---
title: Events in Actions
slug: events-in-actions
docTags: 
createdAt: 2026-04-14T03:40:21.546Z
---

When an Action is triggered **by an event**, ChartHop makes the event's data available as variables you can use in your trigger conditions and message templates.

Understanding the structure of those variables helps you write precise conditions — especially when you only want an Action to fire when a *specific field* changed.

## Event types

Every event has a type that describes what happened. Update events follow this format:

```javascript
change.update.<entity>
```

For example:

- `change.update.hire` — a hire record was updated
- `change.update.job` — a job record was updated

You can see the event type that fired an Action in its run log.

## event.before and event.update

When an update event fires, two variables give you access to the field values involved in that specific change:

| Variable               | What it contains                             |
| ---------------------- | -------------------------------------------- |
| `event.before.<field>` | The value of the field *before* this update  |
| `event.update.<field>` | The new value being written *by* this update |

These variables are scoped to the specific fields touched by this event. If a field wasn't part of the update, `event.update.<field>` will be empty.

## Example: Only trigger when startDate changes

Suppose you have an Action on `change.update.hire` and want it to fire only when `startDate` is modified — not when other fields like `announceDate` are updated.

Use this condition:

```javascript
event.update.date != event.before.date
```

This checks whether the `startDate` (stored as `date` on the event) was part of this update and has a different value than before. If `startDate` wasn't touched, the condition won't match and the Action won't fire.

## Tip: Print event values to debug

If you're not sure what an event contains, add a **Send Message** step that prints the before and after values. For example:

```javascript
Before: {{event.before.date}}
After: {{event.update.date}}
```

Trigger the event manually, then check the message to see exactly what values ChartHop captured. This is the fastest way to understand what's in the event before writing your condition.