Api Endpoint

Function selector / event topic

Resolve a 4-byte function selector or a 32-byte event topic hash to its known human-readable Solidity signatures, via the openchain.xyz signature database with 4byte.directory as fallback. Unknown selectors return {found:false} with an empty list, not an error.

Open interactive test console

Offering

Provider: agent402.tools
Method: POST
Offering type: Api Endpoint
Transport type: http
Category: Blockchain And Crypto
Delivery: Not provided
Pricing model: Not provided
x402 version: 2

Endpoint context

URL: https://agent402.tools/api/selector-lookup
MIME type: application/json
First seen: 2026-10-16T01:50:19.913Z
Last seen: 2026-11-02T07:41:15.553Z
Tags: Crypto, selector, 4byte, signature, event

Website

Payment pricing

x402 payment terms are the authoritative price for calling this endpoint.

Payment option 1: 0.002 USDC
Atomic price: 2000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Payment option 2: 0.002 USDC
Atomic price: 2000 · Network: eip155:137 · Asset: USDC · Scheme: exact
Payment option 3: 0.002 USDC
Atomic price: 2000 · Network: eip155:42161 · Asset: USDC · Scheme: exact
Payment option 4: 0.002 USDC
Atomic price: 2000 · Network: eip155:143 · Asset: USDC · Scheme: exact
Payment option 5: 0.002 USDC
Atomic price: 2000 · Network: eip155:43114 · Asset: USDC · Scheme: exact
Payment option 6: 2000 atomic units
Atomic price: 2000 · Network: eip155:1329 · Asset: 0xe15fC38F6D8c56aF07bbCBe3BAf5708A2Bf42392 · Scheme: exact
Payment option 7: 0.003 USDC
Atomic price: 3000 · Network: eip155:10 · Asset: USDC · Scheme: exact
Payment option 8: 0.005 USDC
Atomic price: 5000 · Network: eip155:4663 · Asset: USDC · Scheme: exact
Payment option 9: 2000 atomic units
Atomic price: 2000 · Network: eip155:42220 · Asset: 0xcebA9300f2b948710d2653dD7B07f33A8B32118C · Scheme: exact
Payment option 10: 2000 atomic units
Atomic price: 2000 · Network: eip155:5042 · Asset: 0x3600000000000000000000000000000000000000 · Scheme: exact
Payment option 11: 0.002 USDC
Atomic price: 2000 · Network: eip155:8453 · Asset: USDC · Scheme: upto
Payment option 12: 0.002 USDC
Atomic price: 2000 · Network: solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp · Asset: USDC · Scheme: exact
Payment option 13: 20000 atomic units
Atomic price: 20000 · Network: stellar:pubnet · Asset: CCW67TSZV3SSS2HXMBQ5JFGCKJNXKZM7UQUWUZPUTHXSTZLEO7SJMI75 · Scheme: exact
Payment option 14: 2000 atomic units
Atomic price: 2000 · Network: algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73k · Asset: 31566704 · Scheme: exact
Payment option 15: 0.002 USDC
Atomic price: 2000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Payment option 16: 2000 atomic units
Atomic price: 2000 · Network: eip155:5042 · Asset: 0x3600000000000000000000000000000000000000 · Scheme: exact

Raw x402 terms

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:137",
    "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:42161",
    "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:143",
    "asset": "0x754704Bc059F8C67012fEd69BC8A327a5aafb603",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:43114",
    "asset": "0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:1329",
    "asset": "0xe15fC38F6D8c56aF07bbCBe3BAf5708A2Bf42392",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:10",
    "asset": "0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85",
    "amount": "3000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:4663",
    "asset": "0x5fc5360D0400a0Fd4f2af552ADD042D716F1d168",
    "amount": "5000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:42220",
    "asset": "0xcebA9300f2b948710d2653dD7B07f33A8B32118C",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:5042",
    "asset": "0x3600000000000000000000000000000000000000",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "upto",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "2000",
    "payTo": "J7aN3PLJnTCF5qpEnvJHJsnCjcGuqC2rYtEM8Gv3xwg"
  },
  {
    "scheme": "exact",
    "network": "stellar:pubnet",
    "asset": "CCW67TSZV3SSS2HXMBQ5JFGCKJNXKZM7UQUWUZPUTHXSTZLEO7SJMI75",
    "amount": "20000",
    "payTo": "GDNJXCKW7ZM7GEEVP674TWPU26YJNBQ2FI4ZIPRKTPTNUEJMDHFJWWRL"
  },
  {
    "scheme": "exact",
    "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73k",
    "asset": "31566704",
    "amount": "2000",
    "payTo": "C7IIHG7SPLPZ5H7ZT6HW3UV2OQMQQE6Y2HBNGZXSLRJULE42BEE2OY2XIE"
  },
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  },
  {
    "scheme": "exact",
    "network": "eip155:5042",
    "asset": "0x3600000000000000000000000000000000000000",
    "amount": "2000",
    "payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0"
  }
]

Observed health

Status: Healthy
Latest latency: 130 ms
Average latency: 318 ms
HTTP status: 204
Last checked: 2026-11-03T11:11:25.569Z
Reachability: 100% over 10 checks

Latency is measured to the first response headers. A reachable result does not verify response accuracy or merchant identity.

Input schema

{
  "type": "object",
  "properties": {
    "type": {
      "type": "string",
      "const": "http"
    },
    "method": {
      "type": "string",
      "enum": [
        "POST"
      ]
    },
    "bodyType": {
      "type": "string",
      "enum": [
        "json",
        "form-data",
        "text"
      ]
    },
    "body": {
      "properties": {
        "selector": {
          "type": "string",
          "description": "0x-prefixed 4-byte function selector (10 chars) or 32-byte event topic hash (66 chars)."
        }
      },
      "required": [
        "selector"
      ]
    }
  },
  "required": [
    "type",
    "method",
    "bodyType",
    "body"
  ],
  "additionalProperties": false
}

Output schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "input": {
      "additionalProperties": false,
      "properties": {
        "body": {
          "properties": {
            "selector": {
              "description": "0x-prefixed 4-byte function selector (10 chars) or 32-byte event topic hash (66 chars).",
              "type": "string"
            }
          },
          "required": [
            "selector"
          ]
        },
        "bodyType": {
          "enum": [
            "json",
            "form-data",
            "text"
          ],
          "type": "string"
        },
        "method": {
          "enum": [
            "POST"
          ],
          "type": "string"
        },
        "type": {
          "const": "http",
          "type": "string"
        }
      },
      "required": [
        "type",
        "method",
        "bodyType",
        "body"
      ],
      "type": "object"
    },
    "output": {
      "properties": {
        "example": {
          "properties": {
            "found": {
              "type": "boolean"
            },
            "kind": {
              "type": "string"
            },
            "selector": {
              "type": "string"
            },
            "signatures": {
              "items": {
                "type": "string"
              },
              "type": "array"
            },
            "source": {
              "type": "string"
            }
          },
          "required": [
            "selector",
            "kind",
            "found",
            "signatures",
            "source"
          ],
          "type": "object"
        },
        "type": {
          "type": "string"
        }
      },
      "required": [
        "type"
      ],
      "type": "object"
    }
  },
  "required": [
    "input"
  ],
  "type": "object"
}