Powered by x402 Protocol

Easy exchange
rates for your

dApp

The first exchange rate API that stays out of your way. One-line integration via programmatic payment flow.

Start Building

Pay-as-you-go simplicity

Currex uses HTTP 402 (Payment Required) to facilitate instant, micro-transactional access to exchange rate data. No registration, no signup, no credit card.

✓ Request rate from /v1/latest/:quote/:base
✓ Receive 402 Challenge with invoice
✓ Settle payment programmatically
✓ Get excahnge rate response

Terminal — zsh

➜ ~ curl -I https://currex.fouroh.xyz/api/v1/latest/eth/usd

HTTP/1.1 402 Payment Required
Content-Type: application/json
PAYMENT-REQUIRED: ewoicGF5bW...

➜ ~ # Payment Settled via x402 Middleware

➜ ~ curl https://currex.fouroh.xyz/api/v1/latest/eth/usd -H "PAYMENT-SIGNATURE: ..."

{
  "base": "USD",
  "quote": "ETH",
  "rate": 0.92,
  "validFrom": "2024-10-24T14:30:01Z",
  "path": "USD -> EUR",
  "hope": 1
}

Simple, Honest Value.

$0.05

Per Exchange Rate Quote

Pay only for what you use.

No monthly minimums.

No overages.

⚠

Operational Guardrails

"Transparency is the highest form of precision."

Market Estimates Only

Data is provided as a sophisticated market estimate for UI/UX purposes. Perfect for valuing portfolio assets, displaying product prices in dApps, or calculating estimated transaction fees.

Usage Restriction

This API is NOT engineered for high-frequency trading, automated liquidations, or oracle-critical financial settlement where sub-millisecond latency and absolute consensus are required.

Precision vs. Speed

We prioritize data cleanliness and completeness over precision. Expect exchange rates to be approximate.

Multi-Chain Native

Native support for L1s, L2s, and traditional FX pairs via a single unified schema.

Stateless Auth

No API keys to rotate. Authentication is handled via cryptographically signed payment preimages.

99.9% Uptime

Distributed edge nodes ensure that pricing data is always available, even during peak market volatility.

Easy exchangerates for your dApp