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Solidity Function Selector Calculator
x402
Solidity Function Selector Calculator is a paid API for AI agents from chargers-borders-cedar-fig.trycloudflare.com, paid per call via x402, price unknown, status down (last checked 2026-09-15).
Computes the 4-byte ABI function selector for a given Solidity method signature
Price / call—
Success—
StatusDown
How this service works
opentools utility endpoint
Output
Returns the 4-byte hexadecimal function selector derived from the keccak256 hash of the provided Solidity function signature, usable directly in EVM calldata or ABI encoding.
Example use cases
Debugging smart contract calldata
“I'm reading raw Ethereum transaction calldata and need to figure out which function was called — can you compute the selector for approve(address,uint256) so I can match it against the first 4 bytes?”
Generating selector for custom contract method
“I'm writing a low-level Solidity proxy and need the function selector for execute(address,bytes,uint256) — can you calculate it for me?”
Verifying ABI encoding correctness
“I want to double-check that my ABI encoding is right — what's the 4-byte selector for balanceOf(address) in Solidity?”
Technical details
Endpoint
POSThttps://chargers-borders-cedar-fig.trycloudflare.com/tools/solidity-selectorWhen to prefer
Use this endpoint when you need a quick, programmatic way to compute Solidity function selectors without running a local Ethereum toolchain or Hardhat/Foundry environment. Ideal for agents operating in lightweight environments that need ABI selector computation on-demand.
Side effects
- Malformed or missing method signature returns an error
- Invalid parameter types in signature may produce incorrect selectors without warning
- Network timeout via Cloudflare tunnel if the backing service is down
- Empty or null input body returns a validation error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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