TypeScript Trading and Fees

Install the optional trading dependencies:

npm install polynode-sdk@^0.12.2 viem better-sqlite3 \
  @polymarket/clob-client \
  @polymarket/builder-relayer-client \
  @polymarket/builder-signing-sdk

Polymarket V2 is the default. You do not need to set exchangeVersion, but setting it explicitly can make a migration easier to review:

import { PolyNodeTrader } from 'polynode-sdk';

const apiKey = process.env.POLYNODE_API_KEY;
const privateKey = process.env.POLYGON_PRIVATE_KEY;
if (!apiKey || !privateKey) throw new Error('Set the required environment variables');

const trader = new PolyNodeTrader({
  polynodeKey: apiKey,
  exchangeVersion: 'v2',
  builderCode: process.env.POLYMARKET_BUILDER_CODE,
});

const ready = await trader.ensureReady(privateKey);
console.log('funder address', ready.funderAddress);

ensureReady() can deploy or approve wallet contracts and is state-changing for a new wallet. After the returned funder address is funded, trader.order(...) places a real order. V2 fees are applied by Polymarket at match time. Do not add legacy feeRateBps, nonce, or taker fields to a V2 signed order. A builder code attributes eligible volume; it does not itself charge an application fee. feeConfig is a separate, optional application-fee feature and remains disabled unless you configure it.

try {
  const result = await trader.order({
    tokenId: process.env.POLYMARKET_TOKEN_ID!,
    side: 'BUY',
    price: 0.55,
    size: 10,
    type: 'GTC',
    postOnly: true,
  });
  if (!result.success) throw new Error(result.error ?? 'Order rejected');
  console.log(result.orderId);
} finally {
  trader.close();
}

Read Trading and fees before running state-changing examples. It covers funding, cancellations, builder overrides, current V2 fee behavior, position operations, and cleanup.

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TypeScript Trading and Fees