diff --git a/ViewModel/DataLayer.php b/ViewModel/DataLayer.php
new file mode 100644
index 0000000..8dcf6f5
--- /dev/null
+++ b/ViewModel/DataLayer.php
@@ -0,0 +1,149 @@
+<?php
+declare(strict_types=1);
+
+namespace Salesfire\Salesfire\ViewModel;
+
+use Magento\Catalog\Helper\Data\Proxy as TaxHelper;
+use Magento\Checkout\Model\Session as CheckoutSession;;
+use Magento\Framework\App\RequestInterface;
+use Magento\Framework\Registry;
+use Magento\Framework\View\Element\Block\ArgumentInterface;
+use Salesfire\Formatter as SalesfireFormatter;
+use Salesfire\Salesfire\Block\Script as SalesfireScript;
+use Salesfire\Salesfire\Helper\Data as SalesfireHelper;
+use Salesfire\Types\Product as SalesfireProductType;
+use Salesfire\Types\Transaction as SalesfireTransactionType;
+
+class DataLayer implements ArgumentInterface
+{
+    /** @var TaxHelper */
+    private $taxHelper;
+
+    /** @var CheckoutSession $checkoutSession */
+    private $checkoutSession;
+
+    /** @var RequestInterface */
+    private $request;
+
+    /** @var Registry */
+    private $registry;
+
+    /** @var SalesfireHelper $helper */
+    private $helper;
+
+    public function __construct(
+        TaxHelper $taxHelper,
+        CheckoutSession $checkoutSession,
+        RequestInterface $request,
+        Registry $registry,
+        SalesfireHelper $helper
+    ) {
+        $this->taxHelper = $taxHelper;
+        $this->checkoutSession = $checkoutSession;
+        $this->request = $request;
+        $this->registry = $registry;
+        $this->helper = $helper;
+    }
+
+    public function getSiteId()
+    {
+        return $this->helper->getSiteId();
+    }
+
+    public function getData()
+    {
+        if (!($siteId = $this->getSiteId())) {
+            return json_encode([]);
+        }
+
+        /**
+         * The logic is functionally-equivalent to the _toHtml() function of the custom Salesfire block class herein.
+         * Additional comments have been added to highlight specifically where customisations have been made.
+         * @see SalesfireScript::_toHtml()
+         */
+
+        $formatter = new SalesfireFormatter($siteId);
+        $formatter->addPlatform('magento2');
+
+        if ($this->request->getFullActionName() == 'checkout_onepage_success'
+            && $order = $this->checkoutSession->getLastRealOrder() // customisation: use checkout session directly rather than class-level helper function
+        ) {
+            $transaction = new SalesfireTransactionType([
+                'id'       => $order->getIncrementId(),
+                'shipping' => round((float)$order->getShippingAmount(), 2), // customisation: float type casting
+                'currency' => $order->getOrderCurrencyCode(),
+                'coupon'   => $order->getCouponCode(),
+            ]);
+
+            foreach ($order->getAllVisibleItems() as $product) {
+                $variant = '';
+                $options = $product->getProductOptions();
+                $parent_product_id = $product_id = $product->getProductId();
+
+                if ($product->getHasChildren()) {
+                    foreach ($product->getChildrenItems() as $child) {
+                        $product_id = $child->getProductId();
+                    }
+                }
+
+                if (!empty($options) && !empty($options['attribute_info'])) {
+                    $variant = implode(', ', array_map(function ($item) {
+                        return $item['label'].': '.$item['value'];
+                    }, $options['attribute_info']));
+                }
+
+                $quantity = $product->getQtyOrdered() ?? 1;
+                $pricing = $this->calculateItemPriceAndTax($product, $quantity);
+
+                $transaction->addProduct(new SalesfireProductType([
+                    'sku'        => $product_id,
+                    'parent_sku' => $parent_product_id,
+                    'name'       => $product->getName(),
+                    'price'      => round((float)$pricing['price'], 2), // customisation: float type casting
+                    'tax'        => round((float)$pricing['tax'], 2), // customisation: float type casting
+                    'quantity'   => round((float)$quantity, 2), // customisation: float type casting
+                    'variant'    => $variant,
+                ]));
+            }
+
+            $formatter->addTransaction($transaction);
+        }
+
+        if ($product = $this->registry->registry('product')) { // customisation: use registry directly rather than class-level helper function
+            // Calculate product tax
+            $price = round((float)$this->taxHelper->getTaxPrice($product, $product->getFinalPrice(), false), 2); // customisation: float type casting
+            $tax = round((float)$this->taxHelper->getTaxPrice($product, $product->getFinalPrice(), true), 2) - $price; // customisation: float type casting
+
+            $formatter->addProductView(new SalesfireProductType([
+                'sku'        => $product->getId(),
+                'parent_sku' => $product->getId(),
+                'name'       => $product->getName(),
+                'price'      => $price,
+                'tax'        => $tax,
+            ]));
+        }
+
+        // customisation: return only the JSON as the template is responsible for pushing the data to the sfDataLayer
+        return $formatter->toJson();
+    }
+
+    /**
+     * This function has been copied as-is from the custom Salesfire block class, save for the function visibility which
+     * has been set to public rather than private for improved extensibility.
+     */
+    public function calculateItemPriceAndTax($product, $quantity)
+    {
+        // Row totals represent all items in the order line (e.g., if qty=4, this is the total for all 4)
+        $rowTotal = $product->getRowTotal() ?: 0;
+        $rowTax = $product->getTaxAmount() ?: 0;
+
+        if ($quantity <= 0) {
+            return ['price' => 0, 'tax' => 0];
+        }
+
+        return [
+            'price' => $rowTotal / $quantity,
+            'tax' => $rowTax / $quantity,
+        ];
+    }
+}
diff --git a/view/frontend/layout/hyva_default.xml b/view/frontend/layout/hyva_default.xml
new file mode 100644
index 0000000..d113f80
--- /dev/null
+++ b/view/frontend/layout/hyva_default.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0"?>
+<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+      xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
+    <body>
+        <referenceBlock name="head.additional">
+            <block name="salesfire_script"
+                   ifconfig="salesfire/general/is_enabled"
+                   template="Salesfire_Salesfire::sfgetid.phtml"/>
+            <block name="salesfire_script.datalayer"
+                   ifconfig="salesfire/general/is_enabled"
+                   template="Salesfire_Salesfire::sf-datalayer.phtml"/>
+            <block name="salesfire_script.cdn"
+                   ifconfig="salesfire/general/is_enabled"
+                   template="Salesfire_Salesfire::sf-cdn.phtml">
+                <arguments>
+                    <argument name="url" xsi:type="string">https://cdn.salesfire.co.uk/code/</argument>
+                    <argument name="async" xsi:type="boolean">false</argument>
+                    <argument name="defer" xsi:type="boolean">true</argument>
+                </arguments>
+            </block>
+        </referenceBlock>
+    </body>
+</page>
diff --git a/view/frontend/templates/sf-cdn.phtml b/view/frontend/templates/sf-cdn.phtml
new file mode 100644
index 0000000..3f86fc5
--- /dev/null
+++ b/view/frontend/templates/sf-cdn.phtml
@@ -0,0 +1,32 @@
+<?php
+declare(strict_types=1);
+
+use Hyva\Theme\Model\ViewModelRegistry;
+use Hyva\Theme\ViewModel\HyvaCsp;
+use Magento\Framework\Escaper;
+use Magento\Framework\View\Element\Template;
+use Salesfire\Salesfire\ViewModel\DataLayer;
+
+/** @var Escaper $escaper */
+/** @var HyvaCsp $hyvaCsp */
+/** @var Template $block */
+if (!($url = $block->getData('url'))) {
+    return;
+}
+
+/** @var ViewModelRegistry $viewModels */
+/** @var DataLayer $dataLayer */
+$dataLayer = $viewModels->require(DataLayer::class);
+$siteId = $dataLayer->getSiteId();
+
+if (!$siteId) {
+    return;
+}
+
+$url .= $siteId . '.js';
+?>
+<script src="<?= $escaper->escapeUrl($url); ?>"
+        <?php if ($block->getData('async')): ?>async<?php endif; ?>
+        <?php if ($block->getData('defer')): ?>defer<?php endif; ?>>
+</script>
+<?php isset($hyvaCsp) && $hyvaCsp->registerInlineScript(); ?>
diff --git a/view/frontend/templates/sf-datalayer.phtml b/view/frontend/templates/sf-datalayer.phtml
new file mode 100644
index 0000000..4c4a0a1
--- /dev/null
+++ b/view/frontend/templates/sf-datalayer.phtml
@@ -0,0 +1,30 @@
+<?php
+declare(strict_types=1);
+
+use Hyva\Theme\Model\ViewModelRegistry;
+use Hyva\Theme\ViewModel\HyvaCsp;
+use Magento\Framework\Escaper;
+use Magento\Framework\View\Element\Template;
+use Salesfire\Salesfire\ViewModel\DataLayer;
+
+/** @var Escaper $escaper */
+/** @var Template $block */
+/** @var HyvaCsp $hyvaCsp */
+/** @var ViewModelRegistry $viewModels */
+/** @var DataLayer $dataLayer */
+$dataLayer = $viewModels->require(DataLayer::class);
+$data = $dataLayer->getData();
+
+if (!$data) {
+    return;
+}
+?>
+<script>
+    window.addEventListener('DOMContentLoaded', () => {
+        sfDataLayer = window.sfDataLayer || [];
+
+        <?php /** @link https://developer.adobe.com/commerce/php/development/security/cross-site-scripting/#phtml-templates */ ?>
+        sfDataLayer.push(<?= /** @noEscape */ $data; ?>);
+    });
+</script>
+<?php isset($hyvaCsp) && $hyvaCsp->registerInlineScript(); ?>
diff --git a/view/frontend/templates/sfgetid.phtml b/view/frontend/templates/sfgetid.phtml
new file mode 100644
index 0000000..e008cb7
--- /dev/null
+++ b/view/frontend/templates/sfgetid.phtml
@@ -0,0 +1,42 @@
+<?php
+declare(strict_types=1);
+
+use Hyva\Theme\ViewModel\HyvaCsp;
+use Magento\Framework\Escaper;
+use Magento\Framework\View\Element\Template;
+
+/** @var Escaper $escaper */
+/** @var Template $block */
+/** @var HyvaCsp $hyvaCsp */
+?>
+<script>
+    window.addEventListener('DOMContentLoaded', async () => {
+        let sfCuid = localStorage.getItem('sf_cuid') || null;
+
+        if (!sfCuid) {
+            sfCuid = await fetch(
+                `${BASE_URL}salesfire/ajax/sfgetid`,
+                {
+                    method: 'GET',
+                    headers: {
+                        'Content-Type': 'application/json',
+                    },
+                }).then(async response => await response.json())
+                .catch(error => {
+                    console.error('Error: ' + error);
+                    return null;
+                });
+        }
+
+        if (sfCuid) {
+            localStorage.setItem('sf_cuid', sfCuid);
+            window.sfDataLayer = window.sfDataLayer || [];
+            window.sfDataLayer.push({
+                session: {
+                    id: sfCuid,
+                },
+            });
+        }
+    });
+</script>
+<?php isset($hyvaCsp) && $hyvaCsp->registerInlineScript(); ?>