# AgentShelf SHAKE-128 Digest (Base64URL)

> AgentShelf SHAKE-128 Digest (Base64URL) is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-01).

Computes a SHAKE-128 (XOF) hash of input text and returns the digest encoded as a base64url string.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/digest-shake128-base64url?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-shake-128-digest-base64url-64160d2e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_H-9Uu5Mxr6samF6_6PicX

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 agentshelf-shake-128-digest-base64url-64160d2e -d '<json body>'
```

Example prompt: Compute the SHAKE-128 hash of the text 'Hello, world!' and give me the result as a base64url-encoded string.

## When to prefer this

Choose this endpoint when you need a SHAKE-128 (extendable output function / XOF) hash of text and specifically require the output in base64url encoding — ideal for URL-safe tokens, compact identifiers, or systems that consume base64url-formatted digests. Prefer the free sandbox endpoint (/v1/sandbox/digest-shake128-base64url) first for testing. Use alternative sibling endpoints if you need a different hash algorithm (SHA-512, SHA3-384, etc.) or a different encoding (hex, base32, base64).

## Known failure modes

- Empty or missing 'text' field returns a validation error
- Text exceeding 100,000 characters is rejected
- Missing or invalid key parameter may cause authentication failure
- Payment not fulfilled results in 402 Payment Required response
- Malformed request body returns 400 Bad Request

## How this service works

Call when an agent needs a shake128 digest of text, encoded as base64url. No network and no LLM. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/digest-shake128-base64url first.

## Output

Returns a base64url-encoded string representing the SHAKE-128 digest of the provided input text. The output is a compact, URL-safe hash suitable for use in tokens, checksums, or identifiers.

## 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/agentshelf-shake-128-digest-base64url-64160d2e/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)