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

# Link Wallet

> Link a wallet address to a customer created with a reference key

Links an Ethereum wallet address to an existing customer that was created without a wallet. This is the second step of the deferred wallet flow: first [create a customer](/endpoints/customers/create) without a `walletAddress` to receive a `referenceKey`, then call this endpoint when the end-customer connects their wallet in your application.

The endpoint validates that the reference key exists, the customer does not already have a wallet, and the wallet is not already assigned to another customer in the same instance.

## Request Body

<ParamField body="referenceKey" type="string" required>
  The reference key returned when the customer was created without a wallet address. Format: `ref_` followed by 32 hex characters.
</ParamField>

<ParamField body="walletAddress" type="string" required>
  Ethereum wallet address to link. Must be a valid checksummed or lowercased address.
</ParamField>

## Response Fields

<ResponseField name="success" type="boolean">Request status</ResponseField>
<ResponseField name="data" type="object">The updated customer object with the linked wallet address</ResponseField>

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST "https://api.trusset.org/customers/api/manage/link-wallet" \
    -H "Content-Type: application/json" \
    -H "X-API-Key: trusset_abc123xy_secret..." \
    -d '{
      "referenceKey": "ref_a1b2c3d4e5f67890abcdef12345678",
      "walletAddress": "0xAbC123dEf456789012345678901234567890AbCd"
    }'
  ```

  ```typescript TypeScript theme={null}
  const response = await fetch('https://api.trusset.org/customers/api/manage/link-wallet', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'X-API-Key': 'trusset_abc123xy_secret...'
    },
    body: JSON.stringify({
      referenceKey: 'ref_a1b2c3d4e5f67890abcdef12345678',
      walletAddress: '0xAbC123dEf456789012345678901234567890AbCd'
    })
  });
  const { data: customer } = await response.json();
  ```

  ```python Python theme={null}
  import requests

  response = requests.post(
      'https://api.trusset.org/customers/api/manage/link-wallet',
      headers={
          'Content-Type': 'application/json',
          'X-API-Key': 'trusset_abc123xy_secret...'
      },
      json={
          'referenceKey': 'ref_a1b2c3d4e5f67890abcdef12345678',
          'walletAddress': '0xAbC123dEf456789012345678901234567890AbCd'
      }
  )
  customer = response.json()['data']
  ```
</RequestExample>

<ResponseExample>
  ```json 200 Response theme={null}
  {
    "success": true,
    "data": {
      "id": "cust_abc123",
      "instanceId": "inst_xyz789",
      "walletAddress": "0xAbC123dEf456789012345678901234567890AbCd",
      "referenceKey": "ref_a1b2c3d4e5f67890abcdef12345678",
      "name": "Acme Corp",
      "country": "DE",
      "investorType": "PROFESSIONAL",
      "status": "pending",
      "archived": false,
      "createdAt": "2025-06-15T12:00:00.000Z",
      "updatedAt": "2025-06-15T12:05:00.000Z"
    },
    "metadata": {
      "requestId": "550e8400-e29b-41d4-a716-446655440000",
      "timestamp": "2025-06-15T12:05:00.000Z"
    }
  }
  ```

  ```json Error - Customer not found theme={null}
  {
    "success": false,
    "error": {
      "code": "CUSTOMER_NOT_FOUND",
      "message": "No customer found with this reference key"
    },
    "metadata": {
      "requestId": "550e8400-e29b-41d4-a716-446655440000",
      "timestamp": "2025-06-15T12:05:00.000Z"
    }
  }
  ```

  ```json Error - Wallet already linked theme={null}
  {
    "success": false,
    "error": {
      "code": "WALLET_ALREADY_LINKED",
      "message": "This customer already has a linked wallet"
    },
    "metadata": {
      "requestId": "550e8400-e29b-41d4-a716-446655440000",
      "timestamp": "2025-06-15T12:05:00.000Z"
    }
  }
  ```

  ```json Error - Wallet in use theme={null}
  {
    "success": false,
    "error": {
      "code": "WALLET_IN_USE",
      "message": "This wallet address is already assigned to another customer"
    },
    "metadata": {
      "requestId": "550e8400-e29b-41d4-a716-446655440000",
      "timestamp": "2025-06-15T12:05:00.000Z"
    }
  }
  ```
</ResponseExample>