Create a push subscription with payload unwrapping enabled.

namespace pubsub = ::google::cloud::pubsub;
namespace pubsub_admin = ::google::cloud::pubsub_admin;
[](pubsub_admin::SubscriptionAdminClient client,
   std::string const& project_id, std::string const& topic_id,
   std::string const& subscription_id, std::string const& endpoint) {
  google::pubsub::v1::Subscription request;
  request.set_name(
      pubsub::Subscription(project_id, subscription_id).FullName());
  request.set_topic(pubsub::Topic(project_id, topic_id).FullName());
  request.mutable_push_config()->set_push_endpoint(endpoint);
  request.mutable_push_config()->mutable_no_wrapper()->set_write_metadata(
      true);
  auto sub = client.CreateSubscription(request);
  if (sub.status().code() == google::cloud::StatusCode::kAlreadyExists) {
    std::cout << "The subscription already exists\n";
    return;
  }
  if (!sub) throw std::move(sub).status();

  std::cout << "The subscription was successfully created: "
            << sub->DebugString() << "\n";
}

using Google.Cloud.PubSub.V1;

public class CreateUnwrappedPushSubscriptionSample
{
    public Subscription CreateUnwrappedPushSubscription(string projectId, string topicId, string subscriptionId, string pushEndpoint)
    {
        SubscriberServiceApiClient subscriber = SubscriberServiceApiClient.Create();
        TopicName topicName = TopicName.FromProjectTopic(projectId, topicId);
        SubscriptionName subscriptionName = SubscriptionName.FromProjectSubscription(projectId, subscriptionId);

        // NoWrapper is used to indicate that only the message data should be in the request body
        // sent to the push endpoint. Message metadata is optionally included in headers.
        var noWrapper = new PushConfig.Types.NoWrapper
        {
            // Determines if message metadata is added to the HTTP headers of
            // the delivered message.
            WriteMetadata = true
        };

        PushConfig pushConfig = new PushConfig { PushEndpoint = pushEndpoint, NoWrapper = noWrapper };

        // The approximate amount of time in seconds (on a best-effort basis) Pub/Sub waits for the
        // subscriber to acknowledge receipt before resending the message.
        var ackDeadlineSeconds = 60;
        var subscription = subscriber.CreateSubscription(subscriptionName, topicName, pushConfig, ackDeadlineSeconds);
        return subscription;
    }
}

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/pubsub/v2"
	"cloud.google.com/go/pubsub/v2/apiv1/pubsubpb"
)

// createPushNoWrapperSubscription creates a push subscription where messages are delivered in the HTTP body.
func createPushNoWrapperSubscription(w io.Writer, projectID, topic, subscription, endpoint string) error {
	// projectID := "my-project-id"
	// topic := "projects/my-project-id/topics/my-topic"
	// subscription := "projects/my-project/subscriptions/my-sub"
	// endpoint := "https://my-test-project.appspot.com/push"
	ctx := context.Background()
	client, err := pubsub.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("pubsub.NewClient: %w", err)
	}
	defer client.Close()
	pbSubscription := &pubsubpb.Subscription{
		Name:               subscription,
		Topic:              topic,
		AckDeadlineSeconds: 10,
		PushConfig: &pubsubpb.PushConfig{
			PushEndpoint: endpoint,
			Wrapper: &pubsubpb.PushConfig_NoWrapper_{
				NoWrapper: &pubsubpb.PushConfig_NoWrapper{
					// Determines if message metadata is added to the HTTP headers of
					// the delivered message.
					WriteMetadata: true,
				},
			},
		},
	}
	sub, err := client.SubscriptionAdminClient.CreateSubscription(ctx, pbSubscription)
	if err != nil {
		return fmt.Errorf("CreateSubscription: %w", err)
	}
	fmt.Fprintf(w, "Created push no wrapper subscription: %v\n", sub)
	return nil
}

import com.google.cloud.pubsub.v1.SubscriptionAdminClient;
import com.google.pubsub.v1.PushConfig;
import com.google.pubsub.v1.PushConfig.NoWrapper;
import com.google.pubsub.v1.Subscription;
import com.google.pubsub.v1.SubscriptionName;
import com.google.pubsub.v1.TopicName;
import java.io.IOException;

public class CreateUnwrappedPushSubscriptionExample {
  public static void main(String... args) throws Exception {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "your-project-id";
    String subscriptionId = "your-subscription-id";
    String topicId = "your-topic-id";
    String pushEndpoint = "https://my-test-project.appspot.com/push";

    createPushSubscriptionExample(projectId, subscriptionId, topicId, pushEndpoint);
  }

  public static void createPushSubscriptionExample(
      String projectId, String subscriptionId, String topicId, String pushEndpoint)
      throws IOException {
    try (SubscriptionAdminClient subscriptionAdminClient = SubscriptionAdminClient.create()) {
      TopicName topicName = TopicName.of(projectId, topicId);
      SubscriptionName subscriptionName = SubscriptionName.of(projectId, subscriptionId);
      NoWrapper noWrapper =
          NoWrapper.newBuilder()
              // Determines if message metadata is added to the HTTP headers of
              // the delivered message.
              .setWriteMetadata(true)
              .build();
      PushConfig pushConfig =
          PushConfig.newBuilder().setPushEndpoint(pushEndpoint).setNoWrapper(noWrapper).build();

      // Create a push subscription with default acknowledgement deadline of 10 seconds.
      // Messages not successfully acknowledged within 10 seconds will get resent by the server.
      Subscription subscription =
          subscriptionAdminClient.createSubscription(subscriptionName, topicName, pushConfig, 10);
      System.out.println("Created push subscription: " + subscription.getName());
    }
  }
}

use Google\Cloud\PubSub\PubSubClient;

/**
 * Creates an unwrapped push subscription.
 *
 * @param string $projectId  The Google project ID.
 * @param string $topicName  The Pub/Sub topic name.
 * @param string $subscriptionId  The ID of the subscription.
 */
function create_unwrapped_push_subscription(
    string $projectId,
    string $topicName,
    string $subscriptionId
): void {

    $pubsub = new PubSubClient([
        'projectId' => $projectId,
    ]);
    $pubsub->subscribe($subscriptionId, $topicName, [
        'pushConfig' => [
            'no_wrapper' => [
                'write_metadata' => true
            ]
        ]
    ]);
    printf('Unwrapped push subscription created: %s' . PHP_EOL, $subscriptionId);
}

# topic_id          = "your-topic-id"
# subscription_id   = "your-subscription-id"
# endpoint          = "https://your-test-project.appspot.com/push"

pubsub = Google::Cloud::Pubsub.new
subscription_admin = pubsub.subscription_admin

subscription = subscription_admin.create_subscription \
  name: pubsub.subscription_path(subscription_id),
  topic: pubsub.topic_path(topic_id),
  push_config: {
    push_endpoint: endpoint,
    no_wrapper: {
      write_metadata: true
    }
  }

puts "Unwrapped push subscription #{subscription_id} created."