Pricing

Pay-as-you-go. No subscriptions, no API keys. Pay only for what you use.

Payment Protocols

4SEC supports two payment protocols:

Protocol	Blockchain	Token	Discovery
x402 v2	Base (Coinbase)	USDC on Base	x402scan.com
MPP	Tempo (Stripe)	USDC on Tempo	mppscan.com

Both protocols are supported automatically — your client library handles the negotiation.

Endpoint Pricing

DEX Endpoints

Endpoint	Price (USDC)	Description
GET /price/:symbol	0.01	Real-time aggregated price from 8+ DEXes
GET /price/history/:symbol	0.02	Historical OHLCV candlestick data
GET /volume/:symbol	0.02	24h trading volume across all DEXes
GET /spread/:pair	0.02	Bid/ask spread analysis
GET /arbitrage-opportunity	0.05	Cross-DEX arbitrage scanner
GET /volatility-index/:symbol	0.03	Risk metrics: VaR, Sharpe, volatility
POST /price-alert	0.04	Create webhook price alert
POST /price-alert/:id/extend	0.02	Extend price alert duration

Funding Rate Endpoints

Endpoint	Price (USDC)	Description
GET /funding-rate/:symbol	0.02	Current perpetual funding rate with signal
GET /funding-rate/history/:symbol	0.03	Historical funding rate data
GET /funding-rate/extreme	0.02	Extreme funding rates scanner across markets

Liquidation Endpoints

Endpoint	Price (USDC)	Description
GET /liquidation/heatmap/:symbol	0.05	Liquidation heatmap with cascade risk levels
GET /liquidation/recent	0.03	Recent liquidations with long/short breakdown
POST /liquidation/alert	0.06	Create liquidation cascade alert webhook
POST /liquidation/alert/:id/extend	0.03	Extend liquidation alert duration

Futures Analytics

Endpoint	Price (USDC)	Description
GET /futures/funding-compare/:symbol	0.03	Cross-exchange funding rate comparison
GET /futures/open-interest/:symbol	0.03	Aggregated open interest across 3 exchanges
GET /futures/long-short/:symbol	0.02	Top traders long/short ratio
GET /futures/basis/:symbol	0.02	Spot vs perpetual basis (carry-trade signal)
GET /futures/predicted-funding/:symbol	0.02	Predicted next funding rate

CEX Market Data (v1)

Endpoint	Price (USDC)	Description
GET /api/v1/prices	0.005	Batch CEX prices (e.g. ?symbols=btc,eth,sol)
GET /api/v1/market/:id	0.005	Market details by CoinGecko ID
GET /api/v1/market/:id/history	0.01	Historical market data from CEX sources

Free Endpoints

Endpoint	Description
GET /health	Health check
GET /api/v1/status	Detailed system status
GET /price-alert/:id	Check price alert status
DELETE /price-alert/:id	Cancel a price alert
GET /price-alerts	List all active price alerts
GET /liquidation/alerts	List all active liquidation alerts
GET /liquidation/alert/:id	Check liquidation alert status
DELETE /liquidation/alert/:id	Cancel a liquidation alert
GET /	API info and available endpoints
GET /openapi.json	OpenAPI specification
GET /.well-known/x402.json	x402 payment discovery
GET /metrics	Transaction metrics

Free Cache Window

Same request within 30 seconds returns cached data — no charge.

# First request: 0.01 USDC
curl -i https://api.foursec.xyz/price/ETH

# Same request within 30s: FREE (cached)
curl -i https://api.foursec.xyz/price/ETH

JavaScript Example (x402)

import { wrapFetchWithPayments } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";
import { createWalletClient, http } from "viem";
import { base } from "viem/chains";

const account = privateKeyToAccount("0x_YOUR_KEY");
const walletClient = createWalletClient({
  account,
  chain: base,
  transport: http("https://mainnet.base.org"),
});

const fetchWithPayment = wrapFetchWithPayments(fetch, {
  client: walletClient,
});

// Auto-pays 0.01 USDC per unique request
const res = await fetchWithPayment("https://api.foursec.xyz/price/ETH");
const data = await res.json();
console.log("ETH: $" + data.price_usd);

Rate Limits

• 500 requests/minute per IP address
• Cached responses (within 30s TTL) do not count toward rate limit
• For higher volume needs, contact: support@foursec.xyz

Payment Details

x402 Protocol (Base USDC)

• Token: USDC on Base (Chain ID 8453)
• Contract: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
• Protocol: x402 v2
• No API key required — your wallet address is your identity

MPP Protocol (Tempo USDC)

• Token: USDC on Tempo (Stripe's blockchain)
• Protocol: MPP (Machine Payment Protocol)
• Discovery: mppscan.com
• No API key required — compatible with MPP-enabled wallets