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://api.currex.com/v1/latest/eth/usd

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

➜ ~ # Payment Settled via x402 Middleware

➜ ~ curl https://api.currex.com/v1/latest/eth/usd -H "X-x402-Preimage: ..."

{
    "base": "USD"
    "quote": "ETH"
    "rate": 2451.28,
    "period": "2024-10-24T14:30:01Z"
}

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

RateRail 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 aggregation breadth over raw execution speed. Expect latency between 100ms and 300ms depending on the pair.

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