{"machine":"hmac","slot":"S26","title":"HMAC signature","how_to_call":"POST https://innernetcorp.com/machines/hmac with Content-Type: application/json","price_usd":"$0.003","currencies":["USDC","EURC"],"payment":"x402: send the POST without payment to receive a 402 with signed requirements; pay any option and retry.","input_example":{"text":"payload","key":"secret","algorithm":"sha256"},"input_schema":{"type":"object"},"summary":"Compute an HMAC (SHA-256 or SHA-512) of a message with a secret key - webhook signing and verification.","catalog":"/catalog"}