# SHA-256 Hex Digest

> SHA-256 Hex Digest is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.009/call, status unknown (last checked 2026-10-01).

Computes a SHA-256 hash of input text and returns the result encoded as a lowercase hexadecimal string, with no network calls or LLM involvement.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/digest-sha256-hex?utm_source=zero.xyz
- Price: $0.009/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-hex-digest-5c4f86bd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Z0bdC7DTZI9Mki1JFU0Np

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-hex-digest-5c4f86bd -d '<json body>'
```

Example prompt: Can you SHA-256 hash the text 'Hello, world!' and give me the hex-encoded digest?

## When to prefer this

Choose this endpoint when you need a fast, deterministic SHA-256 hex digest of a text string without setting up a local hashing library or trusting an LLM to compute it. It is preferable to SHA-256 in other encodings (base64, base32) when hexadecimal output is required, and preferred over blake2b or md5 sibling endpoints when specifically SHA-256 compatibility is needed. Try the free sandbox endpoint /v1/sandbox/digest-sha256-hex first before using this paid endpoint.

## Known failure modes

- Missing or empty 'text' field returns a validation error
- Text exceeding 100,000 characters is rejected
- Missing or invalid 'key' field results in authentication failure
- Payment failure (insufficient USDC) blocks the request
- Malformed JSON request body returns a 400 error

## How this service works

Call when an agent needs a sha256 digest of text, encoded as hex. No network and no LLM. Exact $0.009 USDC. Prefer unpaid POST /v1/sandbox/digest-sha256-hex first.

## Output

Returns a 64-character lowercase hexadecimal string representing the SHA-256 digest of the provided input text. The computation is deterministic and performed locally without any external network calls or LLM inference.

## 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-hex-digest-5c4f86bd/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)