File

The File integration allows storing notifications in a file or setting up a sensor based on a file’s content.

Configuration

To add the File integration to your Home Assistant instance, use this My button:

Notifications

Make sure that the file you want to use is added to the allowlist_external_dirs. The file will be created if it doesn’t exist, but make sure the folder exists. Add the path of your configuration folder (for example, /config/file_notifications) to save the file there. Setting timestamp to true adds a timestamp to every logged entry. After creating a config entry, you can change the entry name, the name of the notify entity, or the entity ID, if you prefer.

To use notifications in automations or scripts, see the getting started with automation page.

Use the notify.send_message entity service to store notification messages.

Sensor

The file sensor platform reads the entries from a plain-text file and shows the found value. Only the last line of the file is used. This is similar to do $ tail -n 1 sensor.txt on the command-line. Note that file paths must be added to allowlist_external_dirs.

Examples

In this section you find some real-life examples of how to use this sensor.

Entries as JSON

Assuming that the log file contains multiple values formatted as JSON as shown below:

[...]
{"temperature": 21, "humidity": 39}
{"temperature": 22, "humidity": 36}

This would require the following settings to extract the temperature:

• Name: Temperature
• File path: /home/user/.homeassistant/sensor.json
• Value template: '{{ value_json.temperature }}'
• Unit of measurement: "°C"

Entries as CSV

Assuming the log file contains multiple values formatted as CSV as shown below:

timestamp,temperature,humidity
1631472948,21,39
1631472949,22,36

This would require the following settings to extract the temperature:

• Name: Temperature
• File path: /home/user/.homeassistant/sensor.csv
• Value template: '{{ value.split(",")[1] }}'
• Unit of measurement: "°C"