{"uid":"cap_PWkDaC7J2DAeBFoYHbmd1","slug":"hmac-signature-generator-4d2eb233","name":"HMAC Signature Generator","description":"Machine-payable x402 utilities for hashing, Base64, UUID generation, unit and timezone conversion, realtime crypto market data, webpage/document extraction, URL-to-Markdown, metadata, RAG ingestion and deterministic website change detection.","url":"https://x402-gateway-production-1f21.up.railway.app/hmac?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["text","key"],"properties":{"key":{"type":"string","maxLength":10000},"text":{"type":"string","maxLength":250000},"algorithm":{"enum":["sha256","sha512"],"type":"string"}},"additionalProperties":false},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"status":"ready"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"registry","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_4SannDL7wcfDa-ZYFsjqR","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes an HMAC signature for a given text and secret key using SHA-256 or SHA-512, delivered as a machine-payable x402 microservice.","exampleAgentPrompt":"Compute an HMAC-SHA256 signature for the text 'order_id=42&amount=99.99' using the secret key 'mysecretkey123' so I can authenticate this webhook payload.","exampleUseCases":[{"title":"Webhook payload authentication","prompt":"Sign this incoming webhook body 'user_id=7&event=purchase&total=149.00' with my secret key 'whsec_abc789' using SHA-256 so I can verify it came from our payment provider."},{"title":"API request signing pipeline","prompt":"I need to generate an HMAC-SHA512 signature for the string 'GET /api/orders/2024-05-01' using the key 'api_secret_xyz' before sending this request to our partner's API."},{"title":"Data integrity check for stored records","prompt":"Hash this JSON blob '{\"record_id\":\"ORD-001\",\"status\":\"shipped\"}' with HMAC-SHA256 and the key 'store_secret_99' so I can store the signature alongside the record and detect tampering later."}],"resultDescription":"Returns a JSON response with an HMAC digest (signature) computed from the provided text and secret key using the specified algorithm (SHA-256 or SHA-512), along with a status field confirming the operation completed successfully.","failureModes":["Missing required 'text' or 'key' fields returns a validation error","Unsupported algorithm value (anything other than sha256 or sha512) returns an enum validation error","Text exceeding 250,000 characters or key exceeding 10,000 characters may be rejected","Payment failure via x402 protocol results in a 402 Payment Required response","Network timeout on the Railway deployment returns a 5xx error"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, pay-per-use HMAC computation without provisioning your own crypto infrastructure. Ideal for agents that occasionally need to sign or verify message payloads in automated pipelines, especially when using the x402 micropayment protocol for serverless, wallet-based billing. Prefer over self-hosted solutions when you want zero-maintenance cryptographic utilities billed at $0.001 USDC per call.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T18:45:11.544Z","isFirstParty":false,"canonicalSlug":"hmac-signature-generator-4d2eb233"}