add event debugging

packages/inspector/src/App.tsx

@@ -28,6 +28,8 @@ export type ToolResult = {
   htmlContent: string | null
   isError: boolean
   timestamp: Date
+  executionTime: number // milliseconds
+  bundleSize: number | null // bytes, null if no UI
 }
 
 function App() {
@@ -79,7 +81,9 @@ function App() {
         textContent: err instanceof Error ? err.message : 'Unknown error',
         htmlContent: null,
         isError: true,
-        timestamp: new Date()
+        timestamp: new Date(),
+        executionTime: 0,
+        bundleSize: null
       })
     } finally {
       setIsExecuting(false)

packages/inspector/src/components/ResultsPane.css

@@ -34,7 +34,7 @@
   display: inline-flex;
   align-items: center;
   gap: 6px;
-  padding: 12px 16px;
+  padding: 12px 12px;
   background: transparent;
   border: none;
   border-bottom: 2px solid transparent;
@@ -57,7 +57,7 @@
   display: inline-block;
   width: 5px;
   height: 5px;
-  margin-left: 5px;
+  margin-left: 2px;
   border-radius: 50%;
   background: rgba(255, 255, 255, 0.5);
 }
@@ -80,6 +80,37 @@
   color: var(--text-muted);
 }
 
+.metrics {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+}
+
+.metric {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  font-size: 11px;
+  color: var(--text-secondary);
+  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
+    monospace;
+  font-weight: 400;
+}
+
+.tab-count {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  min-width: 18px;
+  height: 18px;
+  padding: 0 5px;
+  margin-left: 6px;
+  font-size: 10px;
+  background: var(--accent-blue);
+  color: var(--white);
+  border-radius: 9px;
+}
+
 .icon-button {
   display: inline-flex;
   align-items: center;
@@ -188,6 +219,100 @@
   word-break: break-word;
 }
 
+/* Events Panel */
+.events-panel {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  overflow: hidden;
+}
+
+.events-empty {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 12px;
+  color: var(--text-muted);
+  text-align: center;
+  padding: 40px;
+}
+
+.events-empty p {
+  font-size: 14px;
+}
+
+.events-empty span {
+  font-size: 12px;
+  color: var(--text-muted);
+}
+
+.events-list {
+  flex: 1;
+  overflow-y: auto;
+  padding: 12px;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.event-item {
+  background: var(--bg-secondary);
+  border: 1px solid var(--border-color);
+  border-radius: 8px;
+  overflow: hidden;
+}
+
+.event-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 8px 12px;
+  background: var(--bg-tertiary);
+  border-bottom: 1px solid var(--border-color);
+}
+
+.event-type {
+  font-size: 12px;
+  font-weight: 600;
+  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
+    monospace;
+  color: var(--text-primary);
+}
+
+.event-time {
+  font-size: 10px;
+  color: var(--text-muted);
+  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
+    monospace;
+}
+
+.event-payload {
+  padding: 10px 12px;
+  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
+    monospace;
+  font-size: 11px;
+  line-height: 1.5;
+  color: var(--text-secondary);
+  margin: 0;
+  white-space: pre-wrap;
+  word-break: break-word;
+}
+
+/* Event type colors */
+.event-message .event-type {
+  color: var(--accent-blue);
+}
+
+.event-tool .event-type {
+  color: var(--accent-purple, #a855f7);
+}
+
+.event-resize .event-type {
+  color: var(--accent-green, #22c55e);
+}
+
 @media (max-width: 1200px) {
   .results-pane {
     min-width: 0;
@@ -220,7 +345,8 @@
     gap: 8px;
   }
 
-  .timestamp {
+  .timestamp,
+  .metrics {
     display: none;
   }
 
@@ -242,4 +368,18 @@
   .text-output pre {
     font-size: 12px;
   }
+
+  .events-list {
+    padding: 8px;
+    gap: 6px;
+  }
+
+  .event-header {
+    padding: 6px 10px;
+  }
+
+  .event-payload {
+    padding: 8px 10px;
+    font-size: 10px;
+  }
 }

packages/inspector/src/components/ResultsPane.tsx

@@ -1,5 +1,5 @@
-import { useEffect, useState } from 'react'
+import { useEffect, useState, useRef, useCallback } from 'react'
-import { Monitor, FileText, Clock, AlertTriangle, Maximize2, Minimize2, RotateCw } from 'lucide-react'
+import { Monitor, FileText, AlertTriangle, Maximize2, Minimize2, RotateCw, Radio, Trash2, Timer, Package } from 'lucide-react'
 import { Button } from './Button'
 import type { ToolResult } from '../App'
 import './ResultsPane.css'
@@ -10,15 +10,61 @@ interface ResultsPaneProps {
   onReload?: () => void
 }
 
-type Tab = 'ui' | 'text'
+type Tab = 'ui' | 'text' | 'events'
+
+interface IframeEvent {
+  id: number
+  timestamp: Date
+  type: string
+  payload: unknown
+}
+
+function formatBytes(bytes: number): string {
+  if (bytes < 1024) return `${bytes}b`
+  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)}kb`
+  return `${(bytes / (1024 * 1024)).toFixed(1)}mb`
+}
 
 export function ResultsPane({ result, isExecuting, onReload }: ResultsPaneProps) {
   const [activeTab, setActiveTab] = useState<Tab>('ui')
   const [isFullscreen, setIsFullscreen] = useState(false)
+  const [events, setEvents] = useState<IframeEvent[]>([])
+  const eventIdRef = useRef(0)
+  const iframeRef = useRef<HTMLIFrameElement>(null)
 
   const hasUI = result?.htmlContent != null
   const hasText = result?.textContent != null
 
+  // Clear events when result changes (new tool execution)
+  useEffect(() => {
+    setEvents([])
+    eventIdRef.current = 0
+  }, [result])
+
+  // Listen to postMessage events from the iframe
+  useEffect(() => {
+    const handleMessage = (event: MessageEvent) => {
+      // Only capture messages from our iframe
+      if (iframeRef.current && event.source === iframeRef.current.contentWindow) {
+        const newEvent: IframeEvent = {
+          id: ++eventIdRef.current,
+          timestamp: new Date(),
+          type: event.data?.type || 'unknown',
+          payload: event.data?.payload || event.data
+        }
+        setEvents(prev => [...prev, newEvent])
+      }
+    }
+
+    window.addEventListener('message', handleMessage)
+    return () => window.removeEventListener('message', handleMessage)
+  }, [])
+
+  const clearEvents = useCallback(() => {
+    setEvents([])
+    eventIdRef.current = 0
+  }, [])
+
   useEffect(() => {
     if (hasUI) {
       setActiveTab('ui')
@@ -47,14 +93,37 @@ export function ResultsPane({ result, isExecuting, onReload }: ResultsPaneProps)
             Text
             <span className={`tab-badge ${hasText ? 'active' : ''}`} />
           </button>
+          <button
+            className={`tab ${activeTab === 'events' ? 'active' : ''}`}
+            onClick={() => setActiveTab('events')}
+          >
+            Events
+            {events.length > 0 && <span className="tab-count">{events.length}</span>}
+          </button>
         </div>
 
         <div className="results-actions">
-          {result?.timestamp && (
+          {result && !result.isError && (
-            <span className="timestamp">
+            <div className="metrics">
-              <Clock size={12} />
+              <span className="metric" title="Execution time">
-              {result.timestamp.toLocaleTimeString()}
+                <Timer size={12} />
+                {result.executionTime}ms
               </span>
+              {result.bundleSize && (
+                <span className="metric" title="Bundle size">
+                  <Package size={12} />
+                  {formatBytes(result.bundleSize)}
+                </span>
+              )}
+            </div>
+          )}
+          {activeTab === 'events' && events.length > 0 && (
+            <Button
+              variant="ghost"
+              onClick={clearEvents}
+              title="Clear events"
+              icon={<Trash2 size={14} />}
+            />
           )}
           {onReload && (
             <Button
@@ -94,6 +163,7 @@ export function ResultsPane({ result, isExecuting, onReload }: ResultsPaneProps)
         ) : activeTab === 'ui' ? (
           hasUI ? (
             <iframe
+              ref={iframeRef}
               className="ui-frame"
               srcDoc={result.htmlContent!}
               title="Tool UI Output"
@@ -106,10 +176,40 @@ export function ResultsPane({ result, isExecuting, onReload }: ResultsPaneProps)
               <span>This tool may only return text content</span>
             </div>
           )
-        ) : (
+        ) : activeTab === 'text' ? (
           <div className="text-output">
             <pre>{result.textContent || 'No text content'}</pre>
           </div>
+        ) : (
+          <div className="events-panel">
+            {events.length === 0 ? (
+              <div className="events-empty">
+                <Radio size={32} strokeWidth={1} />
+                <p>No events yet</p>
+                <span>Events from the UI (sendPrompt, callTool, resize) will appear here</span>
+              </div>
+            ) : (
+              <div className="events-list">
+                {events.map(event => (
+                  <div key={event.id} className={`event-item event-${event.type}`}>
+                    <div className="event-header">
+                      <span className="event-type">{event.type}</span>
+                      <span className="event-time">
+                        {event.timestamp.toLocaleTimeString([], {
+                          hour: '2-digit',
+                          minute: '2-digit',
+                          second: '2-digit',
+                        })}.{event.timestamp.getMilliseconds().toString().padStart(3, '0')}
+                      </span>
+                    </div>
+                    <pre className="event-payload">
+                      {JSON.stringify(event.payload, null, 2)}
+                    </pre>
+                  </div>
+                ))}
+              </div>
+            )}
+          </div>
         )}
       </div>
     </div>

packages/inspector/src/hooks/useMCP.ts

@@ -16,6 +16,8 @@ interface UseMCPReturn {
     textContent: string
     htmlContent: string | null
     isError: boolean
+    executionTime: number
+    bundleSize: number | null
   }>
 }
 
@@ -195,6 +197,8 @@ export function useMCP(): UseMCPReturn {
       throw new Error('Not connected')
     }
 
+    const startTime = performance.now()
+
     // Build headers - only include session ID if present (stateful server)
     const headers: Record<string, string> = {
       'Content-Type': 'application/json',
@@ -216,6 +220,8 @@ export function useMCP(): UseMCPReturn {
     })
 
     const text = await response.text()
+    const executionTime = Math.round(performance.now() - startTime)
+
     const result = parseSSE(text) as {
       result?: {
         content: Array<{
@@ -232,6 +238,8 @@ export function useMCP(): UseMCPReturn {
         textContent: result.error.message,
         htmlContent: null,
         isError: true,
+        executionTime,
+        bundleSize: null,
       }
     }
 
@@ -247,10 +255,15 @@ export function useMCP(): UseMCPReturn {
       }
     }
 
+    // Calculate bundle size (in bytes) if there's HTML content
+    const bundleSize = htmlContent ? new Blob([htmlContent]).size : null
+
     return {
       textContent,
       htmlContent,
       isError: false,
+      executionTime,
+      bundleSize,
     }
   }, [isConnected, sessionId])