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HMAC Signature Generator
x402
HMAC Signature Generator is a paid API for AI agents from x402-gateway-production-1f21.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-12).
Computes an HMAC signature for a given text and secret key using SHA-256 or SHA-512, delivered as a machine-payable x402 microservice.
Price / call$0.001
Success—
StatusUnknown
How this service works
Machine-payable x402 utilities for hashing, Base64, UUID generation, unit and timezone conversion, realtime crypto market data, webpage/document extraction, URL-to-Markdown, metadata, RAG ingestion and deterministic website change detection.
Output
Returns a JSON response with an HMAC digest (signature) computed from the provided text and secret key using the specified algorithm (SHA-256 or SHA-512), along with a status field confirming the operation completed successfully.
Example use cases
Webhook payload authentication
“Sign this incoming webhook body 'user_id=7&event=purchase&total=149.00' with my secret key 'whsec_abc789' using SHA-256 so I can verify it came from our payment provider.”
API request signing pipeline
“I need to generate an HMAC-SHA512 signature for the string 'GET /api/orders/2024-05-01' using the key 'api_secret_xyz' before sending this request to our partner's API.”
Data integrity check for stored records
“Hash this JSON blob '{"record_id":"ORD-001","status":"shipped"}' with HMAC-SHA256 and the key 'store_secret_99' so I can store the signature alongside the record and detect tampering later.”
Technical details
Endpoint
POSThttps://x402-gateway-production-1f21.up.railway.app/hmac?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a lightweight, pay-per-use HMAC computation without provisioning your own crypto infrastructure. Ideal for agents that occasionally need to sign or verify message payloads in automated pipelines, especially when using the x402 micropayment protocol for serverless, wallet-based billing. Prefer over self-hosted solutions when you want zero-maintenance cryptographic utilities billed at $0.001 USDC per call.
Side effects
- Missing required 'text' or 'key' fields returns a validation error
- Unsupported algorithm value (anything other than sha256 or sha512) returns an enum validation error
- Text exceeding 250,000 characters or key exceeding 10,000 characters may be rejected
- Payment failure via x402 protocol results in a 402 Payment Required response
- Network timeout on the Railway deployment returns a 5xx error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"status": "ready"
}
}Tags
x402
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