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HMAC-SHA3-384 Hex Digest
x402
HMAC-SHA3-384 Hex Digest is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-29).
Computes an HMAC using SHA3-384 with a caller-supplied key over input text and returns the result as a lowercase hex string
Price / call$0.003
Success—
StatusUnknown
How this service works
Call when an agent needs an HMAC-sha3-384 of text with a caller-supplied key, encoded as hex. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha3-384-hex first.
Output
A hex-encoded HMAC-SHA3-384 digest string computed over the provided text using the supplied key. The response is a deterministic, fixed-length (96-character) lowercase hexadecimal string.
Example use cases
Webhook payload integrity signing
“I need to sign the string '{"event":"order.placed","id":"abc123"}' with my secret key 'wh-secret-xyz789' using HMAC-SHA3-384 and get the hex signature so I can attach it to my webhook header.”
API request authentication token
“Can you generate an HMAC-SHA3-384 hex hash of the request body 'amount=500¤cy=USD×tamp=1717200000' using the key 'api-signing-key-prod-42' so I can authenticate this outbound API call?”
Data integrity verification code
“Compute an HMAC-SHA3-384 digest in hex for the text 'user:alice;action:transfer;amount:1000' with the key 'integrity-check-secret' — I need it to verify nobody tampered with this audit log entry.”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/hmac-sha3-384-hex?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need HMAC authentication using the SHA3-384 algorithm specifically (not SHA-256 or SHA-512) and require hex-encoded output. Prefer the unpaid sandbox endpoint POST /v1/sandbox/hmac-sha3-384-hex for testing. Use this paid endpoint when operating in production and needing the SHA3 family specifically for compliance or interoperability reasons.
Side effects
- Empty or missing key returns a validation error
- Empty or missing text returns a validation error
- Key exceeding 512 characters is rejected
- Text exceeding 100,000 characters is rejected
- Payment failure or insufficient USDC balance returns a 402 response
- Malformed JSON request body returns a 400 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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