Documentation Index
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Edge RPC accepts pay-per-request payments over the x402 protocol, settled through Circle Gateway. Fund a USDC balance once with Circle and pay per call against any supported chain, with no Goldsky account, no API key, and no invoice.
x402 is designed for autonomous agents. SDK clients handle the full handshake transparently.
Pricing
$5 per million requests, all methods, all chains.
Each call debits 5 atomic USDC ($0.000005) from your Circle Gateway balance. Settlement is gasless on your side, and Circle batches settlements on Goldsky’s side.
Endpoint
Edge RPC endpoints follow a single URL pattern, with the chain ID in the path:
https://edge.goldsky.com/standard/evm/{chainId}
edge.goldsky.com with no path. It returns a JSON list of every supported network, with CAIP id, alias, block time, and health status:
curl https://edge.goldsky.com | jq '.standard[] | {id, alias, state}'
# {"id": "evm:1", "alias": "ethereum-mainnet", "state": "OK"}
# {"id": "evm:8453", "alias": "base", "state": "OK"}
# {"id": "evm:42161", "alias": "arbitrum", "state": "OK"}
# ...
Supported chains for x402 payments
You can pay over x402 on any chain Circle Gateway currently advertises. The 11 networks below mirror the live list at https://gateway-api.circle.com/v1/x402/supported; Edge serves additional chains that aren’t yet in this list, and those still require a regular API key.
| Network | CAIP id | USDC contract |
|---|
| Ethereum | eip155:1 | 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 |
| Base | eip155:8453 | 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 |
| Arbitrum One | eip155:42161 | 0xaf88d065e77c8cC2239327C5EDb3A432268e5831 |
| Optimism | eip155:10 | 0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85 |
| Polygon | eip155:137 | 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 |
| Avalanche C-Chain | eip155:43114 | 0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E |
| Unichain | eip155:130 | 0x078D782b760474a361dDA0AF3839290b0EF57AD6 |
| Sonic | eip155:146 | 0x29219dd400f2Bf60E5a23d13Be72B486D4038894 |
| World Chain | eip155:480 | 0x79A02482A880bCE3F13e09Da970dC34db4CD24d1 |
| Sei EVM | eip155:1329 | 0xe15fC38F6D8c56aF07bbCBe3BAf5708A2Bf42392 |
| HyperEVM | eip155:999 | 0xb88339CB7199b77E23DB6E890353E22632Ba630f |
Quickstart
1. Fund a Circle Gateway deposit
Use the Circle Gateway dashboard, or do it directly via the SDK:
import { GatewayClient } from "@circle-fin/x402-batching/client";
const gateway = new GatewayClient({
chain: "base", // any supported chain
privateKey: process.env.PK as `0x${string}`,
});
await gateway.deposit("1"); // 1 USDC = 200,000 Edge requests
/v1/balances API after the on-chain transaction confirms.
2. Pay for an Edge request
pay() handles the full 402 → sign → retry flow for you:
const { data, formattedAmount, transaction } = await gateway.pay(
"https://edge.goldsky.com/standard/evm/1",
{
method: "POST",
headers: { "content-type": "application/json" },
body: { jsonrpc: "2.0", id: 1, method: "eth_chainId", params: [] },
},
);
console.log("paid", formattedAmount, "USDC →", JSON.stringify(data));
// paid 0.000005 USDC → {"jsonrpc":"2.0","id":1,"result":"0x1"}
How it works
x402 is an HTTP protocol layered on top of standard requests. The full handshake:
Initial request returns 402
Your client sends an unauthenticated request. Edge responds with HTTP 402 and a body listing every accepted (chain, asset) option:{
"x402Version": 2,
"error": "Payment required for this resource",
"accepts": [
{
"scheme": "exact",
"network": "eip155:8453",
"amount": "5",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"payTo": "0x87aB362fEF2106d24762289410a18e7c42304C68",
"maxTimeoutSeconds": 604800,
"extra": {
"name": "GatewayWalletBatched",
"version": "1",
"verifyingContract": "0x77777777dcc4d5a8b6e418fd04d8997ef11000ee"
}
}
// ...one entry per supported chain
]
}
Sign an EIP-712 authorization
Your client picks an accepts entry it can satisfy (typically the chain your Gateway deposit lives on) and signs an EIP-712 TransferWithAuthorization message against the GatewayWalletBatched contract from the extra block.
Retry with Payment-Signature header
Your client base64-encodes the signed payload and resends the original request with one extra header:POST /standard/evm/1
Content-Type: application/json
Payment-Signature: <base64(payment payload)>
Limits and operational notes
- Authorization validity window: Circle Gateway requires the signed authorization’s
validBefore to be at least ~4 days in the future. Edge advertises maxTimeoutSeconds: 604800 (7 days) so SDK defaults work out of the box.
See also
Can’t find what you’re looking for? Reach out to us at support@goldsky.com for help.
