# How can we help?

## Overview

The Smarty utility `addSendProperties` allows you to add key/value pairs to the properties object of system events related to the message contact ID (message-sent, open, click, bounce, etc.).

Send properties must be added before the message is sent. It is not possible to add send properties to sent messages.

As a best practice, it's recommended that the data object be built first and then passed via the `addSendProperties` utility. Debugging can be used to preview the call and resolve any issues before the call is made.

## Example

```
{* Build a data object *}
{$data.send_properties = ['foo' => 'bar', 'foo2' => 'bar2']}

{* Pass it into the method *}
{$utils->addSendProperties($data.send_properties)}

{* Debug *}
{$debug = 1}
{if $debug == 1}
  {$utils->jsonPrettyPrint($data)}
{/if}
```

This example will add key/values pairs to the properties object of the system event:

```
{$utils->addSendProperties(["foo"=>"bar","foo2"=>"bar2"])}
```

The resulting properties object:

```
"properties":{
  "foo":"bar",
  "foo2":"bar2"
}
```

You may also add a dynamic value to the properties object. This example will add key/values pairs to the properties object of the system event (where `dynamicValue` is `biz`):

```
{$dynamicValue = 'biz'}
{$utils->addSendProperties(["foo"=>"bar","dynamicValue"=>{$dynamicValue}])}
```

The newly defined dynamic value within the properties object:

```
"properties":{
  "foo":"bar",
  "dynamicValue":"biz"
}
```

Send properties can be retrieved and rendered in a message via the [getEventRecords method](https://support.cordial.com/hc/en-us/articles/115005693247-Get-Event-Data-getEventRecords-method), but they are not available for identifying contacts using audience rules.