> For the complete documentation index, see [llms.txt](https://rudderlabs.gitbook.io/rudderlabs-1/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://rudderlabs.gitbook.io/rudderlabs-1/docs/destinations/streaming-platforms/google-pub-sub.md).

# Google Pub/Sub

Step-by-step guide to send event data from RudderStack to Google Pub/Sub.

[Google Pub/Sub](https://cloud.google.com/pubsub/docs/overview) is an asynchronous messaging service that allows you to decouple the services that produce events from the services that process events. With Pub/Sub, you get durable message storage as well as a real-time message delivery system. The Google Pub/Sub servers run reliably with a consistent performance in all the Google Cloud regions over the world.

RudderStack allows you to configure Google Pub/Sub as a destination and send your event data to it directly.

**Find the open-source transformer code for this destination in our** [**GitHub repo**](https://github.com/rudderlabs/rudder-transformer/tree/master/v0/destinations/googlepubsub)**.**

## Getting Started

To enable sending data to Google Pub/Sub, you will first need to add it as a destination to the source from which you are sending your event data. Once the destination is enabled, events from our SDK will start flowing to Google Pub/Sub.

| **Connection Mode** | **Web**       | **Mobile**    | **Server**    |
| ------------------- | ------------- | ------------- | ------------- |
| Device mode         | **-**         | **-**         | **-**         |
| Cloud mode          | **Supported** | **Supported** | **Supported** |

To know more about the difference between Cloud mode and Device mode in RudderStack, read the [RudderStack connection modes](https://rudderstack.com/docs/rudderstack-cloud/rudderstack-connection-modes/) guide.

Once you have confirmed that the platform supports sending events to Google Pub/Sub, perform the steps below:

* From your [RudderStack dashboard](https://app.rudderlabs.com/), add the source. From the list of destinations, select **Google Pub/Sub.**
* Give a name to the destination and click on **Next**. You should then see the following screen:

![](https://876606571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Lq5Ea6fHVg3dSxMCgyQ%2Fuploads%2Fgit-blob-c4727736aa2a9fe2ba5c7493d9a1960fdc384393%2Fimage%20\(79\)%20\(2\)%20\(2\)%20\(3\)%20\(3\)%20\(3\)%20\(2\)%20\(2\).png?alt=media)Google Pub/Sub Connection Settings

* Enter the following details:
  * **Connection Settings**
    * **Project ID** and the **Credentials**: Follow these steps to obtain the project ID as well as the required credentials:
      * Create a service account from Google Cloud Console.
      * You can get the **Project ID** when you log in to your Google Cloud Console.
      * Use the **Select a role** dropdown to add the **Pub/Sub Publisher** role.
      * Create a key as JSON and download it.
      * Paste this downloaded JSON in the **Credentials** field
    * Enter the **Event Name** as well as the corresponding **Topic ID**. You can get the topic id from your topics page, as shown:

![](https://876606571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Lq5Ea6fHVg3dSxMCgyQ%2Fuploads%2Fgit-blob-d2729cb92d12d3e3cc9843baee3d2a40881b8728%2Fimage%20\(48\).png?alt=media)Google Pub/Sub Topic ID and Name

You can send an event `type` like `page,` `identify,` `track`. For the `track` events you can specify the event name based on the `event` name in the payload.

For example:

* If the event name is **`page`** it will send all the calls with the `type` page.
* If the event name is **`product added`** , it will send all the track events with the **`event`** as **`product added`**.

If you want to send all the events to a particular stream irrespective of the type or name, you can use **`*`** as the event name.

The **topic ID** is **case-sensitive** and has to be exactly as seen in Google Pub/Sub. On the other hand, the **event name** is **case insensitive**, and thus `Page` or `page` will both be considered as valid.

* Finally, click on **Next** to complete the configuration. Pub/Sub should now be added and enabled as a destination in RudderStack.

## Attributes

You can send attributes to Google Pub/Sub along with the message. In order to send the attributes, enter the required attribute mapping in the RudderStack dashboard as seen below:

![](https://876606571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Lq5Ea6fHVg3dSxMCgyQ%2Fuploads%2Fgit-blob-0e60caa95d3f45cb599106a1afe5bc33e6ed36aa%2Fimage%20\(113\).png?alt=media)

The following are some examples:

* If the `event` is **`Product Viewed`** and the `key` is **`coupon`**, RudderStack will add the `coupon` key-value pair from the message to the attributes' metadata object.
* If multiple mappings are provided for **`Product Viewed`**, all such key-value pairs from the message body will be added to attributes' metadata object.
* If the event name is **`page`** it will send all the calls with the `type` page.

For the `key` fields provided in the attributes map, the `key` is searched in the message body in **`root`**, **`properties`**, **`traits`** and **`context.traits`** - in that specific order.

**Note: You can also specify the key path in the payload using the dot notation.**

For example:

```javascript
rudderanalytics.track("Track me", {
  category: "category",
  label: "label",
  value: "value",
  metadata: {
    metadataId: "sample-id"
  }
});
```

For the above `track` call, you can specify an attribute mapping for `metadataID` as shown below:

| **Event** | **Field**             |
| --------- | --------------------- |
| Track me  | `metadata.metadataId` |

This will create the below attribute metadata object:

```javascript
{
   metadataId: "sample-id"
}
```

## Page

The `page` call contains information related to the page, such as the URL of the web page visited by the user.

For more information on the `page` method, please refer to our [RudderStack API Specification](https://rudderstack.com/docs/rudderstack-api) guide.

A sample `page` payload is as shown in the snippet below:

```javascript
rudderanalytics.page({
  path: "path",
  url: "url",
  title: "title",
  search: "search",
  referrer: "referrer",
})
```

## Identify

The `identify` call captures the relevant details about the visiting user.

For more information on the `identify` method, please refer to our [RudderStack API Specification](https://rudderstack.com/docs/rudderstack-api) guide.

A sample `identify` payload is as shown in the snippet below:

```javascript
rudderanalytics.identify("abc123", {
  name: "FirstName LastName",
  email: "example@gmail.com",
})
```

## Track

The `track` call captures the information related to the actions performed by the user, along with their properties, or traits.

For more information on the `track` method, please refer to our [RudderStack API Specification](https://rudderstack.com/docs/rudderstack-api) guide.

A sample `track` payload is as shown in the snippet below:

```javascript
rudderanalytics.track("Track me", {
  category: "category",
  label: "label",
  value: "value",
})
```

## FAQs

### How does event mapping work with the topic ID?

* If there is no topic ID set for an event, it will not be sent.
* If an event is set with a topic id, the payload will be sent to Pub/Sub to that particular topic id.

If you have set all event type, event and \* for mapping the priority will be given to `event` , then `type` , followed by \*.

For example, let the type of event be `track`, the event name be `product added`. The mapping is done as:

![](https://876606571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Lq5Ea6fHVg3dSxMCgyQ%2Fuploads%2Fgit-blob-1d32f1cc162d47246d6fb74d7152a1995265d82b%2Fscreenshot-2020-09-09-at-6.56.02-pm.png?alt=media)

Now all the events should go to the topic mapped with **`product added`**.

### How do I provide multiple Attribute mapping for a particular event?

In order to send multiple attribute keys for a particular event, enter the required mappings in the RudderStack dashboard as seen below:

![](https://876606571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Lq5Ea6fHVg3dSxMCgyQ%2Fuploads%2Fgit-blob-6423986e19b7b2727a7b096be714dea22a22199c%2Fimage%20\(112\).png?alt=media)

## Contact Us

If you come across any issues while configuring or using Google Pub/Sub with RudderStack, please feel free to [contact us](mailto:%20contact@rudderstack.com). You can also start a conversation in our [Slack](https://rudderstack.com/join-rudderstack-slack-community) community; we will be happy to talk to you!