Neon as logical replication publisher: enable once, carefully

TL;DR: Enable logical replication on the project (Console project settings, CLI, or API). # Publishing logical replication from Neon ## The trap The toggle looks harmless in the Console. It is not: enabling logical replication changes

Fix

1. Enable logical replication on the project (Console project settings, CLI, or API). Expected: this specific failure stops.

2. Create the publication and replication slot on the publisher:. Expected: this specific failure stops.

3. hostname will not work. ## Checklist - Irreversible wal_level change: be sure before enabling. - Subscriber connection string: direct, no. Expected: this specific failure stops.

4. If you use IP Allow, add the subscriber's IPs to the list. - Tables need a replica identity (primary key) for updates/deletes to replicate. Expected: this specific failure stops.

Details

It is not: enabling logical replication changes wal_level from replica to logical Plan a maintenance window. Warn stakeholders: connections will drop and reconnect. 2. 3. ```sql CREATE PUBLICATION [pub-name] FOR TABLES [table1], [table2]; SELECT pgcreatelogicalreplicationslot('[slot-name]', 'pgoutput');

## When to use
You hit exactly this: Neon as logical replication publisher: enable once, carefully in Neon as logical replication publisher.

## When not to use
A different error, or the same symptom in a different tool. This page only covers the failure above.

## Compatibility
Neon as logical replication publisher.

## Root cause
and the slot name, because you created the slot manually.

## Edge cases
- # Publishing logical replication from Neon ## The trap The toggle looks harmless in the Console.
- for all databases in the project, it cannot be reverted, and it restarts all computes, dropping every active connection. ## The rule 1.

Neon's logical replication guide (verified live 2026-09-26): enabling changes wallevel from replica to logical for all databases, cannot be reverted, restarts all computes dropping connections; subscriber must use a direct connection string, not pooled; manual slot creation pairs with createslot=false on the subscription.