Table created in Supabase is not showing up from n8n workflow ("Supabase Vector Store")

Questions
1

I created table “documents” following the ‘quickstart for setting up your vector store’ link on n8n document (used SQL code from ‘Long Chain’ to create the table on Supabase). The Run was success. When I go to tables on Supabase, I can see ‘documents’ having 4 columns and 0 rows. However, on ‘Supabase Vector Store’ page from n8n workflow, after selecting my Supabase Credential and Operation = Insert Document, when I search for Table Name (from List) ‘documents’ is not showing up. It returns 404 - “The resource you are requesting could not be found”.

I have n8n installed on my MAC (Docker installation) and using Supabase on the cloud

What is the error message (if any)?

Please share your workflow

(Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.)

Share the output returned by the last node

Information on your n8n setup

  • n8n version:
  • Database (default: SQLite):
  • n8n EXECUTIONS_PROCESS setting (default: own, main):
  • Running n8n via (Docker, npm, n8n cloud, desktop app):
  • Operating system:
2

Hi @subroto

These are what you can do:

1)Ensure the table is in public. If it’s not, you will need to move it or recreate it in the public schema.
2)You can force a schema reload. The simplest way is to make a small change to the table (e.g., add a dummy column and delete it, or change a column description) via the Table Editor UI, which often triggers a cache refresh.
3) For vector store operations (Insert/Query), you should use the service_role secret key. The anon key is subject to Row Level Security (RLS) and may not have permission to “see” the table structure via the API.

3

Let me understand correctly: Are you suggesting I do all these at once or do the first one and check for result and so on…
Also, while creating the table I did not select RLS (Row Level Secuirty).
Thanks

4

@subroto, this is what I meant

5

Thanks for your suggestions will try and let you knwo.
You gues are great!

6

Welcome @subroto!

The 404 from the Vector Store node is usually a credential issue rather than a schema issue. Quick checklist:

  1. In n8n’s Supabase credential, use the service_role key (not anon) - the anon key often can’t access the REST schema endpoint that the node uses to list tables.
  2. Make sure the vector extension is enabled in Supabase: go to Database > Extensions and enable pgvector. If the extension is missing, the table creation SQL runs fine but the node can’t interact with it properly.
  3. Confirm the table is in the public schema - run SELECT schemaname FROM pg_tables WHERE tablename = 'documents'; in the Supabase SQL editor to verify.

If all three are in order and the 404 persists, try deleting the credential in n8n and re-creating it - there’s a known case where the cached endpoint URL doesn’t refresh after credential edits.

7

@subroto One thing worth flagging before you go through the checklist, the SQL from the LangChain quickstart that n8n links to creates the documents table in the extensions schema, not public. Supabase’s Table Editor will show it, but n8n’s Supabase Vector Store node only lists tables from the public schema, which is why you get a 404 even though the table exists.

Run this in the Supabase SQL Editor to confirm:

SELECT schemaname FROM pg_tables WHERE tablename = 'documents';

If it returns extensions instead of public, recreate the table using this adjusted SQL:

CREATE TABLE public.documents (

After recreating in public, use the service_role key in your n8n credential as @kjooleng mentioned, the table should appear in the dropdown immediately.

8

I ran the query

select schemaname
from pg_tables
where tablename = ‘documents’
limit 100;

It returned public. Thanks and regards,