# Personal Finance Management System (PFM)
> Stack: Python Flask · MySQL · Ubuntu Server · Nginx · Gunicorn · Groq API (free AI)
> App URL: https://pfm.ngodanguyen.tech
> Code: /home/pfm/web · User: pfm · Gitea: gitea.ngodanguyen.tech

---

## 1. Project Overview

Self-hosted personal finance web app. Tracks income, expenses, investments. AI assistant powered by **Groq API** (free tier, fast inference, no local hardware). Receipt OCR via Groq vision model. Bank account sync via Teller API (mTLS) and Schwab Developer API (OAuth 2.0). Bank statement import (CSV, OFX/QFX, PDF). Everything runs on Ubuntu server behind Nginx + Certbot SSL.

**Status: All 7 phases complete + all post-MVP features implemented.**

---

## 2. Core Features (Implemented)

### 2.1 Dashboard
- Net worth snapshot (assets − liabilities)
- Monthly cash flow bar chart (6 months)
- Budget utilization per category
- Recent transactions feed (last 8)
- AI daily insight card (Groq-generated, stored in DB)
- **Savings Rate** stat card — net cash flow ÷ income for the selected period; green ≥ 20%, blue > 0%, red negative
- **Schwab expiry warning** — banner shown when Schwab refresh token expires within 2 days
- USD → VND exchange rate widget — reference only, independent of app currency
  - Click to expand 30-day history chart
  - ↻ refresh button (force-fetches fresh rate without page reload)
  - Source label shown (yfinance / exchangerate-api)
  - Stale indicator if rate > 1 day old
- Period selector: This Month / Last Month / Custom date range
- Credit card accounts display "owed" balance (positive Amount Owed) not raw negative

### 2.2 Transactions
- Income + Expense entry with Income/Expense tabs
- Transfer between accounts
- Filter: search, category, account, date range (safe int parsing — no crash on bad params)
- Pagination (30/page)
- Receipt upload (PNG/JPG/WEBP/GIF/PDF, max 10MB)
- **AI Receipt OCR** — drag-drop receipt image → Groq vision extracts amount/date/merchant/category → auto-fills form
- Re-extract from already-uploaded receipt (edit mode)
- **Inline category change** — Category column is a `<select>` dropdown; change fires AJAX `POST /transactions/<id>/set-category` with no page reload
- Export to CSV / Excel
- Edit form: receipt sub-forms are outside `#txnForm` to prevent nested-form bug

### 2.3 Accounts
- Types: checking, savings, cash, credit_card, crypto, investment, other
- Balance source of truth:
  - **Teller-linked accounts**: balance comes from Teller API (live refresh or after sync); `calc_balance` is NOT called on page load for these
  - **Schwab-linked accounts**: balance comes from Schwab snapshot sync; `calc_balance` is NOT called on page load for these
  - **Unlinked accounts**: balance auto-calculated from all transactions via `calc_balance`
- **Teller badge** (blue) shown on account cards linked to Teller
- **Schwab badge** (green) shown on account cards linked to Schwab
- Per-account action buttons for provider-linked accounts:
  - **Teller**: Refresh (live balance AJAX), Sync (transaction preview), Reset (90-day resync)
  - **Schwab**: Balance & Positions (snapshot sync POST), Transactions (preview link)
- Color + icon picker; soft delete
- Credit cards show "Amount Owed" (positive) and "This Month" charges
- Opening balance field on account creation (negative for credit cards = starting debt)

### 2.4 Categories
- Expense + Income categories with color/icon
- System categories (protected from delete)
- Custom categories (user-created)
- 14 expense + 7 income defaults seeded on init

### 2.5 Budget Planner
- Monthly limits per expense category
- Progress bars: green → amber (80%) → red (100%+)
- Rollover unused budget to next month (toggle)
- Copy previous month's budgets in one click
- Unbudgeted spending shown with "Set Budget" prompt

### 2.6 Goals & Savings
- Goals with target amount, target date, color, icon
- Contribution tracking + history
- Progress bar + projected completion date (based on avg monthly contrib)
- Auto-complete on 100%
- Emergency fund tracker (liquid assets vs 3-month / 6-month expense targets)

### 2.7 Investments
- Asset types: stock, ETF, crypto, real_estate, bond, cash, other
- Buy/sell/dividend/split transaction log
- FIFO cost basis auto-recalculated from transaction log
- yfinance price auto-fetch (daily 4PM weekdays via cron)
- Manual price refresh button (portfolio page)
- Live ticker check on add form
- Doughnut allocation chart + per-asset-type breakdown
- P&L per holding + portfolio total
- **"Sync Schwab"** button (topbar POST) — runs snapshot sync for all mapped Schwab accounts, redirects back to investments page
- **Per-account sections** — when investments span multiple accounts (e.g. Individual + Roth IRA), holdings are grouped into one card per account, each showing account name, total value, and holdings table. Allocation sidebar also shows "By Account" breakdown
- `investments.account_id` FK — each Schwab-synced holding is stamped with its source account; same ticker in different accounts (AAPL in Individual vs Roth IRA) stays as separate rows
- Holdings table uses a Jinja2 `{% macro %}` (reused across single and multi-account views)
- **Price history chart** on investment detail page — 1W / 1M / 3M / 6M / 1Y timeframe buttons; fetches from `/investments/api/price-history/<ticker>`

### 2.8 AI Financial Assistant
- Chat UI with SSE streaming (Groq API, word-by-word response)
- Context: last 90 days transactions + budget status + goals + investments
- 8 suggested question buttons
- Daily auto-insight generated at midnight (stored in `ai_insights` table)
- Manual "Generate Now" button
- Chat history page
- Model: `llama-3.3-70b-versatile` (default) or `llama-3.1-8b-instant` (fast)
- Fallback messages for rate limit / invalid key / unavailable

### 2.9 Receipt OCR (Groq Vision)
- Model: `meta-llama/llama-4-scout-17b-16e-instruct`
- Drag-drop or click-to-upload on new expense form
- Extracts: amount, date, merchant name, category suggestion, notes
- Maps category suggestion → system category ID
- Auto-fills form fields with green flash animation
- Re-extract button on existing receipt (edit mode)
- Auto-triggers OCR when image file selected in edit mode
- Handles fenced markdown JSON output from LLM
- Sanity check: rejects amounts < 1000 (catches garbage values)
- Full error handling: 400/401/429/timeout/bad JSON

### 2.10 Reports & Export
- Monthly / Quarterly / Yearly summary reports
- Tax year summary (all income by source, all expenses by category)
- Net worth history line chart (from monthly snapshots)
- Category spending trends (top 6 categories, 6-month line chart)
- "Snapshot Now" manual button
- Export: CSV, Excel (color-coded, formatted), PDF (WeasyPrint)

### 2.11 Settings
- Profile: name, email, timezone, currency, Groq model
- 8 currency options (USD/VND/EUR/GBP/JPY/AUD/CAD/SGD) — auto-updates symbol
- Password change (requires current password)
- **Two-Factor Authentication (TOTP)** — enable/disable TOTP 2FA; setup shows QR code + manual key entry; disable requires password confirmation
- **Audit Log** (`/settings/audit`) — paginated log of login, 2FA, password, and bank-connection events with IP address; filterable by event type
- Recurring rules: CRUD, pause/enable, frequency (daily/weekly/biweekly/monthly/quarterly/yearly)
- "Run Now" button to process due rules immediately
- CSV import: upload → preview with ⚠ warnings → confirm
- Upcoming recurring transactions (30-day view)

### 2.12 USD → VND Exchange Rate
- **Reference widget only** — not used in transaction calculations
- Primary source: yfinance `USDVND=X` (Yahoo Finance forex)
- Fallback: `open.er-api.com` (free, no key)
- Sanity check: rate must be > 1000 (rejects garbage values)
- `force_refresh()` — always fetches fresh on cron, bypasses cache
- DB caches one record per day (`fx_rates` table)
- Dashboard: shows rate, date, source, stale warning, ↻ refresh button
- 30-day history chart (click widget to expand)

### 2.13 Teller Bank Sync
- Connects US bank accounts via Teller API (mTLS + HTTP Basic Auth)
- **Bank Connections page** (`/teller/`) — connect/disconnect only; no sync buttons here
  - Shows: institution name, connected date, last synced, account list with linked PFM account names
  - "Map Account" button for unmapped accounts
- **Accounts page** — all Teller action buttons live here per account card (see §2.3)
- Transaction sync: preview → confirm → import; after import, live balance fetched from Teller API (not recalculated from transactions)
- Duplicate detection using Teller transaction ID (`Teller:<id>` in notes)
- Balance refresh: uses `ledger` field for credit cards (amount owed), `available` for bank accounts
  - Credit card ledger forced negative (our debt convention: `-abs(ledger)`)
- Auto-categorize: keyword match on description (`auto_categorize` from `bank_import_service`) first; Teller category field as fallback
- Income/expense type: positive Teller `amount` = income (credit), negative = expense (debit)
- Webhook: `transactions.processed` event with HMAC-SHA256 signature + 5-min replay protection
- Config: `TELLER_APP_ID`, `TELLER_ENV`, `TELLER_CERT_PATH`, `TELLER_KEY_PATH`, `TELLER_WEBHOOK_SECRET`
- Models: `teller_enrollments`, `teller_accounts` (2 tables)

### 2.14 Schwab Bank Sync
- Connects Schwab brokerage/IRA accounts via Schwab Developer API (OAuth 2.0)
- **OAuth flow**: `GET /schwab/connect` → redirect to Schwab with PKCE state → `GET /schwab/callback` → exchange code → store tokens
  - State parameter included in auth URL (fix for "OAuth state mismatch" error)
  - `SCHWAB_REDIRECT_URI` must match exactly what's registered in Schwab developer portal
- **Account hashes**: Schwab requires `hashValue` (encrypted account number) in all API paths
  - On connect: calls `GET /trader/v1/accounts/accountNumbers` to get `{accountNumber → hashValue}` map
  - `account_hash` stored in DB is always the `hashValue`, never the raw account number
  - On reconnect: existing `SchwabAccount` records updated in-place (by hash, raw number, or masked display) to preserve `pfm_account_id` mapping
- **Account mapping**: each Schwab account → PFM account (or create new); stored in `schwab_accounts`
- **Transaction sync**: preview → confirm → import; uses same duplicate-skipping as other providers
  - After import: live balance fetched from Schwab API (not recalculated from transactions)
- **Balance + position snapshot** (`POST /schwab/snapshot/<id>` or "Balance & Positions" button):
  - Fetches `GET /trader/v1/accounts/{hash}?fields=positions`
  - Updates linked PFM account balance from `currentBalances.liquidationValue`
  - Upserts `Investment` records for each long position, matched on `(ticker, account_id)`
  - Asset type mapping: EQUITY→stock, ETF→etf, MUTUAL_FUND→etf, FIXED_INCOME→bond, CASH_EQUIVALENT→cash, unknown→other
  - Position zero-quantity and empty-symbol positions skipped; `null` positions array guarded
- **Investments sync**: topbar "Sync Schwab" button on investments page → `POST /investments/sync-schwab` → runs snapshot for all mapped accounts (ignores stale `connection_id` — always uses active connection)
- Token auto-refresh: access token expires 30 min; refreshed automatically before API calls
- **Refresh token expiry**: `refresh_token_expires_at` tracked in DB; reset on every successful token exchange; dashboard warns when ≤ 2 days remain
- **Account type map**: CASH→checking, MARGIN/IRA/ROTH_IRA/ROLLOVER_IRA/TRADITIONAL_IRA/401K/ROTH_401K/BROKERAGE→investment; unknown types fall back to `'other'`
- Config: `SCHWAB_CLIENT_ID`, `SCHWAB_CLIENT_SECRET`, `SCHWAB_REDIRECT_URI`
- Models: `schwab_connections`, `schwab_accounts` (2 tables)

### 2.15 Bank Statement Import
- Sidebar link: "Import Statement" under Money section
- Supported formats: PDF, OFX/QFX, Chase/BofA/Citi/Capital One/Discover/Amex/USAA/Wells Fargo CSV, Generic CSV, Custom column mapping
- Auto-categorizes using 200+ keyword rules across 14 categories
- Preview table: per-row checkboxes, editable category dropdowns
- Duplicate detection: OFX FITID (`import:<id>` in notes) or date+amount+description+account
- AJAX-based: no page reloads

### 2.16 System Logs Viewer
- Log file: `logs/app.log` (rotating, 10 MB, 5 backups)
- Format: `YYYY-MM-DD HH:MM:SS|LEVEL|module.name|message`
- Viewer at `/logs/`: colour-coded pills, free-text search, module filter, auto-refresh, clear, download

---

## 3. Database Schema (MySQL)

### All 19 Tables
```
users                   — single user, hashed password, currency/timezone prefs, totp_secret, totp_enabled
accounts                — bank/wallet accounts (balance managed per provider rules)
categories              — expense/income categories with color/icon
transactions            — income/expense/transfer, receipt_id, recurring_rule_id
receipts                — receipt file metadata (filename, size, mime_type)
recurring_rules         — templates: frequency, next_run, start/end date
budgets                 — monthly limits per category, rollover support
goals                   — savings goals with target amount/date
goal_contributions      — individual deposits toward each goal
investments             — holdings: ticker, shares, avg_cost_basis, current_price, account_id
investment_transactions — buy/sell/dividend/split log
net_worth_snapshots     — monthly snapshots: assets, liabilities, net_worth (JSON)
ai_insights             — stored AI responses: daily_summary / chat_response
fx_rates                — daily USD/VND rate cache (date UNIQUE, source)
audit_logs              — security event log: action, description, ip_address, timestamp
teller_enrollments      — Teller enrollment: enrollment_id, access_token (TEXT, encrypted), institution_name
teller_accounts         — Teller account ↔ PFM account mapping, last_sync_date
schwab_connections      — Schwab OAuth tokens (TEXT, encrypted), token_expires_at, refresh_token_expires_at
schwab_accounts         — Schwab account ↔ PFM account mapping, account_hash (hashValue)
```

### Key Column Notes
- `accounts.balance` — set by `calc_balance()` for unlinked accounts; set directly by Teller/Schwab sync for provider-linked accounts; never overwritten on page load for provider accounts
- `investments.account_id` — nullable FK to `accounts.id`; NULL for manually-added holdings, set to PFM account ID for Schwab-synced holdings; enables per-account grouping on portfolio page
- `investments.shares` / `avg_cost_basis` — recalculated from `investment_transactions` (FIFO) for manual holdings; overwritten directly by Schwab snapshot for synced holdings
- `transactions.notes` — used to store import source IDs: `Teller:<id>`, `Schwab:<activityId>`, or `import:<fitid>`
- `schwab_accounts.account_hash` — Schwab `hashValue` (encrypted account number), required in all API paths
- `teller_enrollments.access_token` — stored as `TEXT` (widened from VARCHAR(128)); encrypted at rest via `EncryptedText` TypeDecorator
- `schwab_connections.access_token` / `refresh_token` — `TEXT`, encrypted at rest; `refresh_token_expires_at` reset on every token exchange
- `users.totp_secret` — base32 TOTP secret (VARCHAR 64); NULL when 2FA disabled

### Migration Scripts
```
scripts/add_investment_account.py   — adds investments.account_id column (run once)
scripts/add_security_columns.py     — adds totp columns, audit_logs table, widens token columns to TEXT (run once)
```

---

## 4. Project File Structure (Actual)

```
pfm/                             # /home/pfm/web on server
├── wsgi.py
├── requirements.txt
├── .env                         # Not committed
├── .env.example
├── .gitignore
├── logs/
│   └── app.log
│
├── app/
│   ├── __init__.py              # session idle timeout hook; Sentry init; limiter init
│   ├── config.py                # SENTRY_DSN, SESSION_IDLE_MINUTES, RATELIMIT_STORAGE_URI added
│   ├── extensions.py            # + limiter (flask-limiter, storage via RATELIMIT_STORAGE_URI)
│   │
│   ├── models/
│   │   ├── user.py              # + totp_secret, totp_enabled columns
│   │   ├── account.py
│   │   ├── category.py
│   │   ├── transaction.py
│   │   ├── receipt.py
│   │   ├── recurring_rule.py
│   │   ├── budget.py
│   │   ├── goal.py
│   │   ├── investment.py        # + account_id FK, account relationship
│   │   ├── net_worth_snapshot.py
│   │   ├── ai_insight.py
│   │   ├── fx_rate.py
│   │   ├── audit_log.py         # AuditLog model (action, description, ip_address, timestamp)
│   │   ├── teller_enrollment.py # access_token now EncryptedText (TEXT column)
│   │   └── schwab_connection.py # tokens now EncryptedText; + refresh_token_expires_at
│   │
│   ├── routes/
│   │   ├── auth.py              # + TOTP verify/setup/disable routes; rate limits; audit calls
│   │   ├── dashboard.py         # + savings_rate; Schwab expiry warning
│   │   ├── accounts.py          # teller_map + schwab_map; skip calc_balance for providers
│   │   ├── categories.py
│   │   ├── transactions.py      # + set-category AJAX; fixed income-form-submits-as-expense bug
│   │   ├── budgets.py
│   │   ├── goals.py
│   │   ├── investments.py       # + sync-schwab route; price-history API
│   │   ├── reports.py
│   │   ├── ai.py
│   │   ├── settings.py          # + audit_log route; audit calls on password change
│   │   ├── teller.py            # balance uses ledger/available correctly
│   │   ├── schwab.py            # OAuth, mapping, sync, snapshot; audit calls; fallback type 'other'
│   │   ├── bank_import.py
│   │   └── logs.py
│   │
│   ├── services/
│   │   ├── account_service.py
│   │   ├── ai_service.py
│   │   ├── budget_service.py
│   │   ├── export_service.py
│   │   ├── fx_service.py
│   │   ├── goal_service.py
│   │   ├── import_service.py
│   │   ├── investment_service.py  # get_portfolio_summary returns account_groups
│   │   ├── ocr_service.py
│   │   ├── recurring_service.py
│   │   ├── report_service.py
│   │   ├── teller_service.py      # auto_categorize; correct sign convention; live balance after sync
│   │   ├── schwab_service.py      # + expanded ACCOUNT_TYPE_MAP; refresh_token_expires_at always reset
│   │   └── bank_import_service.py
│   │
│   ├── templates/
│   │   ├── base.html              # mobile responsive tweaks
│   │   ├── auth/totp_setup.html   # QR code + manual key entry for 2FA setup
│   │   ├── auth/totp_verify.html  # 6-digit code entry on login
│   │   ├── dashboard/index.html   # + savings_rate card; Schwab warning banner
│   │   ├── accounts/index.html    # Teller/Schwab badges + action buttons
│   │   ├── transactions/index.html # inline category <select> + AJAX; pagination info
│   │   ├── investments/index.html  # per-account sections; Sync Schwab btn
│   │   ├── investments/detail.html # + price history chart (1W/1M/3M/6M/1Y)
│   │   ├── settings/audit.html    # audit log viewer with event filter
│   │   ├── settings/index.html    # + 2FA section; audit log nav card
│   │   ├── teller/index.html      # connect/disconnect only
│   │   ├── schwab/                # index.html, map_accounts.html, preview.html
│   │   └── ... (other templates unchanged)
│   │
│   └── utils/
│       ├── formatters.py
│       ├── decorators.py
│       ├── audit.py               # audit() helper — writes AuditLog rows; swallows DB errors
│       └── crypto.py              # EncryptedText SQLAlchemy TypeDecorator (Fernet, key=SHA256(SECRET_KEY))
│
├── scripts/
│   ├── init_db.py
│   ├── process_recurring.py
│   ├── fetch_fx_rate.py
│   ├── fetch_prices.py
│   ├── daily_snapshot.py
│   ├── daily_ai_insight.py
│   ├── add_investment_account.py  # adds investments.account_id column
│   ├── add_security_columns.py    # adds TOTP cols, audit_logs table, widens token cols to TEXT
│   └── sync_schwab.py             # daily Schwab auto-sync (balance + positions + transactions)
│
└── tests/
```

---

## 5. Python Dependencies (`requirements.txt`)

```
flask==3.1.0
flask-sqlalchemy==3.1.1
flask-login==0.6.3
flask-migrate==4.1.0
flask-wtf==1.2.2
pymysql==1.1.1
python-dotenv==1.0.1
gunicorn==23.0.0
groq==0.13.1
weasyprint==63.1
openpyxl==3.1.5
Pillow==11.1.0
apscheduler==3.10.4
requests==2.32.3
cryptography==44.0.2
python-dateutil==2.9.0
pdfplumber==0.11.4
# Security
flask-limiter==3.5.0
pyotp==2.9.0
qrcode==7.4.2
# Monitoring
sentry-sdk[flask]==2.7.0
```

---

## 6. AI Integration — Groq API

### Chat + Daily Insights
- Model: `llama-3.3-70b-versatile` (default) / `llama-3.1-8b-instant` (fast)
- Context: last 90 days transactions, budget status, goals, investments (anonymised)
- SSE streaming: `stream_chat()` yields `data: <chunk>\n\n`
- Daily insight: non-streaming, stored in `ai_insights` table, max 400 tokens

### Receipt OCR (Vision)
- Model: `meta-llama/llama-4-scout-17b-16e-instruct`
- Input: base64-encoded image (JPEG/PNG/GIF/WEBP)
- Prompt: structured JSON extraction (amount, date, merchant, category, notes)
- Temperature: 0.1

### Bank Statement PDF Parsing
- Text extracted by `pdfplumber` then sent to `llama-3.3-70b-versatile`
- Max 30 K chars sent per request
- Scanned PDFs rejected with clear error message

### Free Tier Limits
| Metric | Limit |
|--------|-------|
| Requests/day | 14,400 |
| Tokens/minute | 500,000 |
| Cost | Free |

---

## 7. Teller Bank Sync

- mTLS: client cert + key from `TELLER_CERT_PATH` / `TELLER_KEY_PATH`
- HTTP Basic Auth: `access_token` as username, empty password
- Endpoints: `GET /accounts`, `GET /accounts/:id/balances`, `GET /accounts/:id/transactions`
- All API errors logged with status code + full response body
- Webhook: HMAC-SHA256 `Teller-Signature` header; 5-minute replay window
- **Balance convention**: credit cards use `ledger` (amount owed, stored as negative); bank accounts use `available`
- **After transaction sync**: live balance re-fetched from Teller API instead of computing from transactions

---

## 8. Schwab Developer API

- OAuth 2.0: `SCHWAB_AUTH_URL` + `SCHWAB_TOKEN_URL`
- State parameter sent in auth URL (CSRF protection)
- Account identification: `hashValue` from `/trader/v1/accounts/accountNumbers` (NOT raw account number)
- Token refresh: access tokens expire 30 min; auto-refreshed via `_ensure_fresh(connection)`
- Endpoints:
  - `GET /trader/v1/accounts/accountNumbers` → `{accountNumber: hashValue}` map
  - `GET /trader/v1/accounts?fields=positions` → accounts list with balances + positions
  - `GET /trader/v1/accounts/{hash}?fields=positions` → single account
  - `GET /trader/v1/accounts/{hash}/transactions?startDate&endDate` → transactions

---

## 9. Bank Statement Import

- Route: `/bank-import/` (blueprint `bank_import_bp`)
- Parse: `POST /bank-import/parse` (AJAX, multipart with `X-CSRFToken` header)
- Import: `POST /bank-import/import` (AJAX, JSON with `X-CSRFToken` header)
- Duplicate detection: OFX `import:<FITID>` in notes; CSV/PDF: date+amount+type+description scoped to account_id

---

## 10. Account Balance Rules

| Account type | Balance source | When updated |
|---|---|---|
| Unlinked (no provider) | `calc_balance()` from transactions | After every txn add/edit/delete; on accounts page load |
| Teller-linked | Teller API `available` (bank) or `ledger` (credit card) | After Teller sync; when Refresh button clicked |
| Schwab-linked | Schwab API `liquidationValue` | After Schwab sync; when Balance & Positions clicked |

**Key rule**: accounts page load calls `calc_balance` ONLY for accounts NOT in `teller_map` or `schwab_map`. Dashboard does NOT call `calc_balance` (reads stored values).

---

## 11. Logging System

- Config key: `LOG_FILE_PATH` (default: `<project-root>/logs/app.log`)
- Handler: `RotatingFileHandler` — 10 MB per file, 5 backups
- Format: `YYYY-MM-DD HH:MM:SS|LEVEL|module.name|message`
- Namespace: `logging.getLogger('app')` at INFO; `propagate=False`
- Schwab snapshot sync logs: number of positions returned, per-position symbol/type/qty/mapped-type

---

## 12. UI/UX

- **Sidebar**: collapsible (desktop state saved in localStorage), mobile overlay
- **Charts**: Chart.js 4.x (CDN)
- **Forms**: WTForms + Bootstrap 5.3
- **Icons**: Bootstrap Icons 1.11
- **Fonts**: DM Sans + DM Mono (Google Fonts CDN)
- **Color scheme**: `#0f172a` sidebar, `#f1f5f9` body, `#10b981` income, `#ef4444` expense, `#3b82f6` invest
- **CSS**: All inline in templates (no build step)
- **CSRF meta tag**: `<meta name="csrf-token">` in `base.html` for JS fetch calls

---

## 13. Authentication & Security

- Single-user, Flask-Login, session-based
- Hashed password (Werkzeug `generate_password_hash`)
- `SESSION_COOKIE_SECURE=True`, `SESSION_COOKIE_HTTPONLY=True`, `SESSION_COOKIE_SAMESITE='Lax'`
- **Session idle timeout** — configurable via `SESSION_IDLE_MINUTES` (default 60); enforced in `before_request` hook
- **TOTP 2FA** — optional TOTP second factor (pyotp); setup via QR code; verify endpoint rate-limited `10/min; 30/hr`; 5 failed attempts clears pending session and forces re-login
- **Rate limiting** — flask-limiter on login (`10/min; 30/hr`), TOTP verify (`10/min; 30/hr`), TOTP setup (`10/min`); storage backend set via `RATELIMIT_STORAGE_URI` (use Redis in production to share limits across Gunicorn workers; defaults to `memory://` per-process if unset)
- **At-rest encryption** — Teller and Schwab OAuth tokens encrypted in DB via `EncryptedText` SQLAlchemy TypeDecorator (Fernet symmetric, key = SHA-256(SECRET_KEY)); columns are `TEXT` not `VARCHAR`
- **Audit log** — security events written to `audit_logs` table via `app/utils/audit.py`; events: `login_success`, `login_success_2fa`, `login_failed`, `login_failed_2fa`, `totp_enabled`, `totp_disabled`, `password_changed`, `schwab_connected`, `schwab_disconnected`
- CSRF protection on all forms (Flask-WTF); meta tag in base.html for AJAX
- SQLAlchemy ORM (no raw SQL)
- Schwab OAuth state parameter validated on callback (CSRF protection)
- `next` redirect params validated to start with `/` (no open redirect)
- **Sentry** (optional) — error monitoring; enable via `SENTRY_DSN` env var; `send_default_pii=False`

---

## 14. Scheduled Jobs

| Job | Schedule | Script | Notes |
|-----|----------|--------|-------|
| Process recurring transactions | Daily 6AM | `process_recurring.py` | 90-day catchup cap |
| Fetch USD/VND rate | Daily 8AM | `fetch_fx_rate.py` | force_refresh(), yfinance primary |
| Fetch investment prices | Mon-Fri 4PM | `fetch_prices.py` | yfinance, all tickers |
| Net worth snapshot | 1st of month 00:05 | `daily_snapshot.py` | Saves to net_worth_snapshots |
| AI daily insight | Daily 00:01 | `daily_ai_insight.py` | Skips if already done today |
| Schwab auto-sync | Daily 7AM | `sync_schwab.py` | Balance + positions + transactions; warns if refresh token expires soon |
| DB backup | Daily 2AM | pfm-backup (systemd) | mysqldump → gzip, keep 30 days |

---

## 15. Environment Variables (`.env`)

```
SECRET_KEY=your-secret-key
DATABASE_URL=mysql+pymysql://pfm_user:password@localhost/pfm_db
GROQ_API_KEY=your-groq-api-key-here
GROQ_MODEL=llama-3.3-70b-versatile
UPLOAD_FOLDER=/home/pfm/web/uploads
MAX_CONTENT_LENGTH=10485760
FLASK_ENV=production
FLASK_APP=wsgi:app
APP_CURRENCY=USD
APP_CURRENCY_SYMBOL=$
APP_TIMEZONE=Asia/Ho_Chi_Minh
LOG_FILE_PATH=/home/pfm/web/logs/app.log
# Teller
TELLER_APP_ID=your-teller-app-id
TELLER_ENV=development
TELLER_CERT_PATH=/home/pfm/teller/certificate.pem
TELLER_KEY_PATH=/home/pfm/teller/private_key.pem
TELLER_WEBHOOK_SECRET=your-webhook-secret
# Schwab
SCHWAB_CLIENT_ID=your-schwab-client-id
SCHWAB_CLIENT_SECRET=your-schwab-client-secret
SCHWAB_REDIRECT_URI=https://pfm.ngodanguyen.tech/schwab/callback
# Security (optional)
SENTRY_DSN=                          # leave blank to disable Sentry
SESSION_IDLE_MINUTES=60              # session idle timeout in minutes
RATELIMIT_STORAGE_URI=redis://localhost:6379  # use Redis to share rate limits across Gunicorn workers
```

---

## 16. Blueprints Registered (15 total)

| Blueprint | Prefix | Key routes |
|-----------|--------|------------|
| auth | /auth | login, logout, totp/verify, totp/setup, totp/disable |
| dashboard | / | index, api/fx-history, api/fx-refresh |
| accounts | /accounts | CRUD, adjust |
| categories | /categories | CRUD |
| transactions | /transactions | index, new, edit, delete, transfer, ocr, ocr-file, `<id>/set-category` |
| budgets | /budgets | index, new, edit, delete, copy |
| goals | /goals | index, new, edit, delete, contribute, contributions |
| investments | /investments | index, new, detail, edit, delete, add_transaction, refresh-prices, sync-schwab, api/price, api/daychange, api/price-history |
| reports | /reports | monthly, quarterly, yearly, tax, export/csv\|excel\|pdf, snapshot |
| ai | /ai | index, stream (SSE), history, generate-insight |
| settings | /settings | index, profile, password, audit, recurring, import, recalc-balances, upload_receipt, delete_receipt, view_receipt |
| teller | /teller | callback, map, index, sync, sync/confirm, sync/all, balance, balance/all, resync, disconnect, webhook |
| schwab | /schwab | connect, callback, index, map, sync/`<id>`, sync/confirm, resync, snapshot/`<id>`, disconnect |
| bank_import | /bank-import | index, parse (AJAX), import (AJAX) |
| logs | /logs | index, api (AJAX), clear (AJAX), download |

---

## 17. Known Issues / Notes

- `wsgi.py` has `sys.path.insert(0, ...)` — required for Gunicorn at `/home/pfm/web/`
- FX rate widget: `open.er-api.com` may return stale values; yfinance is the reliable primary
- WeasyPrint PDF: requires `libpango*` system libs on server
- Bank statement PDF import: scanned/image PDFs have no text layer; must use digital download
- Schwab: run `scripts/add_investment_account.py` then `scripts/add_security_columns.py` once after fresh deploy
- Schwab: after first connect, run "Balance & Positions" to populate investments; then re-sync if holdings were already added manually
- Schwab refresh token: Schwab tokens last ~7 days; `refresh_token_expires_at` is reset on every token exchange (including access-only refreshes); dashboard warns at ≤ 2 days
- Teller: `access_token` column is `TEXT` (widened from VARCHAR(128) to fit Fernet-encrypted values); run `scripts/add_security_columns.py` to apply
- Teller: development environment only; requires cert/key from Teller Dashboard
- Rate limiter: defaults to `memory://` per-process if `RATELIMIT_STORAGE_URI` is not set — effective limit is `stated_limit × num_workers`; set `RATELIMIT_STORAGE_URI=redis://localhost:6379` in production
- `EncryptedText` TypeDecorator: key = SHA-256(SECRET_KEY); changing SECRET_KEY invalidates all stored tokens (requires reconnect)
- MySQL does not support `NULLS LAST`; use `func.isnull(column)` for null-last ordering

---

## 18. Security Fixes Applied (session log)

| Date | Fix | File |
|------|-----|------|
| 2026-06 | Path traversal in `view_receipt` — added `os.path.basename()` | settings.py |
| 2026-06 | `int()` crash on bad filter params in transactions index | transactions.py |
| 2026-06 | Teller account mapping validates ID exists in DB | teller.py |
| 2026-06 | Recurring catchup capped at 90 days (prevents runaway loops) | recurring_service.py |
| 2026-06 | CSV/bank import duplicate check scoped by `account_id` | import_service.py |
| 2026-06 | CSRF token added to bank import AJAX parse request | bank_import/index.html |
| 2026-06 | Receipt sub-forms moved outside `#txnForm` (nested-form bug) | transactions/form.html |
| 2026-06 | Drop zone file input moved outside overlay (blocked account select) | bank_import/index.html |
| 2026-06 | Teller balance refresh uses `ledger` for credit cards (not `available`) | teller.py |
| 2026-06 | Schwab OAuth `state` param added to auth URL (state mismatch fix) | schwab_service.py |
| 2026-06 | Schwab uses `hashValue` (not raw account number) in API paths | schwab.py, schwab_service.py |
| 2026-06 | `next` redirect params validated to start with `/` (no open redirect) | teller.py, schwab.py |
| 2026-06 | Teller income/expense type corrected (positive = income) | teller_service.py |
| 2026-06 | `EncryptedText.process_bind_param` removed silent plaintext fallback — raises on encrypt failure | crypto.py |
| 2026-06 | Rate limiter storage moved to `RATELIMIT_STORAGE_URI` config (was hardcoded `memory://` per-worker) | extensions.py, config.py |
| 2026-06 | TOTP verify: added hourly rate limit (`30/hr`) + per-session attempt counter (locks out after 5 failures) | auth.py |
| 2026-06 | TOTP setup endpoint: added `@limiter.limit('10 per minute')` | auth.py |
| 2026-06 | `refresh_token_expires_at` now reset on every token exchange, not only when Schwab rotates the token | schwab_service.py |
| 2026-06 | Schwab unknown account type fallback changed back to `'other'` (was incorrectly changed to `'investment'`) | schwab.py |
| 2026-06 | `teller_enrollments.access_token` widened VARCHAR(128) → TEXT to fit Fernet-encrypted values | add_security_columns.py |
| 2026-06 | New income transaction submitted as expense — `form.transaction_type.data` not set on GET | transactions.py |

---

## 19. To-Do / Roadmap

### High priority
- [ ] **Mobile responsiveness pass** — sidebar auto-collapses on mobile; tables scroll horizontally *(base.html mobile CSS improved; further work needed)*
- [ ] **Budget alerts** — email/Twilio SMS when category spending hits 80% / 100%

### Medium priority
- [ ] **PDF export memory** — stream CSV/Excel exports for users with large transaction history
- [ ] **Receipt MIME validation** — validate file magic bytes server-side, not just extension
- [ ] **OCR ownership check** — verify re-extracted filename belongs to current user's transaction
- [ ] **Bank import progress** — show per-row import progress for large statement files

### Low priority / future
- [ ] iOS companion app
- [ ] Shared household mode (2 users, row-level isolation)
- [ ] Bank statement PDF: table-extraction fallback (pdfplumber tables API) before Groq call
- [ ] Dark mode toggle

### Completed (removed from backlog)
- [x] **Pagination info** — "Page X of Y" added to transactions, AI history, accounts/payments, audit log
- [x] **Schwab IRA account type** — IRA/ROTH_IRA/401K/BROKERAGE types added to ACCOUNT_TYPE_MAP
- [x] **Investment price history chart** — 1W/1M/3M/6M/1Y chart on investment detail page
- [x] **Schwab auto-sync on schedule** — `scripts/sync_schwab.py` (cron at 7AM daily)