diff --git a/backend/src/lib/workforce.js b/backend/src/lib/workforce.js
index 195e095..eefe092 100644
--- a/backend/src/lib/workforce.js
+++ b/backend/src/lib/workforce.js
@@ -259,18 +259,19 @@ export async function runRollingSync() {
 }
 
 // Fetch a raw item list from a path and return a cost summary — used for endpoint comparison
-async function fetchAndSummarise(path) {
+async function fetchAndSummarise(path, includeSample = false) {
   try {
     const items = await wfFetchPaged(path)
-    if (!Array.isArray(items) || items.length === 0) return { count: 0, baseCost: 0, totalCost: 0, byDept: {} }
+    if (!Array.isArray(items) || items.length === 0) return { count: 0, baseCost: 0, totalCost: 0, topDepts: [] }
     let baseCost = 0, totalCost = 0
     const byDept = {}
+    let sampleRecord = null
     for (const s of items) {
-      // timesheets may use start (unix ts) as the date source; shifts have date directly
       const base  = parseFloat(s.cost             ?? 0)
       const total = parseFloat(s.cost_with_oncosts ?? s.cost ?? 0)
       baseCost  += base
       totalCost += total
+      if (includeSample && !sampleRecord && base > 0) sampleRecord = s
       const deptId   = String(s.department_id ?? 'unknown')
       const deptName = s.department_name || deptId
       if (!byDept[deptId]) byDept[deptId] = { name: deptName, baseCost: 0, totalCost: 0, count: 0 }
@@ -281,19 +282,39 @@ async function fetchAndSummarise(path) {
     const deptList = Object.entries(byDept)
       .map(([id, v]) => ({ id, name: v.name, baseCost: +v.baseCost.toFixed(2), totalCost: +v.totalCost.toFixed(2), count: v.count }))
       .sort((a, b) => b.totalCost - a.totalCost)
-    return { count: items.length, baseCost: +baseCost.toFixed(2), totalCost: +totalCost.toFixed(2), topDepts: deptList.slice(0, 15) }
+    const result = { count: items.length, baseCost: +baseCost.toFixed(2), totalCost: +totalCost.toFixed(2), topDepts: deptList.slice(0, 15) }
+    if (includeSample && sampleRecord) {
+      result.sampleFields = Object.fromEntries(Object.entries(sampleRecord).filter(([, v]) => v !== null && v !== undefined && v !== ''))
+    }
+    return result
   } catch (err) {
     return { error: err.message }
   }
 }
 
+// Extract cost from a timesheet record — tries multiple field name conventions
+function tsBaseCost(s) {
+  // Try all known field names in order of likelihood
+  for (const k of ['cost', 'timesheet_cost', 'base_cost', 'employee_cost', 'wage_cost', 'total_cost']) {
+    const v = parseFloat(s[k])
+    if (!isNaN(v) && v > 0) return v
+  }
+  return 0
+}
+function tsTotalCost(s, base) {
+  for (const k of ['cost_with_oncosts', 'total_cost_with_oncosts', 'oncost', 'cost_with_on_costs', 'total_oncost']) {
+    const v = parseFloat(s[k])
+    if (!isNaN(v) && v > 0) return v
+  }
+  return base  // fallback: same as base
+}
+
 // Fetch per-date timesheets for every day in [from, to] in parallel and aggregate.
 // Uses /api/v2/timesheets/on/{date} when the range endpoint returns 404.
 async function fetchTimesheetsByDay(from, to, locationId) {
   const start = new Date(from + 'T00:00:00')
   const end   = new Date(to   + 'T00:00:00')
 
-  // Build list of all dates in range
   const dates = []
   let cur = new Date(start)
   while (cur <= end) {
@@ -301,7 +322,6 @@ async function fetchTimesheetsByDay(from, to, locationId) {
     cur.setDate(cur.getDate() + 1)
   }
 
-  // Fire all days in parallel — ~30 concurrent requests, completes in ~3-5s
   const perDay = await Promise.all(dates.map(async dateStr => {
     let path = `/api/v2/timesheets/on/${dateStr}?show_costs=true&include_oncosts=true`
     if (locationId) path += `&location_id=${locationId}`
@@ -310,12 +330,15 @@ async function fetchTimesheetsByDay(from, to, locationId) {
 
   let baseCost = 0, totalCost = 0, count = 0
   const byDept = {}
+  let sampleRecord = null  // first record with cost > 0 for field inspection
+
   for (const items of perDay) {
     if (!Array.isArray(items)) continue
     for (const s of items) {
-      const base  = parseFloat(s.cost             ?? 0)
-      const total = parseFloat(s.cost_with_oncosts ?? s.cost ?? 0)
+      const base  = tsBaseCost(s)
+      const total = tsTotalCost(s, base)
       baseCost += base; totalCost += total; count++
+      if (!sampleRecord && base > 0) sampleRecord = s
       const deptId = String(s.department_id ?? 'unknown')
       if (!byDept[deptId]) byDept[deptId] = { name: s.department_name || deptId, baseCost: 0, totalCost: 0, count: 0 }
       byDept[deptId].baseCost  += base
@@ -326,7 +349,13 @@ async function fetchTimesheetsByDay(from, to, locationId) {
   const topDepts = Object.entries(byDept)
     .map(([id, v]) => ({ id, name: v.name, baseCost: +v.baseCost.toFixed(2), totalCost: +v.totalCost.toFixed(2), count: v.count }))
     .sort((a, b) => b.totalCost - a.totalCost)
-  return { count, baseCost: +baseCost.toFixed(2), totalCost: +totalCost.toFixed(2), topDepts: topDepts.slice(0, 15) }
+
+  // Expose all keys+values from a sample record so we can identify the correct cost fields
+  const sampleFields = sampleRecord
+    ? Object.fromEntries(Object.entries(sampleRecord).filter(([, v]) => v !== null && v !== undefined && v !== ''))
+    : null
+
+  return { count, baseCost: +baseCost.toFixed(2), totalCost: +totalCost.toFixed(2), topDepts: topDepts.slice(0, 15), sampleFields }
 }
 
 // Compare cost totals from all available endpoints for a given date range.
@@ -351,7 +380,7 @@ export async function compareEndpoints(from, to) {
   if (locationId) tsRange += `&location_id=${locationId}`
 
   const [a, b, c, d] = await Promise.all([
-    fetchAndSummarise(shiftsReportLoc),
+    fetchAndSummarise(shiftsReportLoc, true),  // sample fields from shift object
     fetchAndSummarise(shiftsLocId),
     fetchAndSummarise(shiftsNoFilter),
     fetchAndSummarise(tsRange),