Compute the Keccak-256 hash of a Solidity function or event signature and derive
Compute the Keccak-256 hash of a Solidity function or event signature and derive the 4-byte function selector and the 32-byte event topic. Normalises the signature first — strips parameter names, expands uint to uint256 and the other aliases, flattens tuples — so a signature copied from source code produces the same selector as the canonical form. Also hashes arbitrary text or hex bytes with Keccak-256.
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Endpoint
GET https://api.duoleads.com/v1/chain/selector
| Category | Code and developer |
|---|---|
| Provider host | api.duoleads.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
We never call tools that send, buy, move money or file anything, not even without paying.
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"signature": "transfer(address,uint256)"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"data": {
"description": "Alternative to signature: raw data to Keccak-256 hash.",
"maxLength": 8192,
"type": "string"
},
"encoding": {
"default": "utf8",
"description": "Encoding of data: utf8 (default) or hex.",
"enum": [
"utf8",
"hex"
],
"maxLength": 64,
"type": "string"
},
"kind": {
"default": "function",
"description": "function (default), event or error.",
"enum": [
"function",
"event",
"error"
],
"maxLength": 64,
"type": "string"
},
"signature": {
"description": "Solidity function, event or error signature, e.g. transfer(address to, uint amount).",
"maxLength": 1024,
"type": "string"
}
},
"required": [],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"data": {
"type": "object"
},
"meta": {
"properties": {
"computed_at": {
"type": "string"
},
"deterministic": {
"type": "boolean"
},
"disclaimer": {
"type": "string"
},
"price_usd": {
"type": "string"
},
"request_id": {
"type": "string"
},
"sources": {
"type": "array"
}
},
"required": [
"request_id",
"computed_at",
"price_usd",
"deterministic",
"disclaimer"
],
"type": "object"
},
"ok": {
"const": true,
"type": "boolean"
},
"route": {
"type": "string"
},
"version": {
"type": "string"
}
},
"required": [
"ok",
"route",
"version",
"data",
"meta"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}