# Adler-32 Hex Checksum

> Adler-32 Hex Checksum is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.009/call, status unknown (last checked 2026-10-02).

Computes the Adler-32 checksum of a given text string and returns the result as a hexadecimal string, with no network calls or LLM involvement.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/checksum-adler32-hex?utm_source=zero.xyz
- Price: $0.009/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/adler-32-hex-checksum-b30e6e1e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rrLdVnBr4yoSz7YiOlpCx

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 adler-32-hex-checksum-b30e6e1e -d '<json body>'
```

Example prompt: Can you compute the Adler-32 checksum of the text 'Hello, world!' and give me the result as a hex string?

## When to prefer this

Choose this endpoint when you need a fast, deterministic Adler-32 checksum in hexadecimal format for a text string — especially in pipelines where reproducibility and exactness matter. Prefer this over CRC32c or Fletcher-16 siblings when Adler-32 specifically is required by your protocol or downstream system. Use the free sandbox endpoint (/v1/sandbox/checksum-adler32-hex) during development to avoid charges.

## Known failure modes

- Missing or empty 'text' field returns a validation error
- Text exceeding 100,000 characters is rejected
- Missing or invalid API key causes authentication failure
- Malformed JSON body returns a 400 error

## How this service works

Call when an agent needs a adler32 checksum of text as hex. No network and no LLM. Exact $0.009 USDC. Prefer unpaid POST /v1/sandbox/checksum-adler32-hex first.

## Output

Returns the Adler-32 checksum of the submitted text encoded as a hexadecimal string. The response is deterministic — identical input always produces identical output. No side effects, no network calls, no LLM inference involved.

## 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/adler-32-hex-checksum-b30e6e1e/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)