Compute a keyed HMAC of some data with a secret key — the standard way to sign a
Compute a keyed HMAC of some data with a secret key — the standard way to sign and verify webhooks (Stripe, GitHub, etc.) and API requests. Data and key may each be utf8/hex/base64/base64url; the tag is returned as hex/base64/base64url.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
630 msmedian answer time
$0.002listed price per call
$0.002price 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
POST https://hash.openverbs.com/v1/hmac
| Category | Everything else |
|---|---|
| Provider host | hash.openverbs.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 4 from 2 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.002 | 630 ms |
Example input (from the provider)
{
"body": {
"algorithm": "sha256",
"data": "example",
"inputEncoding": "utf8",
"key": "example",
"keyEncoding": "utf8"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"algorithm": {
"description": "Digest algorithm, one of sha256, sha512, sha384, sha224, sha1, sha3-256, sha3-384, sha3-512, md5, ripemd160, blake2b512, blake2s256.",
"enum": [
"sha256",
"sha512",
"sha384",
"sha224",
"sha1",
"sha3-256",
"sha3-384",
"sha3-512",
"md5",
"ripemd160",
"blake2b512",
"blake2s256"
],
"type": "string"
},
"data": {
"description": "The data to authenticate, in `inputEncoding`.",
"maxLength": 5000000,
"type": "string"
},
"inputEncoding": {
"description": "How to interpret the text as bytes (utf8, hex, base64, base64url). Default utf8.",
"enum": [
"utf8",
"hex",
"base64",
"base64url"
],
"type": "string"
},
"key": {
"description": "The secret key, in `keyEncoding`.",
"maxLength": 16384,
"minLength": 1,
"type": "string"
},
"keyEncoding": {
"description": "How to interpret the key as bytes (utf8, hex, base64, base64url). Default utf8.",
"enum": [
"utf8",
"hex",
"base64",
"base64url"
],
"type": "string"
},
"outputEncoding": {
"description": "How to render the digest (hex, base64, base64url). Default hex.",
"enum": [
"hex",
"base64",
"base64url"
],
"type": "string"
}
},
"required": [
"data",
"key",
"algorithm"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}