{"uid":"cap_sv1mMDiuD2MDza6UFfM8t","slug":"geekvault-hmac-generator-44ba1ca6","name":"GeekVault HMAC Generator","description":"Network, docs, image, web, and dev utility tools paid per call via x402. No signup, no API keys, no subscriptions — just USDC on Base.","url":"https://api.geekvault.dev/dev-tools/v1/hmac?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","required":["key","message"],"properties":{"key":{"type":"string","description":"Clave secreta."},"algo":{"type":"string","description":"Algoritmo de hash. Por defecto `sha256`."},"message":{"type":"string","description":"Mensaje a autenticar."}}},"responseSchema":{"type":"object","required":["algo","hmac"],"properties":{"algo":{"type":"string"},"hmac":{"type":"string"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Rnd1YACyMCo85v6dkWj0b","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes an HMAC (Hash-based Message Authentication Code) for a given message and secret key using a specified hash algorithm (default SHA-256).","exampleAgentPrompt":"Compute an HMAC-SHA256 signature for the message 'order_id=12345&amount=99.99' using the secret key 'mysecretkey123'.","exampleUseCases":[{"title":"Webhook signature verification","prompt":"Generate an HMAC-SHA256 for the payload '{\"event\":\"payment.completed\",\"id\":\"evt_001\"}' using secret key 'whsec_abc789' so I can verify the webhook authenticity."},{"title":"API request signing","prompt":"I need to sign my API request body 'GET /users/42 timestamp=1700000000' with the secret 'api_secret_xyz' using SHA-256 HMAC before sending it."},{"title":"Message integrity token generation","prompt":"Create an HMAC signature for the message 'user_id=88&action=delete' with secret key 'internal_signing_key' — use SHA-256 — so I can attach it as a tamper-proof token."}],"resultDescription":"Returns a JSON object containing the HMAC hex digest string and the algorithm used (e.g. sha256). The 'hmac' field holds the computed authentication code and 'algo' confirms which hash algorithm was applied.","failureModes":["Missing required 'key' parameter returns a validation error","Missing required 'message' parameter returns a validation error","Unsupported algorithm value may return an error or fall back to default","Payment failure via x402 results in 402 response before computation","Empty string key or message may produce unexpected but valid HMAC output"],"whenToPreferThis":"Choose this endpoint when an AI agent needs to compute HMAC signatures on-the-fly without managing cryptographic library dependencies, installing packages, or setting up API keys. Ideal for serverless agents, sandboxed environments, or quick one-off signing tasks where paying $0.002 USDC per call is more practical than running crypto code locally. Prefer over local computation when the execution environment lacks native crypto support.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-27T12:49:34.703Z","isFirstParty":false,"canonicalSlug":"geekvault-hmac-generator-44ba1ca6"}