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HMAC-SHA384 Hex Digest
x402
HMAC-SHA384 Hex Digest is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.008/call, status unknown (last checked 2026-09-29).
Computes an HMAC-SHA384 message authentication code for a given text using a caller-supplied key, returning the result as a lowercase hex string.
Price / call$0.008
Success—
StatusUnknown
How this service works
Call when an agent needs an HMAC-sha384 of text with a caller-supplied key, encoded as hex. Exact $0.008 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha384-hex first.
Output
A hex-encoded HMAC-SHA384 digest string (96 hex characters) derived from the supplied text and key. The response confirms the cryptographic signature computed server-side with no additional metadata.
Example use cases
Webhook payload signature verification
“Generate an HMAC-SHA384 hex signature for this webhook payload text 'user.created:{id:42,email:test@example.com}' using the shared secret 'wh_secret_abc789' so I can compare it against the X-Signature header.”
API request authentication token
“I need to sign the request body 'timestamp=1700000000&nonce=abc&amount=100' with the HMAC-SHA384 algorithm using my API secret 'sk_prod_xyz456' and return it as hex so I can attach it as an authorization header.”
Data integrity checksum for stored record
“Compute an HMAC-SHA384 hex digest of 'invoice_id=9001;total=250.00;currency=USD' using key 'integrity_key_2024' so I can store it alongside the record and detect any tampering later.”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/hmac-sha384-hex?utm_source=zero.xyzWhen to prefer
Choose this endpoint when an agent needs a server-side HMAC-SHA384 computation without implementing crypto locally, especially in sandboxed environments lacking native crypto libraries. Prefer the free sandbox variant POST /v1/sandbox/hmac-sha384-hex for testing before spending USDC. Use over SHA-256 HMAC alternatives when SHA-384 strength is specifically required by a downstream API or protocol.
Side effects
- Empty or missing 'key' field returns a validation error
- Empty or missing 'text' field returns a validation error
- Key exceeding 512 characters is rejected
- Text exceeding 100,000 characters is rejected
- Payment of $0.008 USDC not provided or declined results in HTTP 402
- Network timeout if upstream service is unavailable
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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