Verify a webhook's HMAC signature against the correct per-provider scheme
Verify a webhook's HMAC signature against the correct per-provider scheme: GitHub (X-Hub-Signature-256, sha256=hex), Stripe (Stripe-Signature t/v1 over "<t>.<body>" with replay tolerance), Shopify (X-Shopify-Hmac-Sha256, base64), Slack (X-Slack-Signature, v0:<ts>:<body> with replay tolerance). Constant-time comparison; the secret is never echoed. Pass the RAW request body string - signatures are over the raw bytes. Deterministic.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
949 msmedian answer time
$0.001listed price per call
$0.001price 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://agent402.tools/api/webhook-verify
| Category | Commerce and shopping |
|---|---|
| Provider host | agent402.tools |
| Networks | algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=, eip155:10, eip155:1329, eip155:137, eip155:143, eip155:42161, eip155:42220, eip155:43114, eip155:4663, eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp, stellar:pubnet |
| Payment schemes | exact, upto |
| Self-reported calls, 30 days | 4 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.001 | 949 ms |
Example input (from the provider)
{
"body": {
"payload": "{\"hello\":\"world\"}",
"provider": "github",
"secret": "it's a secret",
"signature": "sha256=8d4063f0a81aa1531d9891a028a68cf2bb537ecdf0e82557674d71e168d570f9"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"payload": {
"description": "the RAW request body string, byte-for-byte as received (never a re-serialized object)",
"type": "string"
},
"provider": {
"description": "github | stripe | shopify | slack",
"type": "string"
},
"secret": {
"description": "the provider signing secret (never echoed back)",
"type": "string"
},
"signature": {
"description": "the signature header value, with or without its scheme prefix (sha256= / v0= / t=...,v1=...)",
"type": "string"
},
"timestamp": {
"description": "provider timestamp, required for stripe + slack (stripe may be parsed from a t= element in the signature)",
"type": "string"
},
"toleranceSeconds": {
"description": "max timestamp age for stripe/slack replay protection (default 300; 0 skips the age check)",
"type": "number"
}
},
"required": [
"provider",
"payload",
"secret",
"signature"
]
},
"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"
},
"output": {
"properties": {
"example": {
"properties": {
"provider": {
"type": "string"
},
"reason": {
"type": "string"
},
"scheme": {
"type": "string"
},
"valid": {
"type": "boolean"
}
},
"required": [
"valid",
"provider",
"scheme",
"reason"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}