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

# Create provider customer link

> Link a client to an external provider customer ID.

<Warning>
  **Deprecated.** This endpoint is no longer available in the public API and is kept for reference only.
</Warning>

Links a client to a specific provider's customer ID for external service integration. Requires an API key with access level 3 or higher.

## Path parameters

<ParamField path="clientId" type="string" required>
  Unique identifier of the client.
</ParamField>

## Body

<ParamField body="provider" type="string" required>
  External provider. One of `BRIDGE`, `REAP`, `UNLIMINT`, `PAXOS`, etc.
</ParamField>

<ParamField body="customer_id" type="string" required>
  Customer ID in the external provider's system.
</ParamField>

## Response

<ResponseField name="id" type="string">
  Mapping identifier.
</ResponseField>

<ResponseField name="client_id" type="string">
  Client identifier.
</ResponseField>

<ResponseField name="provider" type="string">
  External provider.
</ResponseField>

<ResponseField name="customer_id" type="string">
  Customer ID in the external provider's system.
</ResponseField>

<ResponseField name="status" type="string">
  Mapping status.
</ResponseField>

<ResponseField name="created_at" type="string">
  Creation timestamp.
</ResponseField>

<ResponseField name="updated_at" type="string">
  Last update timestamp.
</ResponseField>

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST "https://api.cryptomate.me/management/clients/client_a1b2c3d4-e5f6-4a7b-8c9d-0e1f2a3b4c5d/providers" \
    -H "x-api-key: $CRYPTOMATE_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "provider": "BRIDGE",
      "customer_id": "cust_ext_xyz789"
    }'
  ```
</RequestExample>

<ResponseExample>
  ```json 200 OK theme={null}
  {
    "id": "cpc_abc123",
    "client_id": "client_a1b2c3d4-e5f6-4a7b-8c9d-0e1f2a3b4c5d",
    "provider": "BRIDGE",
    "customer_id": "cust_ext_xyz789",
    "status": "active",
    "created_at": "2026-04-15T10:30:00",
    "updated_at": "2026-04-15T10:30:00"
  }
  ```

  ```json 412 Precondition Failed theme={null}
  {
    "code": "VAL",
    "message": "Client already has a customer ID for provider BRIDGE"
  }
  ```
</ResponseExample>