# AgentUtility Content SimHash

> AgentUtility Content SimHash is a paid API for AI agents from x402.agentutility.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Computes a 64-bit SimHash fingerprint of input text using FNV-1a hashing over character shingles for near-duplicate detection

## Facts

- Endpoint: POST https://x402.agentutility.ai/content-simhash
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentutility-content-simhash-4161e443
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_A74kbe6mLz4EZjxWjOxrR

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 agentutility-content-simhash-4161e443 -d '<json body>'
```

Example prompt: Compute a SimHash fingerprint for this text: 'The quick brown fox jumps over the lazy dog near the riverbank' — use a shingle size of 3 so I can compare it against other documents for near-duplicate detection.

## When to prefer this

Use this endpoint when you need a fast, cheap ($0.005 USDC) locality-sensitive hash for near-duplicate text detection without running your own hashing infrastructure. Ideal for deduplication pipelines, content similarity indexing, or plagiarism detection where exact matching is insufficient. Prefer over cryptographic hash endpoints when near-similarity (not exact equality) is the goal.

## Known failure modes

- Empty or missing text input returns an error
- Extremely long text may time out or be truncated
- Invalid shingle size parameter causes a 400 error
- Payment failure via x402 results in 402 response before processing

## How this service works

Paid x402 endpoints organized into product clusters. USDC-settled on Base. MCP-callable. ERC-8004 identity registry agentId 47167.

## Output

Returns a JSON object with the 64-bit SimHash as both hex string and integer, plus metadata: character count of input text, estimated token count, shingle size used, and number of shingles generated. Useful for Hamming-distance based near-duplicate comparison.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "source": "DIY SimHash (FNV-1a 64)",
  "hash_hex": "0xa3f4b29d12c7e608",
  "hash_int": "11814413120842008072",
  "bit_count": 64,
  "text_chars": 86,
  "token_count": 16,
  "shingle_size": 3,
  "shingle_count": 14
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentutility-content-simhash-4161e443/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.agentutility.ai](https://www.zero.xyz/host/x402.agentutility.ai/llms.txt)