Input Multiselect component for Home Assistant

This is a custom component for Home Assistant that introduces a new helper entity: input_multiselect.

While the native input_select only allows you to pick a single option from a dropdown, this component lets you select multiple options simultaneously. It's perfect for scenarios like selecting which rooms a robot vacuum should clean, choosing multiple media players to group, or picking which days of the week an automation should run.

Note: This component only handles the backend logic (creating the entities, storing the state, and exposing the actions). To actually interact with these entities via a proper UI dropdown with checkboxes on your Lovelace dashboard, you will also need the companion frontend card: Input Multiselect Card.

Installation

HACS (Recommended)

The easiest way to install this is through HACS. Since it's not in the default store yet, you need to add it as a custom repository:

1. Go to HACS -> Integrations.
2. Click the three dots in the top right corner and select Custom repositories.
3. Paste the URL of this repository and select Integration as the category.
4. Click Add, then search for "Input Multiselect" and download it.
5. Restart Home Assistant.

Manual

1. Download the custom_components/input_multiselect folder from this repository.
2. Copy it into your Home Assistant custom_components directory.
3. Restart Home Assistant.

Configuration

Configuration is done entirely via the UI. YAML configuration is not supported.

1. Go to Settings -> Devices & Services -> Integrations.
2. Click + Add Integration and search for "Input Multiselect".
3. Give your entity a name and provide the list of available options (either comma-separated or one per line).

You can edit the options at any time by clicking the Configure button on the integration page.

How it works (States & Attributes)

Home Assistant has a strict 255-character limit for entity states. Storing an array of selected items directly in the state string can easily break this limit. To ensure stability, the entity works as follows:

• State: Displays the numeric count of currently selected items (e.g., 2 selected).
• Attributes: Contains the actual data arrays.
  • options: The full list of available options you configured.
  • selected_options: An array containing only the currently checked items (e.g., ['Kitchen', 'Living Room']).

When writing templates for your automations, you should read from the selected_options attribute.

Available Actions

This integration exposes the following actions that you can call from your scripts and automations:

Action	Description	Payload
input_multiselect.set_options	Overwrites the current selection entirely.	options: List of strings
input_multiselect.add_options	Adds new items to the existing selection.	options: List of strings
input_multiselect.remove_options	Removes specific items from the selection.	options: List of strings

Action Example

action: input_multiselect.add_options
target:
  entity_id: input_multiselect.rooms_to_clean
data:
  options:
    - Kitchen
    - Hallway