# SHA-512/256 Hex Digest

> SHA-512/256 Hex Digest is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-01).

Computes the SHA-512/256 cryptographic hash of a given text string and returns it as a hexadecimal-encoded digest.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/digest-sha512-256-hex?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sha-512-256-hex-digest-62ef2586
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__dlwLfKeU4-Wxyp5OXGeq

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 sha-512-256-hex-digest-62ef2586 -d '<json body>'
```

Example prompt: Can you compute the SHA-512/256 hash of this text and give it back to me as a hex string: 'The quick brown fox jumps over the lazy dog'?

## When to prefer this

Choose this endpoint when you need a SHA-512/256 (truncated SHA-512) hash specifically, as opposed to SHA-256 or SHA-3 variants. It is ideal when security policy mandates SHA-512/256 for its resistance to length-extension attacks. Prefer it over the free sandbox endpoint (/v1/sandbox/digest-sha512-256-hex) only after the sandbox is unavailable or rate-limited. It is fully deterministic, offline, and does not involve any external network requests or LLM processing.

## Known failure modes

- Empty or missing text field returns a validation error
- Text exceeding 100,000 characters is rejected
- Missing or invalid payment (x402) results in a 402 Payment Required response
- Malformed request body returns a 400 Bad Request

## How this service works

Call when an agent needs a sha512-256 digest of text, encoded as hex. No network and no LLM. Exact $0.005 USDC. Prefer unpaid POST /v1/sandbox/digest-sha512-256-hex first.

## Output

Returns a hex-encoded SHA-512/256 digest string (64 characters) computed from the input text. The computation is performed locally with no network calls or LLM involvement, guaranteeing deterministic and fast results.

## 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/sha-512-256-hex-digest-62ef2586/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)