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hash-hmac.underscoredone.com hash
https://hash-hmac.underscoredone.com/hash
answers 402
Give this API any text or binary data and it returns its fingerprint under whichever hash algorithms you choose - SHA-256, SHA-512, MD5, BLAKE2, CRC32 and more. It also signs data with a secret key (HMAC) and safely verifies whether an incoming signature matches, using a timing-safe comparison. Language models cannot hash: they emit a string of the right length and character set that is simply wro
We sent a real
POST request to this endpoint and it
answered 402 with payment requirements we could parse.
- Price
- $0.01
- Network
- base
- Pay to
- 0xE9740820225B3918b4ddd1292C7cA4Ca0e2C2F08
- Spec dialect
- v2 (declares x402Version 2)
- Transport
- PAYMENT-REQUIRED header
- HTTP method
- POST
- Response latency
- 172 ms
- Payment options
- 2 usable of 2
- Last checked
- 2026-09-06T01:09:45.591Z (31d ago)
- Category
- ai-inference
Re-check it yourself:
curl "https://api.the402.dev/validate?url=https%3A%2F%2Fhash-hmac.underscoredone.com%2Fhash"