monthlytracker/openspec/changes/monthly-expense-tracker-v1/tasks.md

1. Project setup

• 1.1 Scaffold the Next.js app with TypeScript, linting, and baseline project configuration.
• 1.2 Add runtime dependencies for Prisma, SQLite, validation, charts, and OpenAI integration.
• 1.3 Add development dependencies and scripts for testing, Prisma generation, and local development.
• 1.4 Add base environment and ignore-file setup for local database and API key configuration.

2. Persistence and shared services

• 2.1 Define Prisma models for Expense, Paycheck, and MonthlyInsight and create the initial SQLite migration.
• 2.2 Implement shared validation schemas for expenses, paychecks, and month query parameters.
• 2.3 Implement shared money and local-date utilities for month boundary calculations.

3. Expense and paycheck workflows

• 3.1 Implement expense API routes for create, list, and delete operations.
• 3.2 Implement paycheck API routes for create, list, and delete operations.
• 3.3 Build the Add Expense view with form submission, validation feedback, and expense listing.
• 3.4 Build the Income/Paychecks view with form submission, validation feedback, and paycheck listing.

4. Dashboard and insights

• 4.1 Implement monthly dashboard aggregation services for totals, category breakdowns, and derived comparisons.
• 4.2 Implement the dashboard API route and render dashboard sections for month-to-date metrics and comparisons.
• 4.3 Implement the offline Ollama insight service with structured monthly snapshot input and sparse-month fallback logic.
• 4.4 Implement insight generation and display in the dashboard, including persisted monthly insight records and offline-runtime fallback messaging.

5. Offline categorization

• 5.1 Implement deterministic merchant-to-category mapping for known merchants.
• 5.2 Implement a local-model category suggestion endpoint for unknown merchants.
• 5.3 Update the expense entry flow to auto-fill known merchants and require confirmation for model-generated suggestions.
• 5.4 Add local runtime availability handling so category suggestion falls back to manual selection without cloud calls.

6. Verification

• 6.1 Add automated tests for validation, persistence, dashboard aggregates, offline insight fallback behavior, and category suggestion rules.
• 6.2 Verify the primary user flows in the browser, including expense entry, paycheck entry, dashboard updates, category suggestion, and insight generation.