{"uid":"cap_L5oi4BeJtl9I0gsXjAMrJ","slug":"delx-hmac-sha256-hex-09174c3f","name":"Delx HMAC SHA256 Hex","description":"HMAC-SHA256 hex of text with a secret. Call when you sign agent webhook test payloads offline. Returns hex digest for $0.001 USDC via x402 on Base. Local HMAC only—caller supplies secret; not stored. No network, no retention. Results are advisory; the caller owns budgets, auth, and production controls.","url":"https://api.delx.ai/api/v1/x402/hmac-sha256-hex","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"text":{"type":"string","description":"Input field: text."},"secret":{"type":"string","description":"Input field: secret."}}},"responseSchema":{"type":"json","example":{"hex":"5d98b45c90a207fa998ce639fea6f02ecc8cc3f36fef81d694fb856b4d0a28ca","schema":"delx/util-hmac-sha256-hex/v1","algorithm":"hmac-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_jyNaU2-r22T-hk-o_JcGQ","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 hex digest of a given text using a caller-supplied secret, without storing or transmitting the secret.","exampleAgentPrompt":"Compute the HMAC-SHA256 hex signature of the text 'user_id=42&event=purchase' using the secret 'mysecretkey123'.","exampleUseCases":[{"title":"Webhook payload signing for testing","prompt":"Sign this webhook payload 'event=order_placed&amount=99.99' with the secret 'webhooksecret456' using HMAC-SHA256 and give me the hex digest so I can test my webhook handler."},{"title":"Request authentication for API calls","prompt":"I need to authenticate an API request — compute the HMAC-SHA256 hex signature of 'GET /api/orders?ts=1700000000' with the secret 'apisecret789'."},{"title":"Cross-checking signature from upstream service","prompt":"An upstream service sent me a payload 'user=alice&action=login' and says it was signed with secret 'sharedkey321' — can you compute the expected HMAC-SHA256 hex so I can verify if the signatures match?"}],"resultDescription":"Returns a hex-encoded HMAC-SHA256 digest string computed from the provided text and secret. The secret is used locally for the computation and is not stored or retained by the service.","failureModes":["Missing 'text' or 'secret' field in request body returns a 400 error","Payment not fulfilled via x402 protocol results in 402 Payment Required","Empty string inputs may return a valid but trivially-signed digest — caller should validate inputs beforehand","Network timeout or service unavailability returns a 5xx error"],"whenToPreferThis":"Use this endpoint when an AI agent needs to compute an HMAC-SHA256 hex signature on-the-fly without executing local code — particularly for signing webhook test payloads, generating request authentication tokens, or verifying expected signatures in agentic pipelines. It is ideal when the agent runtime lacks native crypto libraries. Choose it over local computation when you want a simple, stateless, pay-per-use API call that does not retain the secret.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T00:57:24.344Z","isFirstParty":false}