# SHA-256 Base64URL Digest

> SHA-256 Base64URL 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 SHA-256 cryptographic hash of input text and returns it encoded as a base64url string, with no network or LLM involvement.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/digest-sha256-base64url?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/sha-256-base64url-digest-d11fe681
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_w3JqQgfex3KhKQ7GnRBju

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-256-base64url-digest-d11fe681 -d '<json body>'
```

Example prompt: Hash the text 'Hello, world!' using SHA-256 and give me the result as a base64url string.

## When to prefer this

Choose this endpoint when you need a SHA-256 hash specifically encoded as base64url (not hex or base32), and you want a deterministic, pure-computation result with no external network calls or LLM inference. Prefer the free sandbox endpoint (/v1/sandbox/digest-sha256-base64url) first; use this paid endpoint when the sandbox is unavailable or rate-limited. Prefer sibling endpoints if you need a different algorithm (blake2b512, blake2s256, md5, ripemd160, sha224) or a different encoding (hex, base32).

## Known failure modes

- Text exceeds 100,000 character limit — returns a 400 or size error
- Missing or empty 'text' field — returns a validation error
- Missing or invalid 'key' field — returns an authentication or payment error
- Payment of $0.001 USDC not completed — returns a 402 Payment Required

## How this service works

Call when an agent needs a sha256 digest of text, encoded as base64url. No network and no LLM. Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/digest-sha256-base64url first.

## Output

Returns a base64url-encoded SHA-256 digest of the submitted text. The response is a deterministic, fixed-length string (43 characters without padding) suitable for use in URLs, headers, or anywhere a compact hash representation is needed.

## 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-256-base64url-digest-d11fe681/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)