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Solidity ABI Calldata Encoder
x402
Solidity ABI Calldata Encoder is a paid API for AI agents from chain-tools.use.x402atlas.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).
Encodes canonical typed values into EVM smart-contract ABI calldata, optionally including a 4-byte function selector and exact 256-bit integers.
Price / call$0.005
Success—
StatusUnknown
How this service works
Solidity ABI calldata encoder — encode canonical typed values for an EVM smart-contract function call, with an optional selector and exact 256-bit integers.
Output
Returns a hex-encoded ABI calldata byte string conforming to the Solidity ABI specification. If a function selector is requested, the output is prefixed with the 4-byte keccak256-derived selector followed by the ABI-encoded parameters. Integers are encoded as exact 256-bit values padded to 32-byte slots.
Example use cases
Encode raw ERC-20 transfer calldata
“ABI-encode a call to the ERC-20 transfer(address,uint256) function with recipient 0xDeAdBeEf00000000000000000000000000000001 and amount 500000000 as an exact uint256 — include the function selector so I can use this as raw calldata in a transaction.”
Prepare constructor args for contract deployment
“I need to ABI-encode constructor arguments for a Solidity contract deployment — the constructor is initialize(string,uint256,address) with values 'MyToken', 1000000 as exact uint256, and owner address 0x1234567890abcdef1234567890abcdef12345678, no selector needed.”
Build calldata for a multisig proposal
“Encode calldata for a governance proposal — the target function is setParams(uint256,bool,address) with values 42 as exact uint256, true, and 0xABCDEF1234567890ABcDEF1234567890abCDEF12, and include the 4-byte selector so the multisig can execute it directly.”
Technical details
Endpoint
POSThttps://chain-tools.use.x402atlas.com/evm/abi-encodeWhen to prefer
Choose this endpoint when you need deterministic, canonical Solidity ABI encoding of typed values for EVM smart-contract calls — especially when you require exact 256-bit integer precision or an optional prepended 4-byte function selector. Prefer it over client-side encoding libraries when operating in a serverless or agent context without a Web3 runtime, or when you need a trusted third-party to produce verifiable calldata. The companion ABI decoder endpoint on the same platform handles the inverse operation.
Side effects
- Invalid or malformed Solidity type string causes encoding error
- Type/value mismatch (e.g. passing a string where uint256 is expected) returns validation error
- Malformed Ethereum address (wrong length or non-hex) rejected
- Integer value exceeds 256-bit range returns overflow error
- Missing required function signature when selector is requested
- Unsupported or non-canonical Solidity type returns type-not-found error
Tags
x402
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