# SHA3-512 Hex Digest

> SHA3-512 Hex Digest 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 a SHA3-512 cryptographic hash of input text and returns it as a hexadecimal-encoded string, with no network or LLM calls involved.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/digest-sha3-512-hex?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sha3-512-hex-digest-eb6c5d51
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wyADgxP5WmbNm7jkPY6qg

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 sha3-512-hex-digest-eb6c5d51 -d '<json body>'
```

Example prompt: Can you compute the SHA3-512 hash of the text 'Hello, world!' and give me the result as a hex string?

## When to prefer this

Use this endpoint when you specifically need SHA3-512 (Keccak-based, NIST standard) output in hexadecimal format. Prefer the free sandbox POST /v1/sandbox/digest-sha3-512-hex first; use this paid endpoint when the sandbox is unavailable or rate-limited. Choose this over SHA-2 variants when SHA3 is mandated by your security policy, and over base64-encoded siblings when hex output is required by the consuming system.

## Known failure modes

- Empty or missing 'text' field returns a validation error
- Text exceeding 100,000 characters is rejected
- Missing or invalid API key results in authentication failure
- Payment not settled via x402 protocol results in 402 response

## How this service works

Call when an agent needs a sha3-512 digest of text, encoded as hex. No network and no LLM. Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/digest-sha3-512-hex first.

## Output

Returns a SHA3-512 digest of the submitted text encoded as a lowercase hexadecimal string (128 hex characters representing 512 bits). No external calls are made; the result is purely deterministic.

## 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/sha3-512-hex-digest-eb6c5d51/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)