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HMAC-SHA3-512 Hex Generator
x402
HMAC-SHA3-512 Hex Generator is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.006/call, status unknown (last checked 2026-10-02).
Computes an HMAC using SHA3-512 of a given text with a caller-supplied key, returning the result as a lowercase hex string.
Price / call$0.006
Success—
StatusUnknown
How this service works
Call when an agent needs an HMAC-sha3-512 of text with a caller-supplied key, encoded as hex. Exact $0.006 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha3-512-hex first.
Output
A hex-encoded HMAC-SHA3-512 digest string (128 hex characters) computed from the provided text and key. The response contains the raw cryptographic authentication code that can be used for message signing, integrity verification, or secure token generation.
Example use cases
API request signing with HMAC
“I need to sign the payload 'user_id=42&action=transfer&amount=100' with the secret key 'prod-signing-key-xyz' using HMAC-SHA3-512 — can you give me the hex digest?”
Webhook payload integrity check
“Generate an HMAC-SHA3-512 hex of the webhook body '{"event":"payment.completed","id":"evt_99"}' using the key 'webhook-secret-2024' so I can include it in the signature header.”
Data tamper detection token
“Create an HMAC-SHA3-512 hex tag for the string 'record:user:7891:updated:2024-06-01T12:00:00Z' using key 'audit-integrity-key' so I can store it alongside the record to detect tampering.”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/hmac-sha3-512-hex?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you specifically need HMAC with the SHA3-512 hash function (not SHA-256 or SHA-1) and require hex-encoded output. It is ideal for security-sensitive workflows needing stronger hash functions than the more common HMAC-SHA256. Prefer the free sandbox endpoint POST /v1/sandbox/hmac-sha3-512-hex for testing before paying $0.006 USDC per call on this production endpoint.
Side effects
- Missing or empty key field returns validation error
- Missing or empty text field returns validation error
- Text exceeding 100,000 characters returns payload too large error
- Key exceeding 512 characters returns validation error
- Payment of $0.006 USDC not included or insufficient triggers 402 Payment Required
- Malformed request body returns 400 Bad Request
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| key | string | HMAC secret. Required on HMAC SKUs. Omit it for plain digests and checksums. The key is not stored. |
| text | string | Message to digest. For raw-hex SKUs this is hex bytes; for utf16 or latin1 SKUs it is decoded with that encoding. Otherwise it is UTF-8 text. |
Tags
x402
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