{"uid":"cap_n6Zm-nX_4qrr-TCfviyy4","slug":"hmac-string-signing-7196f93b","name":"HMAC String Signing","description":"HMAC a string. ?algo=sha256&key=k&input=hello","url":"https://pyfile-agent.taile3ff35.ts.net:10000/data/hmac","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","properties":{"key":{"type":"string"},"algo":{"type":"string"},"input":{"type":"string"}}}}},"output":{"type":"object"}}},"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_Xas8V4LM4ofWjQJyAxTKo","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 (Hash-based Message Authentication Code) of an input string using a specified algorithm and secret key","exampleAgentPrompt":"Can you compute the HMAC-SHA256 of the string 'hello world' using the secret key 'mysecretkey'?","exampleUseCases":[{"title":"Webhook signature validation","prompt":"Compute the HMAC-SHA256 of this webhook payload 'user_id=42&event=purchase' using my secret key 'wh_secret_abc123' so I can verify it matches the signature header from the request."},{"title":"API request signing","prompt":"I need to sign the string 'GET /api/orders?timestamp=1718000000' with my API secret 'sk_live_xyz789' using SHA256 HMAC — what's the resulting digest?"},{"title":"Message authentication code generation","prompt":"Generate an HMAC for the message 'transfer:1000:USD:to:alice' using the key 'shared_secret_99' with SHA256 so I can prove it hasn't been tampered with."}],"resultDescription":"Returns the HMAC digest of the input string computed with the specified algorithm (e.g. sha256) and secret key, typically as a hex-encoded string representing the cryptographic signature.","failureModes":["Missing required 'input' parameter returns an error","Unsupported algorithm value returns an error","Empty or missing key may result in an error or weakened HMAC","Invalid or malformed query parameters return a 400-style error","Network or server unavailability returns a 5xx error"],"whenToPreferThis":"Use this endpoint when you need a quick, stateless HMAC computation without setting up a local cryptography library — especially useful in agent workflows where you need to sign payloads, authenticate API requests, or verify message integrity on the fly using SHA256 or similar algorithms.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:50:44.731Z","isFirstParty":false}