# Some useful functions provided by the SDK

The SDK also provides some useful functions that you can use to implement search functionality and check if a token is owned by a given wallet address or not. Here is the complete list of the functions:

## **searchMarketplace**

This function allows you to search for a token on the marketplace by providing a search query. Here is an example call of how you can search for a token on the marketplace:

```typescript
import { Networks, searchMarketplace } from '@lyncworld/fuel-marketplace';

const response = searchMarketplace(
  Networks.Testnet,
  '0x...' // contract address, token id, asset id, or seller address to search
);
```

* Returns -

```typescript
{
  success: boolean;
  data: MarketplaceListings[];
  error: unknown
}
```

* Types -

```typescript
interface MarketplaceListings {
  listingId: number;
  isActive: boolean;
  nftAddress: `0x${string}`;
  tokenStandard: 'NFT' | 'SEMI_FT';
  tokenId: `0x${string}`;
  assetId: `0x${string}`;
  tokenQuantity: number;
  pricePerItem: string;
  sellerAddress: `0x${string}`;
  tokenName: string;
  tokenImage: string;
  tokenAssetMedia: string;
}
```

## **checkNftOwnership**

This function allows you to check if a token is owned by a given wallet address or not. Here is an example call of how you can check if a token is owned by a given wallet address:

```typescript
import { checkNftOwnership, Networks } from '@lyncworld/fuel-marketplace';

const response = checkNftOwnership(
  wallet, // wallet of the user to check the ownership
  '0x...' // contract address of the token to check the ownership
  "0x..." // token id (or sub id) of the token to check the ownership
  "SEMI_FT" // token standard of the token to check the ownership (choose from NFT or SEMI_FT)
);
```

* Returns -

```typescript
{
  success: true;
  data: {
    contractAddress: `0x${string}`;
    subId: `0x${string}`;
    nftStandard: 'NFT' | 'SEMI_FT';
  }
}
```

Or

```typescript
{
  success: false;
  error: string[];
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://lync-1.gitbook.io/lync/fuel/fuel-marketplace-npm-sdk/using-the-sdk/some-useful-functions-provided-by-the-sdk.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.