { createViemAdapterFromProvider } from "@circle-fin/adapter-viem-v2";
const adapter = await createViemAdapterFromProvider({
  provider: window.ethereum,
});

// Swap: percentage-based
config: { customFee: { percentageBps: 50, recipientAddress: "0xYourWallet" } }

// Bridge and Unified Balance spend: absolute value
config: { customFee: { value: "0.10", recipientAddress: "0xYourWallet" } }

const result = await kit.swap({
  from: { adapter, chain: "Arc" },
  tokenIn: "USDT",
  tokenOut: "USDC",
  amountIn: "1.00",
  config: { kitKey: process.env.KIT_KEY },
});

const estimate = await kit.estimateSwap({
  from: { adapter, chain: "Arc" },
  tokenIn: "EURC",
  tokenOut: "USDC",
  amountIn: "1.00",
  config: { kitKey: process.env.KIT_KEY },
});
console.log(estimate.estimatedOutput.amount, estimate.stopLimit.amount);

// Cross-chain: swap USDC on Ethereum, receive on Base at a specific wallet
const result = await kit.swap({
  from: { adapter, chain: "Ethereum" },
  tokenIn: "USDC",
  tokenOut: "USDC",
  amountIn: "100",
  to: { chain: "Base", recipientAddress: "0xRecipient" },
  config: { kitKey: process.env.KIT_KEY },
});

const final = await kit.waitForSwap({ result, kitKey: process.env.KIT_KEY });

const result = await kit.swap({
  from: { adapter, chain: "Arc" },
  tokenIn: "USDT",
  tokenOut: "USDC",
  amountIn: "1.00",
  to: { recipientAddress: "0xDifferentWallet" },
  config: { kitKey: process.env.KIT_KEY },
});

kit.on("bridge.approve", (e) => console.log("Approved", e.values.txHash));
kit.on("bridge.burn", (e) => console.log("Burned", e.values.txHash));
kit.on("bridge.attestation", () => console.log("Attestation received"));
kit.on("bridge.mint", (e) => console.log("Minted", e.values.txHash));
kit.on("*", (e) => console.log(e.method, e.values)); // all events