Neon.

Waltail needs three things from Neon: wal_level = logical, a user that is allowed to replicate, and a way to reach the database over the network. Set them up in the steps below. When you paste the connection string in Waltail, the console runs six checks and tells you if anything is still missing.

1. Turn on logical replication

In the Neon console, open the project's Settings → Logical Replication and enable it. This sets wal_level = logical for the whole project. Neon notes it cannot be turned off again, and existing connections are restarted.

2. Copy the direct connection string

Use the direct connection string, not the -pooler one — the pooler cannot carry a replication connection. The default database role already has the replication attribute and owns the tables it created.

3. Know about autosuspend

An open replication connection keeps a Neon compute awake, so a compute set to autosuspend will stay on while the pipeline runs. Size the compute and its suspend setting with that in mind.

Then, in Waltail

1. Paste the connection string

   Use the direct database host. A transaction-mode pooler (PgBouncer and similar) cannot carry a replication connection, so the reachable check would fail there.

2. Pick tables

   Choose the tables to stream. A table needs a primary key — or REPLICA IDENTITY FULL or an index identity — for updates and deletes to replicate. The console marks any table that does not qualify and says why.

3. Add a destination

   Waltail creates a publication and a replication slot on your database (both named pgcdc_<pipeline>) and starts streaming. The quickstart walks through the rest.