Send message

Use this action to send a message to one or more Matrix rooms, for example to post a notification or share an image.

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 send 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: Send message.
6. Enter the Message and the Target room or rooms. Optionally, set extra options under Data.
7. Select Save.

This action does not support action targets. In the UI, you set the room in the Target field instead of selecting an area, device, entity, or label.

Options in the UI

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.send_message:

action: matrix.send_message
data:
  message: "My cool message"
  target:
    - "#hasstest:matrix.org"
  data:
    images:
      - "/path/to/picture.jpg"
    format: html
    thread_id: "$-abcdeghij_klmnopqrstuvwxyz123"

This sends a message with an attached image to the #hasstest:matrix.org room.

Options in YAML

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.

Related actions

These actions work well alongside this one:

• React: Sends a reaction to a message in a Matrix room.