How can I trigger an n8n workflow when new data is added to a specific Supabase column?

You have a couple of options:

1. Using n8n’s Postgres Trigger node:
   Supabase is built on PostgreSQL. If your Supabase instance is accessible to n8n (with the proper network and authentication setup), you can use the Postgres Trigger node in n8n to listen for events like inserts, updates, or deletes on your table. You can then configure the node to trigger your workflow when there’s a change. Note that the node listens to the entire table events, so if you need to detect changes only in a specific column, you may need to incorporate conditional checks further down in your workflow.

2. Leveraging Supabase Realtime Broadcasting:
   Supabase’s Realtime API lets you set up triggers in the database. For example, you can add a PostgreSQL trigger that fires a function using realtime.broadcast_changes whenever a row is inserted (or updated/deleted). With this setup, you might target only specific columns by tailoring your trigger function logic (and even constructing topics based on column values). Your application (or an n8n webhook) can then subscribe to those broadcasted events and start a workflow. An example trigger function looks like this:

   SQLCopied
   CREATE OR REPLACE FUNCTION public.your_table_changes() RETURNS trigger AS $$
   BEGIN
       PERFORM realtime.broadcast_changes(
           'topic:' || NEW.id::text,   -- Topic (you could customize this)
           TG_OP,                      -- Event type (INSERT, UPDATE, DELETE)
           TG_OP,                      -- Operation (could also be customized)
           TG_TABLE_NAME,              -- Table name
           TG_TABLE_SCHEMA,            -- Schema name
           NEW,                        -- New record data
           OLD                         -- Old record data
       );
       RETURN NULL;
   END;
   $$ LANGUAGE plpgsql;

   Then, you set up a trigger on your table:

   SQLCopied
   CREATE TRIGGER broadcast_changes_for_your_table_trigger
   AFTER INSERT OR UPDATE OR DELETE ON public.your_table
   FOR EACH ROW
   EXECUTE FUNCTION public.your_table_changes();

   On the client side (or within an n8n workflow, via a webhook), you subscribe to these events using the Supabase client, which allows your workflow to start automatically when new data matching your conditions is inserted.

Summary:
Yes, you can trigger an n8n workflow based on new data in a Supabase table. If you can connect n8n directly to your Supabase PostgreSQL database, the Postgres Trigger node is a straightforward option. Otherwise, setting up a Supabase Realtime trigger (and subscribing to its broadcasts) will allow you to start workflows on specific data changes, including those affecting a particular column. Which approach you choose depends on your infrastructure and how granular you need the trigger logic to be.