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agent402.tools HMAC Signature
x402
agent402.tools HMAC Signature is a paid API for AI agents from agent402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).
Computes an HMAC signature of a message using a shared secret key, returning both hex and base64 encodings, with support for SHA-256, SHA-512, and SHA-1 algorithms.
Price / call$0.001
Success—
StatusUnknown
How this service works
HMAC signature of a message with a shared key. Algorithms: sha256 (default), sha512, sha1. Returns hex and base64.
Output
Returns an HMAC signature of the provided message in both hexadecimal and base64 formats, computed using the specified algorithm (sha256, sha512, or sha1) and the shared secret key.
Example use cases
Example prompt
“Compute an HMAC-SHA256 signature for the message 'order_id=12345&amount=99.99' using the shared secret key 'mysecretkey123' and give me both the hex and base64 outputs.”
Technical details
Endpoint
POSThttps://agent402.tools/api/hmacWhen to prefer
Use this endpoint when you need a quick, pay-per-use HMAC signature computation without setting up a local crypto library, especially useful in agent workflows needing message authentication or webhook signature generation. Prefer this over building custom crypto logic when operating in environments without native crypto support.
Side effects
- Missing required fields (key or text) returns a 400 error
- Message exceeds 100KB limit returns a payload too large error
- Invalid algorithm value (not sha256, sha512, or sha1) returns a validation error
- Payment failure returns a 402 Payment Required response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| key | string | Shared secret key |
| algo | string | sha256 | sha512 | sha1 |
| text | string | Message to sign (max 100KB) |
Output
Schema · Response
{
"type": "json",
"example": {
"hex": "f7bc…",
"algo": "sha256",
"base64": "97w…"
}
}Tags
x402
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