Merge action responses: merge_response

The merge_response template function takes the response dictionary from a multi-entity action call and merges it into a single flat list. When you call an action that targets multiple entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more], the response is a dictionary keyed by entity ID, where each value contains the entity’s response data. merge_response flattens this structure into a single list, adding the entity_id to each item for reference.

This is useful when you call actions like calendar.get_events or weather.get_forecasts that target multiple entities at once. Without merge_response, you would need to manually loop through the response dictionary and extract items from each entity. This function handles that for you and produces a unified list that is straightforward to sort, filter, and display. Each item in the result includes an entity_id field so you can still tell which entity it came from.

Usage

Here’s how to use this template function. Copy any example and adjust it to your setup.

{{ merge_response(response) }}

[
  {"start": "2024-03-15", "summary": "Meeting", "entity_id": "calendar.work"},
  {"start": "2024-03-15", "summary": "Dentist", "entity_id": "calendar.personal"},
]

Function signature

The signature is a technical summary of this template function. It shows the name of the function, the values (called parameters) it accepts, and what type of data each parameter expects (for example, a piece of text or a number).

Function parameters that have a = with a value after them are optional. If you leave them out, the default value shown is used automatically. Function parameters without a default are required.

merge_response(
    value: dict,
) -> list

Function parameters

The following parameters can be provided to this function.

Good to know

• Adds an entity_id field to each item, so you can tell which entity each response came from after merging.
• Only works on responses shaped as {entity_id: {key: [items]}}. Responses with a different shape need manual handling.

Try it yourself

Ready to test this? Open Developer tools > Template, paste the example into the Template editor, and watch the result update on the right. Edit the values to see how the function adapts to your own entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more].

More examples

Real scenarios where this function comes up in automations and templates. Copy any example and adapt it to your setup.

Merge calendar events from multiple calendars

Call calendar.get_events targeting multiple calendars and merge all events into a single sorted list.

action:
  - action: calendar.get_events
    target:
      entity_id:
        - calendar.work
        - calendar.personal
    data:
      duration:
        hours: 24
    response_variable: agenda
  - action: notify.mobile
    data:
      message: >
        Today's events:
        {% for event in merge_response(agenda) | sort(attribute="start") %}
        - {{ event.summary }} ({{ event.entity_id.split(".")[1] }})
        {% endfor %}

Merge weather forecasts

Combine forecasts from multiple weather entities into one list for comparison.

action:
  - action: weather.get_forecasts
    target:
      entity_id:
        - weather.home
        - weather.office
    data:
      type: daily
    response_variable: forecasts
  - action: notify.mobile
    data:
      message: >
        {% for item in merge_response(forecasts) %}
        {{ item.entity_id }}: {{ item.temperature }}C
        {% endfor %}

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with your template and expected result, or share on our subreddit /r/homeassistant.

Related template functions

These functions work well alongside this one:

• Merge dictionaries: combine - Merges multiple dictionaries into one.

• Serialize to JSON: to_json - Serializes a value to a JSON string.

• Parse JSON string: from_json - Parses a JSON string into a Python object.

• Flatten nested lists: flatten - Flattens nested lists into a single flat list.