Certain actions in Plesk, such as: - Creating a customer account - Removing an IP address - Updating the hosting settings of a domain, and many others are recognized by Plesk as events. For every event, you can create one or more event handlers that execute a predetermined command every time the event occurs. Event handlers are useful if you want a certain action or a set of actions to be carried out every time a specific event occurs. For example, you can create an event handler that triggers every time a subscription is created and configure it to automatically create a mailbox, send a request to an external service, and so on.
## Adding Event Handlers 1. Go to **Tools & Settings** \> **Event Manager**. 2. Click  **Add Event Handler**. 3. Select the event that will trigger the handler from the “Event” list. 4. Under “Priority”, set the handler execution priority by selecting it from the list or typing a custom number in the field. Priority becomes important if you assign several handlers to a single event. In this case, handlers are triggered according to their priority in descending order (the event triggers the handler with the highest priority first, the handler with the second highest priority next, and so on). 5. Select the system user on whose behalf the handler will be executed from the “User” list.
Note The server administrator can create the event handlers that will be run on the server on behalf of user root. If you wish to restrict usage of the root account, create an empty file with name  `root.event_handler.lock` in the location `/usr/local/psa/var/`.
6. In the “Command” field, type the path to the shell script or a .bat file containing the commands to be executed whenever the event handler triggers (for example, `/usr/local/psa/bin/script.sh` or `C:\Windows\Temp\script.bat`).
Note Make sure to give your script the execute permission. You can do so by running the following command: `chmod`` ``755`` ```
7. Click  **OK**.
## Passing Event Parameters Whenever an event handler triggers, it passes certain data (“Event Parameters”) associated with the event (which data are passed depends on the event handler in question). For example, the “Domain created” event handler passes the following parameters: - The name of the newly created domain. - The GUID of the newly created domain. - The GUID of the customer account owning the newly created domain. Each parameter is passed as an environment variable that you can use in your shell script or .bat file as follows:
### Plesk for Linux Use the placeholder `${ENVIRONMENT_VARIABLE_NAME}` (for example, “`${NEW_DOMAIN_NAME}`”) in your shell script. When the event handler triggers, the placeholder will be replaced by the value corresponding to the event.
### Plesk for Windows Use the placeholder `%N` (for example, “`%1`”) in your bat file, and append the name of the desired environment variable in the corresponding position at the end of the command in the event handler settings. In the following example
image 78436
the placeholder “`%1`” will be replaced with the value of the “`NEW_DOMAIN_NAME`” environment variable, and the “`%2`” will be replaced with the value of “`NEW_DOMAIN_GUID`”. If you use “`%3`” in the .bat file, it will not be replaced with anything, as only two environment variable names were specified after the command. You can see the complete list of event parameters and associated environment variable names for each event handler here. For reference, here are two examples of scripts for the ‘Customer account created’ event: - (Plesk for Linux) `test-handler.sh` 
#!/bin/bash
echo "--------------" >> /tmp/event_handler.log
/bin/date >> /tmp/event_handler.log # information on the event date and time
/usr/bin/id >> /tmp/event_handler.log # information on the user, on behalf of which the script was executed (to ensure control)
echo "customer created" >> /tmp/event_handler.log # information on the created customer account
echo "name: ${NEW_CONTACT_NAME}" >> /tmp/event_handler.log # customer's name
echo "login: ${NEW_LOGIN_NAME}" >> /tmp/event_handler.log # customer's username in Plesk
echo "--------------" >> /tmp/event_handler.log
- (Plesk for Windows) `test-handler.bat` 
echo "--------------" >> c:\windows\temp\event_handler.log
rem information on the event date and time
date /T   >> c:\windows\temp\event_handler.log
rem information on the created customer account
echo "customer created" >> c:\windows\temp\event_handler.log
rem customer's name
echo "name: %1"       >> c:\windows\temp\event_handler.log
rem customer's username in Plesk
echo "login: %2"      >> c:\windows\temp\event_handler.log
echo "--------------" >> c:\windows\temp\event_handler.log
If you log in to Plesk and create a customer account with the name “John Doe” and login “john_doe”, the event handler will trigger and the following records will be added to the event_handler.log file: - (Plesk for Linux) 
Fri Mar 16 15:57:25 NOVT 2007
uid=0(root) gid=0(root) groups=0(root)
customer created
name: John Doe
login: john_doe
- (Plesk for Windows) 
Mon March 15 21:46:34 NOVT 2010
customer created
name: John Doe
login: john_doe
## Editing and Removing Event Handlers To see the list of currently active event handlers, go to **Tools & Settings** \> **Event Manager**. Here, you can also edit and remove event handlers: - To edit an event handler, click its name, make the desired changes, and click **OK**. - To remove an event handler, select the corresponding checkbox and click **Remove**.
## Using Event Handlers with WP Toolkit WP Toolkit actions fire Plesk events, and administrators can attach their scripts using standard Event Handlers. WP Toolkit triggers standard Plesk events whenever it completes specific operations. For details on viewing, editing, and removing event handlers, see Editing and Removing Event Handlers.