{"uid":"cap_WqpE4Ymkdb3WxJoNaBUtf","slug":"agentshelf-syntexa-ch-hmac-sha512-base64url-a33bbe3b","name":"agentshelf.syntexa.ch HMAC-SHA512 Base64URL","description":"Call when an agent needs an HMAC-sha512 of text with a caller-supplied key, encoded as base64url. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha512-base64url first.","url":"https://agentshelf.syntexa.ch/v1/hmac-sha512-base64url?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":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_vGhTh7VC_XJHJ1i9YCEF3","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","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 key and returns the result encoded as base64url.","exampleAgentPrompt":"Compute the HMAC-SHA512 of the text 'Hello, world!' using the key 'my-secret-key' and give me the result as base64url.","exampleUseCases":[{"title":"Webhook signature verification","prompt":"I need to sign the webhook payload '{\"event\":\"order.created\",\"id\":42}' with my secret 'wh_sec_abc123xyz' using HMAC-SHA512 and get the base64url output so I can attach it as the X-Signature header."},{"title":"API request authentication","prompt":"Generate an HMAC-SHA512 base64url signature for the string 'GET /api/v1/users 1718000000' using the key 'api_secret_key_9876' so I can authenticate this API request."},{"title":"Data integrity token generation","prompt":"Take the text 'user_id=42&action=transfer&amount=100' and sign it with the key 'integrity_key_555' using HMAC-SHA512 encoded as base64url so I can include an integrity token in the URL."}],"resultDescription":"Returns a base64url-encoded string representing the HMAC-SHA512 digest of the provided text computed with the supplied key. The output is a compact, URL-safe cryptographic signature.","failureModes":["Empty key or text returns a 400 validation error","Key exceeding 512 characters triggers a length validation error","Text exceeding 100,000 characters is rejected","Payment failure or insufficient USDC balance results in a 402 response","Network timeout or service unavailability returns a 5xx error"],"whenToPreferThis":"Choose this endpoint when you need a hosted, pay-per-call HMAC-SHA512 computation without running your own crypto library — useful in serverless or sandboxed agent environments where native crypto is unavailable or untrusted. Prefer the free sandbox endpoint POST /v1/sandbox/hmac-sha512-base64url for testing before spending USDC.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T06:50:16.176Z","isFirstParty":false,"canonicalSlug":"agentshelf-syntexa-ch-hmac-sha512-base64url-a33bbe3b"}