diff --git a/ui/src/api/schema.d.ts b/ui/src/api/schema.d.ts
index a2e35ae4..90afbf8a 100644
--- a/ui/src/api/schema.d.ts
+++ b/ui/src/api/schema.d.ts
@@ -1487,8 +1487,8 @@ export interface components {
         ExecutionSummary: {
             executionId: string;
             routeId: string;
-            agentId: string;
-            applicationName: string;
+            instanceId: string;
+            applicationId: string;
             status: string;
             /** Format: date-time */
             startTime: string;
@@ -1807,8 +1807,8 @@ export interface components {
         ExecutionDetail: {
             executionId: string;
             routeId: string;
-            agentId: string;
-            applicationName: string;
+            instanceId: string;
+            applicationId: string;
             status: string;
             /** Format: date-time */
             startTime: string;
@@ -1959,8 +1959,8 @@ export interface components {
         AgentEventResponse: {
             /** Format: int64 */
             id: number;
-            agentId: string;
-            appId: string;
+            instanceId: string;
+            applicationId: string;
             eventType: string;
             detail: string;
             /** Format: date-time */
diff --git a/ui/src/components/ExecutionDiagram/DetailPanel.tsx b/ui/src/components/ExecutionDiagram/DetailPanel.tsx
index 1b2b9771..9de312bc 100644
--- a/ui/src/components/ExecutionDiagram/DetailPanel.tsx
+++ b/ui/src/components/ExecutionDiagram/DetailPanel.tsx
@@ -159,7 +159,7 @@ export function DetailPanel({
         )}
         {activeTab === 'log' && (
           <LogTab
-            applicationName={executionDetail.applicationName}
+            applicationId={executionDetail.applicationId}
             exchangeId={executionDetail.exchangeId}
             processorId={selectedProcessor?.processorId ?? null}
           />
diff --git a/ui/src/components/ExecutionDiagram/ExecutionDiagram.tsx b/ui/src/components/ExecutionDiagram/ExecutionDiagram.tsx
index b5239b74..11e923f6 100644
--- a/ui/src/components/ExecutionDiagram/ExecutionDiagram.tsx
+++ b/ui/src/components/ExecutionDiagram/ExecutionDiagram.tsx
@@ -193,7 +193,7 @@ export function ExecutionDiagram({
           ↓ JSON
         </button>
         <ProcessDiagram
-          application={detail.applicationName}
+          application={detail.applicationId}
           routeId={detail.routeId}
           direction={direction}
           diagramLayout={diagramLayout}
diff --git a/ui/src/components/ExecutionDiagram/tabs/InfoTab.tsx b/ui/src/components/ExecutionDiagram/tabs/InfoTab.tsx
index 09685567..b538e5d3 100644
--- a/ui/src/components/ExecutionDiagram/tabs/InfoTab.tsx
+++ b/ui/src/components/ExecutionDiagram/tabs/InfoTab.tsx
@@ -96,7 +96,7 @@ export function InfoTab({ processor, executionDetail }: InfoTabProps) {
         <Field label="Correlation ID" value={executionDetail.correlationId} mono />
         <Field label="Exchange ID" value={executionDetail.exchangeId} mono />
 
-        <Field label="Application" value={executionDetail.applicationName} />
+        <Field label="Application" value={executionDetail.applicationId} />
         <Field label="Route ID" value={executionDetail.routeId} />
         <div>
           <div className={styles.fieldLabel}>Status</div>
diff --git a/ui/src/components/ExecutionDiagram/tabs/LogTab.tsx b/ui/src/components/ExecutionDiagram/tabs/LogTab.tsx
index 6495c540..34f076ac 100644
--- a/ui/src/components/ExecutionDiagram/tabs/LogTab.tsx
+++ b/ui/src/components/ExecutionDiagram/tabs/LogTab.tsx
@@ -4,7 +4,7 @@ import type { LogEntryResponse } from '../../../api/queries/logs';
 import styles from '../ExecutionDiagram.module.css';
 
 interface LogTabProps {
-  applicationName: string;
+  applicationId: string;
   exchangeId?: string;
   processorId: string | null;
 }
@@ -28,11 +28,11 @@ function formatTime(iso: string): string {
   return `${h}:${m}:${s}.${ms}`;
 }
 
-export function LogTab({ applicationName, exchangeId, processorId }: LogTabProps) {
+export function LogTab({ applicationId, exchangeId, processorId }: LogTabProps) {
   const [filter, setFilter] = useState('');
 
   const { data: logs, isLoading } = useApplicationLogs(
-    applicationName,
+    applicationId,
     undefined,
     { exchangeId, limit: 500 },
   );
diff --git a/ui/src/components/LayoutShell.tsx b/ui/src/components/LayoutShell.tsx
index bc3b033a..2827f7ff 100644
--- a/ui/src/components/LayoutShell.tsx
+++ b/ui/src/components/LayoutShell.tsx
@@ -138,8 +138,8 @@ function LayoutContent() {
       category: 'exchange' as const,
       title: e.executionId,
       badges: [{ label: e.status, color: statusToColor(e.status) }],
-      meta: `${e.routeId} · ${e.applicationName ?? ''} · ${formatDuration(e.durationMs)}`,
-      path: `/exchanges/${e.applicationName ?? ''}/${e.routeId}/${e.executionId}`,
+      meta: `${e.routeId} · ${e.applicationId ?? ''} · ${formatDuration(e.durationMs)}`,
+      path: `/exchanges/${e.applicationId ?? ''}/${e.routeId}/${e.executionId}`,
       serverFiltered: true,
       matchContext: e.highlight ?? undefined,
     }));
@@ -156,8 +156,8 @@ function LayoutContent() {
               category: 'attribute' as const,
               title: `${key} = "${value}"`,
               badges: [{ label: e.status, color: statusToColor(e.status) }],
-              meta: `${e.executionId} · ${e.routeId} · ${e.applicationName ?? ''}`,
-              path: `/exchanges/${e.applicationName ?? ''}/${e.routeId}/${e.executionId}`,
+              meta: `${e.executionId} · ${e.routeId} · ${e.applicationId ?? ''}`,
+              path: `/exchanges/${e.applicationId ?? ''}/${e.routeId}/${e.executionId}`,
               serverFiltered: true,
             });
           }
@@ -218,7 +218,7 @@ function LayoutContent() {
         if (parts.length === 4 && parts[0] === 'exchanges') {
           state.selectedExchange = {
             executionId: parts[3],
-            applicationName: parts[1],
+            applicationId: parts[1],
             routeId: parts[2],
           };
         }
diff --git a/ui/src/pages/AgentHealth/AgentHealth.tsx b/ui/src/pages/AgentHealth/AgentHealth.tsx
index fd0da9d5..b897111d 100644
--- a/ui/src/pages/AgentHealth/AgentHealth.tsx
+++ b/ui/src/pages/AgentHealth/AgentHealth.tsx
@@ -199,7 +199,7 @@ export default function AgentHealth() {
             : e.eventType === 'RECOVERED'
               ? ('success' as const)
               : ('running' as const),
-      message: `${e.agentId}: ${e.eventType}${e.detail ? ' \u2014 ' + e.detail : ''}`,
+      message: `${e.instanceId}: ${e.eventType}${e.detail ? ' \u2014 ' + e.detail : ''}`,
       timestamp: new Date(e.timestamp),
     }));
     return eventSortAsc ? mapped.toReversed() : mapped;
diff --git a/ui/src/pages/AgentInstance/AgentInstance.tsx b/ui/src/pages/AgentInstance/AgentInstance.tsx
index d202f666..77817c2b 100644
--- a/ui/src/pages/AgentInstance/AgentInstance.tsx
+++ b/ui/src/pages/AgentInstance/AgentInstance.tsx
@@ -83,7 +83,7 @@ export default function AgentInstance() {
 
   const feedEvents = useMemo<FeedEvent[]>(() => {
     const mapped = (events || [])
-      .filter((e: any) => !instanceId || e.agentId === instanceId)
+      .filter((e: any) => !instanceId || e.instanceId === instanceId)
       .map((e: any) => ({
         id: String(e.id),
         severity:
diff --git a/ui/src/pages/Dashboard/Dashboard.tsx b/ui/src/pages/Dashboard/Dashboard.tsx
index 540f0058..0465b228 100644
--- a/ui/src/pages/Dashboard/Dashboard.tsx
+++ b/ui/src/pages/Dashboard/Dashboard.tsx
@@ -92,11 +92,11 @@ function buildBaseColumns(): Column<Row>[] {
       ),
     },
     {
-      key: 'applicationName',
+      key: 'applicationId',
       header: 'Application',
       sortable: true,
       render: (_: unknown, row: Row) => (
-        <span className={styles.appName}>{row.applicationName ?? ''}</span>
+        <span className={styles.appName}>{row.applicationId ?? ''}</span>
       ),
     },
     {
@@ -147,12 +147,12 @@ function buildBaseColumns(): Column<Row>[] {
       ),
     },
     {
-      key: 'agentId',
+      key: 'instanceId',
       header: 'Agent',
       render: (_: unknown, row: Row) => (
         <span className={styles.agentBadge}>
           <span className={styles.agentDot} />
-          {row.agentId}
+          {row.instanceId}
         </span>
       ),
     },
@@ -163,7 +163,7 @@ function buildBaseColumns(): Column<Row>[] {
 
 export interface SelectedExchange {
   executionId: string;
-  applicationName: string;
+  applicationId: string;
   routeId: string;
 }
 
@@ -226,7 +226,7 @@ export default function Dashboard({ onExchangeSelect }: DashboardProps = {}) {
     if (onExchangeSelect) {
       onExchangeSelect({
         executionId: row.executionId,
-        applicationName: row.applicationName ?? '',
+        applicationId: row.applicationId ?? '',
         routeId: row.routeId,
       })
     }
diff --git a/ui/src/pages/Exchanges/ExchangeHeader.tsx b/ui/src/pages/Exchanges/ExchangeHeader.tsx
index bf409507..07ff4d34 100644
--- a/ui/src/pages/Exchanges/ExchangeHeader.tsx
+++ b/ui/src/pages/Exchanges/ExchangeHeader.tsx
@@ -12,7 +12,7 @@ import styles from './ExchangeHeader.module.css';
 
 interface ExchangeHeaderProps {
   detail: ExecutionDetail;
-  onCorrelatedSelect?: (executionId: string, applicationName: string, routeId: string) => void;
+  onCorrelatedSelect?: (executionId: string, applicationId: string, routeId: string) => void;
   onClearSelection?: () => void;
 }
 
@@ -50,17 +50,17 @@ export function ExchangeHeader({ detail, onCorrelatedSelect, onClearSelection }:
   const attrs = Object.entries(detail.attributes ?? {});
 
   // Look up agent state for icon coloring + route control capability
-  const { data: agents } = useAgents(undefined, detail.applicationName);
+  const { data: agents } = useAgents(undefined, detail.applicationId);
   const { agentState, hasRouteControl, hasReplay } = useMemo(() => {
     if (!agents) return { agentState: undefined, hasRouteControl: false, hasReplay: false };
     const agentList = agents as any[];
-    const agent = detail.agentId ? agentList.find((a: any) => a.id === detail.agentId) : undefined;
+    const agent = detail.instanceId ? agentList.find((a: any) => a.id === detail.instanceId) : undefined;
     return {
       agentState: agent?.state?.toLowerCase() as 'live' | 'stale' | 'dead' | undefined,
       hasRouteControl: agentList.some((a: any) => a.capabilities?.routeControl === true),
       hasReplay: agentList.some((a: any) => a.capabilities?.replay === true),
     };
-  }, [agents, detail.agentId]);
+  }, [agents, detail.instanceId]);
 
   const roles = useAuthStore((s) => s.roles);
   const canControl = roles.some(r => r === 'OPERATOR' || r === 'ADMIN');
@@ -80,21 +80,21 @@ export function ExchangeHeader({ detail, onCorrelatedSelect, onClearSelection }:
           </>
         )}
         <span className={styles.separator} />
-        <button className={styles.linkBtn} onClick={() => { onClearSelection?.(); navigate(`/exchanges/${detail.applicationName}`); }} title="Show all exchanges for this application">
-          <span className={styles.app}>{detail.applicationName}</span>
+        <button className={styles.linkBtn} onClick={() => { onClearSelection?.(); navigate(`/exchanges/${detail.applicationId}`); }} title="Show all exchanges for this application">
+          <span className={styles.app}>{detail.applicationId}</span>
         </button>
-        <button className={styles.linkBtn} onClick={() => { onClearSelection?.(); navigate(`/exchanges/${detail.applicationName}/${detail.routeId}`); }} title="Show all exchanges for this route">
+        <button className={styles.linkBtn} onClick={() => { onClearSelection?.(); navigate(`/exchanges/${detail.applicationId}/${detail.routeId}`); }} title="Show all exchanges for this route">
           <span className={styles.route}>{detail.routeId}</span>
           <GitBranch size={12} className={styles.icon} />
         </button>
-        {detail.agentId && (
+        {detail.instanceId && (
           <>
             <span className={styles.separator} />
-            <button className={styles.linkBtn} onClick={() => navigate(`/runtime/${detail.applicationName}`)} title="All agents for this application">
-              <span className={styles.app}>{detail.applicationName}</span>
+            <button className={styles.linkBtn} onClick={() => navigate(`/runtime/${detail.applicationId}`)} title="All agents for this application">
+              <span className={styles.app}>{detail.applicationId}</span>
             </button>
-            <button className={styles.linkBtn} onClick={() => navigate(`/runtime/${detail.applicationName}/${detail.agentId}`)} title="Agent details">
-              <MonoText size="xs">{detail.agentId}</MonoText>
+            <button className={styles.linkBtn} onClick={() => navigate(`/runtime/${detail.applicationId}/${detail.instanceId}`)} title="Agent details">
+              <MonoText size="xs">{detail.instanceId}</MonoText>
               <Server size={12} className={agentState === 'live' ? styles.iconLive : agentState === 'stale' ? styles.iconStale : agentState === 'dead' ? styles.iconDead : styles.icon} />
             </button>
           </>
@@ -105,11 +105,11 @@ export function ExchangeHeader({ detail, onCorrelatedSelect, onClearSelection }:
       {/* Route control / replay — only if agent supports it AND user has operator+ role */}
       {canControl && (hasRouteControl || hasReplay) && (
         <RouteControlBar
-          application={detail.applicationName}
+          application={detail.applicationId}
           routeId={detail.routeId}
           hasRouteControl={hasRouteControl}
           hasReplay={hasReplay}
-          agentId={detail.agentId}
+          agentId={detail.instanceId}
           exchangeId={detail.exchangeId}
           inputHeaders={detail.inputHeaders}
           inputBody={detail.inputBody}
@@ -135,7 +135,7 @@ export function ExchangeHeader({ detail, onCorrelatedSelect, onClearSelection }:
                   className={`${styles.chainNode} ${statusCls} ${isCurrent ? styles.chainNodeCurrent : ''}`}
                   onClick={() => {
                     if (!isCurrent && onCorrelatedSelect) {
-                      onCorrelatedSelect(ce.executionId, ce.applicationName ?? detail.applicationName, ce.routeId);
+                      onCorrelatedSelect(ce.executionId, ce.applicationId ?? detail.applicationId, ce.routeId);
                     }
                   }}
                   title={`${ce.executionId}\n${ce.routeId} \u2014 ${formatDuration(ce.durationMs)}${isReplay ? '\n(replay)' : ''}`}
diff --git a/ui/src/pages/Exchanges/ExchangesPage.tsx b/ui/src/pages/Exchanges/ExchangesPage.tsx
index 69a7606f..c1ab76bd 100644
--- a/ui/src/pages/Exchanges/ExchangesPage.tsx
+++ b/ui/src/pages/Exchanges/ExchangesPage.tsx
@@ -29,7 +29,7 @@ export default function ExchangesPage() {
   // Derive selection from URL params when no state-based selection exists (Cmd-K, bookmarks)
   const urlDerivedExchange: SelectedExchange | null =
     (scopedExchangeId && scopedAppId && scopedRouteId)
-      ? { executionId: scopedExchangeId, applicationName: scopedAppId, routeId: scopedRouteId }
+      ? { executionId: scopedExchangeId, applicationId: scopedAppId, routeId: scopedRouteId }
       : null;
 
   const [selected, setSelectedInternal] = useState<SelectedExchange | null>(stateSelected ?? urlDerivedExchange);
@@ -42,7 +42,7 @@ export default function ExchangesPage() {
     } else if (scopedExchangeId && scopedAppId && scopedRouteId) {
       setSelectedInternal({
         executionId: scopedExchangeId,
-        applicationName: scopedAppId,
+        applicationId: scopedAppId,
         routeId: scopedRouteId,
       });
     } else {
@@ -62,8 +62,8 @@ export default function ExchangesPage() {
   }, [navigate, location.pathname, location.search, location.state]);
 
   // Select a correlated exchange: push another history entry
-  const handleCorrelatedSelect = useCallback((executionId: string, applicationName: string, routeId: string) => {
-    const exchange = { executionId, applicationName, routeId };
+  const handleCorrelatedSelect = useCallback((executionId: string, applicationId: string, routeId: string) => {
+    const exchange = { executionId, applicationId, routeId };
     setSelectedInternal(exchange);
     navigate(location.pathname + location.search, {
       state: { ...location.state, selectedExchange: exchange },
@@ -106,7 +106,7 @@ export default function ExchangesPage() {
   }
 
   // Determine what the right panel shows
-  const panelAppId = selected?.applicationName ?? scopedAppId!;
+  const panelAppId = selected?.applicationId ?? scopedAppId!;
   const panelRouteId = selected?.routeId ?? scopedRouteId!;
   const panelExchangeId = selected?.executionId ?? undefined;
 
@@ -135,7 +135,7 @@ interface DiagramPanelProps {
   appId: string;
   routeId: string;
   exchangeId?: string;
-  onCorrelatedSelect: (executionId: string, applicationName: string, routeId: string) => void;
+  onCorrelatedSelect: (executionId: string, applicationId: string, routeId: string) => void;
   onClearSelection: () => void;
 }
 
diff --git a/ui/src/stores/tracing-store.ts b/ui/src/stores/tracing-store.ts
index cb506f2d..7fdff759 100644
--- a/ui/src/stores/tracing-store.ts
+++ b/ui/src/stores/tracing-store.ts
@@ -3,7 +3,7 @@ import { create } from 'zustand'
 type CaptureMode = 'NONE' | 'INPUT' | 'OUTPUT' | 'BOTH'
 
 interface TracingState {
-  /** Key: applicationName → { processorId: captureMode } */
+  /** Key: applicationId → { processorId: captureMode } */
   tracedProcessors: Record<string, Record<string, CaptureMode>>
   isTraced: (app: string, processorId: string) => boolean
   /** Toggle processor tracing (BOTH on, remove on off). Returns the full map for the app. */