***

title: addMembership
slug: /reference/typescript/rest/number-groups/add-membership
description: Add a phone number to a group.
max-toc-depth: 3
---------------------

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

Add a phone number to a group.

<EndpointSchemaSnippet endpoint="POST /api/relay/rest/number_groups/{NumberGroupId}/number_group_memberships" />

## **Response Example**

<EndpointResponseSnippet endpoint="POST /api/relay/rest/number_groups/{NumberGroupId}/number_group_memberships" />

## **Example**

```typescript {9}
import { RestClient } from "@signalwire/sdk";

const client = new RestClient({
  project: "your-project-id",
  token: "your-api-token",
  host: "your-space.signalwire.com"
});

const membership = await client.numberGroups.addMembership("group-id", {
    phone_number_id: "phone-number-id",
});
console.log("Membership ID:", membership.id);
```