EVM Calldata Decoder

x402

EVM Calldata Decoder is a paid API for AI agents from golf-evm-math.x402-evm-math.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-30).

Decodes EVM calldata hex strings into human-readable function signatures and typed arguments using a built-in table of ~60 common ERC20/721/1155, Uniswap, and Aave signatures, or a user-supplied signature.

Price / call$0.002

Seller volume →—

Success—

StatusUnknown

How this service works

Exact EVM address, calldata, Uniswap V2/V3 and impermanent-loss math. Pay per call in USDC on Base via x402.

Output

Returns a JSON object indicating whether the function selector is known, the 4-byte selector (e.g. 0xa9059cbb), the resolved function signature name and parameter types, and the decoded typed argument values extracted from the calldata.

Example use cases

Decode ERC20 transfer calldata

“I have this transaction input data from an Ethereum transfer: 0xa9059cbb000000000000000000000000deadbeef...0000000000000000000000000000000000000000000000000de0b6b3a7640000 — can you decode it into a human-readable function call and show me the recipient and amount?”

Identify Uniswap swap function

“I'm analyzing a Uniswap transaction and the input data starts with 0x38ed1739. Can you decode the full calldata and tell me which Uniswap function was called and what the swap parameters are?”

Custom ABI calldata decoding

“I have some calldata from a contract: 0x12345678... and I know the signature is mint(address,uint256). Can you decode the arguments using that custom signature so I can see what was passed in?”

Technical details

Endpoint

GEThttps://golf-evm-math.x402-evm-math.workers.dev/evm/decode?utm_source=zero.xyz

When to prefer

Choose this endpoint when you need to quickly decode EVM transaction calldata without setting up a full ABI decoder or node connection, especially for common DeFi protocols (ERC20, ERC721, ERC1155, Uniswap, Aave). Ideal for transaction analysis pipelines, on-chain monitoring, and debugging tools. Supports custom signatures for non-standard contracts.

Side effects

Unknown selector not in built-in table and no custom signature supplied — returns known:false with no decoded args
Malformed or non-hex calldata input — returns error response
Calldata too short to contain a valid 4-byte selector — parse error
Supplied custom signature does not match the calldata selector — decoding mismatch
Network or payment authorization failure returns 402 Payment Required

Input

Schema · Request body

Field	Type	Description
inputrequired	object
output	object

Output

Schema · Response

{
  "type": "json",
  "example": {
    "known": true,
    "selector": "0xa9059cbb"
  }
}

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