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HMAC-MD5 Hex Digest (agentshelf.syntexa.ch)
x402
HMAC-MD5 Hex Digest (agentshelf.syntexa.ch) is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.009/call, status unknown (last checked 2026-10-01).
Computes an HMAC-MD5 authentication code over supplied text using a caller-provided secret key, returning the result as a lowercase hexadecimal string.
Price / call$0.009
Success—
StatusUnknown
How this service works
Call when an agent needs an HMAC-md5 of text with a caller-supplied key, encoded as hex. Exact $0.009 USDC. Prefer unpaid POST /v1/sandbox/hmac-md5-hex first.
Output
A JSON response containing the hex-encoded HMAC-MD5 digest string computed from the provided text and key. The output is a fixed-length 32-character lowercase hexadecimal string representing the 128-bit HMAC value.
Example use cases
Webhook signature verification
“I need to compute the HMAC-MD5 hex signature of this webhook body — the text is '{"event":"payment.complete","amount":100}' and the shared secret is 'wh_secret_abc789'. What's the hex digest?”
API request authentication
“Generate an HMAC-MD5 hex code for the string 'GET /api/orders/42 timestamp=1716300000' using the key 'api_signing_key_xyz' so I can put it in my request auth header.”
Data integrity tagging
“I want to tag this log entry 'user_id=55 action=delete record=8821' with an HMAC-MD5 fingerprint using the key 'log_secret_key' — give me the hex output.”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/hmac-md5-hex?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need an HMAC-MD5 keyed message authentication code returned as hexadecimal — specifically when MD5 is required (e.g. for compatibility with a legacy system, AWS S3 request signing, or an API that mandates HMAC-MD5). Prefer the free sandbox endpoint POST /v1/sandbox/hmac-md5-hex for testing. Use sibling endpoints if you need a different hash algorithm (SHA-512, SHAKE128) or a different encoding (base64, base32).
Side effects
- 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 of $0.009 USDC not provided or failing results in 402 Payment Required
- Malformed JSON body returns 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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