# CRC32 Hex Checksum

> CRC32 Hex Checksum is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-29).

Computes the CRC32 checksum of a given text string and returns it as a hexadecimal string, with no network or LLM calls.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/checksum-crc32-hex?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crc32-hex-checksum-c9f5b6c9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GoBf7GW_mMQJQSkeSiYAb

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 crc32-hex-checksum-c9f5b6c9 -d '<json body>'
```

Example prompt: Calculate the CRC32 checksum of the text 'Hello, world! This is my payload.' and give me the result as a hex string.

## When to prefer this

Choose this endpoint when you need a fast, deterministic CRC32 hex checksum of a text string without any external network calls or LLM overhead. It is ideal for data integrity checks, deduplication fingerprinting, and protocol framing where CRC32 is the required algorithm. Prefer the free sandbox endpoint (/v1/sandbox/checksum-crc32-hex) for testing; use this paid endpoint in production workflows that require reliability guarantees.

## Known failure modes

- Empty or missing 'text' field returns a validation error
- Text exceeding 100,000 characters is rejected
- Missing or invalid API key results in an authentication/payment error
- Malformed request body returns a 400 Bad Request

## How this service works

Call when an agent needs a crc32 checksum of text as hex. No network and no LLM. Exact $0.005 USDC. Prefer unpaid POST /v1/sandbox/checksum-crc32-hex first.

## Output

Returns a hexadecimal string representing the CRC32 checksum of the provided input text. The result is a deterministic, fixed-length hex value (typically 8 hex characters) computed purely locally without any network or AI model involvement.

## 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/crc32-hex-checksum-c9f5b6c9/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)