# NFT Floor Wash Trade Detector

> NFT Floor Wash Trade Detector is a paid API for AI agents from api.chainmarket-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-24).

Detects wash trading activity in an ERC-721 NFT collection by analyzing recent transfer round-trips on Ethereum

## Facts

- Endpoint: GET https://api.chainmarket-api.workers.dev/api/crypto/nft-floor-wash-detector?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nft-floor-wash-trade-detector-48ce4338
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VIR-eLM0O4W9yyiJ1FBVp

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 nft-floor-wash-trade-detector-48ce4338
```

Example prompt: Can you check if the Bored Ape Yacht Club NFT contract at 0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D has been wash trading — I want to see any round-trip transfers that look suspicious?

## When to prefer this

Choose this endpoint when you need on-chain evidence of wash trading in a specific Ethereum ERC-721 NFT collection without signing up for an analytics platform. It's ideal for due diligence before purchasing NFTs, auditing marketplace listings for price manipulation, or compliance checks — particularly when you want raw round-trip transfer data with transaction hashes rather than a derived score from a third-party oracle.

## Known failure modes

- Invalid or non-ERC-721 contract address returns an error
- Contract address with no transfer history returns empty transfers array
- Rate limiting or Blockscout upstream unavailability causes timeout
- Malformed address (not 0x + 40 hex) rejected at input validation
- Payment failure results in no charge and no response

## How this service works

ERC-721 collection activity on Ethereum from Blockscout: name, holder count, supply and the newest 50 transfers, with round-trip transfers (a token sent A to B and straight back to A) flagged as possible wash signals. No sale prices, floor price or royalties: this source does not provide them.

## Output

Returns the collection name, symbol, contract address, total supply, holders count, a sample of recent transfers with sender/receiver/tokenId/timestamp/txHash, detected round-trip pairs with the wallet addresses involved and transaction hashes, and a total round-trip count — all sourced from Blockscout's Ethereum API.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "description": "ERC-721 contract address on Ethereum, 0x + 40 hex characters"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "name": "BoredApeYachtClub",
  "type": "ERC-721",
  "source": "https://eth.blockscout.com/api/v2/tokens/0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D/transfers",
  "symbol": "BAYC",
  "address": "0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D",
  "checkedAt": "2026-10-23T09:35:54.648Z",
  "transfers": [
   {
    "to": "0x28dDa46BdC0aEB3b4E58E6A9A3774875729367a0",
    "from": "0xE445283D46D814aF9AB554D5afb40aFB28b91935",
    "tokenId": "948",
    "timestamp": "2026-10-23T08:49:47.000000Z",
    "transactionHash": "0x078d40f50a0b7927753a9477e15f80ce87056b2f0eb2a84775ad6f330ce5430a"
   },
   {
    "to": "0x28dDa46BdC0aEB3b4E58E6A9A3774875729367a0",
    "from": "0xE445283D46D814aF9AB554D5afb40aFB28b91935",
    "tokenId": "7510",
    "timestamp": "2026-10-23T08:49:23.000000Z",
    "transactionHash": "0x8e142162d32398c2afcee6c35b57c1fd2c8009a3da0acdb1471b1fdb77eed67d"
   }
  ],
  "roundTrips": [
   {
    "between": [
     "0x29469395eAf6f95920E59F858042f0e28D98a20B",
     "0x1a1660e7d83B3B2e047fb0f26A159F9dd9dCb486"
    ],
    "newerTx": "0x9f4c3a90e57480839f34e5e0bc1146e9340101e3510976e61450c4e8a7f803a9",
    "olderTx": "0xfbff10b9d94ec07e96729d805df1d84fe4c3084153afe23f3e156988ea699d07",
    "tokenId": "2627"
   },
   {
    "between": [
     "0x1a1660e7d83B3B2e047fb0f26A159F9dd9dCb486",
     "0x29469395eAf6f95920E59F858042f0e28D98a20B"
    ],
    "newerTx": "0xfbff10b9d94ec07e96729d805df1d84fe4c3084153afe23f3e156988ea699d07",
    "olderTx": "0x2328e2a1ba3cbf80cac682976f5f7c9d186b0ff73f710860ddea6afba24b3277",
    "tokenId": "2627"
   }
  ],
  "totalSupply": 10000,
  "holdersCount": 8245,
  "roundTripCount": 5,
  "transfersChecked": 50
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nft-floor-wash-trade-detector-48ce4338/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.chainmarket-api.workers.dev](https://www.zero.xyz/host/api.chainmarket-api.workers.dev/llms.txt)