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HMAC-SHA224 Hex Digest API
x402
HMAC-SHA224 Hex Digest API is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-02).
Computes an HMAC-SHA224 message authentication code for a given text using a caller-supplied key, returning the result as a lowercase hex string.
Price / call$0.01
Success—
StatusUnknown
How this service works
Call when an agent needs an HMAC-sha224 of text with a caller-supplied key, encoded as hex. Exact $0.01 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha224-hex first.
Output
Returns a hex-encoded HMAC-SHA224 digest string (56 hex characters) computed over the provided text using the supplied key. The response is a deterministic, fixed-length authentication code that can be used for message integrity verification or API request signing.
Example use cases
Webhook signature verification
“Generate an HMAC-SHA224 hex signature for the webhook payload '{"event":"payment.completed","amount":100}' using the secret key 'whsec_abc123XYZ' so I can validate it matches the incoming header.”
API request signing
“I need to sign the API request body 'user_id=42&action=transfer&amount=500' with HMAC-SHA224 using the key 'api_signing_key_prod' — give me the hex digest.”
Data integrity token for file content
“Create an HMAC-SHA224 hex digest for the text 'report_2024_q4.csv contents here' using the secret 'integrity_token_secret' so I can store it alongside the file and check for tampering later.”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/hmac-sha224-hex?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you specifically need HMAC-SHA224 (not SHA-256 or SHA-512) as a keyed hash for message authentication or integrity verification, and when a hex-encoded output is required. Prefer the free sandbox endpoint POST /v1/sandbox/hmac-sha224-hex during development or testing to avoid the $0.01 USDC charge. Use this paid endpoint for production workloads where reliable uptime and SLA matter.
Side effects
- Missing or empty key parameter returns a validation error
- Missing or empty text parameter returns a validation error
- Text exceeding 100,000 characters is rejected
- Key exceeding 512 characters is rejected
- Payment failure or insufficient USDC balance prevents the call from completing
- Network timeout may occur under load
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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