> For a complete index of all SignalWire documentation pages, fetch https://signalwire.com/docs/llms.txt

# Create number group membership

POST https://%7BYour_Space_Name%7D.signalwire.com/api/relay/rest/number_groups/{NumberGroupId}/number_group_memberships
Content-Type: application/json

Adds one project-owned phone number to a Number Group by phone-number ID. Use it to build or expand a sender pool after creating the group; this operation does not purchase or import the number. A phone number can belong to more than one group.

#### Permissions

The API token used to authenticate must have the following scope(s) enabled to make a successful request: _Numbers_.

[Learn more about API scopes](/docs/platform/your-signalwire-api-space).

Reference: https://signalwire.com/docs/apis/rest/number-groups/create-number-group-membership

## Authentication

- `Authorization` header (basic auth, required) — SignalWire Basic Authentication using Project ID and API Token. The client sends HTTP requests with the Authorization header containing the word Basic followed by a space and a base64-encoded string of project_id:token. The project ID will be used as the username and the API token as the password. Example: ``` Authorization: Basic base64(project_id:token) ```

## Request

### Path parameters

- `NumberGroupId` (string, required) — Unique ID of the number group.

### Body (application/json)

- `phone_number_id` (string, required) — The phone number ID to add to the group.

## Response

### 200

The request has succeeded.

- `id` (string, required) — The unique identifier of the Number Group Membership on SignalWire. This can be used to delete the membership programmatically.
- `number_group_id` (string, required) — The unique identifier of the Number Group this membership is associated with.
- `phone_number` (object, required) — A representation of the phone number this membership is associated with.
  - `id` (string, optional) — The unique identifier of the phone number.
  - `name` (string, optional) — The name given to the phone number.
  - `number` (string, optional) — The phone number in E.164 format.
  - `capabilities` (list of string, optional) — The capabilities of the phone number.
- `created_at` (string, required) — The date and time when the membership was created.
- `updated_at` (string, required) — The date and time when the membership was last updated.

## Examples

**Request**

```json
{
  "phone_number_id": "3fa85f64-5717-4562-b3fc-2c963f66afa6"
}
```

**Response**

```json
{
  "id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "number_group_id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "phone_number": {
    "id": "string",
    "name": "Jenny",
    "number": "+15558675309",
    "capabilities": [
      "voice",
      "sms",
      "mms",
      "fax"
    ]
  },
  "created_at": "2023-01-15T10:30:00Z",
  "updated_at": "2023-01-15T10:30:00Z"
}
```

**SDK Code**

```python
import requests

url = "https://{your_space_name}.signalwire.com/api/relay/rest/number_groups/NumberGroupId/number_group_memberships"

payload = { "phone_number_id": "3fa85f64-5717-4562-b3fc-2c963f66afa6" }
headers = {
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers, auth=("<project_id>", "<api_token>"))

print(response.json())
```

```javascript
const url = 'https://{your_space_name}.signalwire.com/api/relay/rest/number_groups/NumberGroupId/number_group_memberships';
const credentials = btoa("<project_id>:<api_token>");

const options = {
  method: 'POST',
  headers: {
    Authorization: `Basic ${credentials}`,
    'Content-Type': 'application/json'
  },
  body: '{"phone_number_id":"3fa85f64-5717-4562-b3fc-2c963f66afa6"}'
};

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

```go
package main

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

func main() {

	url := "https://{your_space_name}.signalwire.com/api/relay/rest/number_groups/NumberGroupId/number_group_memberships"

	payload := strings.NewReader("{\n  \"phone_number_id\": \"3fa85f64-5717-4562-b3fc-2c963f66afa6\"\n}")

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

	req.SetBasicAuth("<project_id>", "<api_token>")
	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
require 'uri'
require 'net/http'

url = URI("https://{your_space_name}.signalwire.com/api/relay/rest/number_groups/NumberGroupId/number_group_memberships")

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

request = Net::HTTP::Post.new(url)
request.basic_auth("<project_id>", "<api_token>")
request["Content-Type"] = 'application/json'
request.body = "{\n  \"phone_number_id\": \"3fa85f64-5717-4562-b3fc-2c963f66afa6\"\n}"

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

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

HttpResponse<String> response = Unirest.post("https://{your_space_name}.signalwire.com/api/relay/rest/number_groups/NumberGroupId/number_group_memberships")
  .basicAuth("<project_id>", "<api_token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"phone_number_id\": \"3fa85f64-5717-4562-b3fc-2c963f66afa6\"\n}")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://{your_space_name}.signalwire.com/api/relay/rest/number_groups/NumberGroupId/number_group_memberships', [
  'body' => '{
  "phone_number_id": "3fa85f64-5717-4562-b3fc-2c963f66afa6"
}',
  'headers' => [
    'Content-Type' => 'application/json',
  ],
    'auth' => ['<project_id>', '<api_token>'],
]);

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

```csharp
using RestSharp;
using RestSharp.Authenticators;

var client = new RestClient("https://{your_space_name}.signalwire.com/api/relay/rest/number_groups/NumberGroupId/number_group_memberships");
client.Authenticator = new HttpBasicAuthenticator("<project_id>", "<api_token>");
var request = new RestRequest(Method.POST);

request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"phone_number_id\": \"3fa85f64-5717-4562-b3fc-2c963f66afa6\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let credentials = Data("<project_id>:<api_token>".utf8).base64EncodedString()

let headers = [
  "Authorization": "Basic \(credentials)",
  "Content-Type": "application/json"
]
let parameters = ["phone_number_id": "3fa85f64-5717-4562-b3fc-2c963f66afa6"] as [String : Any]

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

let request = NSMutableURLRequest(url: NSURL(string: "https://{your_space_name}.signalwire.com/api/relay/rest/number_groups/NumberGroupId/number_group_memberships")! 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()
```