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# addMembership

> Add a phone number to a group.

Add a phone number to a group.

### Schema

```yaml
openapi: 3.1.0
info:
  title: API
  version: 1.0.0
paths:
  /api/relay/rest/number_groups/{NumberGroupId}/number_group_memberships:
    post:
      operationId: subpackageNumberGroupMembership_create_number_group_membership
      summary: Create number group membership
      description: >-
        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).
      tags:
        - subpackage_numberGroupMembership
      parameters:
        - name: NumberGroupId
          in: path
          description: Unique ID of the number group.
          required: true
          schema:
            $ref: '#/components/schemas/uuid'
      responses:
        '200':
          description: The request has succeeded.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NumberGroupMembershipResponse'
        '401':
          description: Access is unauthorized.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Types.StatusCodes.StatusCode401'
        '404':
          description: The server cannot find the requested resource.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Types.StatusCodes.StatusCode404'
        '422':
          description: The request failed validation. See errors for details.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Types.StatusCodes.ValidationError'
        '500':
          description: An internal server error occurred.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Types.StatusCodes.StatusCode500'
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AddNumberGroupMembershipRequest'
tags:
  - name: subpackage_numberGroupMembership
servers:
  - url: https://%7BYour_Space_Name%7D.signalwire.com
    description: SignalWire API
components:
  schemas:
    uuid:
      type: string
      format: uuid
      description: Universal Unique Identifier.
      title: uuid
    AddNumberGroupMembershipRequest:
      type: object
      properties:
        phone_number_id:
          $ref: '#/components/schemas/uuid'
          description: The phone number ID to add to the group.
      required:
        - phone_number_id
      description: Request body for adding a phone number to a number group.
      title: AddNumberGroupMembershipRequest
    MembershipPhoneNumber:
      type: object
      properties:
        id:
          $ref: '#/components/schemas/uuid'
          description: The unique identifier of the phone number.
        name:
          type: string
          description: The name given to the phone number.
        number:
          type: string
          description: The phone number in E.164 format.
        capabilities:
          type: array
          items:
            type: string
          description: The capabilities of the phone number.
      description: Phone number representation within a membership.
      title: MembershipPhoneNumber
    NumberGroupMembershipResponse:
      type: object
      properties:
        id:
          $ref: '#/components/schemas/uuid'
          description: >-
            The unique identifier of the Number Group Membership on SignalWire.
            This can be used to delete the membership programmatically.
        number_group_id:
          $ref: '#/components/schemas/uuid'
          description: >-
            The unique identifier of the Number Group this membership is
            associated with.
        phone_number:
          $ref: '#/components/schemas/MembershipPhoneNumber'
          description: >-
            A representation of the phone number this membership is associated
            with.
        created_at:
          type: string
          description: The date and time when the membership was created.
        updated_at:
          type: string
          description: The date and time when the membership was last updated.
      required:
        - id
        - number_group_id
        - phone_number
        - created_at
        - updated_at
      description: Response containing a single number group membership.
      title: NumberGroupMembershipResponse
    TypesStatusCodesStatusCode401Error:
      type: string
      enum:
        - Unauthorized
      title: TypesStatusCodesStatusCode401Error
    Types.StatusCodes.StatusCode401:
      type: object
      properties:
        error:
          $ref: '#/components/schemas/TypesStatusCodesStatusCode401Error'
      required:
        - error
      description: Access is unauthorized.
      title: Types.StatusCodes.StatusCode401
    TypesStatusCodesStatusCode404Error:
      type: string
      enum:
        - Not Found
      title: TypesStatusCodesStatusCode404Error
    Types.StatusCodes.StatusCode404:
      type: object
      properties:
        error:
          $ref: '#/components/schemas/TypesStatusCodesStatusCode404Error'
      required:
        - error
      description: The server cannot find the requested resource.
      title: Types.StatusCodes.StatusCode404
    Types.StatusCodes.SpaceApiErrorItem:
      type: object
      properties:
        detail:
          type: string
          description: A description of what caused the error.
        status:
          type: string
          description: The HTTP status code.
        title:
          type: string
          description: A short summary of the error type.
        code:
          type: string
          description: The error code.
      required:
        - detail
        - status
        - title
        - code
      description: Details about a specific validation error.
      title: Types.StatusCodes.SpaceApiErrorItem
    Types.StatusCodes.ValidationError:
      type: object
      properties:
        errors:
          type: array
          items:
            $ref: '#/components/schemas/Types.StatusCodes.SpaceApiErrorItem'
          description: List of validation errors.
      required:
        - errors
      description: The request failed validation. See errors for details.
      title: Types.StatusCodes.ValidationError
    TypesStatusCodesStatusCode500Error:
      type: string
      enum:
        - Internal Server Error
      title: TypesStatusCodesStatusCode500Error
    Types.StatusCodes.StatusCode500:
      type: object
      properties:
        error:
          $ref: '#/components/schemas/TypesStatusCodesStatusCode500Error'
      required:
        - error
      description: An internal server error occurred.
      title: Types.StatusCodes.StatusCode500

```

## **Response Example**

### Response (200)

```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"
}
```

## **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);
```

> Add a phone number to a group.