---
title: Script actions variables and metrics
description: Exchange variables with the test, create custom metrics for Analytics, and attach artifacts from a script.
sidebarTitle: Variables & metrics
lastUpdated: "2026-09-23"
---

> **For AI agents:** the complete documentation index is at [llms.txt](/llms.txt). Append `.md` to any page URL for its markdown version.

<Danger>
  **Deprecated.** Script actions are legacy. Existing ones keep running, but for new tests prefer the [visual builder](/tests/builder). Migrate when you can.
</Danger>

Script actions can read the test's input variables, write output variables for later actions, push custom metrics that behave like any built-in metric in Analytics, and attach arbitrary files to the results.

## Variables

```javascript
const value = test.variables.get("INPUT_VARIABLE_NAME");
test.variables.set("OUTPUT_VARIABLE_NAME", "output variable value");
```

Calling `get` automatically declares the input variable on the test, so you can fill it from the test form, a campaign override, or a previous action. Calling `set` declares an output variable, available to every later action.

## Custom metrics

```javascript
describe('My test suite', function () {
  it('Create a custom metric', function () {
    test.metrics.create("my_custom_metric",
      {
        duration: 1.85,            // numbers, strings, or objects
        status_text: "ok"
      },
      {
        service: "checkout"        // tags (optional)
      }
    );
  });
});
```

`test.metrics.create(measurement, fields, tags)` sends a measurement to Analytics exactly like a built-in metric: chart it in dashboards, alert on it, export it. The results screen does not show that a metric was created; check your dashboards.

Combine with the [Timer](/tests/actions/legacy/script-actions#timers) to produce meaningful values:

```javascript
it('Measure login time', function () {
  const timer = new Timer();
  // ... perform the login ...
  test.metrics.create("login", { duration_seconds: timer.stop() });
});
```

## Artifacts

```javascript
test.artifacts.create(name, content, { encoding, type });
```

Attach any content to the step's results, next to the automatic artifacts:

| Parameter | Description |
|-----------|-------------|
| `name` | File name with extension (the extension is stripped in the UI): `report.json`, `payload.txt`. |
| `content` | A string, an object (stringified), a number, or a base64 payload. |
| `encoding` | Optional. Set to `base64` to decode the content before storing, for binary files. |
| `type` | Optional. Free label used to influence how the artifact is displayed. |

```javascript
test.artifacts.create("hello_world.txt", "Hello world!");
test.artifacts.create("data.json", { key: "value", array: [1, 2, 3] });
```

## What's next?

<Columns cols={2}>
  <Card title="Script actions" icon="code" href="/tests/actions/legacy/script-actions">

    Structure, parameters, hooks, and timers

</Card>
  <Card title="Analytics" icon="chart-line" href="/analytics/dashboards">

    Where custom metrics show up

</Card>
</Columns>