# MEV Exposure Detector

> MEV Exposure Detector is a paid API for AI agents from mevdetector.hergertsynthora.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Detects MEV attacks (sandwich attacks, frontrunning, backrunning) on DEX swap transactions by scanning block-adjacent transactions and returning a signed exposure signal.

## Facts

- Endpoint: POST https://mevdetector.hergertsynthora.com/service
- 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/mev-exposure-detector-06f5e0b5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wlZK-Ifrbz5HfKQitRrgl

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 mev-exposure-detector-06f5e0b5 -d '<json body>'
```

Example prompt: Can you check if this Base chain transaction was sandwich attacked or frontrun: 0x3a9f21c8b47d0e9d2fbc34a1e056c78d9e1234567890abcdef1234567890abcd?

## When to prefer this

Use this endpoint when you need to quickly classify whether a specific DEX swap transaction was exposed to MEV attacks, particularly sandwich attacks, frontrunning, or backrunning. Prefer this over general block explorers when you need a structured, signed signal for programmatic consumption rather than raw transaction data.

## Known failure modes

- Invalid or malformed transaction hash returns an error
- Transaction not found on the specified chain
- Unsupported chain identifier provided
- Network timeout when scanning block-adjacent transactions
- Transaction is not a DEX swap (returns no_swap signal)

## How this service works

Detects sandwich attacks and frontrunning by scanning block-level trade ordering.

## Output

Returns a signed MEV exposure signal with one of four classifications: no_swap, swap_exposed, frontrun_risk, or sandwich — along with an Ed25519 signature attesting to the result's authenticity.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "string",
   "description": "TX hash or wallet address"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ok": {
   "type": "boolean"
  },
  "niche": {
   "type": "string"
  },
  "result": {
   "type": "object"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mev-exposure-detector-06f5e0b5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mevdetector.hergertsynthora.com](https://www.zero.xyz/host/mevdetector.hergertsynthora.com/llms.txt)