> ## Documentation Index
> Fetch the complete documentation index at: https://align.tolbel.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Check ERC-1155 Ownership

> Check if an address owns an ERC-1155 token

## Method Signature

```typescript theme={null}
align.blockchain.nfts.isOwner(
  contractAddress: string,
  owner: string,
  tokenId: string,
  network: Network
): Promise<boolean>
```

## Parameters

<ParamField body="contractAddress" type="string" required>
  ERC-1155 contract address
</ParamField>

<ParamField body="owner" type="string" required>
  Address to check
</ParamField>

<ParamField body="tokenId" type="string" required>
  Token ID to check
</ParamField>

<ParamField body="network" type="string" required>
  Network
</ParamField>

## Returns

Returns `true` if the address owns at least 1 of the token, `false` otherwise.

## Examples

<Tabs>
  <Tab title="TypeScript">
    ```typescript theme={null}
    import Align from "@tolbel/align";

    const align = new Align({
      apiKey: process.env.ALIGN_API_KEY!,
      environment: "sandbox",
    });

    const owns = await align.blockchain.nfts.isOwner(
      "0xERC1155Contract...",
      "0xWalletAddress...",
      "42", // Token ID
      "polygon"
    );

    if (owns) {
      console.log("User owns token #42!");
    } else {
      console.log("User does not own token #42");
    }
    ```
  </Tab>

  <Tab title="JavaScript">
    ```javascript theme={null}
    const owns = await align.blockchain.nfts.isOwner(
      contract,
      walletAddress,
      tokenId,
      "polygon"
    );
    console.log("Owns token:", owns);
    ```
  </Tab>
</Tabs>

### Gate Access Based on NFT Ownership

```typescript theme={null}
async function checkAccess(userAddress: string): Promise<boolean> {
  // Check if user owns the "premium" token (ID 1)
  return align.blockchain.nfts.isOwner(
    MEMBERSHIP_CONTRACT,
    userAddress,
    "1", // Premium membership token ID
    "polygon"
  );
}

const hasAccess = await checkAccess(userWallet);
if (!hasAccess) {
  throw new Error("Premium membership required");
}
```

## Related Methods

<CardGroup cols={2}>
  <Card title="Get ERC-721 Owner" icon="user" href="/docs/api/blockchain/nfts/get-owner">
    Check unique NFT owner
  </Card>

  <Card title="Transfer ERC-1155" icon="paper-plane" href="/docs/api/blockchain/nfts/transfer-erc1155">
    Transfer tokens
  </Card>
</CardGroup>