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# Check for duplicate accounts

POST https://api.vlenseg.com/api/DigitalIdentity/CheckExistenceOfEmailOrPhone
Content-Type: application/json

Before starting registration, verify that the phone number or email is not already associated with an account in this tenant. Call this first to surface duplicate-account errors before the user completes the OTP flow.


Reference: https://docs.vlenseg.com/api-reference/vlens-api/registration/check-existence-of-email-or-phone

## OpenAPI Specification

```yaml
openapi: 3.1.0
info:
  title: example-openapi
  version: 1.0.0
paths:
  /api/DigitalIdentity/CheckExistenceOfEmailOrPhone:
    post:
      operationId: check-existence-of-email-or-phone
      summary: Check for duplicate accounts
      description: >
        Before starting registration, verify that the phone number or email is
        not already associated with an account in this tenant. Call this first
        to surface duplicate-account errors before the user completes the OTP
        flow.
      tags:
        - subpackage_registration
      parameters:
        - name: ApiKey
          in: header
          description: >-
            Static API key issued to your tenant. Obtain from the Vlens
            dashboard.
          required: true
          schema:
            type: string
      responses:
        '200':
          description: Check result.
          content:
            application/json:
              schema:
                $ref: >-
                  #/components/schemas/Registration_checkExistenceOfEmailOrPhone_Response_200
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CheckExistenceInput'
servers:
  - url: https://api.vlenseg.com
components:
  schemas:
    CheckExistenceInput:
      type: object
      properties:
        phoneNumber:
          type:
            - string
            - 'null'
        email:
          type:
            - string
            - 'null'
          format: email
      title: CheckExistenceInput
    ApiDigitalIdentityCheckExistenceOfEmailOrPhonePostResponsesContentApplicationJsonSchemaData:
      type: object
      properties:
        exists:
          type: boolean
      title: >-
        ApiDigitalIdentityCheckExistenceOfEmailOrPhonePostResponsesContentApplicationJsonSchemaData
    Registration_checkExistenceOfEmailOrPhone_Response_200:
      type: object
      properties:
        data:
          $ref: >-
            #/components/schemas/ApiDigitalIdentityCheckExistenceOfEmailOrPhonePostResponsesContentApplicationJsonSchemaData
        error_code:
          type:
            - integer
            - 'null'
        error_message:
          type:
            - string
            - 'null'
      title: Registration_checkExistenceOfEmailOrPhone_Response_200
  securitySchemes:
    ApiKey:
      type: apiKey
      in: header
      name: ApiKey
      description: Static API key issued to your tenant. Obtain from the Vlens dashboard.

```

## SDK Code Examples

```python Registration_checkExistenceOfEmailOrPhone_example
import requests

url = "https://api.vlenseg.com/api/DigitalIdentity/CheckExistenceOfEmailOrPhone"

payload = {
    "phoneNumber": "+201234567890",
    "email": "user@example.com"
}
headers = {
    "ApiKey": "<apiKey>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript Registration_checkExistenceOfEmailOrPhone_example
const url = 'https://api.vlenseg.com/api/DigitalIdentity/CheckExistenceOfEmailOrPhone';
const options = {
  method: 'POST',
  headers: {ApiKey: '<apiKey>', 'Content-Type': 'application/json'},
  body: '{"phoneNumber":"+201234567890","email":"user@example.com"}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go Registration_checkExistenceOfEmailOrPhone_example
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.vlenseg.com/api/DigitalIdentity/CheckExistenceOfEmailOrPhone"

	payload := strings.NewReader("{\n  \"phoneNumber\": \"+201234567890\",\n  \"email\": \"user@example.com\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("ApiKey", "<apiKey>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby Registration_checkExistenceOfEmailOrPhone_example
require 'uri'
require 'net/http'

url = URI("https://api.vlenseg.com/api/DigitalIdentity/CheckExistenceOfEmailOrPhone")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["ApiKey"] = '<apiKey>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"phoneNumber\": \"+201234567890\",\n  \"email\": \"user@example.com\"\n}"

response = http.request(request)
puts response.read_body
```

```java Registration_checkExistenceOfEmailOrPhone_example
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.vlenseg.com/api/DigitalIdentity/CheckExistenceOfEmailOrPhone")
  .header("ApiKey", "<apiKey>")
  .header("Content-Type", "application/json")
  .body("{\n  \"phoneNumber\": \"+201234567890\",\n  \"email\": \"user@example.com\"\n}")
  .asString();
```

```php Registration_checkExistenceOfEmailOrPhone_example
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.vlenseg.com/api/DigitalIdentity/CheckExistenceOfEmailOrPhone', [
  'body' => '{
  "phoneNumber": "+201234567890",
  "email": "user@example.com"
}',
  'headers' => [
    'ApiKey' => '<apiKey>',
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp Registration_checkExistenceOfEmailOrPhone_example
using RestSharp;

var client = new RestClient("https://api.vlenseg.com/api/DigitalIdentity/CheckExistenceOfEmailOrPhone");
var request = new RestRequest(Method.POST);
request.AddHeader("ApiKey", "<apiKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"phoneNumber\": \"+201234567890\",\n  \"email\": \"user@example.com\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift Registration_checkExistenceOfEmailOrPhone_example
import Foundation

let headers = [
  "ApiKey": "<apiKey>",
  "Content-Type": "application/json"
]
let parameters = [
  "phoneNumber": "+201234567890",
  "email": "user@example.com"
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.vlenseg.com/api/DigitalIdentity/CheckExistenceOfEmailOrPhone")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```