Web3 Tools
Split EVM calldata into its 4-byte selector and 32-byte words, naming common ERC-20/721 calls and spotting addresses.
DataLiveeip155:8453Exactvia cdp
CalldataAbiEvmTransactionDecode
Calls · 30d
2
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far.
$24.31
Verified settled volume
1,175 settlements proven x402 by their on-chain EIP-3009 marker.
$0.020
Listed price
As published in the catalog. Always read the live 402 before paying.
2
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-10-20 20:03Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xb531320805C5BED1D46AEaDcF4F008FDF172DBDaThe wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Provider
The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.
Live 402 challenge
Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.
{
"error": "Payment required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
"network": "base",
"mimeType": "application/json",
"resource": "https://web3-tools.x402tookit.com/calldata-split",
"description": "Split EVM calldata into its 4-byte selector and 32-byte words, naming common ERC-20/721 calls and spotting addresses.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"data": "0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000"
}
},
"output": {
"asOf": "2026-10-11T14:21:53.970Z",
"words": [
{
"hex": "0x000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b",
"index": 0,
"address": "0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B",
"asUint256": "978200031609045874420567273872976536139233684635",
"isMaxUint256": false,
"looksLikeAddress": true
},
{
"hex": "0x0000000000000000000000000000000000000000000000000de0b6b3a7640000",
"index": 1,
"address": null,
"asUint256": "1000000000000000000",
"isMaxUint256": false,
"looksLikeAddress": false
}
],
"source": "computed locally",
"reasons": [
"Argument bytes are a whole number of 32-byte words, as ABI encoding requires."
],
"summary": "Selector 0xa9059cbb = transfer(address,uint256); 2 full 32-byte words.",
"verdict": "SPLIT",
"degraded": false,
"selector": "0xa9059cbb",
"wordCount": 2,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"the real argument types: words are interpreted by shape only (a number that looks like an address may not be one)",
"dynamic types (bytes, string, arrays) appear as offsets and lengths in the words, not decoded values",
"…1 more"
],
"totalBytes": 68,
"argumentBytes": 64,
"trailingBytes": 0,
"knownSignature": "transfer(address,uint256)",
"wordsTruncated": false,
"unlimitedApprovalSuspected": false
}
},
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
},
{
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"feePayer": "BFK9TLC3edb13K6v4YyH3DwPb5DSUpkWvb7XnqCL9b4F"
},
"payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
"scheme": "exact",
"network": "solana",
"mimeType": "application/json",
"resource": "https://web3-tools.x402tookit.com/calldata-split",
"description": "Split EVM calldata into its 4-byte selector and 32-byte words, naming common ERC-20/721 calls and spotting addresses.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"data": "0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000"
}
},
"output": {
"asOf": "2026-10-11T14:21:53.970Z",
"words": [
{
"hex": "0x000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b",
"index": 0,
"address": "0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B",
"asUint256": "978200031609045874420567273872976536139233684635",
"isMaxUint256": false,
"looksLikeAddress": true
},
{
"hex": "0x0000000000000000000000000000000000000000000000000de0b6b3a7640000",
"index": 1,
"address": null,
"asUint256": "1000000000000000000",
"isMaxUint256": false,
"looksLikeAddress": false
}
],
"source": "computed locally",
"reasons": [
"Argument bytes are a whole number of 32-byte words, as ABI encoding requires."
],
"summary": "Selector 0xa9059cbb = transfer(address,uint256); 2 full 32-byte words.",
"verdict": "SPLIT",
"degraded": false,
"selector": "0xa9059cbb",
"wordCount": 2,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"the real argument types: words are interpreted by shape only (a number that looks like an address may not be one)",
"dynamic types (bytes, string, arrays) appear as offsets and lengths in the words, not decoded values",
"…1 more"
],
"totalBytes": 68,
"argumentBytes": 64,
"trailingBytes": 0,
"knownSignature": "transfer(address,uint256)",
"wordsTruncated": false,
"unlimitedApprovalSuspected": false
}
},
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
},
{
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
"network": "polygon",
"mimeType": "application/json",
"resource": "https://web3-tools.x402tookit.com/calldata-split",
"description": "Split EVM calldata into its 4-byte selector and 32-byte words, naming common ERC-20/721 calls and spotting addresses.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"data": "0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000"
}
},
"output": {
"asOf": "2026-10-11T14:21:53.970Z",
"words": [
{
"hex": "0x000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b",
"index": 0,
"address": "0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B",
"asUint256": "978200031609045874420567273872976536139233684635",
"isMaxUint256": false,
"looksLikeAddress": true
},
{
"hex": "0x0000000000000000000000000000000000000000000000000de0b6b3a7640000",
"index": 1,
"address": null,
"asUint256": "1000000000000000000",
"isMaxUint256": false,
"looksLikeAddress": false
}
],
"source": "computed locally",
"reasons": [
"Argument bytes are a whole number of 32-byte words, as ABI encoding requires."
],
"summary": "Selector 0xa9059cbb = transfer(address,uint256); 2 full 32-byte words.",
"verdict": "SPLIT",
"degraded": false,
"selector": "0xa9059cbb",
"wordCount": 2,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"the real argument types: words are interpreted by shape only (a number that looks like an address may not be one)",
"dynamic types (bytes, string, arrays) appear as offsets and lengths in the words, not decoded values",
"…1 more"
],
"totalBytes": 68,
"argumentBytes": 64,
"trailingBytes": 0,
"knownSignature": "transfer(address,uint256)",
"wordsTruncated": false,
"unlimitedApprovalSuspected": false
}
},
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1,
"alsoAvailable": {
"llms": "https://web3-tools.x402tookit.com/llms.txt",
"catalog": "https://web3-tools.x402tookit.com/catalog",
"message": "Web3 Tools has 12 pay-per-call endpoints (Check and decode crypto addresses, hashes, selectors and units without a node.), from $0.02 a call. See the full menu and send your agents our way.",
"openapi": "https://web3-tools.x402tookit.com/openapi.json",
"related": [
{
"url": "https://web3-tools.x402tookit.com/contract-address",
"path": "/contract-address",
"what": "Predict a contract address: CREATE from deployer and nonce, or CREATE2 from deployer, sal…",
"price": "$0.02"
},
{
"url": "https://web3-tools.x402tookit.com/evm-address",
"path": "/evm-address",
"what": "Check an EVM address (Ethereum, Base, Polygon...) against its EIP-55 checksum and return…",
"price": "$0.02"
},
{
"url": "https://web3-tools.x402tookit.com/function-selector",
"path": "/function-selector",
"what": "Compute the 4-byte function selector and event topic0 from a Solidity signature such as t…",
"price": "$0.02"
}
]
}
}Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
0.02USDC≈ $0.02 USD
on Base · exact scheme
Pay 0.02 USDC on Base to 0xb531…2DBDa. The signed payment is good for 5 minutes.
- Paid to
- 0xb531…2DBDa
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 20000 smallest units
20000units
on solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp · exact scheme
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- DUPiup…eEm8s
- Token contract
- EPjFWd…TDt1v
- Payment window
- 5 minutes
20000units
on Polygon · exact scheme
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- 0xb531…2DBDa
- Token contract
- 0x3c49…c3359
- Payment window
- 5 minutes
20000units
on Arbitrum · exact scheme
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- 0xb531…2DBDa
- Token contract
- 0xaf88…e5831
- Payment window
- 5 minutes
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
},
{
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"feePayer": "D6ZhtNQ5nT9ZnTHUbqXZsTx5MH2rPFiBBggX4hY1WePM"
},
"payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
"amount": "20000",
"scheme": "exact",
"network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
"maxTimeoutSeconds": 300
},
{
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:137",
"maxTimeoutSeconds": 300
},
{
"asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:42161",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"data": "0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000"
}
},
"output": {
"type": "json",
"example": {
"asOf": "2026-10-11T14:21:53.970Z",
"words": [
{
"hex": "0x000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b",
"index": 0,
"address": "0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B",
"asUint256": "978200031609045874420567273872976536139233684635",
"isMaxUint256": false,
"looksLikeAddress": true
},
{
"hex": "0x0000000000000000000000000000000000000000000000000de0b6b3a7640000",
"index": 1,
"address": null,
"asUint256": "1000000000000000000",
"isMaxUint256": false,
"looksLikeAddress": false
}
],
"source": "computed locally",
"reasons": [
"Argument bytes are a whole number of 32-byte words, as ABI encoding requires."
],
"summary": "Selector 0xa9059cbb = transfer(address,uint256); 2 full 32-byte words.",
"verdict": "SPLIT",
"degraded": false,
"selector": "0xa9059cbb",
"wordCount": 2,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"the real argument types: words are interpreted by shape only (a number that looks like an address may not be one)",
"dynamic types (bytes, string, arrays) appear as offsets and lengths in the words, not decoded values",
"…1 more"
],
"totalBytes": 68,
"argumentBytes": 64,
"trailingBytes": 0,
"knownSignature": "transfer(address,uint256)",
"wordsTruncated": false,
"unlimitedApprovalSuspected": false
}
}
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method"
],
"properties": {
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"type": "object",
"required": [
"data"
],
"properties": {
"data": {
"type": "string",
"description": "Calldata hex, with or without 0x"
}
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"properties": {
"asOf": {
"type": [
"null",
"string"
]
},
"words": {
"type": [
"array",
"null"
],
"items": {
"type": "object",
"properties": {
"hex": {
"type": [
"null",
"string"
]
},
"index": {
"type": [
"null",
"number"
]
},
"address": {
"type": [
"null",
"string"
]
},
"asUint256": {
"type": [
"null",
"string"
]
},
"isMaxUint256": {
"type": [
"boolean",
"null"
]
},
"looksLikeAddress": {
"type": [
"boolean",
"null"
]
}
}
}
},
"source": {
"type": [
"null",
"string"
]
},
"reasons": {
"type": [
"array",
"null"
],
"items": {
"type": "string"
}
},
"summary": {
"type": [
"null",
"string"
]
},
"verdict": {
"type": [
"null",
"string"
]
},
"degraded": {
"type": [
"boolean",
"null"
]
},
"selector": {
"type": [
"null",
"string"
]
},
"wordCount": {
"type": [
"null",
"number"
]
},
"disclaimer": {
"type": [
"null",
"string"
]
},
"notChecked": {
"type": [
"array",
"null"
],
"items": {
"type": "string"
}
},
"totalBytes": {
"type": [
"null",
"number"
]
},
"argumentBytes": {
"type": [
"null",
"number"
]
},
"trailingBytes": {
"type": [
"null",
"number"
]
},
"knownSignature": {
"type": [
"null",
"string"
]
},
"wordsTruncated": {
"type": [
"boolean",
"null"
]
},
"unlimitedApprovalSuspected": {
"type": [
"boolean",
"null"
]
}
}
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-10-20 20:03Z
- Last indexed by Roundhouse
- 2026-10-22 19:30Z
- Last enriched (probe, favicon, geo)
- 2026-10-21 00:15Z
- x402 version
- 2
- Max timeout
- 300s
- Liveness probe
- HTTP 402
Hand this page to an agent
Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.
GET api.roundhouseai.io/v0/endpoints
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.
Show the promptHide the prompt
Using Roundhouse, look up the x402 service Web3 Tools and tell me whether it is worth paying: what a call costs, whether the endpoint answered when last probed, and what its payment record actually shows. curl -s 'https://api.roundhouseai.io/v0/endpoints?q=Web3%20Tools' curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>' Then call it: read the price from the live 402 at https://web3-tools.x402tookit.com/calldata-split, never from a cached figure, and pay with an x402 client. The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except /v0/unified* and /v0/endpoints. Either pay over x402 (mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.