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agentshelf.syntexa.ch HMAC-SHA512 Base64URL
x402
agentshelf.syntexa.ch HMAC-SHA512 Base64URL is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-02).
Computes an HMAC-SHA512 digest of a given text using a caller-supplied key and returns the result encoded as base64url.
Price / call$0.003
Success—
StatusUnknown
How this service works
Call when an agent needs an HMAC-sha512 of text with a caller-supplied key, encoded as base64url. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha512-base64url first.
Output
Returns a base64url-encoded string representing the HMAC-SHA512 digest of the provided text computed with the supplied key. The output is a compact, URL-safe cryptographic signature.
Example use cases
Webhook signature verification
“I need to sign the webhook payload '{"event":"order.created","id":42}' with my secret 'wh_sec_abc123xyz' using HMAC-SHA512 and get the base64url output so I can attach it as the X-Signature header.”
API request authentication
“Generate an HMAC-SHA512 base64url signature for the string 'GET /api/v1/users 1718000000' using the key 'api_secret_key_9876' so I can authenticate this API request.”
Data integrity token generation
“Take the text 'user_id=42&action=transfer&amount=100' and sign it with the key 'integrity_key_555' using HMAC-SHA512 encoded as base64url so I can include an integrity token in the URL.”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/hmac-sha512-base64url?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a hosted, pay-per-call HMAC-SHA512 computation without running your own crypto library — useful in serverless or sandboxed agent environments where native crypto is unavailable or untrusted. Prefer the free sandbox endpoint POST /v1/sandbox/hmac-sha512-base64url for testing before spending USDC.
Side effects
- Empty key or text returns a 400 validation error
- Key exceeding 512 characters triggers a length validation error
- Text exceeding 100,000 characters is rejected
- Payment failure or insufficient USDC balance results in a 402 response
- 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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