{"uid":"cap_5t2zPcSFVPCGwRUdigY6l","slug":"income-2-agent-tools-hmac-sha256-9f2d4edb","name":"INCOME 2 Agent Tools – HMAC-SHA256","description":"Low-cost x402 pay-per-call tools for autonomous buyers. Web extraction returns static public pages as clean markdown; every payable operation declares x-payment-info and a 402 response. Free betas: Agent Purchase Guard adds retry-safe purchase intent controls; Outcome Router accepts a desired result plus max budget and autonomously discovers fulfillment, tries zero-dollar proof-of-work first, and supports buyer-signed x402 paid execution where available.\n\nBuyer-signed paid HYDRA execution\n- Outcome request: POST https://earn-tools-backend.onrender.com/outcome-router\n- Paid execution: POST https://earn-tools-backend.onrender.com/outcome-router/execute/{requestId}\n- First execution call returns the relayed Agent402 Smart Order Router x402 PAYMENT-REQUIRED challenge.\n- An x402-capable buyer wallet signs locally and retries with PAYMENT-SIGNATURE.\n- HYDRA forwards the proof and returns the routed result.\n- HYDRA never receives the buyer private key or uses owner working capital.\n- Current beta platform fee: $0. Higher paid tiers are not auto-escalated.","url":"https://earn-tools-backend.onrender.com/hmac-sha256","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"key":{"type":"string","maxLength":10000},"input":{"type":"string","maxLength":500000}}},"responseSchema":{"type":"json","example":{"ok":true,"result":{"result":"...","operation":"sha256"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/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_5-JhmhjvOVpuiuf60kokM","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes an HMAC-SHA256 hash of an input string using a provided key, returning the hex digest as a pay-per-call x402 microservice.","exampleAgentPrompt":"Compute the HMAC-SHA256 of the string 'order:12345:confirmed' using the secret key 'mysecretkey123' and give me the result.","exampleUseCases":[{"title":"Webhook signature verification","prompt":"I need to verify the integrity of an incoming webhook payload — compute the HMAC-SHA256 of the body string '{\"event\":\"payment.completed\",\"amount\":100}' using the secret key 'wh_secret_abc789' so I can compare it to the header signature."},{"title":"API request signing for authentication","prompt":"Sign this API request payload 'user_id=42&action=transfer&amount=50' with the secret key 'api_signing_key_xyz' using HMAC-SHA256 so I can attach it as an auth header before sending."},{"title":"Data tamper-detection checksum","prompt":"Generate an HMAC-SHA256 checksum for the string 'invoice:2024-06-01:$499.00' using the key 'integrity_key_prod' so I can store it alongside the record and detect any future tampering."}],"resultDescription":"Returns a JSON object with ok: true and a result object containing the HMAC-SHA256 hex digest string and an operation field confirming 'sha256'.","failureModes":["Missing or empty key field returns an error","Input string exceeding 500,000 characters is rejected","Payment not provided or invalid x402 payment signature returns 402 Payment Required","Malformed JSON body returns 400 Bad Request","Service temporarily unavailable on cold-start (Render free tier spin-up latency)"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, pay-per-call HMAC-SHA256 computation without spinning up your own crypto library or server — especially useful for AI agents operating in x402 micropayment ecosystems that need to sign payloads, verify webhook signatures, or produce keyed hashes at $0.001 per call with no subscription or setup required.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:34:06.359Z","isFirstParty":false}