KYO.ag Cross-Chain API Reference

The Cross-Chain API is served from https://cross-chain-api.kyo.ag. Use it to request executable cross-chain quotes, submit the returned user transactions, and poll transaction lifecycle status.

Base URL

https://cross-chain-api.kyo.ag

Authorization is optional for public endpoints. Calls without an API key are supported. Partners with an API key can receive higher RPS limits (up to 10x) and revshare. Visit portal.kyo.ag to generate your API key.

Authorization: Bearer YOUR_API_KEY

GET /v1/chains

List chains currently supported by the Cross-Chain API.

curl https://cross-chain-api.kyo.ag/v1/chains

GET /v1/currencies

List supported currencies for selected chain IDs. Pass chainIds as a comma-separated query parameter such as ?chainIds=8453,999.

curl "https://cross-chain-api.kyo.ag/v1/currencies?chainIds=8453,999"

POST /v1/quote

Request an executable cross-chain quote. The response includes quote amounts and the ordered user-signed transactions to submit.

curl -X POST https://cross-chain-api.kyo.ag/v1/quote \
  -H "Content-Type: application/json" \
  -d '{"userAddress":"0x1111111111111111111111111111111111111111","recipientAddress":"0x2222222222222222222222222222222222222222","originChainId":8453,"destinationChainId":999,"tokenIn":"0x0000000000000000000000000000000000000000","tokenOut":"0xb88339cb7199b77e23db6e890353e22632ba630f","amountIn":"1000000000000000","slippage":0.005}'

GET /v1/transactions/{sourceTxHash}

Poll the lifecycle status of a cross-chain request using the source-chain transaction hash.