diff --git a/packages/@ant/ink/src/components/App.tsx b/packages/@ant/ink/src/components/App.tsx
index 1ba33fdd7..bda0c5609 100644
--- a/packages/@ant/ink/src/components/App.tsx
+++ b/packages/@ant/ink/src/components/App.tsx
@@ -131,8 +131,13 @@ type Props = {
 const MULTI_CLICK_TIMEOUT_MS = 500;
 const MULTI_CLICK_DISTANCE = 1;
 
+type ErrorInfo = {
+  readonly message: string;
+  readonly stack?: string;
+};
+
 type State = {
-  readonly error?: Error;
+  readonly error?: ErrorInfo;
 };
 
 // Root component for all Ink apps
@@ -142,7 +147,7 @@ export default class App extends PureComponent<Props, State> {
   static displayName = 'InternalApp';
 
   static getDerivedStateFromError(error: Error) {
-    return { error };
+    return { error: { message: error.message, stack: error.stack } };
   }
 
   override state = {
@@ -221,7 +226,7 @@ export default class App extends PureComponent<Props, State> {
             <TerminalFocusProvider>
               <ClockProvider>
                 <CursorDeclarationContext.Provider value={this.props.onCursorDeclaration ?? (() => {})}>
-                  {this.state.error ? <ErrorOverview error={this.state.error as Error} /> : this.props.children}
+                  {this.state.error ? <ErrorOverview error={this.state.error} /> : this.props.children}
                 </CursorDeclarationContext.Provider>
               </ClockProvider>
             </TerminalFocusProvider>
diff --git a/packages/@ant/ink/src/components/ErrorOverview.tsx b/packages/@ant/ink/src/components/ErrorOverview.tsx
index 5f215536b..29a4dfff7 100644
--- a/packages/@ant/ink/src/components/ErrorOverview.tsx
+++ b/packages/@ant/ink/src/components/ErrorOverview.tsx
@@ -23,8 +23,13 @@ function getStackUtils(): StackUtils {
 
 /* eslint-enable custom-rules/no-process-cwd */
 
+type ErrorLike = {
+  readonly message: string;
+  readonly stack?: string;
+};
+
 type Props = {
-  readonly error: Error;
+  readonly error: ErrorLike;
 };
 
 export default function ErrorOverview({ error }: Props) {
diff --git a/src/query.ts b/src/query.ts
index a53d238cb..767ba998f 100644
--- a/src/query.ts
+++ b/src/query.ts
@@ -340,6 +340,15 @@ export async function* query(
         terminal?.reason === 'aborted_tools'
       endTrace(langfuseTrace, undefined, isAborted ? 'interrupted' : undefined)
     }
+
+    // Break the closure chain: toolUseContext captures langfuseTrace which
+    // holds SpanImpl → otperformance (the 571MB Performance object). Nulling
+    // these after endTrace allows GC to reclaim the span tree.
+    if (paramsWithTrace !== params) {
+      paramsWithTrace.toolUseContext.langfuseTrace = null
+      paramsWithTrace.toolUseContext.langfuseRootTrace = null
+      paramsWithTrace.toolUseContext.langfuseBatchSpan = null
+    }
   }
 
   // Only reached if queryLoop returned normally. Skipped on throw (error
diff --git a/src/utils/profilerBase.ts b/src/utils/profilerBase.ts
index f70b441d1..83304457e 100644
--- a/src/utils/profilerBase.ts
+++ b/src/utils/profilerBase.ts
@@ -1,22 +1,69 @@
 /**
  * Shared infrastructure for profiler modules (startupProfiler, queryProfiler,
- * headlessProfiler). All three use the same perf_hooks timeline and the same
- * line format for detailed reports.
+ * headlessProfiler).
+ *
+ * Uses process.hrtime.bigint() for timing instead of perf_hooks.performance
+ * to avoid a Bun/JSC memory leak: JSC's Performance object stores marks in a
+ * C++ Vector that never shrinks even after clearMarks(). Long-running sessions
+ * (daemon, /loop) accumulate hundreds of MB of dead capacity.
+ *
+ * The LightweightPerf class provides the same interface the profilers need
+ * (mark, getEntriesByType, clearMarks, now) backed by a plain JS Map.
  */
 
-import type { performance as PerformanceType } from 'perf_hooks'
 import { formatFileSize } from './format.js'
 
-// Lazy-load performance API only when profiling is enabled.
-// Shared across all profilers — perf_hooks.performance is a process-wide singleton.
-let performance: typeof PerformanceType | null = null
+/** Minimal PerformanceEntry-like object used by profilers */
+export interface CheckpointEntry {
+  readonly name: string
+  readonly startTime: number
+  readonly entryType: 'mark'
+}
 
-export function getPerformance(): typeof PerformanceType {
-  if (!performance) {
-    // eslint-disable-next-line @typescript-eslint/no-require-imports
-    performance = require('perf_hooks').performance
+/**
+ * Lightweight replacement for perf_hooks.performance that stores marks in a
+ * plain JavaScript Map instead of JSC's C++ Vector. This avoids the memory
+ * leak where clearMarks() sets the count to 0 but never frees Vector capacity.
+ */
+class LightweightPerf {
+  private marks = new Map<string, number>()
+  private _origin: number
+
+  constructor() {
+    this._origin = Number(process.hrtime.bigint() / 1000n) / 1000
   }
-  return performance!
+
+  mark(name: string): void {
+    this.marks.set(name, this.now())
+  }
+
+  getEntriesByType(type: 'mark'): CheckpointEntry[] {
+    if (type !== 'mark') return []
+    const entries: CheckpointEntry[] = []
+    for (const [name, startTime] of this.marks) {
+      entries.push({ name, startTime, entryType: 'mark' })
+    }
+    return entries
+  }
+
+  clearMarks(name?: string): void {
+    if (name !== undefined) {
+      this.marks.delete(name)
+    } else {
+      this.marks.clear()
+    }
+  }
+
+  now(): number {
+    return Number(process.hrtime.bigint() / 1000n) / 1000 - this._origin
+  }
+}
+
+// Singleton — shared across all profilers (same as the old perf_hooks singleton)
+const perf = new LightweightPerf()
+
+export function getPerformance(): LightweightPerf {
+  return perf
 }
 
 export function formatMs(ms: number): string {