diff --git a/routes/tracker.js b/routes/tracker.js
index 2879c0e..36231a7 100644
--- a/routes/tracker.js
+++ b/routes/tracker.js
@@ -1,6 +1,6 @@
 const express = require('express');
 const router = express.Router();
-const { getTracker, getUpcomingBills, getOverdueCount } = require('../services/trackerService');
+const { getTracker, getUpcomingBills, getOverdueCount } = require('../services/trackerService.cts');
 const { standardizeError } = require('../middleware/errorFormatter');
 
 // GET /api/tracker/overdue-count — lightweight count for sidebar badge
diff --git a/services/trackerService.js b/services/trackerService.cts
similarity index 76%
rename from services/trackerService.js
rename to services/trackerService.cts
index 34036ec..1c786f9 100644
--- a/services/trackerService.js
+++ b/services/trackerService.cts
@@ -1,5 +1,7 @@
 'use strict';
 
+import type { Db } from '../types/db';
+
 const { getDb } = require('../db/database');
 const { buildTrackerRow, getCycleRange, resolveDueDate, isPaidStatus } = require('./statusService.cts');
 const { getUserSettings } = require('./userSettings.cts');
@@ -8,22 +10,24 @@ const { computeAmountSuggestionsBatch } = require('./amountSuggestionService.cts
 const { accountingActiveSql } = require('./paymentAccountingService.cts');
 const { normalizeMerchant } = require('./subscriptionService');
 const { localDateString } = require('../utils/dates.mts');
+// Aggregation-heavy: money results flow through many .filter/.sort/arith, so a
+// plain require (→ any) avoids Dollars|null friction (cf. analyticsService).
 const { sumMoney, roundMoney, fromCents } = require('../utils/money.mts');
 
+type Row = Record<string, any>;
+
 const DEFAULT_PENDING_DAYS = 3;
 
 // Word-boundary match — same semantics as billMerchantRuleService.merchantMatches.
-function txMerchantMatches(txNorm, ruleMerchant) {
+function txMerchantMatches(txNorm: any, ruleMerchant: any): boolean {
   if (!txNorm || !ruleMerchant) return false;
   if (txNorm === ruleMerchant) return true;
-  const esc = s => s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
-  const wb = s => new RegExp(`(^|\\s)${esc(s)}(\\s|$)`);
+  const esc = (s: string) => s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+  const wb = (s: string) => new RegExp(`(^|\\s)${esc(s)}(\\s|$)`);
   return wb(ruleMerchant).test(txNorm) || wb(txNorm).test(ruleMerchant);
 }
 
-// For bills that have merchant rules, count how many of that user's pending bank
-// transactions match each bill. Only bills with at least one rule are checked.
-function fetchBankPendingCounts(db, userId, billIds) {
+function fetchBankPendingCounts(db: Db, userId: number, billIds: any[]): Record<string, number> {
   if (billIds.length === 0) return {};
   const ph = billIds.map(() => '?').join(',');
   const rules = db.prepare(`
@@ -45,18 +49,18 @@ function fetchBankPendingCounts(db, userId, billIds) {
   `).all(userId);
   if (pendingTxs.length === 0) return {};
 
-  const rulesByBill = {};
+  const rulesByBill: Record<string, string[]> = {};
   for (const rule of rules) {
     if (!rulesByBill[rule.bill_id]) rulesByBill[rule.bill_id] = [];
     rulesByBill[rule.bill_id].push(rule.merchant);
   }
 
-  const counts = {};
+  const counts: Record<string, number> = {};
   for (const tx of pendingTxs) {
     const txNorm = normalizeMerchant(tx.payee || tx.description || tx.memo || '');
     if (!txNorm) continue;
     for (const [billId, merchants] of Object.entries(rulesByBill)) {
-      if (merchants.some(m => txMerchantMatches(txNorm, m))) {
+      if (merchants.some((m: string) => txMerchantMatches(txNorm, m))) {
         counts[billId] = (counts[billId] || 0) + 1;
       }
     }
@@ -64,11 +68,7 @@ function fetchBankPendingCounts(db, userId, billIds) {
   return counts;
 }
 
-// `gatedUnpaidThisMonth` (dollars) is the occurrence-gated unpaid total the
-// caller already computed from the tracker rows (which honor resolveDueDate).
-// When provided we use it instead of the ungated SQL below, so annual/quarterly/
-// off-month bills don't inflate `unpaid_this_month` → the bank `remaining`.
-function buildBankTracking(db, userId, year, month, gatedUnpaidThisMonth = null) {
+function buildBankTracking(db: Db, userId: number, year: number, month: number, gatedUnpaidThisMonth: any = null): any {
   try {
   const settings = getUserSettings(userId);
   if (settings.bank_tracking_enabled !== 'true') return { enabled: false };
@@ -85,9 +85,6 @@ function buildBankTracking(db, userId, year, month, gatedUnpaidThisMonth = null)
   const pendingDays = parseInt(settings.bank_tracking_pending_days, 10);
   const days = Number.isInteger(pendingDays) && pendingDays >= 0 ? pendingDays : DEFAULT_PENDING_DAYS;
 
-  // Only count manually-entered payments as pending — bank-synced payments
-  // (provider_sync) are already reflected in the live bank balance, so
-  // including them would double-deduct.
   const pendingRow = days > 0
     ? db.prepare(`
         SELECT COALESCE(SUM(p.amount), 0) AS pending_total
@@ -100,9 +97,6 @@ function buildBankTracking(db, userId, year, month, gatedUnpaidThisMonth = null)
       `).get(userId, days)
     : { pending_total: 0 };
 
-  // Fallback (only when the caller didn't pass a gated total, e.g. a direct
-  // call): the ungated SQL sum. This overcounts off-month bills — prefer the
-  // gated total from getTracker's rows.
   let unpaid;
   if (gatedUnpaidThisMonth != null) {
     unpaid = roundMoney(gatedUnpaidThisMonth);
@@ -145,13 +139,13 @@ function buildBankTracking(db, userId, year, month, gatedUnpaidThisMonth = null)
     remaining:         roundMoney(effective - unpaid),
     last_updated:      account.updated_at,
   };
-  } catch (err) {
+  } catch (err: any) {
     console.error('[buildBankTracking] Error computing bank tracking data:', err.message);
     return { enabled: false };
   }
 }
 
-function validateTrackerMonth(query = {}, now = new Date()) {
+function validateTrackerMonth(query: any = {}, now: Date = new Date()): any {
   const year = parseInt(query.year || now.getFullYear(), 10);
   const month = parseInt(query.month || now.getMonth() + 1, 10);
 
@@ -164,14 +158,14 @@ function validateTrackerMonth(query = {}, now = new Date()) {
   return { year, month };
 }
 
-function previousMonthFor(year, month) {
+function previousMonthFor(year: number, month: number) {
   return {
     year: month === 1 ? year - 1 : year,
     month: month === 1 ? 12 : month - 1,
   };
 }
 
-function monthOffset(year, month, offset) {
+function monthOffset(year: number, month: number, offset: number) {
   let y = year;
   let m = month + offset;
   while (m <= 0) { m += 12; y -= 1; }
@@ -179,12 +173,12 @@ function monthOffset(year, month, offset) {
   return { year: y, month: m };
 }
 
-const FETCH_BILLS_ORDER = {
+const FETCH_BILLS_ORDER: Record<string, string> = {
   due_day: 'CASE WHEN b.sort_order IS NULL THEN 1 ELSE 0 END, b.sort_order ASC, b.due_day ASC, b.name ASC',
   id:      'b.id ASC',
 };
 
-function fetchActiveBills(db, userId, orderKey = 'due_day') {
+function fetchActiveBills(db: Db, userId: number, orderKey = 'due_day'): any[] {
   const orderBy = FETCH_BILLS_ORDER[orderKey] ?? FETCH_BILLS_ORDER.due_day;
   return db.prepare(`
     SELECT b.*, c.name AS category_name,
@@ -199,7 +193,7 @@ function fetchActiveBills(db, userId, orderKey = 'due_day') {
   `).all(userId);
 }
 
-function fetchMonthlyStates(db, billIds, year, month) {
+function fetchMonthlyStates(db: Db, billIds: any[], year: number, month: number): Record<string, any> {
   if (billIds.length === 0) return {};
   const placeholders = billIds.map(() => '?').join(',');
   const rows = db.prepare(`
@@ -207,10 +201,10 @@ function fetchMonthlyStates(db, billIds, year, month) {
     FROM monthly_bill_state
     WHERE bill_id IN (${placeholders}) AND year = ? AND month = ?
   `).all(...billIds, year, month);
-  return Object.fromEntries(rows.map(row => [row.bill_id, row]));
+  return Object.fromEntries(rows.map((row: Row) => [row.bill_id, row]));
 }
 
-function fetchPaymentsForBillCycle(db, bill, year, month) {
+function fetchPaymentsForBillCycle(db: Db, bill: Row, year: number, month: number): any[] {
   const range = getCycleRange(year, month, bill);
   if (!range) return [];
   return db.prepare(`
@@ -223,14 +217,10 @@ function fetchPaymentsForBillCycle(db, bill, year, month) {
   `).all(bill.id, range.start, range.end);
 }
 
-// Batched form of fetchPaymentsForBillCycle: one query for every bill's cycle
-// payments (grouped in JS by each bill's own range) instead of one query per
-// bill. Returns Map<billId, payments[]> with each list still ordered paid_date
-// DESC — identical to calling fetchPaymentsForBillCycle per bill.
-function fetchPaymentsForBillsInMonth(db, bills, year, month) {
-  const ranges = new Map(); // billId → { start, end } (only bills due this month)
-  let minStart = null;
-  let maxEnd = null;
+function fetchPaymentsForBillsInMonth(db: Db, bills: any[], year: number, month: number): Map<any, any> {
+  const ranges = new Map<any, any>(); // billId → { start, end } (only bills due this month)
+  let minStart: any = null;
+  let maxEnd: any = null;
   for (const bill of bills) {
     const range = getCycleRange(year, month, bill);
     if (!range) continue;
@@ -239,7 +229,7 @@ function fetchPaymentsForBillsInMonth(db, bills, year, month) {
     if (maxEnd === null || range.end > maxEnd) maxEnd = range.end;
   }
 
-  const byBill = new Map();
+  const byBill = new Map<any, any>();
   if (minStart === null) return byBill;
 
   const ids = [...ranges.keys()];
@@ -263,7 +253,7 @@ function fetchPaymentsForBillsInMonth(db, bills, year, month) {
   return byBill;
 }
 
-function fetchPreviousMonthPaid(db, billIds, range) {
+function fetchPreviousMonthPaid(db: Db, billIds: any[], range: any): Record<string, any> {
   if (billIds.length === 0) return {};
   const placeholders = billIds.map(() => '?').join(',');
   const rows = db.prepare(`
@@ -274,20 +264,20 @@ function fetchPreviousMonthPaid(db, billIds, range) {
       AND ${accountingActiveSql()}
     GROUP BY bill_id
   `).all(...billIds, range.start, range.end);
-  return Object.fromEntries(rows.map(row => [row.bill_id, row.total_paid]));
+  return Object.fromEntries(rows.map((row: Row) => [row.bill_id, row.total_paid]));
 }
 
-function fetchDismissedSuggestions(db, userId, billIds, year, month) {
+function fetchDismissedSuggestions(db: Db, userId: number, billIds: any[], year: number, month: number): Set<any> {
   if (billIds.length === 0) return new Set();
   const rows = db.prepare(`
     SELECT bill_id
     FROM autopay_suggestion_dismissals
     WHERE user_id = ? AND year = ? AND month = ?
   `).all(userId, year, month);
-  return new Set(rows.map(row => row.bill_id));
+  return new Set(rows.map((row: Row) => row.bill_id));
 }
 
-function fetchSparklines(db, billIds) {
+function fetchSparklines(db: Db, billIds: any[]): Record<string, any> {
   if (billIds.length === 0) return {};
   const ph = billIds.map(() => '?').join(',');
   const rows = db.prepare(`
@@ -299,7 +289,7 @@ function fetchSparklines(db, billIds) {
     GROUP BY bill_id, month_str
     ORDER BY bill_id, month_str
   `).all(...billIds);
-  const out = {};
+  const out: Record<string, any> = {};
   for (const r of rows) {
     if (!out[r.bill_id]) out[r.bill_id] = [];
     out[r.bill_id].push(fromCents(r.total));
@@ -307,7 +297,7 @@ function fetchSparklines(db, billIds) {
   return out;
 }
 
-function fetchAutopayStats(db, billIds) {
+function fetchAutopayStats(db: Db, billIds: any[]): Record<string, any> {
   if (billIds.length === 0) return {};
   const ph = billIds.map(() => '?').join(',');
   const rows = db.prepare(`
@@ -325,7 +315,7 @@ function fetchAutopayStats(db, billIds) {
       AND p.paid_date >= date('now', '-12 months')
     GROUP BY p.bill_id
   `).all(...billIds);
-  return Object.fromEntries(rows.map(r => [r.bill_id, {
+  return Object.fromEntries(rows.map((r: Row) => [r.bill_id, {
     total: r.total,
     failures: r.failures || 0,
     last_failure_date: r.last_failure_date || null,
@@ -333,65 +323,53 @@ function fetchAutopayStats(db, billIds) {
   }]));
 }
 
-function rowDueAmount(row) {
+function rowDueAmount(row: Row): number {
   const amount = Number(row.actual_amount ?? row.expected_amount);
   return Number.isFinite(amount) ? amount : 0;
 }
 
-function rowPaidTowardDue(row) {
+function rowPaidTowardDue(row: Row): number {
   const cappedPaid = Number(row.paid_toward_due);
   if (Number.isFinite(cappedPaid)) return cappedPaid;
   return Math.min(Number(row.total_paid) || 0, rowDueAmount(row));
 }
 
-function rowOutstanding(row) {
+function rowOutstanding(row: Row): number {
   return Math.max(Number(row.balance) || 0, 0);
 }
 
 /**
- * Safe-to-spend projection for the current 1st/15th pay period.
- *
- * Pure function (no DB) so it is unit-testable: takes serialized tracker rows
- * (dollar-denominated, post buildTrackerRow) plus the cash available for the
- * period, and answers: "after every bill still due before the next payday is
- * covered — including overdue carry-over — what is left to spend?"
- *
- * The next payday is the next bucket boundary (the 15th, or the 1st of the
- * following month), matching the app's semi-monthly bucket model.
+ * Safe-to-spend projection for the current 1st/15th pay period. Pure (no DB).
  */
-function buildSafeToSpend({ activeRows, available, todayStr, year, month, dayOfMonth }) {
+function buildSafeToSpend({ activeRows, available, todayStr, year, month, dayOfMonth }: { activeRows: any[]; available: any; todayStr: string; year: number; month: number; dayOfMonth: number }): any {
   const nextPayday = dayOfMonth < 15
     ? `${year}-${String(month).padStart(2, '0')}-15`
     : (month === 12 ? `${year + 1}-01-01` : `${year}-${String(month + 1).padStart(2, '0')}-01`);
 
-  // Both strings are YYYY-MM-DD → Date.parse treats them as UTC midnight,
-  // so the difference is an exact whole number of days.
   const daysUntilPayday = Math.max(0, Math.round((Date.parse(nextPayday) - Date.parse(todayStr)) / 86400000));
 
   const stillDueRows = activeRows
-    .filter(r => !isPaidStatus(r.status))
-    .filter(r => rowOutstanding(r) > 0)
-    .filter(r => r.due_date < nextPayday)
-    .sort((a, b) => a.due_date.localeCompare(b.due_date) || String(a.name).localeCompare(String(b.name)));
+    .filter((r: Row) => !isPaidStatus(r.status))
+    .filter((r: Row) => rowOutstanding(r) > 0)
+    .filter((r: Row) => r.due_date < nextPayday)
+    .sort((a: Row, b: Row) => a.due_date.localeCompare(b.due_date) || String(a.name).localeCompare(String(b.name)));
 
   const stillDueTotal = sumMoney(stillDueRows, rowOutstanding);
   const safeToSpend = roundMoney(available - stillDueTotal);
 
-  // Daily projection from today to payday: balance steps down as bills hit.
-  // Overdue bills land on "today" — they need to be paid now, not in the past.
-  const byDate = new Map();
+  const byDate = new Map<any, any>();
   for (const r of stillDueRows) {
     const date = r.due_date > todayStr ? r.due_date : todayStr;
     if (!byDate.has(date)) byDate.set(date, []);
     byDate.get(date).push({ id: r.id, name: r.name, amount: rowOutstanding(r) });
   }
 
-  const timeline = [];
+  const timeline: any[] = [];
   let running = roundMoney(available);
   if (!byDate.has(todayStr)) timeline.push({ date: todayStr, balance: running, bills: [] });
   for (const date of [...byDate.keys()].sort()) {
     const bills = byDate.get(date);
-    running = roundMoney(running - sumMoney(bills, b => b.amount));
+    running = roundMoney(running - sumMoney(bills, (b: Row) => b.amount));
     timeline.push({ date, balance: running, bills });
   }
   if (timeline.length === 0 || timeline[timeline.length - 1].date !== nextPayday) {
@@ -405,7 +383,7 @@ function buildSafeToSpend({ activeRows, available, todayStr, year, month, dayOfM
     safe_to_spend: safeToSpend,
     still_due_total: stillDueTotal,
     still_due_count: stillDueRows.length,
-    upcoming: stillDueRows.slice(0, 8).map(r => ({
+    upcoming: stillDueRows.slice(0, 8).map((r: Row) => ({
       id: r.id,
       name: r.name,
       due_date: r.due_date,
@@ -416,7 +394,7 @@ function buildSafeToSpend({ activeRows, available, todayStr, year, month, dayOfM
   };
 }
 
-function applyAutopaySuggestions(db, bill, payments, mbs, year, month, todayStr, dismissedSuggestions) {
+function applyAutopaySuggestions(db: Db, bill: Row, payments: any[], mbs: any, year: number, month: number, todayStr: string, dismissedSuggestions: Set<any>): any {
   const dueDate = resolveDueDate(bill, year, month);
   if (!dueDate) return null;
 
@@ -452,9 +430,6 @@ function applyAutopaySuggestions(db, bill, payments, mbs, year, month, todayStr,
     }
 
     const balCalc = computeBalanceDelta(bill, suggestedAmount);
-    // Atomic: the auto-mark payment INSERT and its balance update must both land
-    // or neither. This runs on a GET /tracker, so a mid-way failure would
-    // otherwise leave a payment without its balance adjustment (or vice versa).
     const insertAutoPayment = db.transaction(() => {
       const r = db.prepare(`
         INSERT INTO payments (bill_id, amount, paid_date, method, notes, balance_delta, interest_delta, payment_source)
@@ -492,7 +467,7 @@ function applyAutopaySuggestions(db, bill, payments, mbs, year, month, todayStr,
   };
 }
 
-function buildThreeMonthTrend(db, userId, year, month, end, currentMonthPaid) {
+function buildThreeMonthTrend(db: Db, userId: number, year: number, month: number, end: any, currentMonthPaid: any): any {
   const threeMonthsAgo = monthOffset(year, month, -2);
   const threeMonthStart = getCycleRange(threeMonthsAgo.year, threeMonthsAgo.month).start;
   const rows = db.prepare(`
@@ -505,12 +480,12 @@ function buildThreeMonthTrend(db, userId, year, month, end, currentMonthPaid) {
     GROUP BY strftime('%Y-%m', p.paid_date)
   `).all(userId, threeMonthStart, end);
 
-  const monthlyPaymentsMap = new Map();
-  rows.forEach(payment => {
+  const monthlyPaymentsMap = new Map<any, any>();
+  rows.forEach((payment: Row) => {
     monthlyPaymentsMap.set(payment.month_key, payment.total_paid);
   });
 
-  const months = [];
+  const months: any[] = [];
   for (let i = 2; i >= 0; i--) {
     const date = new Date(year, month - 1 - i);
     const monthKey = `${date.getFullYear()}-${String(date.getMonth() + 1).padStart(2, '0')}`;
@@ -522,7 +497,7 @@ function buildThreeMonthTrend(db, userId, year, month, end, currentMonthPaid) {
     });
   }
 
-  const threeMonthAvg = sumMoney(months, m => m.payment) / 3;
+  const threeMonthAvg = sumMoney(months, (m: Row) => m.payment) / 3;
   let percentChange = 0;
   let direction = 'flat';
   if (threeMonthAvg > 0) {
@@ -539,11 +514,11 @@ function buildThreeMonthTrend(db, userId, year, month, end, currentMonthPaid) {
   };
 }
 
-function getTracker(userId, query = {}, now = new Date()) {
+function getTracker(userId: number, query: any = {}, now: Date = new Date()): any {
   const parsed = validateTrackerMonth(query, now);
   if (parsed.error) return parsed;
 
-  const db = getDb();
+  const db: Db = getDb();
   const { year, month } = parsed;
   const todayStr = localDateString(now);
   const userSettings = getUserSettings(userId);
@@ -553,18 +528,16 @@ function getTracker(userId, query = {}, now = new Date()) {
   const prevMonthRange = getCycleRange(previousMonth.year, previousMonth.month);
 
   const bills = fetchActiveBills(db, userId);
-  const billIds = bills.map(bill => bill.id);
+  const billIds = bills.map((bill: Row) => bill.id);
   const monthlyStates = fetchMonthlyStates(db, billIds, year, month);
   const prevMonthPayments = fetchPreviousMonthPaid(db, billIds, prevMonthRange);
   const dismissedSuggestions = fetchDismissedSuggestions(db, userId, billIds, year, month);
   const sparklines = fetchSparklines(db, billIds);
   const autopayStatsMap = fetchAutopayStats(db, billIds);
-  // Batched to avoid an N+1 across bills (was ~2–3 queries × N bills every load):
-  // one query for all cycle payments, two for all amount suggestions.
   const paymentsByBill = fetchPaymentsForBillsInMonth(db, bills, year, month);
   const amountSuggestions = computeAmountSuggestionsBatch(db, billIds, year, month);
 
-  const rows = bills.map(bill => {
+  const rows = bills.map((bill: Row) => {
     bill.sparkline = sparklines[bill.id] ?? null;
     bill.autopay_stats = autopayStatsMap[bill.id] ?? null;
     if (!resolveDueDate(bill, year, month)) return null;
@@ -572,14 +545,7 @@ function getTracker(userId, query = {}, now = new Date()) {
     const payments = paymentsByBill.get(bill.id) || [];
     const mbs = monthlyStates[bill.id];
     const autopaySuggestion = applyAutopaySuggestions(
-      db,
-      bill,
-      payments,
-      mbs,
-      year,
-      month,
-      todayStr,
-      dismissedSuggestions,
+      db, bill, payments, mbs, year, month, todayStr, dismissedSuggestions,
     );
 
     const billForStatus = mbs?.actual_amount != null
@@ -599,7 +565,7 @@ function getTracker(userId, query = {}, now = new Date()) {
     return row;
   }).filter(Boolean);
 
-  const activeRows = rows.filter(r => !r.is_skipped);
+  const activeRows = rows.filter((r: Row) => !r.is_skipped);
   const startingAmounts = db.prepare(`
     SELECT COALESCE(first_amount, 0) AS first_amount,
            COALESCE(fifteenth_amount, 0) AS fifteenth_amount,
@@ -618,7 +584,7 @@ function getTracker(userId, query = {}, now = new Date()) {
 
   const dayOfMonth = now.getDate();
   const activeRemainingPeriod = dayOfMonth < 15 ? '1st' : '15th';
-  const periodRows = activeRows.filter(r => r.bucket === activeRemainingPeriod);
+  const periodRows = activeRows.filter((r: Row) => r.bucket === activeRemainingPeriod);
   const periodPaidTowardDue = sumMoney(periodRows, rowPaidTowardDue);
   const periodOutstandingBalance = sumMoney(periodRows, rowOutstanding);
   const periodStartingAmount = activeRemainingPeriod === '1st'
@@ -626,11 +592,7 @@ function getTracker(userId, query = {}, now = new Date()) {
     : (startingAmounts?.fifteenth_amount || 0);
   const periodLabel = activeRemainingPeriod === '1st' ? '1st balance' : '15th balance';
 
-  // Occurrence-gated unpaid total for this month: the still-owed amount across
-  // bills actually due this month (activeRows already honor resolveDueDate),
-  // netting partial payments. Feeds the bank card so its unpaid/remaining agree
-  // with the rows instead of over-counting annual/off-month bills.
-  const activeMonthUnpaid = sumMoney(activeRows, r => Math.max(rowDueAmount(r) - rowPaidTowardDue(r), 0));
+  const activeMonthUnpaid = sumMoney(activeRows, (r: Row) => Math.max(rowDueAmount(r) - rowPaidTowardDue(r), 0));
   const bankTracking = buildBankTracking(db, userId, year, month, activeMonthUnpaid);
   const bankPendingCounts = bankTracking.enabled ? fetchBankPendingCounts(db, userId, billIds) : {};
   const totalStarting = bankTracking.enabled
@@ -638,47 +600,34 @@ function getTracker(userId, query = {}, now = new Date()) {
     : (startingAmounts?.combined_amount || 0);
   const hasStartingAmounts = bankTracking.enabled || !!startingAmounts;
 
-  // ── Cash flow projection ───────────────────────────────────────────────────
-  // "Projected" means starting minus ALL bills due — paid or not.
-  // This tells the user what they'll have left after everything clears,
-  // not just what remains after what they've already paid.
   const lastDayOfMonth = new Date(year, month, 0).getDate();
   const periodEndDay   = activeRemainingPeriod === '1st' ? 14 : lastDayOfMonth;
   const periodEndLabel = `${['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'][month - 1]} ${periodEndDay}`;
 
-  const activeTotalPaid = sumMoney(activeRows, r => r.total_paid);
+  const activeTotalPaid = sumMoney(activeRows, (r: Row) => r.total_paid);
   const activePaidTowardDue = sumMoney(activeRows, rowPaidTowardDue);
   const activeTotalExpected = sumMoney(activeRows, rowDueAmount);
   const activeOutstandingBalance = sumMoney(activeRows, rowOutstanding);
 
   const periodBillsTotal   = sumMoney(periodRows, rowDueAmount);
-  const periodPaidCount    = periodRows.filter(r => isPaidStatus(r.status)).length;
+  const periodPaidCount    = periodRows.filter((r: Row) => isPaidStatus(r.status)).length;
   const periodTotalCount   = periodRows.length;
 
-  // When bank tracking is on use the effective balance as the period starting point
   const periodCashStart = bankTracking.enabled
     ? bankTracking.effective_balance
     : periodStartingAmount;
   const periodProjected = roundMoney(periodCashStart - periodBillsTotal);
 
   const monthBillsTotal  = activeTotalExpected;
-  const monthPaidCount   = activeRows.filter(r => isPaidStatus(r.status)).length;
+  const monthPaidCount   = activeRows.filter((r: Row) => isPaidStatus(r.status)).length;
   const monthTotalCount  = activeRows.length;
   const monthProjected   = roundMoney(totalStarting - monthBillsTotal);
 
-  // Safe to spend: cash on hand for this period after already-made payments
-  // (bank mode: effective balance already nets them out), minus everything
-  // still due before the next payday.
   const availableNow = bankTracking.enabled
     ? bankTracking.effective_balance
     : roundMoney(periodStartingAmount - periodPaidTowardDue);
   const safeToSpend = buildSafeToSpend({
-    activeRows,
-    available: availableNow,
-    todayStr,
-    year,
-    month,
-    dayOfMonth,
+    activeRows, available: availableNow, todayStr, year, month, dayOfMonth,
   });
 
   const cashflow = {
@@ -701,9 +650,9 @@ function getTracker(userId, query = {}, now = new Date()) {
     month_projected:    monthProjected,
   };
   const totalOverdue = sumMoney(
-    rows.filter(r => !r.is_skipped && (r.status === 'late' || r.status === 'missed')),
-    r => r.balance);
-  const previousMonthTotal = sumMoney(activeRows, r => r.previous_month_paid);
+    rows.filter((r: Row) => !r.is_skipped && (r.status === 'late' || r.status === 'missed')),
+    (r: Row) => r.balance);
+  const previousMonthTotal = sumMoney(activeRows, (r: Row) => r.previous_month_paid);
 
   return {
     year,
@@ -715,11 +664,6 @@ function getTracker(userId, query = {}, now = new Date()) {
       has_starting_amounts: hasStartingAmounts,
       total_paid: activeTotalPaid,
       paid_toward_due: activePaidTowardDue,
-      // In bank mode the effective bank balance is a single pool (no per-period
-      // split), so both remaining figures use the bank card's own remaining
-      // (effective_balance − gated unpaid) — keeping the summary consistent with
-      // safe-to-spend and the bank card instead of showing a different number
-      // derived from manual starting amounts.
       remaining: roundMoney(bankTracking.enabled
         ? bankTracking.remaining
         : (hasStartingAmounts ? periodStartingAmount - periodPaidTowardDue : periodOutstandingBalance)),
@@ -732,23 +676,19 @@ function getTracker(userId, query = {}, now = new Date()) {
         ? `${periodLabel}: ${periodStartingAmount.toFixed(2)} starting minus ${periodPaidTowardDue.toFixed(2)} paid toward due`
         : `${periodLabel}: unpaid bills due in this period`,
       overdue: totalOverdue,
-      count_paid: activeRows.filter(r => r.status === 'paid').length,
-      count_upcoming: activeRows.filter(r => r.status === 'upcoming' || r.status === 'due_soon').length,
-      count_late: activeRows.filter(r => r.status === 'late' || r.status === 'missed').length,
-      count_autodraft: activeRows.filter(r => r.status === 'autodraft').length,
+      count_paid: activeRows.filter((r: Row) => r.status === 'paid').length,
+      count_upcoming: activeRows.filter((r: Row) => r.status === 'upcoming' || r.status === 'due_soon').length,
+      count_late: activeRows.filter((r: Row) => r.status === 'late' || r.status === 'missed').length,
+      count_autodraft: activeRows.filter((r: Row) => r.status === 'autodraft').length,
       previous_month_total: previousMonthTotal,
       trend: buildThreeMonthTrend(db, userId, year, month, end, activeTotalPaid),
     },
     bank_tracking: bankTracking,
     cashflow,
     rows: bankTracking.enabled
-      ? rows.map(r => {
+      ? rows.map((r: Row) => {
           const bank_pending_count = bankPendingCounts[r.id] || 0;
-          // Only flag manually-entered payments as pending-cleared — bank-synced
-          // or bank-matched payments are already settled so they don't need the badge.
           const isManualPayment = r.payment_source !== 'provider_sync' && r.payment_source !== 'transaction_match';
-          // Amber "Pending" only makes sense for bills linked to the bank — for unlinked bills
-          // there's no bank clearing to wait for, so they should just show "Paid".
           const isBankLinked = !!(r.has_merchant_rule || r.has_linked_transactions);
           if (r.status === 'paid' && r.last_paid_date && isManualPayment && isBankLinked) {
             const cutoff = new Date();
@@ -762,8 +702,8 @@ function getTracker(userId, query = {}, now = new Date()) {
   };
 }
 
-function getUpcomingBills(userId, query = {}, now = new Date()) {
-  const db = getDb();
+function getUpcomingBills(userId: number, query: any = {}, now: Date = new Date()): any {
+  const db: Db = getDb();
   const days = Math.max(1, Math.min(parseInt(query.days || '30', 10) || 30, 365));
   const todayStr = localDateString(now);
   const userSettings = getUserSettings(userId);
@@ -773,8 +713,8 @@ function getUpcomingBills(userId, query = {}, now = new Date()) {
   const cutoff = new Date(now);
   cutoff.setDate(cutoff.getDate() + days);
   const cutoffStr = localDateString(cutoff);
-  const upcoming = [];
-  const seen = new Set();
+  const upcoming: any[] = [];
+  const seen = new Set<any>();
   const monthCount = (cutoff.getFullYear() - now.getFullYear()) * 12
     + (cutoff.getMonth() - now.getMonth()) + 1;
 
@@ -792,10 +732,7 @@ function getUpcomingBills(userId, query = {}, now = new Date()) {
       const row = buildTrackerRow(
         bill,
         fetchPaymentsForBillCycle(db, bill, target.year, target.month),
-        target.year,
-        target.month,
-        todayStr,
-        rowOptions,
+        target.year, target.month, todayStr, rowOptions,
       );
       if (!row || row.status === 'paid') continue;
 
@@ -806,17 +743,17 @@ function getUpcomingBills(userId, query = {}, now = new Date()) {
         due_date: dueDate,
         expected_amount: row.expected_amount,
         status: row.status,
-        days_until_due: Math.floor((new Date(`${dueDate}T00:00:00`) - new Date(`${todayStr}T00:00:00`)) / 86400000),
+        days_until_due: Math.floor((new Date(`${dueDate}T00:00:00`).getTime() - new Date(`${todayStr}T00:00:00`).getTime()) / 86400000),
       });
     }
   }
 
-  upcoming.sort((a, b) => a.due_date.localeCompare(b.due_date));
+  upcoming.sort((a: Row, b: Row) => a.due_date.localeCompare(b.due_date));
   return { days, today: todayStr, upcoming };
 }
 
-function getOverdueCount(userId, now = new Date()) {
-  const db = getDb();
+function getOverdueCount(userId: number, now: Date = new Date()): any {
+  const db: Db = getDb();
   const todayStr = localDateString(now);
   const year  = now.getFullYear();
   const month = now.getMonth() + 1;
@@ -842,14 +779,13 @@ function getOverdueCount(userId, now = new Date()) {
   `).all(year, month, rangeStart, rangeEnd, userId);
 
   let count = 0;
-  const overdueNames = [];
+  const overdueNames: any[] = [];
   for (const bill of bills) {
     if (bill.is_skipped) continue;
     if (bill.snoozed_until && bill.snoozed_until > todayStr) continue;
     if (bill.autopay_enabled && bill.autodraft_status === 'assumed_paid') continue;
 
     const dueDate = resolveDueDate(bill, year, month);
-    // Use >= so bills due TODAY are not counted as overdue — only strictly past dates
     if (!dueDate || dueDate >= todayStr) continue;
 
     const threshold = bill.actual_amount != null ? bill.actual_amount : bill.expected_amount;
diff --git a/tests/billReorder.test.js b/tests/billReorder.test.js
index 0b467ae..7992162 100644
--- a/tests/billReorder.test.js
+++ b/tests/billReorder.test.js
@@ -8,7 +8,7 @@ const dbPath = path.join(os.tmpdir(), `bill-tracker-reorder-test-${process.pid}.
 process.env.DB_PATH = dbPath;
 
 const { getDb, closeDb } = require('../db/database');
-const { getTracker } = require('../services/trackerService');
+const { getTracker } = require('../services/trackerService.cts');
 
 function createUser(db, suffix) {
   return db.prepare(`
diff --git a/tests/reconciliation.test.js b/tests/reconciliation.test.js
index 23714bf..92cd635 100644
--- a/tests/reconciliation.test.js
+++ b/tests/reconciliation.test.js
@@ -18,7 +18,7 @@ const dbPath = path.join(os.tmpdir(), `bill-tracker-recon-${process.pid}.sqlite`
 process.env.DB_PATH = dbPath;
 
 const { getDb, closeDb } = require('../db/database');
-const { getTracker } = require('../services/trackerService');
+const { getTracker } = require('../services/trackerService.cts');
 const { getAnalyticsSummary } = require('../services/analyticsService.cts');
 const { resolveDueDate } = require('../services/statusService.cts');
 const summaryRouter = require('../routes/summary');
diff --git a/tests/safeToSpend.test.js b/tests/safeToSpend.test.js
index e40fc1f..60358dc 100644
--- a/tests/safeToSpend.test.js
+++ b/tests/safeToSpend.test.js
@@ -1,7 +1,7 @@
 const test = require('node:test');
 const assert = require('node:assert/strict');
 
-const { buildSafeToSpend } = require('../services/trackerService');
+const { buildSafeToSpend } = require('../services/trackerService.cts');
 
 function row(overrides = {}) {
   return {
diff --git a/tests/trackerService.test.js b/tests/trackerService.test.js
index 5dcd637..8e7a4b8 100644
--- a/tests/trackerService.test.js
+++ b/tests/trackerService.test.js
@@ -15,7 +15,7 @@ const dbPath = path.join(os.tmpdir(), `bill-tracker-trackersvc-${process.pid}.sq
 process.env.DB_PATH = dbPath;
 
 const { getDb, closeDb } = require('../db/database');
-const { getTracker, getOverdueCount } = require('../services/trackerService');
+const { getTracker, getOverdueCount } = require('../services/trackerService.cts');
 
 // Fixed "now" so occurrence gating + statuses are deterministic (mid-June 2026).
 const JUNE_20 = new Date(2026, 5, 20, 12, 0, 0);
diff --git a/tests/transactionMatchService.test.js b/tests/transactionMatchService.test.js
index f07f36b..5834a7b 100644
--- a/tests/transactionMatchService.test.js
+++ b/tests/transactionMatchService.test.js
@@ -9,7 +9,7 @@ process.env.DB_PATH = dbPath;
 
 const { getDb, closeDb } = require('../db/database');
 const { ensureManualDataSource } = require('../services/transactionService.cts');
-const { getTracker } = require('../services/trackerService');
+const { getTracker } = require('../services/trackerService.cts');
 const {
   listMatchSuggestions,
   rejectMatchSuggestion,