Decode EVM smart-contract transaction calldata into the function name and typed parameters
Decode EVM smart-contract transaction calldata into the function name and typed parameters. Supply an ABI (from /api/contract-abi) or a signature like transfer(address,uint256) for a fully offline decode; with neither, the 4-byte selector is resolved via the openchain.xyz signature database (4byte.directory fallback) and each candidate signature is tried. Unknown selectors return a documented partial decode (selector + raw 32-byte words) instead of an error.
3000 (raw units)
price
4
calls / 30d
1
unique payers
2026-08-31
updated
Provider
agent402.tools · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:137",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:42161",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:143",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0x754704Bc059F8C67012fEd69BC8A327a5aafb603",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:43114",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:1329",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0xe15fC38F6D8c56aF07bbCBe3BAf5708A2Bf42392",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:10",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85",
"amount": "4000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:4663",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0x5fc5360D0400a0Fd4f2af552ADD042D716F1d168",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:42220",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0xcebA9300f2b948710d2653dD7B07f33A8B32118C",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "upto",
"network": "eip155:8453",
"payTo": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
"payTo": "J7aN3PLJnTCF5qpEnvJHJsnCjcGuqC2rYtEM8Gv3xwg",
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"amount": "3000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "stellar:pubnet",
"payTo": "GDNJXCKW7ZM7GEEVP674TWPU26YJNBQ2FI4ZIPRKTPTNUEJMDHFJWWRL",
"asset": "CCW67TSZV3SSS2HXMBQ5JFGCKJNXKZM7UQUWUZPUTHXSTZLEO7SJMI75",
"amount": "30000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
"payTo": "C7IIHG7SPLPZ5H7ZT6HW3UV2OQMQQE6Y2HBNGZXSLRJULE42BEE2OY2XIE",
"asset": "31566704",
"amount": "3000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"body": {
"data": "0xa9059cbb000000000000000000000000abf4fabd7c416fb67202e5f9002389fc75e2a9d000000000000000000000000000000000000000000000000000000000000f4240"
},
"bodyType": "json",
"method": "POST",
"type": "http"
},
"output": {
"example": {
"decoded": true,
"name": "transfer",
"params": [
{
"name": null,
"type": "address",
"value": "0xabf4fabd7c416fb67202e5f9002389fc75e2a9d0"
},
{
"name": null,
"type": "uint256",
"value": "1000000"
}
],
"selector": "0xa9059cbb",
"signature": "transfer(address,uint256)",
"source": "openchain.xyz"
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"abi": {
"description": "Optional contract ABI (JSON array) - enables a fully offline decode with parameter names.",
"type": "array"
},
"data": {
"description": "0x-prefixed calldata (selector + encoded args). Max 100KB.",
"type": "string"
},
"signature": {
"description": "Optional function signature, e.g. transfer(address,uint256) - offline decode without a full ABI.",
"type": "string"
}
},
"required": [
"data"
]
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"decoded": {
"type": "boolean"
},
"name": {
"type": "string"
},
"params": {
"items": {
"properties": {
"name": {},
"type": {
"type": "string"
},
"value": {
"type": "string"
}
},
"type": "object"
},
"type": "array"
},
"selector": {
"type": "string"
},
"signature": {
"type": "string"
},
"source": {
"type": "string"
}
},
"required": [
"selector",
"decoded",
"name",
"signature",
"params",
"source"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
},
"builder-code": {
"info": {
"a": "bc_b4aw4uzd"
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"properties": {
"a": {
"description": "App builder code",
"pattern": "^[a-z0-9_]{1,32}$",
"type": "string"
},
"s": {
"description": "Service builder codes",
"items": {
"pattern": "^[a-z0-9_]{1,32}$",
"type": "string"
},
"maxItems": 11,
"type": "array"
},
"w": {
"description": "Wallet builder code",
"pattern": "^[a-z0-9_]{1,32}$",
"type": "string"
}
},
"type": "object"
}
},
"payment-identifier": {
"info": {
"required": false
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"id": {
"maxLength": 128,
"minLength": 16,
"pattern": "^[a-zA-Z0-9_-]+$",
"type": "string"
},
"required": {
"type": "boolean"
}
},
"required": [
"required"
],
"type": "object"
}
}
}Use it
curl
curl "https://agent402.tools/api/calldata-decode" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://agent402.tools/api/calldata-decode");
if (res.status === 402) {
const { accepts } = await res.json();
// pay one of accepts[] via an x402 client, then retry with the payment header
}Python
import httpx
res = httpx.get("https://agent402.tools/api/calldata-decode")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/1699.json, and this resource appears in /discovery/resources and /discovery/search.