OKX DEX Aggregator Quote Skill

Overview

This skill generates production-ready code for fetching optimal swap quotes from the OKX DEX Aggregator API v6. The API finds the best price across multiple DEX protocols (Uniswap, SushiSwap, Curve, etc.) and returns detailed routing information including price impact, gas estimates, and token safety flags.

Key capabilities:

• Authenticated API requests with HMAC-SHA256 signing
• Correct handling of token decimals and amount formatting
• Support for exactIn (fixed input) and exactOut (fixed output) swap modes
• Multi-chain support (Ethereum, BSC, Arbitrum, Base, Solana, and 20+ chains)
• Price impact protection and honeypot detection
• Fee/commission splitting configuration

Prerequisites

Required Credentials

Users must have an OKX Web3 API key set. The skill needs three values:

• OKX_ACCESS_KEY — API key
• OKX_SECRET_KEY — Secret key for HMAC signing
• OKX_PASSPHRASE — Account passphrase

Environment

• Python: requests, hmac, hashlib, base64, datetime (all stdlib except requests)
• Node.js: axios or node-fetch, built-in crypto
• No additional blockchain dependencies required (this is a read-only quote endpoint)

API Endpoint

GET https://web3.okx.com/api/v6/dex/aggregator/quote

Workflow

Step 1: Validate User Input

Before constructing the API call, validate:

1. Chain ID (chainIndex) — Must be a supported chain. Common values:

   • 1 = Ethereum
   • 56 = BSC
   • 137 = Polygon
   • 42161 = Arbitrum
   • 8453 = Base
   • 130 = Unichain
   • 501 = Solana

2. Token addresses — Must be valid contract addresses or the native token placeholder:

   • Native tokens (ETH, BNB, etc.): 0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
   • Contract tokens: Full 42-character hex address (EVM) or base58 (Solana)

3. Amount — MUST include token decimals. This is the #1 source of errors:

   • 1 ETH (18 decimals) → "1000000000000000000"
   • 1 USDT (6 decimals) → "1000000"
   • 1 WBTC (8 decimals) → "100000000"
   • Formula: amount_raw = human_amount * (10 ** token_decimals)

4. Swap mode — exactIn (default) or exactOut

   • exactOut only supported on: Ethereum, Base, BSC, Arbitrum
   • exactOut only works with Uniswap V2/V3 pools

Step 2: Construct Authentication Headers

OKX API requires HMAC-SHA256 signed requests with 4 headers:

OK-ACCESS-KEY: <api_key>
OK-ACCESS-SIGN: <hmac_signature>
OK-ACCESS-PASSPHRASE: <passphrase>
OK-ACCESS-TIMESTAMP: <iso8601_timestamp>

Signing algorithm:

timestamp = ISO 8601 UTC time (e.g., "2025-01-15T12:00:00.000Z")
prehash = timestamp + "GET" + request_path_with_query
signature = Base64(HMAC-SHA256(secret_key, prehash))

CRITICAL: The request_path_with_query must include the full path starting from /api/... plus the query string. Example:

/api/v6/dex/aggregator/quote?chainIndex=1&amount=1000000000000000000&fromTokenAddress=0xeee...&toTokenAddress=0xa0b...

Step 3: Send Request and Parse Response

Success response structure:

{
  "code": "0",
  "data": [{
    "chainIndex": "1",
    "fromToken": { "tokenSymbol": "ETH", "decimal": "18", ... },
    "toToken": { "tokenSymbol": "USDC", "decimal": "6", ... },
    "fromTokenAmount": "1000000000000000000",
    "toTokenAmount": "3521432100",
    "dexRouterList": [...],
    "tradeFee": "2.45",
    "estimateGasFee": "150000",
    "priceImpactPercent": "-0.12"
  }],
  "msg": ""
}

Key fields to extract:

• toTokenAmount — The amount you'll receive (in raw units with decimals)
• tradeFee — Estimated network fee in USD
• priceImpactPercent — Negative = losing value; large negative = danger
• dexRouterList — Routing path through various DEX protocols
• fromToken.isHoneyPot / toToken.isHoneyPot — Scam token flag
• fromToken.taxRate / toToken.taxRate — Token buy/sell tax

Step 4: Format Output for User

Convert raw amounts back to human-readable:

human_amount = raw_amount / (10 ** decimal)

Always display:

1. Exchange rate (e.g., "1 ETH = 3,521.43 USDC")
2. Price impact percentage with warning if > 3%
3. Estimated gas fee in USD
4. Routing summary (which DEXes are used)
5. Honeypot warnings if detected
6. Token tax rates if > 0

Best Practices

Security

• NEVER hardcode API credentials in generated code. Always use environment variables or config files.
• NEVER log the secret key or signature in debug output.
• Validate all token addresses against expected format before sending.
• Check isHoneyPot flag on both tokens and warn the user prominently.

Amount Handling

• Always use string type for amounts to avoid floating-point precision loss.
• Python: Use int() for amount calculations, never float().
• JavaScript: Use BigInt or string math for amounts > 2^53.
• When user provides a human-readable amount like "1.5 ETH", convert: str(int(1.5 * 10**18)).

Error Handling

• Check response["code"] == "0" before accessing data.
• Common error codes:
  • Non-zero code with msg = API error (e.g., insufficient liquidity, invalid params)
  • HTTP 401 = Authentication failure (check signature algorithm)
  • HTTP 429 = Rate limited
• If priceImpactPercent is null, warn that price impact couldn't be calculated.

Rate Limits

• Respect OKX rate limits. For production use, implement exponential backoff.
• Cache quotes if polling repeatedly (quotes are valid for ~15-30 seconds).

Optional Parameters Usage

• dexIds — Use when you want to restrict to specific DEXes (e.g., only Uniswap).
• directRoute=true — Only for Solana; forces single-pool routing.
• priceImpactProtectionPercent — Set to a sensible default like 10 for safety. Set to 100 to disable.
• feePercent — For integrators taking commission. Max 3% (EVM) or 10% (Solana). Up to 9 decimal places.

Examples

Example 1: Python — Get ETH to USDC Quote on Ethereum

import os, hmac, hashlib, base64, requests
from datetime import datetime, timezone
from urllib.parse import urlencode

API_KEY = os.environ["OKX_ACCESS_KEY"]
SECRET_KEY = os.environ["OKX_SECRET_KEY"]
PASSPHRASE = os.environ["OKX_PASSPHRASE"]

def get_okx_quote(chain_index, from_token, to_token, amount, swap_mode="exactIn"):
    base_url = "https://web3.okx.com"
    path = "/api/v6/dex/aggregator/quote"

    params = {
        "chainIndex": chain_index,
        "fromTokenAddress": from_token,
        "toTokenAddress": to_token,
        "amount": amount,
        "swapMode": swap_mode,
    }

    query_string = urlencode(params)
    request_path = f"{path}?{query_string}"

    # Generate timestamp and signature
    timestamp = datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%S.%f")[:-3] + "Z"
    prehash = timestamp + "GET" + request_path
    signature = base64.b64encode(
        hmac.new(SECRET_KEY.encode(), prehash.encode(), hashlib.sha256).digest()
    ).decode()

    headers = {
        "OK-ACCESS-KEY": API_KEY,
        "OK-ACCESS-SIGN": signature,
        "OK-ACCESS-PASSPHRASE": PASSPHRASE,
        "OK-ACCESS-TIMESTAMP": timestamp,
    }

    resp = requests.get(base_url + request_path, headers=headers)
    resp.raise_for_status()
    data = resp.json()

    if data["code"] != "0":
        raise Exception(f"OKX API error: {data['msg']}")

    return data["data"][0]


# Swap 1 ETH -> USDC on Ethereum
ETH = "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee"
USDC = "0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48"
amount = str(1 * 10**18)  # 1 ETH in wei

quote = get_okx_quote("1", ETH, USDC, amount)

to_decimals = int(quote["toToken"]["decimal"])
received = int(quote["toTokenAmount"]) / (10 ** to_decimals)

print(f"You will receive: {received:,.2f} {quote['toToken']['tokenSymbol']}")
print(f"Price impact: {quote['priceImpactPercent']}%")
print(f"Gas fee (USD): ${quote['tradeFee']}")
print(f"Honeypot check: {'WARNING' if quote['toToken']['isHoneyPot'] else 'Safe'}")

Example 2: Node.js — Get Quote with Commission Fee

const crypto = require("crypto");
const https = require("https");

const API_KEY = process.env.OKX_ACCESS_KEY;
const SECRET_KEY = process.env.OKX_SECRET_KEY;
const PASSPHRASE = process.env.OKX_PASSPHRASE;

function getQuote(chainIndex, fromToken, toToken, amount, options = {}) {
  const params = new URLSearchParams({
    chainIndex,
    fromTokenAddress: fromToken,
    toTokenAddress: toToken,
    amount,
    swapMode: options.swapMode || "exactIn",
    ...(options.feePercent && { feePercent: options.feePercent }),
    ...(options.priceImpactProtectionPercent && {
      priceImpactProtectionPercent: options.priceImpactProtectionPercent,
    }),
  });

  const path = `/api/v6/dex/aggregator/quote?${params}`;
  const timestamp = new Date().toISOString();
  const prehash = timestamp + "GET" + path;
  const signature = crypto
    .createHmac("sha256", SECRET_KEY)
    .update(prehash)
    .digest("base64");

  return new Promise((resolve, reject) => {
    const req = https.get(
      `https://web3.okx.com${path}`,
      {
        headers: {
          "OK-ACCESS-KEY": API_KEY,
          "OK-ACCESS-SIGN": signature,
          "OK-ACCESS-PASSPHRASE": PASSPHRASE,
          "OK-ACCESS-TIMESTAMP": timestamp,
        },
      },
      (res) => {
        let body = "";
        res.on("data", (chunk) => (body += chunk));
        res.on("end", () => {
          const data = JSON.parse(body);
          if (data.code !== "0") reject(new Error(`OKX: ${data.msg}`));
          else resolve(data.data[0]);
        });
      }
    );
    req.on("error", reject);
  });
}

Example 3: Understanding the Routing Path

Router: ETH -> WBTC -> USDC
dexRouterList shows:
  - 55% ETH -> WBTC via Uniswap V4
  - 30% ETH -> USDC via Uniswap V4 (direct)
  - WBTC -> USDC via Euler (73%) + Uniswap V4 (27%)

This means the aggregator splits the trade across multiple paths
to minimize price impact and maximize output.

Troubleshooting

Reference: Common Chain IDs

Reference: Common Token Addresses (Ethereum)

Reference: Request Parameters Summary