# BLAKE2b-512 Hex Digest of UTF-16LE Text

> BLAKE2b-512 Hex Digest of UTF-16LE Text is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-29).

Computes a keyed or unkeyed BLAKE2b-512 cryptographic hash of text encoded as UTF-16LE bytes, returning the digest as a lowercase hex string.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/digest-blake2b512-hex-utf16?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blake2b-512-hex-digest-of-utf-16le-text-cacd5e46
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nUM6asaS3mkZXcAh-glC9

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability blake2b-512-hex-digest-of-utf-16le-text-cacd5e46 -d '<json body>'
```

Example prompt: Compute a BLAKE2b-512 hash of the text 'Hello, World!' using UTF-16LE encoding and give me the result as a hex string, using the key 'mysecretkey'.

## When to prefer this

Choose this endpoint when you specifically need a BLAKE2b-512 digest computed over UTF-16LE bytes (the native encoding used by Windows, .NET, and many Microsoft file formats) and want the output as a hex string. Use it over SHA-3 siblings when BLAKE2b's speed or keying capability is required, and over the sandbox variant (/v1/sandbox/digest-blake2b512-hex-utf16) when you need a production, paid call. Prefer this over generic hashing libraries when operating in an agent environment that cannot run native code.

## Known failure modes

- Text or key exceeds maximum length (100,000 chars for text, 512 chars for key) — validation error returned
- Missing required 'text' field — request rejected
- Invalid UTF-16LE encoding edge cases for certain emoji or surrogate pairs may produce unexpected results
- Payment failure or insufficient USDC balance — 402 Payment Required response
- Network timeout if service is temporarily unavailable

## How this service works

Call when an agent needs a blake2b512 digest of utf16le bytes, encoded as hex. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/digest-blake2b512-hex-utf16 first.

## Output

A hex-encoded BLAKE2b-512 digest string (128 hex characters) computed over the UTF-16LE byte representation of the input text, optionally keyed. The response is a deterministic, fixed-length hash suitable for integrity checks, deduplication, or keyed message authentication.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "key": {
   "type": "string",
   "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."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/blake2b-512-hex-digest-of-utf-16le-text-cacd5e46/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)