Bug with local instance auth - inconsistency between RLS and stored procedure

• [x] I confirm this is a bug with Supabase, not with my own application. • [x] I confirm I have searched the [Docs](https://docs.supabase.com), GitHub [Discussions](https:// github.com/supabase/supabase/discussions), and [Discord](https://discord.supabase.com). ## Describe the bug I'm not that experienced with supabase so it's possible I'm doing something wrong and this is completely irrelevant. If so, I'd like to understand how to get this RLS policy working properly locally. auth.uid() returns correct values when called via RPC functions but fails/returns NULL when used in RLS policy evaluation during INSERT operations in local Supabase development environment. This inconsistency makes it impossible to reliably test RLS policies locally. The exact same auth.uid() function with identical authentication context: • ✅ Works correctly when called via SELECT auth.uid() in RPC functions • ✅ Evaluates correctly when tested as auth.uid() = user_id in function context • ❌ Fails silently when used as auth.uid() = user_id in RLS policy WITH CHECK clause ## To Reproduce Complete minimal reproduction attached in bug.tar.gz [bug.tar.gz](https://github.com/user-attachments/files/20645379/bug.tar.gz) ### Quick reproduction steps: 1. Initialize new Supabase project: ```bash mkdir supabase-auth-bug-demo && cd supabase-auth-bug-demo supabase init && supabase start ``` 2. Create migration supabase/migrations/20240101000000_auth_bug_demo.sql: ```sql -- Simple test table CREATE TABLE auth_test ( id uuid DEFAULT gen_random_uuid() PRIMARY KEY, title text NOT NULL, owner_id uuid NOT NULL ); -- Enable RLS ALTER TABLE auth_test ENABLE ROW LEVEL SECURITY; -- RLS policy using auth.uid() - THIS FAILS CREATE POLICY "auth_test_insert_policy" ON auth_test FOR INSERT TO authenticated WITH CHECK (auth.uid() = owner_id); -- Debug function - THIS WORKS CREATE FUNCTION get_current_auth_uid() RETURNS jsonb AS $$ SE…