# DeFi Shield Mempool MEV Scanner

> DeFi Shield Mempool MEV Scanner is a paid API for AI agents from defi-shield-hazel.vercel.app, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-15).

Scans recent mempool transactions for a token to detect large pending trades and MEV (Maximal Extractable Value) activity

## Facts

- Endpoint: POST https://defi-shield-hazel.vercel.app/api/mev/mempool-scan
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/defi-shield-hazel-vercel-app-ae8b20a8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_LLyDLfQeTEpAgHF3k9l29

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 defi-shield-hazel-vercel-app-ae8b20a8 -d '<json body>'
```

Example prompt: Scan the mempool for MEV activity and large pending trades on token 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 — I want to know if there are any sandwich attacks or frontrunning bots targeting it right now.

## When to prefer this

Use this endpoint when you need real-time detection of MEV activity and large pending trades for a specific DeFi token before executing a swap or analyzing market conditions. Prefer this over generic blockchain explorers when you specifically need mempool-level (pre-confirmation) data and MEV pattern recognition rather than confirmed transaction history.

## Known failure modes

- Invalid or unrecognized token address returns error
- Token has no recent mempool activity, resulting in empty results
- Mempool data provider unavailable or rate-limited
- Network congestion causing stale or incomplete mempool snapshot
- Unsupported chain or token standard

## Output

Returns a structured report of recent mempool activity for the specified token, including detected large pending trades, identified MEV bot activity, sandwich attack signals, frontrunning indicators, and relevant transaction metadata such as gas prices and trade sizes.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "bodyType",
    "body",
    "method"
   ],
   "properties": {
    "body": {
     "properties": {
      "chain": {
       "type": "string",
       "description": "Chain (default: base)"
      },
      "token_address": {
       "type": "string",
       "description": "Token address to scan mempool for"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/defi-shield-hazel-vercel-app-ae8b20a8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from defi-shield-hazel.vercel.app](https://www.zero.xyz/host/defi-shield-hazel.vercel.app/llms.txt)