Fix Supabase Realtime subscriptions that don't receive events

Supabase Realtime subscriptions may silently fail to deliver events if the table isn't configured for replication, RLS blocks the subscription, or the channel setup is incorrect.

Error messages you might see

Realtime connection closed unexpectedly
Error subscribing to channel: {"message":"relation not found"}

Why this happens in AI-generated code

1

Table not added to Realtime publication

AI-generated Supabase setup often enables Realtime in the client code but skips adding the table to the supabase_realtime publication in the database.

2

RLS blocking Realtime events

AI tools don't account for RLS on Realtime channels. If the subscribed user doesn't have SELECT permission via RLS policies, events are silently filtered out.

3

Incorrect channel configuration

AI-generated subscription code uses outdated .on() syntax or wrong event names, so the listener never matches incoming database changes.

How to fix it

1

Enable Realtime for your table

In the Supabase dashboard, go to Database > Replication and ensure your table is added to the supabase_realtime publication. Or run: ALTER PUBLICATION supabase_realtime ADD TABLE your_table;

2

Ensure RLS policies allow SELECT for subscribers

Realtime events are filtered through RLS. Add a SELECT policy that allows the subscribing user to read the rows they should receive notifications about.

3

Get professional help

Still stuck? Our engineers can configure and debug your Realtime setup. Visit /products to get started.

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Frequently asked questions

How do I know if Realtime is connected?

Check the channel status after subscribing: channel.subscribe((status) => console.log(status)). It should log 'SUBSCRIBED'. You can also check the Realtime inspector in the Supabase dashboard.

Does Realtime work with Supabase Edge Functions?

Edge Functions can trigger database changes that Realtime picks up, but you typically subscribe to Realtime from client-side code, not from within Edge Functions.

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