diff --git a/Payment/LiqPay.php b/Payment/LiqPay.php
new file mode 100644
index 0000000..b6f3e4e
--- /dev/null
+++ b/Payment/LiqPay.php
@@ -0,0 +1,208 @@
+<?php
+
+namespace WH1\PaygateLiqPay\Payment;
+
+use Exception;
+use XF;
+use XF\Entity\PaymentProfile;
+use XF\Entity\PurchaseRequest;
+use XF\Http\Request;
+use XF\Mvc\Controller;
+use XF\Payment\AbstractProvider;
+use XF\Payment\CallbackState;
+use XF\Purchasable\Purchase;
+
+class LiqPay extends AbstractProvider
+{
+	public function getTitle(): string
+	{
+		return 'LiqPay';
+	}
+
+	public function getApiEndpoint(): string
+	{
+		return 'https://www.liqpay.ua/api/3/checkout';
+	}
+
+	public function verifyConfig(array &$options, &$errors = []): bool
+	{
+		if (empty($options['private_key']) || empty($options['public_key']))
+		{
+			$errors[] = XF::phrase('wh1_liqpay_you_must_provide_all_data');
+		}
+
+		return !$errors;
+	}
+
+	public function getPaymentParams(PurchaseRequest $purchaseRequest, Purchase $purchase): array
+	{
+		$profileOptions = $purchase->paymentProfile->options;
+
+		$payment = [
+			'version'     => 3,
+			'public_key'  => $profileOptions['public_key'],
+			'action'      => 'pay',
+			'amount'      => $purchase->cost,
+			'currency'    => $purchase->currency,
+			'description' => $purchase->title,
+			'order_id'    => $purchaseRequest->request_key,
+
+			'result_url' => $purchase->returnUrl,
+			'server_url' => $this->getCallbackUrl(),
+		];
+
+		return $this->getDataAndSignature($payment, $profileOptions['private_key']);
+	}
+
+	public function initiatePayment(Controller $controller, PurchaseRequest $purchaseRequest, Purchase $purchase): XF\Mvc\Reply\Redirect
+	{
+		$paymentParams = $this->getPaymentParams($purchaseRequest, $purchase);
+
+		return $controller->redirect($this->getApiEndpoint() . '?' . http_build_query($paymentParams));
+	}
+
+	public function setupCallback(Request $request): CallbackState
+	{
+		$state = new CallbackState();
+
+		$state->dataRaw = $request->filter('data', 'str');
+		$state->data = json_decode(base64_decode($state->dataRaw), true);
+		$state->signature = $request->filter('signature', 'str');
+
+		$state->amount = $state->data['amount'] ?? 0;
+		$state->currency = $state->data['currency'] ?? '';
+		$state->status = $state->data['status'] ?? '';
+		$state->subscriberId = $state->data['customer'] ?? 0;
+
+		$state->ip = $request->getIp();
+
+		$state->httpCode = 200;
+
+		return $state;
+	}
+
+	public function validateCallback(CallbackState $state): bool
+	{
+		$state->requestKey = $state->data['order_id'] ?? '';
+		$state->transactionId = $state->input['payment_id'] ?? '';
+
+		if (!empty($state->signature) && $state->data['version'] == 3 && $state->data['action'] == 'pay')
+		{
+			return true;
+		}
+
+		$state->logType = 'info';
+		$state->logMessage = 'Auth failed';
+
+		return false;
+	}
+
+	public function validateTransaction(CallbackState $state): bool
+	{
+		if (!$state->requestKey)
+		{
+			$state->logType = 'info';
+			$state->logMessage = 'Metadata is empty!';
+
+			return false;
+		}
+
+		if(!empty($state->data['err_code']))
+		{
+			$state->logType = 'error';
+			$state->logMessage = $state->data['err_description'] ?? $state->data['err_code'];
+
+			return false;
+		}
+
+		return parent::validateTransaction($state);
+	}
+
+	public function validatePurchasableData(CallbackState $state): bool
+	{
+		$paymentProfile = $state->getPaymentProfile();
+
+		$options = $paymentProfile->options;
+		if (!empty($options['public_key']) && !empty($options['private_key']) && !empty($state->signature))
+		{
+			if ($this->verifySignature($state->dataRaw, $state->signature, $options['private_key']))
+			{
+				return true;
+			}
+
+			$state->logType = 'error';
+			$state->logMessage = "Invalid signature";
+
+			return false;
+		}
+
+		$state->logType = 'error';
+		$state->logMessage = 'Invalid public_key or secret_key.';
+
+		return false;
+	}
+
+	public function validateCost(CallbackState $state): bool
+	{
+		$purchaseRequest = $state->getPurchaseRequest();
+
+		if (($state->currency == $purchaseRequest->cost_currency)
+			&& round($state->amount, 2) == round($purchaseRequest->cost_amount, 2))
+		{
+			return true;
+		}
+
+		$state->logType = 'error';
+		$state->logMessage = 'Invalid cost amount.';
+
+		return false;
+	}
+
+	public function getPaymentResult(CallbackState $state): void
+	{
+		if (strtolower($state->status) == 'success')
+		{
+			$state->paymentResult = CallbackState::PAYMENT_RECEIVED;
+		}
+	}
+
+	public function prepareLogData(CallbackState $state): void
+	{
+		$state->logDetails = array_merge($state->data, [
+			'ip' => $state->ip,
+			'signature' => $state->signature
+		]);
+	}
+
+	public function verifyCurrency(PaymentProfile $paymentProfile, $currencyCode): bool
+	{
+		return in_array($currencyCode, $this->supportedCurrencies);
+	}
+
+	protected $supportedCurrencies = [
+		'RUB', 'USD', 'EUR', 'UAH', 'BYN', 'KZT'
+	];
+
+	public function supportsRecurring(PaymentProfile $paymentProfile, $unit, $amount, &$result = self::ERR_NO_RECURRING): bool
+	{
+		$result = self::ERR_NO_RECURRING;
+
+		return false;
+	}
+
+	protected function getDataAndSignature(array $payment, string $privateKey): array
+	{
+		$data = base64_encode(json_encode($payment));
+		$signature = base64_encode(hash('sha1', $privateKey . $data . $privateKey, true));
+
+		return [
+			'data'      => $data,
+			'signature' => $signature
+		];
+	}
+
+	protected function verifySignature(string $data, string $signature, string $privateKey): bool
+	{
+		return hash_equals($signature, base64_encode(hash('sha1', $privateKey . $data . $privateKey, true)));
+	}
+}
\ No newline at end of file
diff --git a/Setup.php b/Setup.php
new file mode 100644
index 0000000..41567c6
--- /dev/null
+++ b/Setup.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace WH1\PaygateLiqPay;
+
+use XF\AddOn\AbstractSetup;
+use XF\AddOn\StepRunnerInstallTrait;
+use XF\AddOn\StepRunnerUninstallTrait;
+use XF\AddOn\StepRunnerUpgradeTrait;
+
+class Setup extends AbstractSetup
+{
+	use StepRunnerInstallTrait;
+	use StepRunnerUpgradeTrait;
+	use StepRunnerUninstallTrait;
+
+	public function installStep1()
+	{
+		$db = $this->db();
+
+		$db->insert('xf_payment_provider', [
+			'provider_id'    => "wh1LiqPay",
+			'provider_class' => "WH1\\PaygateLiqPay:LiqPay",
+			'addon_id'       => "WH1/PaygateLiqPay"
+		]);
+	}
+
+	public function uninstallStep1()
+	{
+		$db = $this->db();
+
+		$db->delete('xf_payment_profile', "provider_id = 'wh1LiqPay'");
+		$db->delete('xf_payment_provider', "provider_id = 'wh1LiqPay'");
+	}
+}
\ No newline at end of file
diff --git a/_data/activity_summary_definitions.xml b/_data/activity_summary_definitions.xml
new file mode 100644
index 0000000..a55af11
--- /dev/null
+++ b/_data/activity_summary_definitions.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<activity_summary_definitions/>
diff --git a/_data/admin_navigation.xml b/_data/admin_navigation.xml
new file mode 100644
index 0000000..8aa506b
--- /dev/null
+++ b/_data/admin_navigation.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<admin_navigation/>
diff --git a/_data/admin_permission.xml b/_data/admin_permission.xml
new file mode 100644
index 0000000..67760e7
--- /dev/null
+++ b/_data/admin_permission.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<admin_permission/>
diff --git a/_data/advertising_positions.xml b/_data/advertising_positions.xml
new file mode 100644
index 0000000..32059fa
--- /dev/null
+++ b/_data/advertising_positions.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<advertising_positions/>
diff --git a/_data/api_scopes.xml b/_data/api_scopes.xml
new file mode 100644
index 0000000..3510b36
--- /dev/null
+++ b/_data/api_scopes.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<api_scopes/>
diff --git a/_data/bb_code_media_sites.xml b/_data/bb_code_media_sites.xml
new file mode 100644
index 0000000..bdf7d27
--- /dev/null
+++ b/_data/bb_code_media_sites.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<bb_code_media_sites/>
diff --git a/_data/bb_codes.xml b/_data/bb_codes.xml
new file mode 100644
index 0000000..8c337bf
--- /dev/null
+++ b/_data/bb_codes.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<bb_codes/>
diff --git a/_data/class_extensions.xml b/_data/class_extensions.xml
new file mode 100644
index 0000000..bd0ad9f
--- /dev/null
+++ b/_data/class_extensions.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<class_extensions/>
diff --git a/_data/code_event_listeners.xml b/_data/code_event_listeners.xml
new file mode 100644
index 0000000..a9a91ea
--- /dev/null
+++ b/_data/code_event_listeners.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<code_event_listeners/>
diff --git a/_data/code_events.xml b/_data/code_events.xml
new file mode 100644
index 0000000..7752d3e
--- /dev/null
+++ b/_data/code_events.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<code_events/>
diff --git a/_data/content_type_fields.xml b/_data/content_type_fields.xml
new file mode 100644
index 0000000..3040a1f
--- /dev/null
+++ b/_data/content_type_fields.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<content_type_fields/>
diff --git a/_data/cron.xml b/_data/cron.xml
new file mode 100644
index 0000000..b45f056
--- /dev/null
+++ b/_data/cron.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<cron/>
diff --git a/_data/help_pages.xml b/_data/help_pages.xml
new file mode 100644
index 0000000..31828b1
--- /dev/null
+++ b/_data/help_pages.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<help_pages/>
diff --git a/_data/member_stats.xml b/_data/member_stats.xml
new file mode 100644
index 0000000..a80a38b
--- /dev/null
+++ b/_data/member_stats.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<member_stats/>
diff --git a/_data/navigation.xml b/_data/navigation.xml
new file mode 100644
index 0000000..752ce9a
--- /dev/null
+++ b/_data/navigation.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<navigation/>
diff --git a/_data/option_groups.xml b/_data/option_groups.xml
new file mode 100644
index 0000000..b453ed4
--- /dev/null
+++ b/_data/option_groups.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<option_groups/>
diff --git a/_data/options.xml b/_data/options.xml
new file mode 100644
index 0000000..140bd10
--- /dev/null
+++ b/_data/options.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<options/>
diff --git a/_data/permission_interface_groups.xml b/_data/permission_interface_groups.xml
new file mode 100644
index 0000000..87ad617
--- /dev/null
+++ b/_data/permission_interface_groups.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<permission_interface_groups/>
diff --git a/_data/permissions.xml b/_data/permissions.xml
new file mode 100644
index 0000000..16b1408
--- /dev/null
+++ b/_data/permissions.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<permissions/>
diff --git a/_data/phrases.xml b/_data/phrases.xml
new file mode 100644
index 0000000..8c2b1c0
--- /dev/null
+++ b/_data/phrases.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<phrases>
+  <phrase title="wh1_liqpay_private_key" version_id="1" version_string="1"><![CDATA[Private key]]></phrase>
+  <phrase title="wh1_liqpay_public_key" version_id="1" version_string="1"><![CDATA[Public key]]></phrase>
+  <phrase title="wh1_liqpay_you_must_provide_all_data" version_id="1" version_string="1"><![CDATA[You must provide all data]]></phrase>
+</phrases>
diff --git a/_data/routes.xml b/_data/routes.xml
new file mode 100644
index 0000000..608d809
--- /dev/null
+++ b/_data/routes.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<routes/>
diff --git a/_data/style_properties.xml b/_data/style_properties.xml
new file mode 100644
index 0000000..231b9f0
--- /dev/null
+++ b/_data/style_properties.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<style_properties/>
diff --git a/_data/style_property_groups.xml b/_data/style_property_groups.xml
new file mode 100644
index 0000000..563c56d
--- /dev/null
+++ b/_data/style_property_groups.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<style_property_groups/>
diff --git a/_data/template_modifications.xml b/_data/template_modifications.xml
new file mode 100644
index 0000000..04c9d33
--- /dev/null
+++ b/_data/template_modifications.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<template_modifications/>
diff --git a/_data/templates.xml b/_data/templates.xml
new file mode 100644
index 0000000..e9181db
--- /dev/null
+++ b/_data/templates.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<templates>
+  <template type="admin" title="payment_profile_wh1LiqPay" version_id="1" version_string="1"><![CDATA[<xf:textboxrow name="options[public_key]" value="{$profile.options.public_key}"
+	label="{{ phrase('wh1_liqpay_public_key') }}"
+	hint="{{ phrase('required') }}">
+</xf:textboxrow>
+
+<xf:textboxrow name="options[private_key]" value="{$profile.options.private_key}"
+	label="{{ phrase('wh1_liqpay_private_key') }}"
+	hint="{{ phrase('required') }}">
+</xf:textboxrow>]]></template>
+</templates>
diff --git a/_data/widget_definitions.xml b/_data/widget_definitions.xml
new file mode 100644
index 0000000..fbdae64
--- /dev/null
+++ b/_data/widget_definitions.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<widget_definitions/>
diff --git a/_data/widget_positions.xml b/_data/widget_positions.xml
new file mode 100644
index 0000000..65d80ac
--- /dev/null
+++ b/_data/widget_positions.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<widget_positions/>
diff --git a/addon.json b/addon.json
new file mode 100644
index 0000000..8eeefea
--- /dev/null
+++ b/addon.json
@@ -0,0 +1,23 @@
+{
+    "legacy_addon_id": "",
+    "title": "[WH1] Paygate: LiqPay",
+    "description": "LiqPay payment profile for XenForo.",
+    "version_id": 1000070,
+    "version_string": "1.0.0",
+    "dev": "wh1teend",
+    "dev_url": "https://t.me/wh1teend",
+    "faq_url": "",
+    "support_url": "",
+    "extra_urls": [],
+    "require": {
+        "php": [
+            "7.4",
+            "PHP 7.4+"
+        ],
+        "XF": [
+            2010270,
+            "XenForo 2.1.2+"
+        ]
+    },
+    "icon": "icon.png"
+}
\ No newline at end of file
diff --git a/icon.png b/icon.png
new file mode 100644
index 0000000..6033398
Binary files /dev/null and b/icon.png differ