diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..fd02076
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,21 @@
+# EditorConfig helps developers define and maintain consistent coding styles between different editors and IDEs
+# editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = space
+indent_size = 4
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.json]
+indent_size = 2
+
+[composer.json]
+indent_size = 4
diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..0e24132
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,8 @@
+* text=auto eol=lf
+
+*.json text eol=lf
+*.md text eol=lf
+*.php text eol=lf
+
+LICENSE export-ignore
+README export-ignore
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..9637274
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,7 @@
+###> editors ###
+/nbproject/*
+/.settings
+/.buildpath
+/.project
+.idea
+###< editors ###
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..145cd7a
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,6 @@
+CHANGELOG
+=========
+
+## 1.0.0
+
+[new] Implementation
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..20175a9
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022 snortlin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..5d69254
--- /dev/null
+++ b/README.md
@@ -0,0 +1,62 @@
+# Google Pub/Sub Messenger
+
+## Installation
+
+### Step 1: Install
+
+The preferred method of installation is via [Composer](https://getcomposer.org/):
+
+```bash
+composer require snortlin/google-pubsub-messenger
+```
+
+### Step 2: Register Messenger Transport
+
+```yaml
+# config/services.yaml
+services:
+    Snortlin\GooglePubsubMessenger\Transport\GpsTransportFactory:
+        tags: [ messenger.transport_factory ]
+```
+
+### Step 3: Configure Symfony Messenger
+
+Create a connection based on the DSN and options:
+
+```yaml
+framework:
+    messenger:
+        transports:
+            google-pubsub:
+                dsn: 'gps://default?topic=topic_name&subscription=subscription_name&key=base64_key'
+```
+
+## Usage
+
+### Configuration options
+
+* `topic`: Topic name
+* `subscription`: Subscription name
+* `key`: GPS key JSON format
+* `pull_max_messages`: Limit the amount of messages pulled; default=0 (GPC default => 1000)
+* `pull_ack_deadline`: The new ack deadline pulled messages; default=0 (GPC default => 10)
+* `redelivery_ack_deadline`: Default ack deadline on redelivered messages, default=0
+
+### OrderingKeyStamp for ordering messages
+
+```php
+use Snortlin\GooglePubsubMessenger\Transport\Stamp\OrderingKeyStamp
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\MessageBusInterface;
+
+public function index(MessageBusInterface $bus)
+{
+    $bus->dispatch(new MyMessage('...'), [
+        new OrderingKeyStamp('my_ordering_key'),
+    ]);
+
+    // ...
+}
+```
+
+[Official documentation](https://cloud.google.com/pubsub/docs/ordering)
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..179718f
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,26 @@
+{
+    "name": "snortlin/google-pubsub-messenger",
+    "description": "Symfony Google Pub/Sub extension Messenger Bridge",
+    "type": "symfony-messenger-bridge",
+    "license": "MIT",
+    "authors": [
+        {
+            "name": "Petr Leixner",
+            "email": "snortlin@volny.cz"
+        }
+    ],
+    "require": {
+        "php": "^8.0",
+        "google/cloud-pubsub": "^1.35",
+        "symfony/messenger": "^5.4|^6.0"
+    },
+    "require-dev": {
+        "jetbrains/phpstorm-attributes": "^1.0"
+    },
+    "autoload": {
+        "psr-4": {
+            "Snortlin\\GooglePubsubMessenger\\": "src/"
+        }
+    },
+    "minimum-stability": "dev"
+}
diff --git a/src/Transport/Connection.php b/src/Transport/Connection.php
new file mode 100644
index 0000000..ee4cd8d
--- /dev/null
+++ b/src/Transport/Connection.php
@@ -0,0 +1,140 @@
+<?php
+
+namespace Snortlin\GooglePubsubMessenger\Transport;
+
+use Google\Cloud\PubSub\Message;
+use Google\Cloud\PubSub\MessageBuilder;
+use Google\Cloud\PubSub\PubSubClient;
+use JetBrains\PhpStorm\ArrayShape;
+use Symfony\Component\Messenger\Exception\InvalidArgumentException;
+
+class Connection
+{
+    private PubSubClient $client;
+
+    private function __construct(string         $key,
+                                 private string $topicName,
+                                 private string $subscriptionName,
+                                 private int    $pullMaxMessages = 0,
+                                 private int    $pullAckDeadline = 0,
+                                 private int    $redeliveryAckDeadline = 0)
+    {
+        try {
+            $key = json_decode($key, true, flags: JSON_THROW_ON_ERROR);
+        } catch (\JsonException $e) {
+            throw new InvalidArgumentException(sprintf('Error when decoding Google Pub/Sub Key: %s', $e->getMessage()), $e->getCode(), $e);
+        }
+
+        try {
+            $this->client = new PubSubClient([
+                'keyFile' => $key,
+                'projectId' => $key['project_id'] ?? null,
+            ]);
+        } catch (\Throwable $e) {
+            throw new InvalidArgumentException(sprintf('Error when creating Google Pub/Sub Client: %s', $e->getMessage()), $e->getCode(), $e);
+        }
+    }
+
+    /**
+     * Creates a connection based on the DSN and options.
+     *
+     * Available options:
+     *
+     *   * topic: Topic name
+     *   * subscription: Subscription name
+     *   * key: GPS key JSON format
+     *   * pull_max_messages: Limit the amount of messages pulled
+     *   * pull_ack_deadline: The new ack deadline pulled messages
+     *   * redelivery_ack_deadline: The new ack deadline on reject messages
+     *
+     * gps://default?topic=topic_name&subscription=subscription_name&key=base64_key
+     * gps://default?topic=topic_name&subscription=subscription_name&key=base64_key&pull_max_messages=100
+     * gps://default?topic=topic_name&subscription=subscription_name&key=base64_key&pull_max_messages=100&pull_ack_deadline=10&redelivery_ack_deadline=10
+     */
+    public static function fromDsn(string $dsn, array $options = []): self
+    {
+        if (false === $parsedUrl = parse_url($dsn)) {
+            throw new InvalidArgumentException(sprintf('The given GPS DSN "%s" is invalid.', $dsn));
+        }
+
+        parse_str($parsedUrl['query'] ?? '', $parsedQuery);
+
+        $options['topic'] = $parsedQuery['topic'] ?? $options['topic'] ?? '';
+        $options['subscription'] = $parsedQuery['subscription'] ?? $options['subscription'] ?? '';
+        $options['key'] = base64_decode($parsedQuery['key'] ?? $options['key'] ?? '');
+        $options['pull_max_messages'] = (int)($parsedQuery['pull_max_messages'] ?? $options['pull_max_messages'] ?? 0);
+        $options['pull_ack_deadline'] = (int)($parsedQuery['pull_ack_deadline'] ?? $options['pull_ack_deadline'] ?? 0);
+        $options['redelivery_ack_deadline'] = (int)($parsedQuery['redelivery_ack_deadline'] ?? $options['redelivery_ack_deadline'] ?? 0);
+
+        return new self($options['key'], $options['topic'], $options['subscription'], $options['pull_max_messages'], $options['pull_ack_deadline'], $options['redelivery_ack_deadline']);
+    }
+
+    public function publish(string $body, array $attributes = [], ?string $orderingKey = null): array
+    {
+        $messageBuilder = (new MessageBuilder())
+            ->setData($body)
+            ->setAttributes($attributes)
+            ->setOrderingKey($orderingKey);
+
+        return $this->client
+            ->topic($this->topicName)
+            ->publish($messageBuilder->build());
+    }
+
+    public function get(): iterable
+    {
+        $options = [];
+
+        if ($this->pullMaxMessages > 0) {
+            $options['maxMessages'] = $this->pullMaxMessages;
+        }
+
+        $messages = $this->client
+            ->subscription($this->subscriptionName)
+            ->pull($options);
+
+        if ($this->pullAckDeadline > 0 && !empty($messages)) {
+            $this->modifyAckDeadlineBatch($messages, $this->pullAckDeadline);
+        }
+
+        return $messages;
+    }
+
+    public function ack(Message $message): void
+    {
+        $this->client
+            ->subscription($this->subscriptionName)
+            ->acknowledge($message);
+    }
+
+    public function reject(Message $message): void
+    {
+        $this->ack($message);
+    }
+
+    public function modifyAckDeadline(Message $message, int $seconds = 0): void
+    {
+        $this->client
+            ->subscription($this->subscriptionName)
+            ->modifyAckDeadline($message, $seconds > 0 ? $seconds : $this->redeliveryAckDeadline);
+    }
+
+    public function modifyAckDeadlineBatch(array $messages, int $seconds): void
+    {
+        $this->client
+            ->subscription($this->subscriptionName)
+            ->modifyAckDeadlineBatch($messages, $seconds);
+    }
+
+    #[ArrayShape([
+        'client' => 'array',
+        'subscription' => 'array',
+    ])]
+    public function getDebugInfo(): array
+    {
+        return [
+            'client' => $this->client->__debugInfo(),
+            'subscription' => $this->client->subscription($this->subscriptionName)->__debugInfo(),
+        ];
+    }
+}
diff --git a/src/Transport/GpsReceiver.php b/src/Transport/GpsReceiver.php
new file mode 100644
index 0000000..932d159
--- /dev/null
+++ b/src/Transport/GpsReceiver.php
@@ -0,0 +1,94 @@
+<?php
+
+namespace Snortlin\GooglePubsubMessenger\Transport;
+
+use Google\Cloud\PubSub\Message;
+use Snortlin\GooglePubsubMessenger\Transport\Stamp\GpsReceivedStamp;
+use Snortlin\GooglePubsubMessenger\Transport\Stamp\RedeliveryAsModifyAckDeadlineStamp;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\Exception\MessageDecodingFailedException;
+use Symfony\Component\Messenger\Exception\TransportException;
+use Symfony\Component\Messenger\Transport\Receiver\ReceiverInterface;
+use Symfony\Component\Messenger\Transport\Serialization\PhpSerializer;
+use Symfony\Component\Messenger\Transport\Serialization\SerializerInterface;
+
+final class GpsReceiver implements ReceiverInterface
+{
+    public function __construct(private Connection           $connection,
+                                private ?SerializerInterface $serializer = null)
+    {
+        $this->serializer = $serializer ?? new PhpSerializer();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function get(): iterable
+    {
+        try {
+            foreach ($this->connection->get() as $message) {
+                yield from $this->getEnvelope($message);
+            }
+        } catch (MessageDecodingFailedException $e) {
+            throw $e;
+        } catch (\Throwable $e) {
+            throw new TransportException($e->getMessage(), 0, $e);
+        }
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function ack(Envelope $envelope): void
+    {
+        try {
+            $this->connection->ack($this->findReceivedStamp($envelope)->getMessage());
+        } catch (\Throwable $e) {
+            throw new TransportException($e->getMessage(), 0, $e);
+        }
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function reject(Envelope $envelope): void
+    {
+        try {
+            $stamp = $envelope->last(RedeliveryAsModifyAckDeadlineStamp::class);
+
+            if ($stamp instanceof RedeliveryAsModifyAckDeadlineStamp) {
+                $this->connection->modifyAckDeadline($this->findReceivedStamp($envelope)->getMessage(), $stamp->getDelay());
+            } else {
+                $this->connection->ack($this->findReceivedStamp($envelope)->getMessage());
+            }
+        } catch (\Throwable $e) {
+            throw new TransportException($e->getMessage(), 0, $e);
+        }
+    }
+
+    private function getEnvelope(Message $message): iterable
+    {
+        try {
+            $envelope = $this->serializer->decode([
+                'body' => $message->data(),
+                'headers' => $message->attributes(),
+                'message' => $message,
+            ]);
+        } catch (MessageDecodingFailedException $e) {
+            $this->connection->reject($message);
+
+            throw $e;
+        }
+
+        yield $envelope->with(new GpsReceivedStamp($message));
+    }
+
+    private function findReceivedStamp(Envelope $envelope): GpsReceivedStamp
+    {
+        $stamp = $envelope->last(GpsReceivedStamp::class);
+
+        return $stamp instanceof GpsReceivedStamp
+            ? $stamp
+            : throw new \LogicException(sprintf('No "%s" stamp found on the Envelope.', GpsReceivedStamp::class));
+    }
+}
diff --git a/src/Transport/GpsSender.php b/src/Transport/GpsSender.php
new file mode 100644
index 0000000..c610f7e
--- /dev/null
+++ b/src/Transport/GpsSender.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace Snortlin\GooglePubsubMessenger\Transport;
+
+use Snortlin\GooglePubsubMessenger\Transport\Stamp\OrderingKeyStamp;
+use Snortlin\GooglePubsubMessenger\Transport\Stamp\RedeliveryAsModifyAckDeadlineStamp;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\Exception\TransportException;
+use Symfony\Component\Messenger\Stamp\RedeliveryStamp;
+use Symfony\Component\Messenger\Stamp\TransportMessageIdStamp;
+use Symfony\Component\Messenger\Transport\Sender\SenderInterface;
+use Symfony\Component\Messenger\Transport\Serialization\PhpSerializer;
+use Symfony\Component\Messenger\Transport\Serialization\SerializerInterface;
+
+final class GpsSender implements SenderInterface
+{
+    public function __construct(private Connection           $connection,
+                                private ?SerializerInterface $serializer = null)
+    {
+        $this->serializer = $serializer ?? new PhpSerializer();
+    }
+
+    /**
+     * @inheritDoc
+     * @throws \Exception
+     */
+    public function send(Envelope $envelope): Envelope
+    {
+        if ($envelope->last(RedeliveryStamp::class) instanceof RedeliveryStamp) {
+            if ($envelope->last(RedeliveryAsModifyAckDeadlineStamp::class) instanceof RedeliveryAsModifyAckDeadlineStamp) {
+                return $envelope;
+            }
+        }
+
+        $encodedMessage = $this->serializer->encode($envelope);
+        $orderingKeyStamp = $envelope->last(OrderingKeyStamp::class);
+
+        try {
+            $id = $this->connection->publish(
+                $encodedMessage['body'],
+                $encodedMessage['headers'] ?? [],
+                $orderingKeyStamp instanceof OrderingKeyStamp ? $orderingKeyStamp->getOrderingKey() : null
+            )['messageIds'];
+        } catch (\Throwable $e) {
+            throw new TransportException($e->getMessage(), 0, $e);
+        }
+
+        return $envelope->with(new TransportMessageIdStamp($id));
+    }
+}
diff --git a/src/Transport/GpsTransport.php b/src/Transport/GpsTransport.php
new file mode 100644
index 0000000..967939c
--- /dev/null
+++ b/src/Transport/GpsTransport.php
@@ -0,0 +1,81 @@
+<?php
+
+namespace Snortlin\GooglePubsubMessenger\Transport;
+
+use JetBrains\PhpStorm\ArrayShape;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\Transport\Serialization\PhpSerializer;
+use Symfony\Component\Messenger\Transport\Serialization\SerializerInterface;
+use Symfony\Component\Messenger\Transport\TransportInterface;
+
+class GpsTransport implements TransportInterface
+{
+    private GpsReceiver $receiver;
+    private GpsSender $sender;
+
+    public function __construct(private Connection           $connection,
+                                private ?SerializerInterface $serializer = null)
+    {
+        $this->serializer = $serializer ?? new PhpSerializer();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function get(): iterable
+    {
+        return $this->getReceiver()->get();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function ack(Envelope $envelope): void
+    {
+        $this->getReceiver()->ack($envelope);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function reject(Envelope $envelope): void
+    {
+        $this->getReceiver()->reject($envelope);
+    }
+
+    /**
+     * @inheritDoc
+     * @throws \Exception
+     */
+    public function send(Envelope $envelope): Envelope
+    {
+        return $this->getSender()->send($envelope);
+    }
+
+    #[ArrayShape([
+        'client' => 'array',
+        'subscription' => 'array',
+    ])]
+    public function getDebugInfo(): array
+    {
+        return $this->connection->getDebugInfo();
+    }
+
+    private function getReceiver(): GpsReceiver
+    {
+        if (!isset($this->receiver)) {
+            $this->receiver = new GpsReceiver($this->connection, $this->serializer);
+        }
+
+        return $this->receiver;
+    }
+
+    private function getSender(): GpsSender
+    {
+        if (!isset($this->sender)) {
+            $this->sender = new GpsSender($this->connection, $this->serializer);
+        }
+
+        return $this->sender;
+    }
+}
diff --git a/src/Transport/GpsTransportFactory.php b/src/Transport/GpsTransportFactory.php
new file mode 100644
index 0000000..8e285a9
--- /dev/null
+++ b/src/Transport/GpsTransportFactory.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Snortlin\GooglePubsubMessenger\Transport;
+
+use Symfony\Component\Messenger\Transport\Serialization\SerializerInterface;
+use Symfony\Component\Messenger\Transport\TransportFactoryInterface;
+use Symfony\Component\Messenger\Transport\TransportInterface;
+
+class GpsTransportFactory implements TransportFactoryInterface
+{
+    public function createTransport(string $dsn, array $options, SerializerInterface $serializer): TransportInterface
+    {
+        return new GpsTransport(Connection::fromDsn($dsn, $options), $serializer);
+    }
+
+    public function supports(string $dsn, array $options): bool
+    {
+        return str_starts_with($dsn, 'gps://');
+    }
+}
diff --git a/src/Transport/Stamp/GpsReceivedStamp.php b/src/Transport/Stamp/GpsReceivedStamp.php
new file mode 100644
index 0000000..3442ba1
--- /dev/null
+++ b/src/Transport/Stamp/GpsReceivedStamp.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Snortlin\GooglePubsubMessenger\Transport\Stamp;
+
+use Google\Cloud\PubSub\Message;
+use Symfony\Component\Messenger\Stamp\NonSendableStampInterface;
+
+class GpsReceivedStamp implements NonSendableStampInterface
+{
+    public function __construct(private Message $message)
+    {
+    }
+
+    public function getMessage(): Message
+    {
+        return $this->message;
+    }
+}
diff --git a/src/Transport/Stamp/OrderingKeyStamp.php b/src/Transport/Stamp/OrderingKeyStamp.php
new file mode 100644
index 0000000..454dfe1
--- /dev/null
+++ b/src/Transport/Stamp/OrderingKeyStamp.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace Snortlin\GooglePubsubMessenger\Transport\Stamp;
+
+use Symfony\Component\Messenger\Stamp\NonSendableStampInterface;
+
+class OrderingKeyStamp implements NonSendableStampInterface
+{
+    public function __construct(private string $orderingKey)
+    {
+    }
+
+    public function getOrderingKey(): string
+    {
+        return $this->orderingKey;
+    }
+}
diff --git a/src/Transport/Stamp/RedeliveryAsModifyAckDeadlineStamp.php b/src/Transport/Stamp/RedeliveryAsModifyAckDeadlineStamp.php
new file mode 100644
index 0000000..4cf56a1
--- /dev/null
+++ b/src/Transport/Stamp/RedeliveryAsModifyAckDeadlineStamp.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace Snortlin\GooglePubsubMessenger\Transport\Stamp;
+
+use Symfony\Component\Messenger\Stamp\NonSendableStampInterface;
+
+class RedeliveryAsModifyAckDeadlineStamp implements NonSendableStampInterface
+{
+    public function __construct(private int $delay = 0)
+    {
+    }
+
+    public function getDelay(): int
+    {
+        return $this->delay;
+    }
+}