# 402utils Hash / Checksum API

> 402utils Hash / Checksum API is a paid API for AI agents from 402utils.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Computes cryptographic hashes (SHA-256, SHA-512, SHA-1, MD5) of a UTF-8 string or raw bytes, returning lowercase hex digests for each requested algorithm.

## Facts

- Endpoint: POST https://402utils.com/v1/hash
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/402utils-hash-checksum-api-d0028c43
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yxDQNsIO-lBgVxm-KHvrb

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 402utils-hash-checksum-api-d0028c43 -d '<json body>'
```

Example prompt: Can you hash the string 'Hello, World!' and give me both the SHA-256 and SHA-512 hex digests?

## When to prefer this

Use this endpoint when you need a quick, serverless hash computation without running local crypto libraries — especially useful in agent pipelines needing integrity verification, when you want multiple algorithms in one call, or when you need SHA-256/SHA-512 via Web Crypto with a pay-per-call model rather than maintaining infrastructure. Prefer over alternatives when you need the input kept out of URLs and logs (POST body), and when you want MD5/SHA-1 flagged for legacy interop.

## Known failure modes

- Missing both 'text' and 'bytes' fields — returns 400 error
- Both 'text' and 'bytes' provided simultaneously — ambiguous input, likely 400
- Invalid base64 encoding in 'bytes' field — returns 400 or decoding error
- Unsupported algorithm value outside enum — returns 400 validation error
- Empty string or zero-length input — may return valid hash of empty input or 400 depending on implementation
- Payment failure (402) if USDC not provided via x402 protocol

## How this service works

Compute cryptographic hashes / checksums of a string or of raw bytes (base64). Returns lowercase hex for each requested algorithm: sha256 (default), sha512, sha1, md5. SHA via native Web Crypto; md5 and sha1 are offered for legacy interop only and flagged — not for security. POST so the input never lands in a URL/log. Verification/checksums only, not a hash cracker.

## Output

A JSON object mapping each requested algorithm name to its lowercase hex digest string, e.g. {"sha256": "dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986d", "sha512": "..."}. SHA-1 and MD5 results are flagged as legacy/not for security use.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "description": "UTF-8 text to hash."
  },
  "bytes": {
   "type": "string",
   "description": "Raw bytes as base64 (standard or url-safe) — alternative to `text`."
  },
  "algorithms": {
   "type": "array",
   "items": {
    "enum": [
     "sha256",
     "sha512",
     "sha1",
     "md5"
    ],
    "type": "string"
   },
   "default": [
    "sha256"
   ],
   "description": "Which digests to compute (default [\"sha256\"])."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/402utils-hash-checksum-api-d0028c43/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 402utils.com](https://www.zero.xyz/host/402utils.com/llms.txt)