> ## Documentation Index
> Fetch the complete documentation index at: https://docs.declarativeforms.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Capture campaign data

If you have not created a form before, start with [Create a form](/getting-started/create-a-form).

```yaml form.yaml theme={null}
version: 1
title: "Lead capture"
description: "A simple form that captures campaign data from the URL."

sections:
  - id: section_1
    title: "Your details"
    fields:
      # Prefill this hidden field with ?utm_source=...
      - id: utm_source
        type: hidden

      # Prefill this hidden field with ?utm_campaign=...
      - id: utm_campaign
        type: hidden

      - id: email
        type: email
        label: "Email address"
        validators:
          - required

    next: done
```

Example URL: `https://frms.dev/example-form?utm_source=newsletter&utm_campaign=spring_launch`