---
type: docs
title: "Pub/Sub without CloudEvents"
linkTitle: "Pub/Sub without CloudEvents"
weight: 7000
description: "Use Pub/Sub without CloudEvents."
---

## Introduction

Dapr uses CloudEvents to provide additional context to the event payload, enabling features like:
* Tracing
* Deduplication by message Id
* Content-type for proper deserialization of event's data

For more information about CloudEvents, read the [CloudEvents specification](https://github.com/cloudevents/spec).

When adding Dapr to your application, some services may still need to communicate via raw pub/sub messages not encapsulated in CloudEvents. This may be for compatibility reasons, or because some apps are not using Dapr. Dapr enables apps to publish and subscribe to raw events that are not wrapped in a CloudEvent.

{{% alert title="Warning" color="warning" %}}
Not using CloudEvents disables support for tracing, event deduplication per messageId, content-type metadata, and any other features built using the CloudEvent schema.
{{% /alert %}}

## Publishing raw messages

Dapr apps are able to publish raw events to pub/sub topics without CloudEvent encapsulation, for compatibility with non-Dapr apps.

<img src="/images/pubsub_publish_raw.png" alt="Diagram showing how to publish with Dapr when subscriber does not use Dapr or CloudEvent" width=1000>

To disable CloudEvent wrapping, set the `rawPayload` metadata to `true` as part of the publishing request. This allows subscribers to receive these messages without having to parse the CloudEvent schema.

{{< tabs curl "Python SDK" "PHP SDK">}}

{{% codetab %}}
```bash
curl -X "POST" http://localhost:3500/v1.0/publish/pubsub/TOPIC_A?metadata.rawPayload=true -H "Content-Type: application/json" -d '{"order-number": "345"}'
```
{{% /codetab %}}

{{% codetab %}}
```python
from dapr.clients import DaprClient

with DaprClient() as d:
    req_data = {
        'order-number': '345'
    }
    # Create a typed message with content type and body
    resp = d.publish_event(
        pubsub_name='pubsub',
        topic='TOPIC_A',
        data=json.dumps(req_data),
        metadata=(
                     ('rawPayload', 'true')
                 )
    )
    # Print the request
    print(req_data, flush=True)
```
{{% /codetab %}}

{{% codetab %}}

```php
<?php

require_once __DIR__.'/vendor/autoload.php';

$app = \Dapr\App::create();
$app->run(function(\DI\FactoryInterface $factory) {
    $publisher = $factory->make(\Dapr\PubSub\Publish::class, ['pubsub' => 'pubsub']);
    $publisher->topic('TOPIC_A')->publish('data', ['rawPayload' => 'true']);
});
```

{{% /codetab %}}

{{< /tabs >}}

## Subscribing to raw messages

Dapr apps are also able to subscribe to raw events coming from existing pub/sub topics that do not use CloudEvent encapsulation.

<img src="/images/pubsub_subscribe_raw.png" alt="Diagram showing how to subscribe with Dapr when publisher does not use Dapr or CloudEvent" width=1000>

### Programmatically subscribe to raw events

When subscribing programmatically, add the additional metadata entry for `rawPayload` so the Dapr sidecar automatically wraps the payloads into a CloudEvent that is compatible with current Dapr SDKs.

{{< tabs "Python" "PHP SDK" >}}

{{% codetab %}}

```python
import flask
from flask import request, jsonify
from flask_cors import CORS
import json
import sys

app = flask.Flask(__name__)
CORS(app)

@app.route('/dapr/subscribe', methods=['GET'])
def subscribe():
    subscriptions = [{'pubsubname': 'pubsub',
                      'topic': 'deathStarStatus',
                      'route': 'dsstatus',
                      'metadata': {
                          'rawPayload': 'true',
                      } }]
    return jsonify(subscriptions)

@app.route('/dsstatus', methods=['POST'])
def ds_subscriber():
    print(request.json, flush=True)
    return json.dumps({'success':True}), 200, {'ContentType':'application/json'}

app.run()
```

{{% /codetab %}}
{{% codetab %}}

```php
<?php

require_once __DIR__.'/vendor/autoload.php';

$app = \Dapr\App::create(configure: fn(\DI\ContainerBuilder $builder) => $builder->addDefinitions(['dapr.subscriptions' => [
    new \Dapr\PubSub\Subscription(pubsubname: 'pubsub', topic: 'deathStarStatus', route: '/dsstatus', metadata: [ 'rawPayload' => 'true'] ),
]]));

$app->post('/dsstatus', function(
    #[\Dapr\Attributes\FromBody]
    \Dapr\PubSub\CloudEvent $cloudEvent,
    \Psr\Log\LoggerInterface $logger
    ) {
        $logger->alert('Received event: {event}', ['event' => $cloudEvent]);
        return ['status' => 'SUCCESS'];
    }
);

$app->start();
```
{{% /codetab %}}

{{< /tabs >}}

## Declaratively subscribe to raw events

Similarly, you can subscribe to raw events declaratively by adding the `rawPayload` metadata entry to your Subscription Custom Resource Definition (CRD):

```yaml
apiVersion: dapr.io/v1alpha1
kind: Subscription
metadata:
  name: myevent-subscription
spec:
  topic: deathStarStatus
  route: /dsstatus
  pubsubname: pubsub
  metadata:
    rawPayload: "true"
scopes:
- app1
- app2
```

## Related links

- Learn more about [how to publish and subscribe]({{< ref howto-publish-subscribe.md >}})
- List of [pub/sub components]({{< ref supported-pubsub >}})
- Read the [API reference]({{< ref pubsub_api.md >}})
