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

# How to stream Postgres to AWS SNS

> Setup Postgres change data capture (CDC) and stream changes to Amazon SNS topics with Sequin. Power event-driven architectures, fan‑out to SQS queues, Lambdas, and more.

This guide shows you how to set up Postgres change data capture (CDC) and stream changes to Amazon SNS using Sequin.

With Postgres data streaming to SNS you can fan‑out events to SQS queues, trigger AWS Lambdas, send emails, stream to AWS Kinesis, and more.

By the end of this how‑to, you'll have database changes flowing into an SNS topic.

<Tip>
  This is the how-to guide for streaming Postgres to SNS. See the [quickstart](/quickstart/sns) for a step-by-step walkthrough or the [reference](/reference/sinks/sns) for details on all configuration options.
</Tip>

## Prerequisites

If you're self‑hosting Sequin, you'll need:

1. [Sequin installed](/running-sequin)
2. [A database connected](/connect-postgres)
3. An AWS account

## Basic setup

### Create an SNS topic

If you don't have a topic already, create one in the [SNS console](https://console.aws.amazon.com/sns/v3/home):

1. Click "Create topic".
2. Choose "Standard" unless you need FIFO ordering. Note that FIFO SNS topics can only fan‑out to SQS queues. (Read more about [FIFO vs standard topics in the reference](/reference/sinks/sns#fifo-vs-standard-topics).)
3. Give the topic a name, e.g. `postgres-changes`.
4. Click "Create topic".
5. Copy the **Topic ARN** – you'll need it when configuring the sink.

### Create an IAM user for Sequin

Create an IAM user with permission to publish to the topic:

1. Open the [IAM console](https://console.aws.amazon.com/iam/).

2. Click "Users" → "Add users".

3. Name the user (e.g. `sequin-sns-publisher`) and select "Access key – Programmatic access".

4. Attach the policy below (replace `<your-topic-arn>`):

   ```json theme={null}
   {
     "Version": "2012-10-17",
     "Statement": [
       {
         "Effect": "Allow",
         "Action": [
           "sns:Publish",
           "sns:PublishBatch",
           "sns:GetTopicAttributes"
         ],
         "Resource": "<your-topic-arn>"
       }
     ]
   }
   ```

5. Finish the wizard and save the Access Key ID and Secret Access Key. You'll enter these in Sequin next.

### (Optional) Enable retention for changes

Changes from your source table are transient; if you need to replay them later consider [change retention](/reference/change-retention) or streaming a retention table instead.

## Create SNS sink

In Sequin, navigate to the "Sinks" tab, click "Create Sink", and select "SNS Sink".

### Configure the source

<Steps>
  <Step title="Select source tables">
    Under **Source**, select the schemas and tables you want to stream data from.
  </Step>

  <Step title="Add filters (optional)">
    Add [filters](/reference/filters) to the sink to control which database changes are sent to your SNS topic.
  </Step>

  <Step title="Specify transforms">
    Optionally transform the shape of messages using [transforms](/reference/transforms).
  </Step>

  <Step title="Specify backfill">
    Optionally send a [backfill](/reference/backfills) of existing rows. Toggle **Backfill** off if you only need new changes.
  </Step>

  <Step title="Specify message grouping">
    Leave the default grouping (primary key) so events for the same row share a `MessageGroupId` when using FIFO topics.
  </Step>
</Steps>

### Configure SNS

<Steps>
  <Step title="Enter topic details">
    Fill in:

    * Topic ARN (required): The ARN you copied earlier.
    * AWS Access Key ID / Secret Access Key (required): Credentials you created for Sequin.
  </Step>

  <Step title="Test connection">
    Click "Test Connection" to ensure Sequin can publish to the topic.
  </Step>

  <Step title="Create the sink">
    Give your sink a name, then click "Create SNS Sink".
  </Step>
</Steps>

## Verify & debug

To verify your sink:

1. Make changes in the source table.
2. Watch the message count increase in Sequin's "Messages" tab.
3. Check your subscription (email, SQS queue, etc.) – you should receive the events.

If messages aren't flowing:

1. In Sequin click the "Messages" tab.
2. Inspect any failed message to see the AWS error.
3. Confirm:
   * Credentials are correct and active.
   * IAM policy includes `sns:Publish*` permissions for the topic.
   * Topic ARN and region are correct.

## Next steps

* **Process the events**

  Subscribe an SQS queue or Lambda function to the topic and build your processor. Refer to the [SNS sink reference](/reference/sinks/sns) for the exact message shape.

* **Deploy to production**

  When you're ready, see "[How to deploy to production](/how-to/deploy-to-production)".

* **Advanced configuration**

  Explore transforms, filtering, and grouping options in the [sink reference](/reference/sinks/sns).