{"uid":"cap_VNPB_EqrX00eVLEE0y649","slug":"hmac-sha1-base64url-signer-6be33cb7","name":"HMAC-SHA1 Base64URL Signer","description":"Call when an agent needs an HMAC-sha1 of text with a caller-supplied key, encoded as base64url. Exact $0.004 USDC. Prefer unpaid POST /v1/sandbox/hmac-sha1-base64url first.","url":"https://agentshelf.syntexa.ch/v1/hmac-sha1-base64url?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"key":{"type":"string","examples":["secret"],"maxLength":512,"minLength":1,"description":"HMAC secret. Required on HMAC SKUs. Omit it for plain digests and checksums. The key is not stored."},"text":{"type":"string","examples":["hello"],"maxLength":100000,"minLength":1,"description":"Message to digest. For raw-hex SKUs this is hex bytes; for utf16 or latin1 SKUs it is decoded with that encoding. Otherwise it is UTF-8 text."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.004","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":"$0.004/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_7Q3i2FR9Q7gxL0R9XK6p7","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.004","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes an HMAC-SHA1 digest of a given text using a caller-supplied key, returning the result encoded as base64url.","exampleAgentPrompt":"Compute an HMAC-SHA1 signature of the text 'order_id=12345&amount=99.99' using the secret key 'mysecretkey123' and give me the result as base64url.","exampleUseCases":[{"title":"Webhook payload signature verification","prompt":"I need to sign the raw webhook body 'user_id=42&event=purchase' with the secret key 'wh_secret_abc' using HMAC-SHA1 and get the base64url result so I can compare it against the X-Signature header."},{"title":"OAuth 1.0 request signing","prompt":"Can you compute the HMAC-SHA1 signature for this OAuth base string 'GET&https%3A%2F%2Fapi.example.com%2Fresource&oauth_token%3Dabc' using the signing key 'consumer_secret&token_secret'? I need it base64url encoded."},{"title":"API request authentication token","prompt":"Sign the string 'timestamp=1700000000&nonce=xyz987&endpoint=/api/orders' with the key 'my_api_secret' using HMAC-SHA1 and base64url encode it so I can include it in the Authorization header."}],"resultDescription":"A base64url-encoded HMAC-SHA1 digest string computed from the provided text and key. This is a compact, URL-safe representation of the keyed hash suitable for use in HTTP headers, query parameters, or signature comparison.","failureModes":["Empty or missing key field returns a validation error","Empty or missing text field returns a validation error","Key exceeding 512 characters is rejected","Text exceeding 100,000 characters is rejected","Payment not provided or insufficient USDC triggers a 402 response — use the free /v1/sandbox/hmac-sha1-base64url endpoint first for testing"],"whenToPreferThis":"Use this endpoint when you need a fully hosted, pay-per-call HMAC-SHA1 base64url computation without running your own crypto library — ideal for sandboxed agents, serverless workflows, or environments where adding a crypto dependency is impractical. Prefer the free sandbox endpoint (/v1/sandbox/hmac-sha1-base64url) for development and testing before switching to this paid endpoint for production use.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T06:46:45.778Z","isFirstParty":false,"canonicalSlug":"hmac-sha1-base64url-signer-6be33cb7"}