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EVM Calldata Decoder
x402
EVM Calldata Decoder is a paid API for AI agents from api.anchor-x402.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).
Decodes raw EVM calldata hex into a human-readable function name and typed parameter list via openchain.xyz
Price / call$0.001
Success—
StatusUnknown
How this service works
Decode raw EVM calldata into function + typed params via openchain.xyz — $0.001 USDC
Output
Returns the decoded function name/signature and a list of typed, named parameters extracted from the calldata hex, making raw transaction input data human-readable.
Example use cases
Example prompt
“Can you decode this raw EVM calldata for me and tell me which function it's calling and what the typed arguments are: 0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000?”
Technical details
Endpoint
POSThttps://api.anchor-x402.com/v1/decode/calldataWhen to prefer
Use this endpoint when you have a raw hex calldata string from an EVM transaction and need to understand which smart contract function it invokes and with what parameters, without needing to supply your own ABI. Especially useful for transaction auditing, wallet activity explanation, or debugging on-chain interactions.
Side effects
- Unknown or unregistered 4-byte selector — openchain.xyz has no matching signature, returns null or error
- Malformed hex input — calldata is not valid hex or is truncated
- ABI mismatch — selector is known but arguments cannot be decoded against any known ABI
- Payment failure — x402 USDC payment not accepted or insufficient funds
Input
{
"input": {
"body": {
"chain": "ethereum",
"calldata_hex": "0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000"
},
"type": "http",
"method": "POST",
"bodyType": "json"
}
}Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
{
"params": [
{
"name": null,
"type": "address",
"value": "0xab5801a7d398351b8be11c439e05c5b3259aec9b"
},
{
"name": null,
"type": "uint256",
"value": "1000000000000000000"
}
],
"source": "openchain.xyz",
"decoded": true,
"candidates": [],
"function_name": "transfer",
"function_selector": "0xa9059cbb",
"function_signature": "transfer(address,uint256)"
}Schema · Response
{
"type": "json",
"example": {
"params": [
{
"name": null,
"type": "address",
"value": "0xab5801a7d398351b8be11c439e05c5b3259aec9b"
},
{
"name": null,
"type": "uint256",
"value": "1000000000000000000"
}
],
"source": "openchain.xyz",
"decoded": true,
"candidates": [],
"function_name": "transfer",
"function_selector": "0xa9059cbb",
"function_signature": "transfer(address,uint256)"
}
}Tags
x402
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