Database-driven realtime architectures are becoming more and more common as evidenced by key backers and widespread use of software like Firebase and Supabase. The two key priorities for an app following database-driven realtime messaging are long-term storage and change data capture (CDC) updates from the database. In this two part article series, we’ll take a detailed look at a fully serverless chat app where you can edit previously published messages.

In Part 1 of this two-part series, we walked through how to bypass Ably’s SDKs and connect to Ably’s backend using websocat, where every JSON message has to be typed out by hand. In this second part, we’ll fix that tedious bit by switching to NodeJS, and we’ll continue our process of building our own minimal Ably (NodeJS) SDK.

Built by our long-time community expert Apoorv Vardhan, the Ably-Postgres connector can listen to changes in a Postgres table and publish realtime messages on Ably channels whenever a change occurs. The connector enables building database-driven realtime applications where long-term storage and update triggers from previously published messages are essential. One such example is an editable chat app, which we’ll talk about later in this article.