---
phase: 06
plan: 03
subsystem: first-run-detection
tags: [hooks, supabase, migrations, first-run]
started: "2026-04-20T17:32:09Z"
completed: "2026-04-20T18:07:20Z"
status: complete
dependency_graph:
  requires: [06-01, 06-02]
  provides: [useFirstRunState-hook, db-schema-live]
  affects: [phase-07-wizard]
tech_stack:
  added: []
  patterns: [derived-state-hook, loading-guard-pattern]
key_files:
  created:
    - src/hooks/useFirstRunState.ts
  modified: []
decisions:
  - "Hook derives state from existing React Query caches (useCategories + useTemplate) with zero additional network calls"
  - "DB migrations applied manually by user via supabase db push after checkpoint gate"
metrics:
  duration: ~35min (including checkpoint wait)
  tasks_completed: 3
  files_created: 1
  files_modified: 0
---

# Phase 06 Plan 03: useFirstRunState Hook and DB Schema Push Summary

Derived first-run detection hook reading from React Query cache with loading guard to prevent spurious redirects, plus live DB schema with uniqueness constraints and setup_completed column.

## What Was Built

### useFirstRunState Hook (src/hooks/useFirstRunState.ts)

A read-only derived state hook that composes `useCategories()` and `useTemplate()` to determine whether the current user is a first-run user (no categories or no template items). Returns `{ isFirstRun: boolean, loading: boolean }`. The `loading` flag is critical -- callers in Phase 7 must check `!loading && isFirstRun` before redirecting to prevent false positives while queries are in flight.

### DB Schema Push (migrations 006 + 007)

User applied both migrations via `supabase db push`:
- Migration 006: UNIQUE constraints on `budgets(user_id, start_date)` and `categories(user_id, name)` with safe deduplication
- Migration 007: `setup_completed` boolean column on `profiles` with backfill for existing users

## Task Execution

| Task | Name | Commit | Status |
|------|------|--------|--------|
| 1 | Create useFirstRunState.ts | 0c1105f | Complete |
| 2 | DB schema push (migrations 006+007) | Manual (user) | Complete - user applied |
| 3 | Human verification checkpoint | N/A | Approved by user |

## Decisions Made

1. **Zero-network-call design** -- Hook reads from existing React Query caches rather than making its own Supabase calls, avoiding redundant fetches.
2. **Manual DB push** -- `supabase db push` required interactive confirmation; user ran it manually after checkpoint gate.

## Deviations from Plan

None -- plan executed exactly as written.

## Known Stubs

None -- hook is fully wired to existing data sources.

## Verification Results

- `export function useFirstRunState` found in hook file
- Both `useCategories` and `useTemplate` imports present
- `npx tsc --noEmit` passes with zero errors
- Migration files 006 and 007 exist in supabase/migrations/
- User confirmed DB constraints and setup_completed column are live in Supabase dashboard

## Requirements Covered

- **AUTO-01**: useFirstRunState provides first-run detection for auto-budget flow
- **AUTO-03**: No hardcoded currency -- amounts are plain numbers throughout
- **SETUP-01**: setup_completed column + backfill (plan 01) + useFirstRunState detection (plan 03)
- **SETUP-02**: Preset library with 19 items delivered in plan 02

## Self-Check: PASSED

- [x] src/hooks/useFirstRunState.ts exists
- [x] Commit 0c1105f verified in git log
- [x] TypeScript compiles cleanly
- [x] Migration files present on disk