diff --git a/ui/src/App.jsx b/ui/src/App.jsx
index 50abb9f..bac0aeb 100644
--- a/ui/src/App.jsx
+++ b/ui/src/App.jsx
@@ -33,6 +33,7 @@ export default function App() {
   // Sets of names whose dfv view is out of sync with current definitions
   const [staleSources, setStaleSources] = useState(new Set())
   const [staleStacks, setStaleStacks] = useState(new Set())
+  const [reprocessSources, setReprocessSources] = useState(new Set())
   const [generating, setGenerating] = useState({}) // { 'source:name': true }
 
   async function handleLogin(user, pass) {
@@ -56,6 +57,7 @@ export default function App() {
     setSources([])
     setStaleSources(new Set())
     setStaleStacks(new Set())
+    setReprocessSources(new Set())
   }
 
   // Load initial stale state from DB once on login
@@ -70,6 +72,17 @@ export default function App() {
   function markSourceStale(name) {
     setStaleSources(prev => new Set([...prev, name]))
   }
+  function markNeedsReprocess(name) {
+    setReprocessSources(prev => new Set([...prev, name]))
+  }
+  async function handleReprocessSource(name) {
+    setGenerating(g => ({ ...g, [`rp:${name}`]: true }))
+    try {
+      await api.reprocess(name)
+      setReprocessSources(prev => { const n = new Set(prev); n.delete(name); return n })
+    } catch (e) { alert(e.message) }
+    finally { setGenerating(g => { const n = { ...g }; delete n[`rp:${name}`]; return n }) }
+  }
   function markStackStale(name) {
     setStaleStacks(prev => new Set([...prev, name]))
   }
@@ -214,6 +227,23 @@ export default function App() {
               ))}
             </div>
           )}
+          {reprocessSources.size > 0 && (
+            <div className="bg-blue-50 border-b border-blue-200 px-4 py-1.5 text-xs text-blue-800 flex flex-wrap items-center gap-x-3 gap-y-1">
+              <span className="font-medium">Mappings updated:</span>
+              {[...reprocessSources].map(name => (
+                <span key={name} className="flex items-center gap-1">
+                  {name}
+                  <button
+                    onClick={() => handleReprocessSource(name)}
+                    disabled={generating[`rp:${name}`]}
+                    className="px-1.5 py-0.5 rounded bg-blue-200 hover:bg-blue-300 disabled:opacity-50 font-medium"
+                  >
+                    {generating[`rp:${name}`] ? '…' : 'Reprocess'}
+                  </button>
+                </span>
+              ))}
+            </div>
+          )}
 
           <div className="flex-1 overflow-auto">
             <Routes>
@@ -221,7 +251,7 @@ export default function App() {
               <Route path="/sources" element={<Sources source={source} sources={sources} setSources={setSources} setSource={setSource} />} />
               <Route path="/import" element={<Import source={source} />} />
               <Route path="/rules" element={<Rules source={source} onStale={markSourceStale} />} />
-              <Route path="/mappings" element={<Mappings source={source} onStale={markSourceStale} />} />
+              <Route path="/mappings" element={<Mappings source={source} onNeedsReprocess={markNeedsReprocess} />} />
               <Route path="/remap" element={<Remap />} />
               <Route path="/records" element={<Records source={source} />} />
               <Route path="/pivot" element={<Pivot source={source} />} />
diff --git a/ui/src/pages/Mappings.jsx b/ui/src/pages/Mappings.jsx
index 1cc2d26..cde4670 100644
--- a/ui/src/pages/Mappings.jsx
+++ b/ui/src/pages/Mappings.jsx
@@ -109,7 +109,7 @@ function SortHeader({ col, label, sortBy, onSort, className = '' }) {
   )
 }
 
-export default function Mappings({ source, onStale }) {
+export default function Mappings({ source, onNeedsReprocess }) {
   const [rules, setRules] = useState([])
   const [selectedRule, setSelectedRule] = useState('')
   const [allValues, setAllValues] = useState([])
@@ -268,7 +268,7 @@ export default function Mappings({ source, onStale }) {
           valueKey(x.extracted_value) === k ? { ...x, is_mapped: true, mapping_id: created.id, output } : x
         ))
       }
-      onStale?.(source)
+      onNeedsReprocess?.(source)
       setDrafts(d => { const n = { ...d }; delete n[k]; return n })
     } catch (err) {
       alert(err.message)
@@ -315,7 +315,7 @@ export default function Mappings({ source, onStale }) {
         setSaving(s => ({ ...s, [k]: false }))
       }
     }))
-    onStale?.(source)
+    onNeedsReprocess?.(source)
     setSelected(new Set())
     setBulkDraft({})
   }
@@ -324,7 +324,7 @@ export default function Mappings({ source, onStale }) {
     if (!row.mapping_id) return
     try {
       await api.deleteMapping(row.mapping_id)
-      onStale?.(source)
+      onNeedsReprocess?.(source)
       setAllValues(av => av.map(x =>
         valueKey(x.extracted_value) === valueKey(row.extracted_value)
           ? { ...x, is_mapped: false, mapping_id: null, output: null }