What is Sequin?

Sequin is a tool for capturing changes and streaming data out of your Postgres database. You can use Sequin to setup HTTP endpoints that you can use to stream rows from your database in real-time. Or, you can receive rows as they change via webhooks.

Sequin is great for:

1. Replicating data from your existing tables to other apps, databases, caches, materialized views, or frontend clients.
2. Building event processing workflows such as triggering side effects when data in Postgres changes.

Sequin guarantees exactly-once processing. That means you can use it to:

• Replace listen/notify with something more reliable.
• Fan-out data to other services.
• Replace Postgres triggers with functions in your app.
• Guarantee functions in your code are called given certain changes in Postgres.
• Streamline workflows by converting them to an event-driven model.
• Provide webhooks or sync endpoints to your customers.
• Replace Debezium/Kafka pipelines.
• Use Postgres instead of Kafka for streaming use cases.

Sequin is a Docker image you can run next to your Postgres database. Sequin itself is built on Postgres and uses Postgres to store consumer state.

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Killer features

• Never miss a row or change: Sequin ensures all database changes are delivered and processed exactly once by consumers.
• SQL-based routing: Filter and route messages to consumers using SQL where conditions.
• Replays: Rewind consumers to any row on your table. Or republish select messages that match a SQL query.
• Start anywhere: Consumers can start processing rows from any point in a table.
• Bring your database: Sequin is not an extension. It works with any Postgres database version 12+.
• No PL/pgSQL: Define business logic in the language of your choice and in your application.
• Transforms (coming soon!): Transform message payloads by writing functions in Lua, JavaScript, or Go.

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Why Sequin?

We all know Postgres is great for storing and querying data. But what about when you need to stream data?

Postgres has limited support for streaming. Postgres is not a log, so tracking changes is difficult. Logical replication slots are ephemeral, and don’t support all the features developers need. And Postgres doesn’t have the concept of consumer groups or delivery tracking.

So, Sequin adds streaming features to Postgres. And importantly, Sequin keeps your data in Postgres. You can use your existing database in a new way without copying the data to a new system or mastering a new technology.

With Sequin, you can:

1. Stream a Postgres table in real-time and with exactly-once processing over an HTTP interface.
2. Receive webhooks whenever rows change, with retries and backoff.
3. Capture changes to Postgres tables as a series of events in an event log table.

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Watch

Watch a recent demo of Sequin in action:

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Getting started

Sequin is available as a cloud version or self-hosted. See the following docs to get up and running:

Cloud Quickstart

Get started in about 3 minutes.

Self-hosted Quickstart

Self-host Sequin and start with a local Postgres database.

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Getting help