# OnChaiNinja MEV Detection

> OnChaiNinja MEV Detection is a paid API for AI agents from nininonchain.vercel.app, paid per call via x402, $3/call, status unknown (last checked 2026-10-20).

Detects MEV (Maximal Extractable Value) activity for a specific transaction on a given blockchain chain

## Facts

- Endpoint: GET https://nininonchain.vercel.app/api/mev/%7Bchain%7D/%7Btx%7D?utm_source=zero.xyz
- Price: $3/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/onchaininja-mev-detection-5f5bf2f0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IEtVkpv8M4NsoLNRXTvsY

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 onchaininja-mev-detection-5f5bf2f0
```

Example prompt: Can you check if this Arbitrum transaction 0xabc123...def was subject to any MEV — like a sandwich attack or front-running?

## When to prefer this

Use this endpoint when you need to determine post-hoc whether a specific on-chain transaction was subject to MEV extraction (front-running, sandwiching, back-running) across multi-chain environments including Base, Solana, and Arbitrum. Prefer this over generic block explorers when you need a structured, machine-readable MEV verdict rather than raw transaction data.

## Known failure modes

- Invalid or unrecognized chain identifier — endpoint may return an error or empty result
- Transaction hash not found on the specified chain — may return not-found or null result
- Unsupported chain — chain not among Base, Solana, Arbitrum, or other supported networks
- Malformed transaction hash — returns validation error
- Payment failure — $3 USDC per call not fulfilled, request rejected
- Network timeout — blockchain RPC latency causing delayed or failed response

## How this service works

Alpha signals, whale tracking, rug scanning, and MEV protection across Base, Solana, Arbitrum, and more.

## Output

Returns a JSON object indicating whether MEV was detected on the given transaction (e.g. {"mevDetected": false}), signaling whether the transaction was subject to front-running, sandwiching, or other MEV extraction techniques.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "mevDetected": false
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/onchaininja-mev-detection-5f5bf2f0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from nininonchain.vercel.app](https://www.zero.xyz/host/nininonchain.vercel.app/llms.txt)