{"uid":"cap_XMjqn5QkDwiR-Q4Fb9Kd0","slug":"agentshelf-syntexa-ch-hmac-sha512-hex-cfcbec88","name":"agentshelf.syntexa.ch HMAC-SHA512 Hex","description":"Call when an agent needs an HMAC-sha512 of text with a caller-supplied key, encoded as hex. Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha512-hex first.","url":"https://agentshelf.syntexa.ch/v1/hmac-sha512-hex?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"key":{"type":"string","examples":["secret"],"maxLength":512,"minLength":1,"description":"HMAC secret. Required on HMAC SKUs. Omit it for plain digests and checksums. The key is not stored."},"text":{"type":"string","examples":["hello"],"maxLength":100000,"minLength":1,"description":"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."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_SgfQA4m3Vr4ehQhJYTuzd","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes an HMAC-SHA512 digest of a given text using a caller-supplied secret key, returning the result as a lowercase hex string.","exampleAgentPrompt":"Compute the HMAC-SHA512 hex digest of the message 'order_id=12345&amount=99.00' using the secret key 'mySuperSecretKey42'.","exampleUseCases":[{"title":"Webhook payload signing","prompt":"Sign this webhook body with my secret key 'wh_secret_abc123' using HMAC-SHA512 and give me the hex digest — the body is '{\"event\":\"payment.completed\",\"amount\":50}'"},{"title":"API request authentication","prompt":"I need to authenticate an outgoing API request by computing an HMAC-SHA512 hex signature of 'GET /api/orders/987?ts=1700000000' using my signing key 'sigkey_xyz789'."},{"title":"Data integrity verification","prompt":"Compute the HMAC-SHA512 hex of the string 'user_id=42|action=delete|ts=1699999999' with key 'integrity_key_prod' so I can attach it as a verification tag."}],"resultDescription":"Returns a JSON object containing the HMAC-SHA512 digest of the input text, keyed with the provided secret and encoded as a lowercase hexadecimal string.","failureModes":["Empty or missing key returns a 400/422 validation error","Empty or missing text returns a 400/422 validation error","Text exceeding 100,000 characters is rejected","Key exceeding 512 characters is rejected","Payment failure or insufficient USDC balance returns a 402 error","Network timeout or service unavailability returns a 5xx error"],"whenToPreferThis":"Use this endpoint when an agent needs a server-side HMAC-SHA512 hex computation without running local cryptographic code. Prefer this over client-side alternatives when the environment lacks crypto libraries. Note the free sandbox endpoint POST /v1/sandbox/hmac-sha512-hex should be tried first before incurring the $0.001 USDC charge.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T06:47:47.111Z","isFirstParty":false,"canonicalSlug":"agentshelf-syntexa-ch-hmac-sha512-hex-cfcbec88"}