Tool detail

4-Byte Selector Decoder

Resolves a 4-byte Ethereum function selector or full calldata to candidate human-readable function signatures via 4byte.directory.

Categories: Utilities

Use when

decode an unknown 4-byte function selector to a likely signature
identify what function a piece of calldata is calling

Not for

not a full ABI decoder for arguments - signature candidates only

Inputs

GET query param: selector (string, required) - a bare 4-byte selector or full calldata

Admitted input schema

{
  "type": "object",
  "properties": {
    "selector": {
      "type": "string",
      "minLength": 0,
      "maxLength": 4096,
      "description": "Function selector"
    }
  },
  "required": [
    "selector"
  ],
  "additionalProperties": false
}

Endpoint

Method: GET
URL: https://402.com.tr/api/x402/decode-selector

Payment

Protocol: x402
Listed price: 0.01 USDC per call on Base
Payment method: exact
Network: eip155:8453
Asset: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Listed terms are catalog metadata. The caller supplies inputs and calls the tool outside Onelayer. If payment is required, the caller uses a compatible wallet to pay.

Source

Directory: Coinbase x402 Bazaar
Record: GET https://402.com.tr/api/x402/decode-selector
Retrieved: 2026-09-30T20:37:07.382Z
Catalog file SHA-256: 6837ccddf886f0007cf3727ea9d27faaa5047b51b4f425345c554ce1c271a524
Catalog built: 2026-09-30T22:31:58.034Z