# SHA-512/256 Digest (Base64url) — agentshelf.syntexa.ch

> SHA-512/256 Digest (Base64url) — agentshelf.syntexa.ch is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.007/call, status unknown (last checked 2026-10-01).

Computes a SHA-512/256 cryptographic hash of the provided text and returns it encoded as a base64url string.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/digest-sha512-256-base64url?utm_source=zero.xyz
- Price: $0.007/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-digest-base64url-agentshelf-syntexa-ch-6130037b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tAGg9deAJ8-Kf8nBxNB7K

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-digest-base64url-agentshelf-syntexa-ch-6130037b -d '<json body>'
```

Example prompt: Can you compute the SHA-512/256 hash of the text 'Hello, world! This is my document content.' and give it back as a base64url-encoded digest?

## When to prefer this

Choose this endpoint when you specifically need a SHA-512/256 hash (a truncated variant of SHA-512 with a different initialization vector) encoded in URL-safe base64url format. Prefer this over the hex or base32 variants when the digest will be embedded in URLs, JWT tokens, or other contexts where padding-free URL-safe encoding is required. Use the free sandbox endpoint (/v1/sandbox/digest-sha512-256-base64url) for testing before paying.

## Known failure modes

- Text or key field missing or empty (minLength:1 violated) — returns 400 Bad Request
- Text exceeds 100,000 character limit — returns 400 or 413
- Payment of exactly $0.007 USDC not provided — returns 402 Payment Required
- Invalid input types (e.g. non-string values) — returns 400 Bad Request

## How this service works

Call when an agent needs a sha512-256 digest of text, encoded as base64url. No network and no LLM. Exact $0.007 USDC. Prefer unpaid POST /v1/sandbox/digest-sha512-256-base64url first.

## Output

Returns a base64url-encoded string representing the SHA-512/256 cryptographic hash of the input text. The digest is computed locally with no network calls or LLM involvement, guaranteeing deterministic and reproducible output for identical inputs.

## 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-digest-base64url-agentshelf-syntexa-ch-6130037b/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)