How to build an autonomous trading bot with XAUConnect

This guide walks through a minimal server-side bot that swaps on BNB Chain using the XAUConnect API and viem. The same pattern applies to other EVM chains — change chainKey and RPC.

1. Configure the SDK client

import { XauApiClient } from "@xauconnect/sdk";
import { createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { bsc } from "viem/chains";

const api = new XauApiClient({
  baseUrl: "https://xauconnect.com/api",
  clientId: "treasury-rebalancer",
  clientName: "Treasury Rebalancer",
  clientSource: "agent",
});

const account = privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`);
const wallet = createWalletClient({ account, chain: bsc, transport: http() });

2. Quote and pick the best executable route

const quote = await api.quote({
  chainKey: "bsc",
  tokenIn: "0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c", // WBNB
  tokenOut: "0x55d398326f99059fF775485246999027B3197955", // USDT
  amountIn: "1000000000000000000",
  slippageBps: 50,
  taker: account.address,
});

const route = quote.best ?? quote.quotes.find((q) => q.executable);
if (!route) throw new Error("No executable route");

3. Build, approve if needed, sign, and record

Call GET /swap/allowance before swapping ERC-20 tokens. After the transaction confirms, always POST /swap/record with source: agent so volume shows in admin.

const built = await api.buildSwap({
  request: { chainKey: "bsc", tokenIn, tokenOut, amountIn, slippageBps: 50, taker: account.address },
  route,
  minAmountOut: quote.minAmountOut!,
});

const hash = await wallet.sendTransaction({
  to: built.evm!.to as `0x${string}`,
  data: built.evm!.data as `0x${string}`,
  value: BigInt(built.evm!.value),
});

await api.recordSwap({
  chainKey: "bsc",
  dexId: route.dexId,
  tokenIn, tokenOut,
  amountIn, amountOut: route.amountOutAfterFee,
  protocolFee: route.protocolFee,
  feeBps: quote.protocolFeeBps,
  txHash: hash,
  address: account.address,
  status: "confirmed",
  source: "agent",
});