EIP-712 typed data hashing
EIP-712 typed data hashing: signing digest, domain separator and struct hash from JSON, with an optional signature check against an address.
Answeringour last check, 2026-10-21
1 of 1checks answered this week
659 msmedian answer time
$0.01listed price per call
$0.01price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://saylorinnovations.com/api/chain/eip712-hash
| Category | Everything else |
|---|---|
| Provider host | saylorinnovations.com |
| Networks | eip155:137, eip155:42161, eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-21 | valid payment request | 402 | $0.01 | 659 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"typed_data": "{\"domain\":{\"name\":\"Ether Mail\",\"version\":\"1\",\"chainId\":1,\"verifyingContract\":\"0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC\"},\"types\":{\"Person\":[{\"name\":\"name\",\"type\":\"string\"},{\"name\":\"wallet\",\"type\":\"address\"}],\"Mail\":[{\"name\":\"from\",\"type\":\"Person\"},{\"name\":\"to\",\"type\":\"Person\"},{\"name\":\"contents\",\"type\":\"string\"}]},\"primaryType\":\"Mail\",\"message\":{\"from\":{\"name\":\"Cow\",\"wallet\":\"0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826\"},\"to\":{\"name\":\"Bob\",\"wallet\":\"0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB\"},\"contents\":\"Hello, Bob!\"}}"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"typed_data": {
"description": "JSON with domain, types, primaryType and message (EIP-712 typed data, up to 12,000 characters)",
"type": "string"
}
},
"required": [
"typed_data"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"digest": {
"description": "final 32-byte signing digest",
"type": "string"
},
"domain_separator": {
"description": "hash of the EIP-712 domain",
"type": "string"
},
"note": {
"description": "plain-language reading of the result",
"type": "string"
},
"primary_type": {
"description": "the struct type being signed",
"type": "string"
},
"recovered_address": {
"description": "address recovered from the signature",
"type": [
"string",
"null"
]
},
"signature_checked": {
"description": "true when a signature was supplied",
"type": "boolean"
},
"signature_valid": {
"description": "true when the signer matches the address",
"type": [
"boolean",
"null"
]
},
"source": {
"description": "where the data was read from or how it was computed",
"type": "string"
},
"struct_hash": {
"description": "hash of the message struct",
"type": "string"
}
},
"required": [
"primary_type",
"digest",
"domain_separator",
"struct_hash",
"signature_checked",
"note",
"source"
],
"type": "object"
},
"type": {
"const": "json",
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}