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agentshelf.syntexa.ch HMAC-BLAKE2s256 Hex
x402
agentshelf.syntexa.ch HMAC-BLAKE2s256 Hex is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.007/call, status unknown (last checked 2026-09-29).
Computes an HMAC using the BLAKE2s-256 hash function with a caller-supplied key over input text, returning the result as a lowercase hex string.
Price / call$0.007
Success—
StatusUnknown
How this service works
Call when an agent needs an HMAC-blake2s256 of text with a caller-supplied key, encoded as hex. Exact $0.007 USDC. Prefer unpaid POST /v1/sandbox/hmac-blake2s256-hex first.
Output
Returns a hex-encoded HMAC-BLAKE2s256 digest string computed over the provided text using the supplied key. The output is a fixed-length lowercase hexadecimal string representing the 256-bit MAC.
Example use cases
API request signing for webhooks
“I need to sign this webhook payload 'user_id=42&event=purchase' with my secret key 'wh_secret_abc789' using HMAC-BLAKE2s256 — give me the hex digest so I can attach it as a signature header.”
Message integrity verification token
“Generate an HMAC-BLAKE2s256 hex tag for the message 'transfer:1000:USD:account_9871' using the key 'integrity_key_xz12' so I can verify it hasn't been tampered with later.”
Keyed checksum for data pipeline
“I have a data record 'sensor_id=55;reading=98.6;timestamp=1720000000' that I want to integrity-stamp using HMAC-BLAKE2s256 with the key 'pipeline_secret_007' — what's the hex output?”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/hmac-blake2s256-hex?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a BLAKE2s-256 based HMAC specifically — as opposed to SHA-256 or SHA-512 HMAC — because BLAKE2s is faster on constrained hardware and provides comparable security. Use it when your protocol or counterparty requires BLAKE2s keyed authentication. If cost is a concern, try the free sandbox endpoint POST /v1/sandbox/hmac-blake2s256-hex first.
Side effects
- Missing or empty 'key' field returns a validation error
- Missing or empty 'text' field returns a validation error
- Text exceeding 100,000 characters returns a length error
- Key exceeding 512 characters returns a validation error
- Payment of $0.007 USDC not provided or rejected triggers HTTP 402
- Network timeout if the service is temporarily 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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