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HMAC-SHA256 Message Authentication
x402
HMAC-SHA256 Message Authentication is a paid API for AI agents from x402render-u5vwpxpyua-uc.a.run.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).
Computes an HMAC-SHA256 digest of a given text string using a provided secret key
Price / call$0.01
Success—
StatusUnknown
How this service works
HMAC-SHA256 of a string with a secret key
Output
Returns the HMAC-SHA256 hexadecimal digest (message authentication code) computed from the input text using the provided secret key, allowing the caller to authenticate or verify the integrity of the original message.
Example use cases
Webhook signature verification
“Generate an HMAC-SHA256 signature for the payload '{"event":"payment.completed","amount":150}' using my webhook secret 'whsec_abc123xyz' so I can validate it matches what the sender claims.”
API request signing
“Sign the string 'GET /api/orders/42 timestamp=1715000000' with the HMAC-SHA256 algorithm using my API secret key 'prod_secret_key_789' to include as an auth header.”
Data integrity token generation
“Create an HMAC-SHA256 digest for the text 'user_id=987&action=delete&resource=account' with the key 'internalSharedSecret' so I can attach it to the request as a tamper-proof token.”
Technical details
Endpoint
POSThttps://x402render-u5vwpxpyua-uc.a.run.app/hmac-sha256When to prefer
Choose this endpoint when you need a simple, stateless HMAC-SHA256 computation as a service without setting up local crypto libraries — especially useful in low-code or agent workflows where running native crypto code is inconvenient. Prefer it over generic hashing endpoints (MD5, SHA-512 siblings) when you need keyed authentication rather than a plain hash, and when the $0.01 per-call cost is acceptable for on-demand signing.
Side effects
- Missing 'key' or 'text' field in request body returns a 400 error
- Empty string key or text may produce a valid but trivially weak HMAC
- Payment not attached or insufficient USDC balance results in 402 Payment Required
- Server error on the cloud run instance returns 500 with no digest
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| key | string | string |
| text | string | string |
Tags
x402
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