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HMAC-MD5 Base64URL Encoder
x402
HMAC-MD5 Base64URL Encoder is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).
Computes an HMAC-MD5 message authentication code of input text using a caller-supplied key and returns the result encoded as base64url.
Price / call$0.001
Success—
StatusUnknown
How this service works
Call when an agent needs an HMAC-md5 of text with a caller-supplied key, encoded as base64url. Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/hmac-md5-base64url first.
Output
Returns a base64url-encoded HMAC-MD5 digest string — the message authentication code computed over the input text using the supplied key. No additional metadata; just the compact, URL-safe encoded MAC value.
Example use cases
Webhook signature verification
“I need to sign the webhook payload '{"event":"user.created","id":42}' with HMAC-MD5 using my secret key 'wh_secret_abc123' and get the result as base64url so I can compare it against the signature header.”
API request authentication token
“Generate an HMAC-MD5 of the string 'GET /api/orders/2024-05-20' using my API signing key 'k3y-x9z2' encoded as base64url — I need it to authenticate my request.”
Data integrity checksum for storage
“Compute an HMAC-MD5 base64url tag for the text 'invoice_id=9871&amount=250.00¤cy=USD' using the key 'integrity_key_prod' so I can store it alongside the record for tamper detection.”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/hmac-md5-base64url?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a URL-safe (base64url) encoded HMAC-MD5 MAC — for example, when constructing webhook signatures, API authentication headers, or integrity tags that must be embedded in URLs or filenames without padding issues. Prefer the free sandbox endpoint POST /v1/sandbox/hmac-md5-base64url first if available. Use this paid endpoint when the sandbox is unavailable or when production guarantees are required.
Side effects
- Missing or empty 'key' field returns a validation error
- Missing or empty 'text' field returns a validation error
- Text exceeding 100,000 characters is rejected
- Key exceeding 512 characters is rejected
- Payment failure or insufficient USDC balance results in a 402 Payment Required response
- Malformed JSON body returns a 400 Bad Request
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| key | string | HMAC secret. Required on HMAC SKUs. Omit it for plain digests and checksums. The key is not stored. |
| text | string | 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. |
Tags
x402
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