In this quickstart, you’ll create a real-time data pipeline that streams changes from a Postgres database to a Kafka topic. You’ll:

  • Boot Sequin
  • Connect to a sample playground database
  • Configure a Kafka topic to receive database changes
  • See your changes flow in real-time

By the end, you’ll have hands-on experience setting up Postgres change data capture (CDC) with Sequin. This same pattern can be used to keep other systems in sync with your database changes.

Boot Kafka (optional)

If you don’t already have Kafka running, start Kafka with Docker Compose. You can use the following commands to get started:

mkdir kafka-quickstart && cd kafka-quickstart
wget https://raw.githubusercontent.com/sequinstream/sequin/main/docs/static/kafka-docker-compose.yaml
docker compose up

If you’re using another Kafka instance, ensure you have the connection details ready.

Run Sequin

The easiest way to get started with Sequin is with our Docker Compose file. This file starts a Postgres database, Redis instance, and Sequin server.

1

Create directory and start services

Create a directory for Sequin, download the Docker Compose file, and start the services:

mkdir sequin && cd sequin
wget https://raw.githubusercontent.com/sequinstream/sequin/main/docker/docker-compose.yaml
docker compose up -d
2

Verify services are running

Check that Sequin is running using docker ps:

docker ps

You should see output like the following:

CONTAINER ID   IMAGE                                 STATUS          PORTS                                       NAMES
abc123def456   sequinstream/sequin:latest           Up 10 seconds    0.0.0.0:7376->7376/tcp                     sequin
def456ghi789   redis:7.0                            Up 10 seconds    0.0.0.0:6379->6379/tcp                     sequin-redis
ghi789jkl012   postgres:15                          Up 10 seconds    0.0.0.0:5432->5432/tcp                     sequin-postgres

All three containers should be up and running (status: Up).

Login

The Docker Compose file automatically configures Sequin with an admin user and a playground database.

Let’s log in to the Sequin web console:

1

Open the web console

After starting the Docker Compose services, open the Sequin web console at http://localhost:7376:

2

Login with default credentials

Use the following default credentials to login:

  • Email:
admin@sequinstream.com
  • Password:
sequinpassword!

View the playground database

To get you started quickly, Sequin’s Docker Compose file creates a logical database called sequin_playground with a sample dataset in the public.products table.

Let’s take a look:

1

Navigate to Databases

In the Sequin web console, click Databases in the sidebar.

2

Select playground database

Click on the pre-configured sequin-playground database:

The database “Health” should be green.

3

View contents of the products table

Let’s get a sense of what’s in the products table. Run the following command:

docker exec -i sequin-sequin_postgres-1 \
  psql -U postgres -d sequin_playground -c \
  "select id, name, price from products;"

This command connects to the running Postgres container and runs a psql command.

You should see a list of the rows in the products table:

  id |         name          | price 
----+-----------------------+-------
  1 | Avocados (3 pack)     |  5.99
  2 | Flank Steak (1 lb)    |  8.99
  3 | Salmon Fillet (12 oz) | 14.99
  4 | Baby Spinach (16 oz)  |  4.99
  5 | Sourdough Bread       |  6.99
  6 | Blueberries (6 oz)    |  3.99
(6 rows)

We’ll make modifications to this table in a bit.

Create a Kafka Sink

With the playground database connected, you can create a sink. This sink will send changes to the products table to your Kafka topic:

1

Navigate to Sinks

Click “Sinks” in the sidebar navigation, then click “Create Sink”.

2

Select sink type

Select “Kafka” as the sink type and click “Continue”.

3

Note "Source" configuration

In the “Source” card, note that the sequin-playground database and products table are pre-selected. Leave these defaults:

4

Setup a backfill

In the “Initial backfill” card, click the toggle to enable an initial backfill. You can leave the default start position, which will backfill all existing rows in the products table:

5

Configure "Kafka Configuration"

In the “Kafka Configuration” card, enter your Kafka connection details:

  • Hosts: If running locally with the provided docker-compose, use host.docker.internal:9092
  • Topic: The Kafka topic to stream to (e.g., products)
  • SASL Mechanism: Select if your Kafka cluster requires authentication
  • Username/Password: Required if SASL is enabled
  • TLS: Toggle on if your Kafka cluster requires TLS
6

Test the connection

At the bottom of the form, click the “Test Connection” button. If you provided proper credentials, it should succeed.

Sequin can connect to your Kafka cluster.

7

Create the sink

You can leave the rest of the defaults. As configured, the Kafka topic will first receive a backfill of all rows currently in the products table. Then, it will receive all changes to the products table in real-time.

Click “Create Sink” to finish setting up your Kafka sink.

See changes flow to your Kafka topic

On the new sink’s overview page, you should see the “Health” status turn green, indicating data is flowing to your Kafka topic.

Let’s confirm messages are flowing:

1

Messages tab

Click the “Messages” tab. You’ll see a list of the recently delivered messages:

Sequin indicates it backfilled the products table to your Kafka topic.

2

View in Kafka CLI

In your terminal, run the following command to read from the topic:

docker exec playground-kafka-kafka-1 \
  kafka-console-consumer --bootstrap-server localhost:9092 \
  --topic products \
  --from-beginning \
  --max-messages 10

You should see the messages that were sent from Sequin. These are read events from the initial backfill of the products table.

Messages are flowing from Sequin to your Kafka topic.

3

Make some changes

Let’s make some changes to the products table and see them flow to your topic.

In your terminal, run the following command to insert a new row into the products table:

docker exec -i sequin-sequin_postgres-1 \
  psql -U postgres -d sequin_playground -c \
  "insert into products (name, price) values ('Organic Honey (16 oz)', 12.99);"

In another terminal, consume messages from your Kafka topic:

docker exec playground-kafka-kafka-1 \
  kafka-console-consumer --bootstrap-server localhost:9092 \
  --topic products \
  --from-beginning

You should see a message corresponding to the inserted row.

Feel free to try other changes:

Each change will appear in your Kafka topic within a few seconds.

Great work!

You’ve successfully:

  • Set up a complete Postgres CDC pipeline
  • Loaded existing data through a backfill
  • Made changes to the products table
  • Verified changes are flowing to your Kafka topic

​
Ready to stream

Now you’re ready to connect your own database to Sequin and start streaming changes:

Guide: Connect Postgres

Connect your Postgres database to Sequin.

Guide: Setting up a Kafka sink

Setup a Kafka sink to send changes to your topic.

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