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Configuring Crypto Deposits with Link

This guide explains how to configure Link to enable your users to deposit cryptocurrency assets into specified addresses. You’ll learn how to define the destination addresses and streamline the deposit experience.

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Understanding Deposit Configuration via toAddresses

The toAddresses array within the TransferOptions object of your link token request is the primary mechanism for configuring where users can deposit their cryptocurrency assets. Each object in this array defines a specific cryptocurrency, the network it resides on, and the receiving address.

Key Requirement: For each item in the toAddresses array, you must provide the Mesh-specific Unique Identifier (UID) for the target network. You can find a comprehensive list of supported tokens, networks, and their corresponding Mesh UIDs here: Tokens | Networks | Integrations.

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Streamlined Deposits to a Single Crypto Address

For the most direct user experience, especially when you intend users to deposit a specific asset to a specific address, configure a single entry in the toAddresses array. This will instruct the Link UI to skip the asset and network selection screens, taking the user directly to the connection and authorization steps.

Link Token Request Body:

{
  "UserId": "unique_end_user_identifier",
  "TransferOptions": {
    "ToAddresses": [
      {
        "NetworkId": "e3c7fdd8-b1fc-4e51-85ae-bb276e075611",
        "Symbol": "ETH",
        "Address": "0x9Bf6207f8A3f4278E0C989527015deFe10e5D7c6"
      }
    ]
  }
}

• NetworkId: The Mesh UID of the target network (e.g., Ethereum Mainnet in this case).
• Symbol: The symbol of the cryptocurrency being deposited (e.g., ETH).
• Address: The receiving cryptocurrency address.

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Offering Deposits for Multiple Crypto Tokens or Networks

To provide users with more flexibility in their deposit options, you can include multiple objects within the toAddresses array. Each object will represent a specific token and the network it can be deposited over.

Link Token Request Body:

{
  "UserId": "unique_end_user_identifier",
  "TransferOptions": {
    "ToAddresses": [
      {
        "NetworkId": "e3c7fdd8-b1fc-4e51-85ae-bb276e075611",
        "Symbol": "ETH",
        "Address": "0x9Bf6207f8A3f4278E0C989527015deFe10e5D7c6"
      },
      {
        "NetworkId": "e3c7fdd8-b1fc-4e51-85ae-bb276e075611",
        "Symbol": "USDC",
        "Address": "0x9Bf6207f8A3f4278E0C989527015deFe10e5D7c6"
      },
      {
        "NetworkId": "e3c7fdd8-b1fc-4e51-85ae-bb276e075611",
        "Symbol": "USDT",
        "Address": "0x9Bf6207f8A3f4278E0C989527015deFe10e5D7c6"
      },
      {
        "NetworkId": "7436e9d0-ba42-4d2b-b4c0-8e4e606b2c12",
        "Symbol": "MATIC",
        "Address": "0x9Bf6207f8A3f4278E0C989527015deFe10e5D7c6"
      }
    ]
  }
}

• Each object in the ToAddresses array defines a specific deposit option (Network and Symbol).

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Seamless Return Customer Experience

Step 1: Retrieving the Access Token

During the initial connection, you’ll use the onIntegrationConnected SDK event (more information about UI Events can be found here) to capture and save the accessToken. You will need to construct the accessToken object prior to sending it back to Mesh for the reconnection. Here’s how:

const meshLink = await createLink({
  clientId: clientId,
  linkToken: linkToken,
  onIntegrationConnected: async (payload) => {
    var accessToken = [
      {
        "accessToken": payload.accessToken.accountTokens[0].accessToken,
        "brokerType": payload.accessToken.brokerType,
        "accountId": payload.accessToken.accountTokens[0].account.accountId,
        "accountName": payload.accessToken.accountTokens[0].account.accountName,
        "brokerName": payload.accessToken.brokerName
      }
    ] // Store the accessToken
    // IMPORTANT: Store the accessToken securely on your server or in a secure storage location.
  },
  // ... other options
});

Key Points:

• Saving the Access Token: The most crucial step is to securely save the accessToken. Never store it directly in client-side code (e.g., local storage) for production applications.
• User Association: Associate the accessToken with the corresponding user in your application’s database.

Step 2: Using the Access Token for Reconnections

The next time you initialize createLink for the same user, include the stored accessToken in the accessTokens property:

const meshLink = await createLink({
  clientId: clientId,
  linkToken: linkToken,
  accessTokens: accessToken, // Use the stored accessToken
  // ... other options
});

Connecting Multiple Accounts

If a user has connected multiple accounts, you can store an array of accessTokens and pass them to the accessTokens property:

const meshLink = await createLink({
  clientId: clientId,
  linkToken: linkToken,
  accessTokens: [accessToken1, accessToken2, ...], // Array of accessTokens
  // ... other options
});

🚨 IMPORTANT — You will need a feature flag enabled on your backend to enable your user to select their desired account from the catalog. Please speak with your Mesh team to enable the feature.

In this case you need to provide an empty toAddresses array to the LinkToken endpoint, to indicate that you wish to use the transfers workflow.

const fetchLinkToken = async () => {
    const response = await fetch(baseUrl + "/api/v1/linktoken", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        "X-Client-Id": clientId,
        "X-Client-Secret": apiSecret,
      },
      body: JSON.stringify({
        userId: "Mesh",
        transferOptions: {
          toAddresses: [],
        }
        // ... other options
      }),
    });
  };

Important Reminders:

• Integration ID: Be sure to not include the integrationId when creating the linkToken for the reconnection. This will cause the Link UI to ignore the accessTokens provided.
• Expiration: Access tokens have an expiration time (expiresInSeconds). You’ll need to handle token refreshes or re-authentication before the tokens expire.
• Security: Always prioritize security when storing and handling access tokens.

Workflow:

1. The user initiates a deposit within your application.
2. You fetch a link token with an empty ToAddresses array.
3. On the client-side, you initialize createLink .
4. When the user goes through the Link flow, they will be presented with their previously connected accounts as potential deposit destinations.