Cruce

Live at https://usecruce.xyz (also https://cruce-phi.vercel.app). Code: https://github.com/Spagero763/cruce

Every stablecoin venue on Celo trades local currency against the dollar. Someone holding pesos who needs reais does two trades and pays two spreads; off-chain, a casa de cambio takes 5 to 10%. And x402 settles only in the exact asset a seller names, so an agent holding naira can't pay a service priced in dollars.

Cruce is a currency exchange agent that closes both gaps. A person or agent says what they hold and what they need. The agent prices every hop on Textile FX, Uniswap (v3 and v4) and Mento, takes the better venue for each, and returns an estimate plus a guaranteed minimum. One x402 signature pays: EIP-3009 for the dollars, Permit2 with sponsored approval for wFIAT. USDm, and cNGN from a wallet that never approved Permit2, are paid by a plain transfer whose calldata ends with the order id; the same transfer is the fallback whenever the facilitator refuses, and the page says before signing which rail an order takes. The agent sells what was paid, holds dollars for seconds, buys the target currency and sends it to any wallet. If the market moves under the minimum, the payer is refunded, not short-changed.

Pay any x402 service in the currency you hold: give Cruce the service's URL and your currency. It reads the seller's price, converts, pays the seller in its own asset from the agent's wallet, returns the change and hands back the seller's answer. Proven on mainnet: an agent holding only pesos bought a buy AI call priced in USD₮.

Currencies: wARS, wBRL, wCOP, cNGN, USD₮, USDC, USA₮ and USDm, each into any other, 56 live pairs. IDRX, wMXN, wCLP and wPEN switch on by themselves when their venues have depth both ways. Reference rates (official, blue, tourist dollar) come from public feeds and boards read through a rented buy browser; quotes far from the reference are refused.

Builders integrate with one call (npm install cruce-sdk, or a link) and receive a third of the fee on every conversion they send, paid on-chain with the order. No contract holds balances; every step is a tagged public transaction; orders recover from any point without ever sending the same money twice.

buy services the agent pays for, with settlement transactions: https://usecruce.xyz/api/proof/buy

Where the users came from: a launch post on X, the Celo builders Telegram, and people I messaged directly on WhatsApp. Each swapped from their own wallet with their own money.