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agentshelf.syntexa.ch HMAC-SHA512 Hex
x402
agentshelf.syntexa.ch HMAC-SHA512 Hex is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).
Computes an HMAC-SHA512 digest of a given text using a caller-supplied secret key, returning the result as a lowercase hex string.
Price / call$0.001
Success—
StatusUnknown
How this service works
Call when an agent needs an HMAC-sha512 of text with a caller-supplied key, encoded as hex. Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha512-hex first.
Output
Returns a JSON object containing the HMAC-SHA512 digest of the input text, keyed with the provided secret and encoded as a lowercase hexadecimal string.
Example use cases
Webhook payload signing
“Sign this webhook body with my secret key 'wh_secret_abc123' using HMAC-SHA512 and give me the hex digest — the body is '{"event":"payment.completed","amount":50}'”
API request authentication
“I need to authenticate an outgoing API request by computing an HMAC-SHA512 hex signature of 'GET /api/orders/987?ts=1700000000' using my signing key 'sigkey_xyz789'.”
Data integrity verification
“Compute the HMAC-SHA512 hex of the string 'user_id=42|action=delete|ts=1699999999' with key 'integrity_key_prod' so I can attach it as a verification tag.”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/hmac-sha512-hex?utm_source=zero.xyzWhen to prefer
Use this endpoint when an agent needs a server-side HMAC-SHA512 hex computation without running local cryptographic code. Prefer this over client-side alternatives when the environment lacks crypto libraries. Note the free sandbox endpoint POST /v1/sandbox/hmac-sha512-hex should be tried first before incurring the $0.001 USDC charge.
Side effects
- Empty or missing key returns a 400/422 validation error
- Empty or missing text returns a 400/422 validation error
- Text exceeding 100,000 characters is rejected
- Key exceeding 512 characters is rejected
- Payment failure or insufficient USDC balance returns a 402 error
- Network timeout or service unavailability returns a 5xx error
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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