2026.6.3
Home ▸ Actions

React

Use this action to send a reaction to a message in a Matrix room, for example to acknowledge a message with a 👍.

Using this action from the user interface

If you prefer building automations and scripts visually, Home Assistant walks you through this action step by step. You pick what to target, tweak a few options, and save. No YAML knowledge required.

To react to a Matrix message from an automation or a script:

  1. Go to Settings > Automations & scenes.
  2. Open an existing automation or script, or select Create automation > Create new automation.
  3. If you’re setting up a new automation, add a trigger in the When section. Scripts don’t need a trigger. They run when something else calls them.
  4. In the Then do section, select Add action.
  5. Search for and select Matrix: React.
  6. Enter the Reaction, the Room, and the Message ID to react to.
  7. Select Save.

This action does not support targets. In the UI, you are not prompted to choose an area, device, entity, or label.

Options in the UI

Reaction (Required)

The reaction to send.
Room (Required)

The room to send the reaction to.
Message ID (Required)

The ID of the message to react to.

Using this action in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this action as matrix.react:

ActionActions are used in several places in Home Assistant. As part of a script or automation, actions define what is going to happen once a trigger is activated. In scripts, an action is called *sequence*. [Learn more] 
action: matrix.react
data:
  reaction: "✅"
  room: "#hasstest:matrix.org"
  message_id: "$-abcdeghij_klmnopqrstuvwxyz123"

This adds a ✅ reaction to the given message.

Options in YAML

reaction string Required

The reaction to send.

room string Required

The room to send the reaction to.

message_id string Required

The ID of the message to react to.

Good to know

  • A reaction does not have to be an emoji. It can be any valid string, but emoji are the typical use.

Try it yourself

Ready to test this? Open Developer tools > Actions, search for this action, fill in the fields, and select Perform action. You see what happens on your actual 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] without writing a line of YAML.

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the action you’re calling and what you expected to happen, or share on our subreddit /r/homeassistant.

Tip

AI assistants like ChatGPT or Claude can also explain actions or suggest the right one when you describe what you want in plain language.

Related actions

These actions work well alongside this one:

  • Send message: Sends a message to one or more Matrix rooms.