# Blake2b-512 Digest → Base64 (UTF-16LE Encoding)

> Blake2b-512 Digest → Base64 (UTF-16LE Encoding) is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.006/call, status unknown (last checked 2026-10-02).

Computes a BLAKE2b-512 cryptographic hash of the UTF-16LE byte representation of a text string and returns the digest encoded as Base64.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/digest-blake2b512-base64-utf16?utm_source=zero.xyz
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blake2b-512-digest-base64-utf-16le-encoding-b9a8453c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jNg40gO6QO_eRRRUGOv84

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-digest-base64-utf-16le-encoding-b9a8453c -d '<json body>'
```

Example prompt: Hash the text 'Hello, World!' using BLAKE2b-512 over its UTF-16LE bytes with the key 'mysecretkey' and give me the result as Base64.

## When to prefer this

Choose this endpoint when you specifically need a BLAKE2b-512 hash computed over UTF-16LE byte representation of a string (e.g., for compatibility with Windows/.NET systems that default to UTF-16LE) and want the result as Base64. Use the free sandbox variant (/v1/sandbox/digest-blake2b512-base64-utf16) first; fall back to this paid endpoint when the sandbox is unavailable or rate-limited.

## Known failure modes

- Text or key exceeds maximum allowed length (text: 100,000 chars, key: 512 chars) — returns 4xx validation error
- Missing required 'text' field — returns 4xx bad request
- Payment not provided or insufficient — returns 402 Payment Required
- Service unavailable or transient error — returns 5xx

## How this service works

Call when an agent needs a blake2b512 digest of utf16le bytes, encoded as base64. Exact $0.006 USDC. Prefer unpaid POST /v1/sandbox/digest-blake2b512-base64-utf16 first.

## Output

Returns a Base64-encoded BLAKE2b-512 digest computed over the UTF-16LE byte encoding of the input text, optionally keyed with the provided key string.

## 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-digest-base64-utf-16le-encoding-b9a8453c/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)