{"uid":"cap_dER8qh2RuKnHM1PVmyh5X","slug":"hmac-sha3-384-hex-digest-a2075972","name":"HMAC-SHA3-384 Hex Digest","description":"Call when an agent needs an HMAC-sha3-384 of text with a caller-supplied key, encoded as hex. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha3-384-hex first.","url":"https://agentshelf.syntexa.ch/v1/hmac-sha3-384-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":"0.003","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_kv1EHrOTxrwbty1nTuGZX","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 using SHA3-384 with a caller-supplied key over input text and returns the result as a lowercase hex string","exampleAgentPrompt":"Compute an HMAC-SHA3-384 hex digest of the text 'Hello, World!' using the secret key 'my-secret-key-12345'.","exampleUseCases":[{"title":"Webhook payload integrity signing","prompt":"I need to sign the string '{\"event\":\"order.placed\",\"id\":\"abc123\"}' with my secret key 'wh-secret-xyz789' using HMAC-SHA3-384 and get the hex signature so I can attach it to my webhook header."},{"title":"API request authentication token","prompt":"Can you generate an HMAC-SHA3-384 hex hash of the request body 'amount=500&currency=USD&timestamp=1717200000' using the key 'api-signing-key-prod-42' so I can authenticate this outbound API call?"},{"title":"Data integrity verification code","prompt":"Compute an HMAC-SHA3-384 digest in hex for the text 'user:alice;action:transfer;amount:1000' with the key 'integrity-check-secret' — I need it to verify nobody tampered with this audit log entry."}],"resultDescription":"A hex-encoded HMAC-SHA3-384 digest string computed over the provided text using the supplied key. The response is a deterministic, fixed-length (96-character) lowercase hexadecimal string.","failureModes":["Empty or missing key returns a validation error","Empty or missing text returns a validation error","Key exceeding 512 characters is rejected","Text exceeding 100,000 characters is rejected","Payment failure or insufficient USDC balance returns a 402 response","Malformed JSON request body returns a 400 error"],"whenToPreferThis":"Choose this endpoint when you need HMAC authentication using the SHA3-384 algorithm specifically (not SHA-256 or SHA-512) and require hex-encoded output. Prefer the unpaid sandbox endpoint POST /v1/sandbox/hmac-sha3-384-hex for testing. Use this paid endpoint when operating in production and needing the SHA3 family specifically for compliance or interoperability reasons.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T06:50:09.842Z","isFirstParty":false,"canonicalSlug":"hmac-sha3-384-hex-digest-a2075972"}