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

# Change Binding

> <Note>This content applies to WaaS 1.0 only. We highly recommend that you upgrade to [WaaS 2.0](https://www.cobo.com/developers/v2/guides/overview/introduction).</Note> This endpoint allows authenticated users to change their binding to a new Prime Broker. The user's `broker_user_id` is passed in the request body, and the new `binder_id` is returned in the JSON response.

#### Request

<ParamField body="user_id" type="String" required>unique user ID</ParamField>

#### Response

<ResponseField name="success" type="bool">request successful or failed</ResponseField>

<ResponseField name="result" type="object">
  <Expandable title="object">
    <ResponseField name="binder_id" type="String">Binding ID, the binding ID needs to be prefixed with binder\_id= to generate a QR code for the user to scan the code to bind, or the user can directly copy the binding code in the form of binder\_id=xxxx to Cobo Auth for the binding operation</ResponseField>
  </Expandable>
</ResponseField>

<RequestExample>
  ```python Python theme={null}
  request(
      "POST",
      "/v1/custody/guard/change_binding/",
      {
          "user_id": "cobo_168108513539918"
      },
      api_key, api_secret, host
  )
  ```

  ```javascript JavaScript theme={null}
  coboFetch('POST', '/v1/custody/guard/change_binding/',
          {
             "user_id": "cobo_168108513539918"
          },
          api_key, api_secret, host
      ).then(res => {
          res.json().then((data)=>{
              console.log(JSON.stringify(data, null, 4));
          })
      }).catch(err => {
          console.log(err)
      });
  ```

  ```go Go theme={null}
  Request("POST", "/v1/custody/guard/change_binding/", map[string]string{
      "user_id": "cobo_168108513539918"
  })
  ```
</RequestExample>

<ResponseExample>
  ```json theme={null}
  {
    "success": true,
    "result": {
      "binder_id": "Ph8YP+LTQyqcfHE/A+eXUw=="
    }
  }

  ```
</ResponseExample>