> ## Documentation Index
> Fetch the complete documentation index at: https://docs.peerdb.io/llms.txt
> Use this file to discover all available pages before exploring further.

# PubSub Setup Guide

1. [Create a dedicated Service Account](https://cloud.google.com/iam/docs/keys-create-delete#iam-service-account-keys-create-console)
   for PeerDB through Google Cloud Console and specify the following roles:

* `Pub/Sub Viewer` : PeerDB requires this role to check if your provided topic exists.
* `Pub/Sub Publisher` : PeerDB requires this role to publish messages to the topic.

  <Frame caption="Create a dedicated Service Account For PeerDB and grant the necessary permissions">
    <img src="https://mintcdn.com/peerdb/L54DxDXK99_p-wL9/images/setup/pubsub-setup.png?fit=max&auto=format&n=L54DxDXK99_p-wL9&q=85&s=d35071b73f098398df077126fd99b93b" width="916" height="579" data-path="images/setup/pubsub-setup.png" />
  </Frame>

2. Add a key to the above created service account
   <Frame caption="Add Key to the Service Account">
     <img src="https://mintcdn.com/peerdb/L54DxDXK99_p-wL9/images/setup/bq-add-key-1.png?fit=max&auto=format&n=L54DxDXK99_p-wL9&q=85&s=848581b8fb9968cf2e0d7ad9e2a5d97e" width="2118" height="1490" data-path="images/setup/bq-add-key-1.png" />
   </Frame>
   <Frame caption="Key Added to the Service Account">
     <img src="https://mintcdn.com/peerdb/L54DxDXK99_p-wL9/images/setup/bq-add-key-2.png?fit=max&auto=format&n=L54DxDXK99_p-wL9&q=85&s=ab351ed15edb842642b172d8fa3ca31f" width="2080" height="1432" data-path="images/setup/bq-add-key-2.png" />
   </Frame>

3. Using this service account key create the peer using PeerDB UI

   <Frame caption="Create PubSub Peer">
     <img src="https://mintcdn.com/peerdb/L54DxDXK99_p-wL9/images/setup/pubsub-create-peer.png?fit=max&auto=format&n=L54DxDXK99_p-wL9&q=85&s=eff6d6f3c73810f56aa0257c2445f87f" width="1234" height="752" data-path="images/setup/pubsub-create-peer.png" />
   </Frame>

***

### Topic creation

By default, you would need to create the destination topic in PubSub before creating a mirror.
However, if you'd like PeerDB to create the topic for you, you can turn on the following setting in PeerDB UI:

<Frame caption="Add Key to the Service Account">
  <img src="https://mintcdn.com/peerdb/MRN5BST_xrBv7brJ/images/cdc_kafka/topiccreate.png?fit=max&auto=format&n=MRN5BST_xrBv7brJ&q=85&s=dac6b53da4cc089b7131b9a49296ea21" width="2132" height="636" data-path="images/cdc_kafka/topiccreate.png" />
</Frame>

Note that you must create a subscription on the topic for messages to be retained.