Slippage and price impact

import { olympexRequest } from "./sign-request.ts"; // /authentication/sign-requests

type QuoteData = { quote: { outAmount: string } };

const quote = (amount: string) =>
  olympexRequest<QuoteData>("POST", "/quotes", {
    mode: "single-chain",
    params: {
      chainId: 137,
      inTokenAddress: "0xc2132d05d31c914a87c6611c10748aeb04b58e8f", // USDT
      outTokenAddress: "0x3c499c542cef5e3811e1192ce70d8cc03d5c3359", // USDC
      amount,
      slippage: "1",
      gasPrice: "35",
    },
  });

const [reference, trade] = await Promise.all([quote("1"), quote("10000")]);

// Token decimals cancel out, so the base-unit outAmount values compare directly.
const referenceRate = Number(reference.quote.outAmount) / 1;
const tradeRate = Number(trade.quote.outAmount) / 10000;
const priceImpactPercent = (1 - tradeRate / referenceRate) * 100;
console.log(`Price impact: ${priceImpactPercent.toFixed(2)} %`);

from sign_request import olympex_request  # /authentication/sign-requests


def quote(amount):
    return olympex_request("POST", "/quotes", {
        "mode": "single-chain",
        "params": {
            "chainId": 137,
            "inTokenAddress": "0xc2132d05d31c914a87c6611c10748aeb04b58e8f",  # USDT
            "outTokenAddress": "0x3c499c542cef5e3811e1192ce70d8cc03d5c3359",  # USDC
            "amount": amount,
            "slippage": "1",
            "gasPrice": "35",
        },
    })


reference, trade = quote("1"), quote("10000")

# Token decimals cancel out, so the base-unit outAmount values compare directly.
reference_rate = int(reference["quote"]["outAmount"]) / 1
trade_rate = int(trade["quote"]["outAmount"]) / 10000
price_impact_percent = (1 - trade_rate / reference_rate) * 100
print(f"Price impact: {price_impact_percent:.2f} %")