---
title: System Log
description: Summary of errors and warnings in Home Assistant during runtime.
ha_category:
  - Other
ha_release: 0.58
ha_quality_scale: internal
ha_domain: system_log
ha_integration_type: system
---

The `system_log` integration stores information about all logged errors and warnings in Home Assistant. To view your logs, navigate to {% my logs title="**Settings** > **System** > **Logs**" %} (condensed and full raw logs are available). In order to not overload Home Assistant with log data, only the 50 last errors and warnings will be stored inside a condensed log. Older entries are automatically discarded from a condensed log; a full raw log keeps all records. It is possible to change the number of stored log entries in a condensed log using the parameter `max_entries`.

## Configuration

This integration is automatically loaded by the `frontend` (so no need to do anything if you are using the frontend). If you are not doing so, or if you wish to change a parameter, add the following section to your {% term "`configuration.yaml`" %} file:

```yaml
system_log:
  max_entries: MAX_ENTRIES
```

{% configuration %}
max_entries:
  description: Number of entries to store in a condensed log (older entries are discarded).
  required: false
  type: integer
  default: 50
fire_event:
  description: Whether events are fired (required when used for triggers).
  required: false
  type: string
  default: false
{% endconfiguration %}

## Actions

### Action `clear`

To manually clear the system log, use this action.

### Action `write`

Write a log entry

| Data attribute | Optional | Description                                                                    |
| ---------------------- | -------- | ------------------------------------------------------------------------------ |
| `message`              | no       | Message to log                                                                 |
| `level`                | yes      | Log level: debug, info, warning, error, critical. Defaults to 'error'.         |
| `logger`               | yes      | Logger name under which to log the message. Defaults to 'system_log.external'. |

## Events

Errors and warnings are posted as the event `system_log_event`, so it is possible to write automations that trigger whenever a warning or error occurs. The following information is included in each event:

| Field       | Description                                                                 |
| ----------- | --------------------------------------------------------------------------- |
| `level`     | Either `WARNING` or `ERROR` depending on severity.                          |
| `source`    | File that triggered the error, e.g., `core.py` or `media_player/yamaha.py`. |
| `exception` | Full stack trace if available, an empty string otherwise.                   |
| `message`   | Descriptive message of the error, e.g., "Error handling request".           |
| `name`      | Name of the integration, e.g., `homeassistant.components.device_tracker`    |
| `timestamp` | Unix timestamp with as a double, e.g., 1517241010.237416.                   |

Live examples of these events can be found in the Home Assistant log file (`home-assistant.log`) or by just looking in the system log. An example could, for instance, look like this:

```text
2019-02-14 16:20:35 ERROR (MainThread) [homeassistant.loader] Unable to find integration system_healt
2019-02-14 16:20:36 ERROR (MainThread) [homeassistant.components.device_tracker] Error setting up platform google_maps
Traceback (most recent call last):
  File "/home/fab/Documents/repos/ha/home-assistant/homeassistant/integrations/device_tracker/__init__.py", line 184, in
[...]
```

The message ("Unable to find integration system_healt"), name (`homeassistant.loader`) and level (`ERROR`) can easily be extracted from the log. The exact timestamp and if there is a stack trace that's shown as well. 

## Examples 

Here are some examples using the events posted by `system_log`. `fire_event` must be set to `true` for these to work.

### Counting Number of Warnings

This will create a `counter` that increases every time a warning is logged:

```yaml
counter:
  warning_counter:
    name: Warnings
    icon: mdi:alert

automation:
  - alias: "Count warnings"
    triggers:
      - trigger: event
        event_type: system_log_event
        event_data:
          level: WARNING
    actions:
      - action: counter.increment
        target:
          entity_id: counter.warning_counter
```

### Conditional Messages

This automation will create a persistent notification whenever an error or warning is logged that has the word "action" in the message:

{% raw %}

```yaml
automation:
  - alias: "Create notifications for 'action' errors"
    triggers:
      - trigger: event
        event_type: system_log_event
    conditions:
      - condition: template
        value_template: '{{ "action" in trigger.event.data.message[0] }}'
    actions:
      - action: persistent_notification.create
        data:
          title: "Something bad happened"
          message: "{{ trigger.event.data.message[0] }}"
```

{% endraw %}

### Writing to log

This automation will create a new log entry when the door is opened:

```yaml
automation:
  - alias: "Log door opened"
    triggers:
      - trigger: state
        entity_id: binary_sensor.door
        from: "off"
        to: "on"
    actions:
      - action: system_log.write
        data:
          message: "Door opened!"
          level: info
```