{"uid":"cap_W6yhH_X9Fpc_WCgYeEAW0","slug":"alice-s-deterministic-toolkit-hmac-9d8352b2","name":"Alice's Deterministic Toolkit – HMAC","description":"Deterministic encoding/crypto primitives served per call over x402: hashing, HMAC, base64/hex/URL encode+decode, JWT payload decoding, cryptographic randomness — plus the payout-gate intelligence set: which bounty/AI-security platforms require identity or a tax form before paying, what their automation and human-review clauses actually say, and which ones pay to a self-custody wallet. No model inference, no rate of change — same input, same output, every time.","url":"https://alice-deterministic-tools.judicious-entrance.workers.dev/v1/hmac","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"key":{"type":"string"},"algo":{"type":"string"},"text":{"type":"string"},"encoding":{"type":"string"}}},"responseSchema":{"type":"json","example":{"ok":true,"algo":"hmac-sha256","digest":"f7bc83f4…","encoding":"hex"}},"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_asRarAvp5M8NKjwDwzFb_","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 digest for a given text using a specified key, algorithm, and output encoding","exampleAgentPrompt":"Compute an HMAC-SHA256 digest of the text 'hello world' using the secret key 'mysecretkey' and give me the result as a hex string.","exampleUseCases":[{"title":"Webhook signature verification","prompt":"Sign this webhook payload 'user.created:{id:42}' with HMAC-SHA256 using my secret key 'whsec_abc123' and return the hex digest so I can compare it against the incoming X-Signature header."},{"title":"API request authentication","prompt":"I need to authenticate a request to an API that requires HMAC-SHA256 — compute the HMAC of the string 'GET /orders/99 1700000000' with key 'api_secret_xyz' and encode the output as base64."},{"title":"Data integrity tagging for storage","prompt":"Generate an HMAC-SHA256 tag in hex for the text 'invoice:2024-001:$500.00' using the key 'ledger_secret' so I can store it alongside the record and detect tampering later."}],"resultDescription":"A JSON object containing a boolean 'ok' field, the algorithm name used (e.g. 'hmac-sha256'), the computed digest as a string in the requested encoding (hex or base64), and the encoding label. The digest is fully deterministic: identical inputs always produce identical outputs.","failureModes":["Missing or empty key/text fields → likely 4xx or error JSON with ok:false","Unsupported algorithm name → error response indicating invalid algo","Invalid encoding value → error response or fallback to default encoding","Payment not included or rejected → HTTP 402 payment required","Network timeout on Cloudflare Worker cold start → transient 5xx"],"whenToPreferThis":"Choose this endpoint when you need a fast, deterministic, pay-per-call HMAC computation without managing your own crypto library or runtime. Ideal for AI agents that need to sign payloads, verify webhook authenticity, or produce authentication tags on-the-fly without standing up infrastructure. The x402 micropayment model ($0.002 USDC) makes it suitable for low-volume or sporadic calls where a subscription API key would be overkill.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-18T06:44:15.251Z","isFirstParty":false}