# x402 Chain Intel – Mempool Sandwich Detector

> x402 Chain Intel – Mempool Sandwich Detector is a paid API for AI agents from x402-chain-intel.vercel.app, paid per call via x402, $0.2/call, status unknown (last checked 2026-10-13).

Detects sandwich attack opportunities or sandwich attacks targeting a given transaction in the mempool

## Facts

- Endpoint: POST https://x402-chain-intel.vercel.app/api/mempool/sandwich?utm_source=zero.xyz
- Price: $0.2/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-chain-intel-mempool-sandwich-detector-59ef6caa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Nlg2lyO8l44mKaa2t29zo

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 x402-chain-intel-mempool-sandwich-detector-59ef6caa -d '<json body>'
```

Example prompt: Check the mempool right now for any sandwich attacks targeting transaction 0xabc123... on Ethereum — I want to know the attacker address, the front-run and back-run txs, and how much profit they extracted.

## When to prefer this

Use this endpoint when you need real-time or near-real-time sandwich attack detection for specific transactions or tokens in the Ethereum mempool, especially for trading bots that need to protect swaps from MEV exploitation or conduct post-trade forensics on suspicious price impact.

## Known failure modes

- Transaction hash not found in mempool or already confirmed — returns empty result or 404
- Invalid transaction hash format — returns 400 validation error
- Mempool data unavailable due to node connectivity issues — returns 503
- Payment not received or insufficient USDC — returns 402 payment required
- Rate limit exceeded — returns 429 too many requests

## How this service works

27 paid endpoints for trading bots

## Output

Returns structured data about detected sandwich attacks including attacker wallet addresses, front-run and back-run transaction hashes, estimated MEV profit extracted, and a risk or severity score for the targeted transaction.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-chain-intel-mempool-sandwich-detector-59ef6caa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-chain-intel.vercel.app](https://www.zero.xyz/host/x402-chain-intel.vercel.app/llms.txt)