Read-only EVM contract call (eth_call) with decoded revert reason and optional gas estimat

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x43B85AE58f0A2505c710Bc715d6f3EB16b1f63dE",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "20000",
    "maxTimeoutSeconds": 120
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "chain": "base",
          "data": "0x70a0823100000000000000000000000043b85ae58f0a2505c710bc715d6f3eb16b1f63de",
          "to": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      },
      "output": {
        "example": {
          "chain": "base",
          "gasEstimate": "26000",
          "result": "0x0000000000000000000000000000000000000000000000000000000001e1e5a0",
          "reverted": false,
          "status": "delivered"
        },
        "type": "json"
      }
    },
    "schema": {
      "properties": {
        "input": {
          "properties": {
            "body": {
              "properties": {
                "block": {
                  "description": "Block tag (latest/safe/finalized/earliest) or hex block number; default latest",
                  "type": "string"
                },
                "chain": {
                  "enum": [
                    "base",
                    "ethereum",
                    "arbitrum",
                    "optimism",
                    "polygon"
                  ],
                  "type": "string"
                },
                "data": {
                  "description": "ABI-encoded calldata (0x…); defaults to 0x",
                  "type": "string"
                },
                "from": {
                  "description": "Optional caller address — enables gas estimation",
                  "pattern": "^0x[0-9a-fA-F]{40}$",
                  "type": "string"
                },
                "to": {
                  "description": "Contract to call",
                  "pattern": "^0x[0-9a-fA-F]{40}$",
                  "type": "string"
                },
                "value": {
                  "description": "Optional value in wei (hex 0x… or decimal string)",
                  "type": "string"
                }
              },
              "required": [
                "chain",
                "to"
              ],
              "type": "object"
            }
          }
        },
        "output": {
          "properties": {
            "example": {
              "chain": "base",
              "gasEstimate": "26000",
              "result": "0x0000000000000000000000000000000000000000000000000000000001e1e5a0",
              "reverted": false,
              "status": "delivered"
            }
          }
        }
      }
    }
  }
}

curl "https://agent.connskill.com/chain/v1/chain-call"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://agent.connskill.com/chain/v1/chain-call");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
res = httpx.get("https://agent.connskill.com/chain/v1/chain-call")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header