docs: fix append_diagram instructions for consistency

- Change 'Do NOT include' to 'Do NOT start with' (clearer intent)
- Add <mxCell id="0"> to prohibited start patterns
- Change 'closing tags </root></mxGraphModel>' to just '</root>' (wrapWithMxFile handles the rest)

README.md

@@ -207,7 +207,7 @@ All providers except AWS Bedrock and OpenRouter support custom endpoints.
 
 **Model Requirements**: This task requires strong model capabilities for generating long-form text with strict formatting constraints (draw.io XML). Recommended models include Claude Sonnet 4.5, GPT-5.1, Gemini 3 Pro, and DeepSeek V3.2/R1.
 
-Note that `claude` series has trained on draw.io diagrams with cloud architecture logos like AWS, Azure, GCP. So if you want to create cloud architecture diagrams, this is the best choice.
+Note that `claude` series has trained on draw.io diagrams with cloud architecture logos like AWS, Azue, GCP. So if you want to create cloud architecture diagrams, this is the best choice.
 
 
 ## How It Works

app/api/chat/route.ts

@@ -202,9 +202,6 @@ async function handleChatRequest(req: Request): Promise<Response> {
         modelId: req.headers.get("x-ai-model"),
     }
 
-    // Read minimal style preference from header
-    const minimalStyle = req.headers.get("x-minimal-style") === "true"
-
     // Get AI model with optional client overrides
     const { model, providerOptions, headers, modelId } =
         getAIModel(clientOverrides)
@@ -216,7 +213,7 @@ async function handleChatRequest(req: Request): Promise<Response> {
     )
 
     // Get the appropriate system prompt based on model (extended for Opus/Haiku 4.5)
-    const systemMessage = getSystemPrompt(modelId, minimalStyle)
+    const systemMessage = getSystemPrompt(modelId)
 
     // Extract file parts (images) from the last message
     const fileParts =
@@ -370,32 +367,36 @@ ${userInputText}
         tools: {
             // Client-side tool that will be executed on the client
             display_diagram: {
-                description: `Display a diagram on draw.io. Pass ONLY the mxCell elements - wrapper tags and root cells are added automatically.
+                description: `Display a diagram on draw.io. Pass the XML content inside <root> tags.
 
 VALIDATION RULES (XML will be rejected if violated):
-1. Generate ONLY mxCell elements - NO wrapper tags (<mxfile>, <mxGraphModel>, <root>)
-2. Do NOT include root cells (id="0" or id="1") - they are added automatically
-3. All mxCell elements must be siblings - never nested
-4. Every mxCell needs a unique id (start from "2")
-5. Every mxCell needs a valid parent attribute (use "1" for top-level)
-6. Escape special chars in values: &lt; &gt; &amp; &quot;
+1. All mxCell elements must be DIRECT children of <root> - never nested
+2. Every mxCell needs a unique id
+3. Every mxCell (except id="0") needs a valid parent attribute
+4. Edge source/target must reference existing cell IDs
+5. Escape special chars in values: &lt; &gt; &amp; &quot;
+6. Always start with: <mxCell id="0"/><mxCell id="1" parent="0"/>
 
-Example (generate ONLY this - no wrapper tags):
-<mxCell id="lane1" value="Frontend" style="swimlane;" vertex="1" parent="1">
-  <mxGeometry x="40" y="40" width="200" height="200" as="geometry"/>
-</mxCell>
-<mxCell id="step1" value="Step 1" style="rounded=1;" vertex="1" parent="lane1">
-  <mxGeometry x="20" y="60" width="160" height="40" as="geometry"/>
-</mxCell>
-<mxCell id="lane2" value="Backend" style="swimlane;" vertex="1" parent="1">
-  <mxGeometry x="280" y="40" width="200" height="200" as="geometry"/>
-</mxCell>
-<mxCell id="step2" value="Step 2" style="rounded=1;" vertex="1" parent="lane2">
-  <mxGeometry x="20" y="60" width="160" height="40" as="geometry"/>
-</mxCell>
-<mxCell id="edge1" style="edgeStyle=orthogonalEdgeStyle;endArrow=classic;" edge="1" parent="1" source="step1" target="step2">
-  <mxGeometry relative="1" as="geometry"/>
-</mxCell>
+Example with swimlanes and edges (note: all mxCells are siblings):
+<root>
+  <mxCell id="0"/>
+  <mxCell id="1" parent="0"/>
+  <mxCell id="lane1" value="Frontend" style="swimlane;" vertex="1" parent="1">
+    <mxGeometry x="40" y="40" width="200" height="200" as="geometry"/>
+  </mxCell>
+  <mxCell id="step1" value="Step 1" style="rounded=1;" vertex="1" parent="lane1">
+    <mxGeometry x="20" y="60" width="160" height="40" as="geometry"/>
+  </mxCell>
+  <mxCell id="lane2" value="Backend" style="swimlane;" vertex="1" parent="1">
+    <mxGeometry x="280" y="40" width="200" height="200" as="geometry"/>
+  </mxCell>
+  <mxCell id="step2" value="Step 2" style="rounded=1;" vertex="1" parent="lane2">
+    <mxGeometry x="20" y="60" width="160" height="40" as="geometry"/>
+  </mxCell>
+  <mxCell id="edge1" style="edgeStyle=orthogonalEdgeStyle;endArrow=classic;" edge="1" parent="1" source="step1" target="step2">
+    <mxGeometry relative="1" as="geometry"/>
+  </mxCell>
+</root>
 
 Notes:
 - For AWS diagrams, use **AWS 2025 icons**.
@@ -443,9 +444,9 @@ IMPORTANT: Keep edits concise:
 WHEN TO USE: Only call this tool after display_diagram was truncated (you'll see an error message about truncation).
 
 CRITICAL INSTRUCTIONS:
-1. Do NOT include any wrapper tags - just continue the mxCell elements
+1. Do NOT start with <mxGraphModel>, <root>, or <mxCell id="0"> - they already exist in the partial
 2. Continue from EXACTLY where your previous output stopped
-3. Complete the remaining mxCell elements
+3. End with the closing </root> tag to complete the diagram
 4. If still truncated, call append_diagram again with the next fragment
 
 Example: If previous output ended with '<mxCell id="x" style="rounded=1', continue with ';" vertex="1">...' and complete the remaining elements.`,

app/api/chat/xml_guide.md

@@ -81,15 +81,16 @@ Contains the actual diagram data.
 
 ## Root Cell Container: `<root>`
 
-Contains all the cells in the diagram. **Note:** When generating diagrams, you only need to provide the mxCell elements - the root container and root cells (id="0", id="1") are added automatically.
+Contains all the cells in the diagram.
 
-**Internal structure (auto-generated):**
+**Example:**
 
 ```xml
 <root>
-  <mxCell id="0"/>           <!-- Auto-added -->
-  <mxCell id="1" parent="0"/> <!-- Auto-added -->
-  <!-- Your mxCell elements go here (start from id="2") -->
+<mxCell id="0"/>
+<mxCell id="1" parent="0"/>
+
+  <!-- Other cells go here -->
 </root>
 ```
 
@@ -202,15 +203,15 @@ Draw.io files contain two special cells that are always present:
 1.  **Root Cell** (id = "0"): The parent of all cells
 2.  **Default Parent Cell** (id = "1", parent = "0"): The default layer and parent for most cells
 
-## Tips for Creating Draw.io XML
+## Tips for Manually Creating Draw.io XML
 
-1.  **Generate ONLY mxCell elements** - wrapper tags and root cells (id="0", id="1") are added automatically
-2.  Start IDs from "2" (id="0" and id="1" are reserved for root cells)
+1.  Start with the basic structure (`mxfile`, `diagram`, `mxGraphModel`, `root`)
+2.  Always include the two special cells (id = "0" and id = "1")
 3.  Assign unique and sequential IDs to all cells
-4.  Define parent relationships correctly (use parent="1" for top-level shapes)
+4.  Define parent relationships correctly
 5.  Use `mxGeometry` elements to position shapes
 6.  For connectors, specify `source` and `target` attributes
-7.  **CRITICAL: All mxCell elements must be siblings. NEVER nest mxCell inside another mxCell.**
+7.  **CRITICAL: All mxCell elements must be DIRECT children of `<root>`. NEVER nest mxCell inside another mxCell.**
 
 ## Common Patterns
 

components/chat-input.tsx

@@ -17,13 +17,7 @@ import { HistoryDialog } from "@/components/history-dialog"
 import { ResetWarningModal } from "@/components/reset-warning-modal"
 import { SaveDialog } from "@/components/save-dialog"
 import { Button } from "@/components/ui/button"
-import { Switch } from "@/components/ui/switch"
 import { Textarea } from "@/components/ui/textarea"
-import {
-    Tooltip,
-    TooltipContent,
-    TooltipTrigger,
-} from "@/components/ui/tooltip"
 import { useDiagram } from "@/contexts/diagram-context"
 import { isPdfFile, isTextFile } from "@/lib/pdf-utils"
 import { FilePreviewList } from "./file-preview-list"
@@ -135,8 +129,6 @@ interface ChatInputProps {
     onToggleHistory?: (show: boolean) => void
     sessionId?: string
     error?: Error | null
-    minimalStyle?: boolean
-    onMinimalStyleChange?: (value: boolean) => void
 }
 
 export function ChatInput({
@@ -152,8 +144,6 @@ export function ChatInput({
     onToggleHistory = () => {},
     sessionId,
     error = null,
-    minimalStyle = false,
-    onMinimalStyleChange = () => {},
 }: ChatInputProps) {
     const { diagramHistory, saveDiagramToFile } = useDiagram()
     const textareaRef = useRef<HTMLTextAreaElement>(null)
@@ -353,32 +343,6 @@ export function ChatInput({
                             showHistory={showHistory}
                             onToggleHistory={onToggleHistory}
                         />
-
-                        <Tooltip>
-                            <TooltipTrigger asChild>
-                                <div className="flex items-center gap-1.5">
-                                    <Switch
-                                        id="minimal-style"
-                                        checked={minimalStyle}
-                                        onCheckedChange={onMinimalStyleChange}
-                                        className="scale-75"
-                                    />
-                                    <label
-                                        htmlFor="minimal-style"
-                                        className={`text-xs cursor-pointer select-none ${
-                                            minimalStyle
-                                                ? "text-primary font-medium"
-                                                : "text-muted-foreground"
-                                        }`}
-                                    >
-                                        {minimalStyle ? "Minimal" : "Styled"}
-                                    </label>
-                                </div>
-                            </TooltipTrigger>
-                            <TooltipContent side="top">
-                                Use minimal for faster generation (no colors)
-                            </TooltipContent>
-                        </Tooltip>
                     </div>
 
                     {/* Right actions */}

components/chat-message-display.tsx

@@ -29,12 +29,7 @@ import {
     ReasoningTrigger,
 } from "@/components/ai-elements/reasoning"
 import { ScrollArea } from "@/components/ui/scroll-area"
-import {
-    convertToLegalXml,
-    isMxCellXmlComplete,
-    replaceNodes,
-    validateAndFixXml,
-} from "@/lib/utils"
+import { convertToLegalXml, replaceNodes, validateAndFixXml } from "@/lib/utils"
 import ExamplePanel from "./chat-example-panel"
 import { CodeBlock } from "./code-block"
 
@@ -193,14 +188,6 @@ export function ChatMessageDisplay({
     const messagesEndRef = useRef<HTMLDivElement>(null)
     const previousXML = useRef<string>("")
     const processedToolCalls = processedToolCallsRef
-    // Track the last processed XML per toolCallId to skip redundant processing during streaming
-    const lastProcessedXmlRef = useRef<Map<string, string>>(new Map())
-    // Debounce streaming diagram updates - store pending XML and timeout
-    const pendingXmlRef = useRef<string | null>(null)
-    const debounceTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(
-        null,
-    )
-    const STREAMING_DEBOUNCE_MS = 150 // Only update diagram every 150ms during streaming
     const [expandedTools, setExpandedTools] = useState<Record<string, boolean>>(
         {},
     )
@@ -292,31 +279,24 @@ export function ChatMessageDisplay({
 
     const handleDisplayChart = useCallback(
         (xml: string, showToast = false) => {
-            console.time("perf:handleDisplayChart")
             const currentXml = xml || ""
             const convertedXml = convertToLegalXml(currentXml)
             if (convertedXml !== previousXML.current) {
                 // Parse and validate XML BEFORE calling replaceNodes
-                console.time("perf:DOMParser")
                 const parser = new DOMParser()
                 const testDoc = parser.parseFromString(convertedXml, "text/xml")
-                console.timeEnd("perf:DOMParser")
                 const parseError = testDoc.querySelector("parsererror")
 
                 if (parseError) {
-                    // Use console.warn instead of console.error to avoid triggering
-                    // Next.js dev mode error overlay for expected streaming states
-                    // (partial XML during streaming is normal and will be fixed by subsequent updates)
+                    console.error(
+                        "[ChatMessageDisplay] Malformed XML detected - skipping update",
+                    )
+                    // Only show toast if this is the final XML (not during streaming)
                     if (showToast) {
-                        // Only log as error and show toast if this is the final XML
-                        console.error(
-                            "[ChatMessageDisplay] Malformed XML detected in final output",
-                        )
                         toast.error(
                             "AI generated invalid diagram XML. Please try regenerating.",
                         )
                     }
-                    console.timeEnd("perf:handleDisplayChart")
                     return // Skip this update
                 }
 
@@ -326,14 +306,10 @@ export function ChatMessageDisplay({
                     const baseXML =
                         chartXML ||
                         `<mxfile><diagram name="Page-1" id="page-1"><mxGraphModel><root><mxCell id="0"/><mxCell id="1" parent="0"/></root></mxGraphModel></diagram></mxfile>`
-                    console.time("perf:replaceNodes")
                     const replacedXML = replaceNodes(baseXML, convertedXml)
-                    console.timeEnd("perf:replaceNodes")
 
                     // Validate and auto-fix the XML
-                    console.time("perf:validateAndFixXml")
                     const validation = validateAndFixXml(replacedXML)
-                    console.timeEnd("perf:validateAndFixXml")
                     if (validation.valid) {
                         previousXML.current = convertedXml
                         // Use fixed XML if available, otherwise use original
@@ -370,9 +346,6 @@ export function ChatMessageDisplay({
                         )
                     }
                 }
-                console.timeEnd("perf:handleDisplayChart")
-            } else {
-                console.timeEnd("perf:handleDisplayChart")
             }
         },
         [chartXML, onDisplayChart],
@@ -391,17 +364,7 @@ export function ChatMessageDisplay({
     }, [editingMessageId])
 
     useEffect(() => {
-        console.time("perf:message-display-useEffect")
-        let processedCount = 0
-        let skippedCount = 0
-        let debouncedCount = 0
-
-        // Only process the last message for streaming performance
-        // Previous messages are already processed and won't change
-        const messagesToProcess =
-            messages.length > 0 ? [messages[messages.length - 1]] : []
-
-        messagesToProcess.forEach((message) => {
+        messages.forEach((message) => {
             if (message.parts) {
                 message.parts.forEach((part) => {
                     if (part.type?.startsWith("tool-")) {
@@ -420,82 +383,25 @@ export function ChatMessageDisplay({
                             input?.xml
                         ) {
                             const xml = input.xml as string
-
-                            // Skip if XML hasn't changed since last processing
-                            const lastXml =
-                                lastProcessedXmlRef.current.get(toolCallId)
-                            if (lastXml === xml) {
-                                skippedCount++
-                                return // Skip redundant processing
-                            }
-
                             if (
                                 state === "input-streaming" ||
                                 state === "input-available"
                             ) {
-                                // Debounce streaming updates - queue the XML and process after delay
-                                pendingXmlRef.current = xml
-
-                                if (!debounceTimeoutRef.current) {
-                                    // No pending timeout - set one up
-                                    debounceTimeoutRef.current = setTimeout(
-                                        () => {
-                                            const pendingXml =
-                                                pendingXmlRef.current
-                                            debounceTimeoutRef.current = null
-                                            pendingXmlRef.current = null
-                                            if (pendingXml) {
-                                                console.log(
-                                                    "perf:debounced-handleDisplayChart executing",
-                                                )
-                                                handleDisplayChart(
-                                                    pendingXml,
-                                                    false,
-                                                )
-                                                lastProcessedXmlRef.current.set(
-                                                    toolCallId,
-                                                    pendingXml,
-                                                )
-                                            }
-                                        },
-                                        STREAMING_DEBOUNCE_MS,
-                                    )
-                                }
-                                debouncedCount++
+                                // During streaming, don't show toast (XML may be incomplete)
+                                handleDisplayChart(xml, false)
                             } else if (
                                 state === "output-available" &&
                                 !processedToolCalls.current.has(toolCallId)
                             ) {
-                                // Final output - process immediately (clear any pending debounce)
-                                if (debounceTimeoutRef.current) {
-                                    clearTimeout(debounceTimeoutRef.current)
-                                    debounceTimeoutRef.current = null
-                                    pendingXmlRef.current = null
-                                }
                                 // Show toast only if final XML is malformed
                                 handleDisplayChart(xml, true)
                                 processedToolCalls.current.add(toolCallId)
-                                // Clean up the ref entry - tool is complete, no longer needed
-                                lastProcessedXmlRef.current.delete(toolCallId)
-                                processedCount++
                             }
                         }
                     }
                 })
             }
         })
-        console.log(
-            `perf:message-display-useEffect processed=${processedCount} skipped=${skippedCount} debounced=${debouncedCount}`,
-        )
-        console.timeEnd("perf:message-display-useEffect")
-
-        // Cleanup: clear any pending debounce timeout on unmount
-        return () => {
-            if (debounceTimeoutRef.current) {
-                clearTimeout(debounceTimeoutRef.current)
-                debounceTimeoutRef.current = null
-            }
-        }
     }, [messages, handleDisplayChart])
 
     const renderToolPart = (part: ToolPartLike) => {
@@ -551,7 +457,8 @@ export function ChatMessageDisplay({
                                 const isTruncated =
                                     (toolName === "display_diagram" ||
                                         toolName === "append_diagram") &&
-                                    !isMxCellXmlComplete(input?.xml)
+                                    (!input?.xml ||
+                                        !input.xml.includes("</root>"))
                                 return isTruncated ? (
                                     <span className="text-xs font-medium text-yellow-600 bg-yellow-50 px-2 py-0.5 rounded-full">
                                         Truncated
@@ -600,7 +507,7 @@ export function ChatMessageDisplay({
                         const isTruncated =
                             (toolName === "display_diagram" ||
                                 toolName === "append_diagram") &&
-                            !isMxCellXmlComplete(input?.xml)
+                            (!input?.xml || !input.xml.includes("</root>"))
                         return (
                             <div
                                 className={`px-4 py-3 border-t border-border/40 text-sm ${isTruncated ? "text-yellow-600" : "text-red-600"}`}

components/chat-panel.tsx

@@ -26,7 +26,7 @@ import { findCachedResponse } from "@/lib/cached-responses"
 import { isPdfFile, isTextFile } from "@/lib/pdf-utils"
 import { type FileData, useFileProcessor } from "@/lib/use-file-processor"
 import { useQuotaManager } from "@/lib/use-quota-manager"
-import { formatXML, isMxCellXmlComplete, wrapWithMxFile } from "@/lib/utils"
+import { formatXML, wrapWithMxFile } from "@/lib/utils"
 import { ChatMessageDisplay } from "./chat-message-display"
 
 // localStorage keys for persistence
@@ -40,7 +40,6 @@ interface MessagePart {
     type: string
     state?: string
     toolName?: string
-    input?: { xml?: string; [key: string]: unknown }
     [key: string]: unknown
 }
 
@@ -146,7 +145,6 @@ export default function ChatPanel({
     const [dailyTokenLimit, setDailyTokenLimit] = useState(0)
     const [tpmLimit, setTpmLimit] = useState(0)
     const [showNewChatDialog, setShowNewChatDialog] = useState(false)
-    const [minimalStyle, setMinimalStyle] = useState(false)
 
     // Check config on mount
     useEffect(() => {
@@ -202,15 +200,6 @@ export default function ChatPanel({
     // Persist processed tool call IDs so collapsing the chat doesn't replay old tool outputs
     const processedToolCallsRef = useRef<Set<string>>(new Set())
 
-    // Debounce timeout for localStorage writes (prevents blocking during streaming)
-    const localStorageDebounceRef = useRef<ReturnType<
-        typeof setTimeout
-    > | null>(null)
-    const xmlStorageDebounceRef = useRef<ReturnType<typeof setTimeout> | null>(
-        null,
-    )
-    const LOCAL_STORAGE_DEBOUNCE_MS = 1000 // Save at most once per second
-
     const {
         messages,
         sendMessage,
@@ -233,16 +222,9 @@ export default function ChatPanel({
             if (toolCall.toolName === "display_diagram") {
                 const { xml } = toolCall.input as { xml: string }
 
-                // DEBUG: Log raw input to diagnose false truncation detection
-                console.log(
-                    "[display_diagram] XML ending (last 100 chars):",
-                    xml.slice(-100),
-                )
-                console.log("[display_diagram] XML length:", xml.length)
-
-                // Check if XML is truncated (incomplete mxCell indicates truncated output)
-                const isTruncated = !isMxCellXmlComplete(xml)
-                console.log("[display_diagram] isTruncated:", isTruncated)
+                // Check if XML is truncated (missing </root> indicates incomplete output)
+                const isTruncated =
+                    !xml.includes("</root>") && !xml.trim().endsWith("/>")
 
                 if (isTruncated) {
                     // Store the partial XML for continuation via append_diagram
@@ -262,9 +244,9 @@ ${partialEnding}
 \`\`\`
 
 NEXT STEP: Call append_diagram with the continuation XML.
-- Do NOT include wrapper tags or root cells (id="0", id="1")
+- Do NOT start with <mxGraphModel>, <root>, or <mxCell id="0"> (they already exist)
 - Start from EXACTLY where you stopped
-- Complete all remaining mxCell elements`,
+- End with the closing </root> tag to complete the diagram`,
                     })
                     return
                 }
@@ -394,21 +376,17 @@ Please retry with an adjusted search pattern or use display_diagram if retries a
                 const { xml } = toolCall.input as { xml: string }
 
                 // Detect if LLM incorrectly started fresh instead of continuing
-                // LLM should only output bare mxCells now, so wrapper tags indicate error
-                const trimmed = xml.trim()
                 const isFreshStart =
-                    trimmed.startsWith("<mxGraphModel") ||
-                    trimmed.startsWith("<root") ||
-                    trimmed.startsWith("<mxfile") ||
-                    trimmed.startsWith('<mxCell id="0"') ||
-                    trimmed.startsWith('<mxCell id="1"')
+                    xml.trim().startsWith("<mxGraphModel") ||
+                    xml.trim().startsWith("<root") ||
+                    xml.trim().startsWith('<mxCell id="0"')
 
                 if (isFreshStart) {
                     addToolOutput({
                         tool: "append_diagram",
                         toolCallId: toolCall.toolCallId,
                         state: "output-error",
-                        errorText: `ERROR: You started fresh with wrapper tags. Do NOT include wrapper tags or root cells (id="0", id="1").
+                        errorText: `ERROR: You started fresh with wrapper tags. Do NOT include <mxGraphModel>, <root>, or <mxCell id="0">.
 
 Continue from EXACTLY where the partial ended:
 \`\`\`
@@ -423,8 +401,8 @@ Start your continuation with the NEXT character after where it stopped.`,
                 // Append to accumulated XML
                 partialXmlRef.current += xml
 
-                // Check if XML is now complete (last mxCell is complete)
-                const isComplete = isMxCellXmlComplete(partialXmlRef.current)
+                // Check if XML is now complete
+                const isComplete = partialXmlRef.current.includes("</root>")
 
                 if (isComplete) {
                     // Wrap and display the complete diagram
@@ -461,7 +439,7 @@ Please use display_diagram with corrected XML.`,
                         tool: "append_diagram",
                         toolCallId: toolCall.toolCallId,
                         state: "output-error",
-                        errorText: `XML still incomplete (mxCell not closed). Call append_diagram again to continue.
+                        errorText: `XML still incomplete (missing </root>). Call append_diagram again to continue.
 
 Current ending:
 \`\`\`
@@ -523,10 +501,6 @@ Continue from EXACTLY where you stopped.`,
                 | Record<string, unknown>
                 | undefined
 
-            // DEBUG: Log finish reason to diagnose truncation
-            console.log("[onFinish] finishReason:", metadata?.finishReason)
-            console.log("[onFinish] metadata:", metadata)
-
             if (metadata) {
                 // Use Number.isFinite to guard against NaN (typeof NaN === 'number' is true)
                 const inputTokens = Number.isFinite(metadata.inputTokens)
@@ -632,10 +606,6 @@ Continue from EXACTLY where you stopped.`,
             }
         } catch (error) {
             console.error("Failed to restore from localStorage:", error)
-            // On complete failure, clear storage to allow recovery
-            localStorage.removeItem(STORAGE_MESSAGES_KEY)
-            localStorage.removeItem(STORAGE_XML_SNAPSHOTS_KEY)
-            toast.error("Session data was corrupted. Starting fresh.")
         }
     }, [setMessages])
 
@@ -680,71 +650,32 @@ Continue from EXACTLY where you stopped.`,
         }, 500)
     }, [isDrawioReady, onDisplayChart])
 
-    // Save messages to localStorage whenever they change (debounced to prevent blocking during streaming)
+    // Save messages to localStorage whenever they change
     useEffect(() => {
         if (!hasRestoredRef.current) return
-
-        // Clear any pending save
-        if (localStorageDebounceRef.current) {
-            clearTimeout(localStorageDebounceRef.current)
-        }
-
-        // Debounce: save after 1 second of no changes
-        localStorageDebounceRef.current = setTimeout(() => {
-            try {
-                console.time("perf:localStorage-messages")
-                localStorage.setItem(
-                    STORAGE_MESSAGES_KEY,
-                    JSON.stringify(messages),
-                )
-                console.timeEnd("perf:localStorage-messages")
-            } catch (error) {
-                console.error("Failed to save messages to localStorage:", error)
-            }
-        }, LOCAL_STORAGE_DEBOUNCE_MS)
-
-        // Cleanup on unmount
-        return () => {
-            if (localStorageDebounceRef.current) {
-                clearTimeout(localStorageDebounceRef.current)
-            }
+        try {
+            localStorage.setItem(STORAGE_MESSAGES_KEY, JSON.stringify(messages))
+        } catch (error) {
+            console.error("Failed to save messages to localStorage:", error)
         }
     }, [messages])
 
-    // Save diagram XML to localStorage whenever it changes (debounced)
+    // Save diagram XML to localStorage whenever it changes
     useEffect(() => {
         if (!canSaveDiagram) return
-        if (!chartXML || chartXML.length <= 300) return
-
-        // Clear any pending save
-        if (xmlStorageDebounceRef.current) {
-            clearTimeout(xmlStorageDebounceRef.current)
-        }
-
-        // Debounce: save after 1 second of no changes
-        xmlStorageDebounceRef.current = setTimeout(() => {
-            console.time("perf:localStorage-xml")
+        if (chartXML && chartXML.length > 300) {
             localStorage.setItem(STORAGE_DIAGRAM_XML_KEY, chartXML)
-            console.timeEnd("perf:localStorage-xml")
-        }, LOCAL_STORAGE_DEBOUNCE_MS)
-
-        return () => {
-            if (xmlStorageDebounceRef.current) {
-                clearTimeout(xmlStorageDebounceRef.current)
-            }
         }
     }, [chartXML, canSaveDiagram])
 
     // Save XML snapshots to localStorage whenever they change
     const saveXmlSnapshots = useCallback(() => {
         try {
-            console.time("perf:localStorage-snapshots")
             const snapshotsArray = Array.from(xmlSnapshotsRef.current.entries())
             localStorage.setItem(
                 STORAGE_XML_SNAPSHOTS_KEY,
                 JSON.stringify(snapshotsArray),
             )
-            console.timeEnd("perf:localStorage-snapshots")
         } catch (error) {
             console.error(
                 "Failed to save XML snapshots to localStorage:",
@@ -1001,9 +932,6 @@ Continue from EXACTLY where you stopped.`,
                         }),
                         ...(config.aiModel && { "x-ai-model": config.aiModel }),
                     }),
-                    ...(minimalStyle && {
-                        "x-minimal-style": "true",
-                    }),
                 },
             },
         )
@@ -1189,7 +1117,6 @@ Continue from EXACTLY where you stopped.`,
                     style: {
                         maxWidth: "480px",
                     },
-                    duration: 2000,
                 }}
             />
             {/* Header */}
@@ -1319,8 +1246,6 @@ Continue from EXACTLY where you stopped.`,
                     onToggleHistory={setShowHistory}
                     sessionId={sessionId}
                     error={error}
-                    minimalStyle={minimalStyle}
-                    onMinimalStyleChange={setMinimalStyle}
                 />
             </footer>
 

contexts/diagram-context.tsx

@@ -86,20 +86,16 @@ export function DiagramProvider({ children }: { children: React.ReactNode }) {
         chart: string,
         skipValidation?: boolean,
     ): string | null => {
-        console.time("perf:loadDiagram")
         let xmlToLoad = chart
 
         // Validate XML structure before loading (unless skipped for internal use)
         if (!skipValidation) {
-            console.time("perf:loadDiagram-validation")
             const validation = validateAndFixXml(chart)
-            console.timeEnd("perf:loadDiagram-validation")
             if (!validation.valid) {
                 console.warn(
                     "[loadDiagram] Validation error:",
                     validation.error,
                 )
-                console.timeEnd("perf:loadDiagram")
                 return validation.error
             }
             // Use fixed XML if auto-fix was applied
@@ -116,14 +112,11 @@ export function DiagramProvider({ children }: { children: React.ReactNode }) {
         setChartXML(xmlToLoad)
 
         if (drawioRef.current) {
-            console.time("perf:drawio-iframe-load")
             drawioRef.current.load({
                 xml: xmlToLoad,
             })
-            console.timeEnd("perf:drawio-iframe-load")
         }
 
-        console.timeEnd("perf:loadDiagram")
         return null
     }
 
@@ -145,20 +138,14 @@ export function DiagramProvider({ children }: { children: React.ReactNode }) {
         setLatestSvg(data.data)
 
         // Only add to history if this was a user-initiated export
-        // Limit to 20 entries to prevent memory leaks during long sessions
-        const MAX_HISTORY_SIZE = 20
         if (expectHistoryExportRef.current) {
-            setDiagramHistory((prev) => {
-                const newHistory = [
-                    ...prev,
-                    {
-                        svg: data.data,
-                        xml: extractedXML,
-                    },
-                ]
-                // Keep only the last MAX_HISTORY_SIZE entries (circular buffer)
-                return newHistory.slice(-MAX_HISTORY_SIZE)
-            })
+            setDiagramHistory((prev) => [
+                ...prev,
+                {
+                    svg: data.data,
+                    xml: extractedXML,
+                },
+            ])
             expectHistoryExportRef.current = false
         }
 

lib/cached-responses.ts

@@ -9,7 +9,12 @@ export const CACHED_EXAMPLE_RESPONSES: CachedResponse[] = [
         promptText:
             "Give me a **animated connector** diagram of transformer's architecture",
         hasImage: false,
-        xml: `<mxCell id="title" value="Transformer Architecture" style="text;html=1;strokeColor=none;fillColor=none;align=center;verticalAlign=middle;whiteSpace=wrap;rounded=0;fontSize=20;fontStyle=1;" vertex="1" parent="1">
+        xml: `<root>
+  <mxCell id="0"/>
+  <mxCell id="1" parent="0"/>
+
+
+  <mxCell id="title" value="Transformer Architecture" style="text;html=1;strokeColor=none;fillColor=none;align=center;verticalAlign=middle;whiteSpace=wrap;rounded=0;fontSize=20;fontStyle=1;" vertex="1" parent="1">
     <mxGeometry x="300" y="20" width="250" height="30" as="geometry"/>
   </mxCell>
 
@@ -249,12 +254,18 @@ export const CACHED_EXAMPLE_RESPONSES: CachedResponse[] = [
 
   <mxCell id="output_label" value="Outputs&#xa;(shifted right)" style="text;html=1;strokeColor=none;fillColor=none;align=center;verticalAlign=middle;whiteSpace=wrap;rounded=0;fontSize=12;fontStyle=1;" vertex="1" parent="1">
     <mxGeometry x="660" y="530" width="100" height="30" as="geometry"/>
-  </mxCell>`,
+  </mxCell>
+</root>`,
     },
     {
         promptText: "Replicate this in aws style",
         hasImage: true,
-        xml: `<mxCell id="2" value="AWS" style="sketch=0;outlineConnect=0;gradientColor=none;html=1;whiteSpace=wrap;fontSize=12;fontStyle=0;container=1;pointerEvents=0;collapsible=0;recursiveResize=0;shape=mxgraph.aws4.group;grIcon=mxgraph.aws4.group_aws_cloud;strokeColor=#232F3E;fillColor=none;verticalAlign=top;align=left;spacingLeft=30;fontColor=#232F3E;dashed=0;rounded=1;arcSize=5;" vertex="1" parent="1">
+        xml: `<root>
+  <mxCell id="0"/>
+  <mxCell id="1" parent="0"/>
+
+
+  <mxCell id="2" value="AWS" style="sketch=0;outlineConnect=0;gradientColor=none;html=1;whiteSpace=wrap;fontSize=12;fontStyle=0;container=1;pointerEvents=0;collapsible=0;recursiveResize=0;shape=mxgraph.aws4.group;grIcon=mxgraph.aws4.group_aws_cloud;strokeColor=#232F3E;fillColor=none;verticalAlign=top;align=left;spacingLeft=30;fontColor=#232F3E;dashed=0;rounded=1;arcSize=5;" vertex="1" parent="1">
     <mxGeometry x="340" y="40" width="880" height="520" as="geometry"/>
   </mxCell>
 
@@ -313,12 +324,18 @@ export const CACHED_EXAMPLE_RESPONSES: CachedResponse[] = [
       <mxPoint x="700" y="350" as="sourcePoint"/>
       <mxPoint x="750" y="300" as="targetPoint"/>
     </mxGeometry>
-  </mxCell>`,
+  </mxCell>
+</root>`,
     },
     {
         promptText: "Replicate this flowchart.",
         hasImage: true,
-        xml: `<mxCell id="2" value="Lamp doesn't work" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#ffcccc;strokeColor=#000000;strokeWidth=2;fontSize=18;fontStyle=0;" vertex="1" parent="1">
+        xml: `<root>
+  <mxCell id="0"/>
+  <mxCell id="1" parent="0"/>
+
+
+  <mxCell id="2" value="Lamp doesn't work" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#ffcccc;strokeColor=#000000;strokeWidth=2;fontSize=18;fontStyle=0;" vertex="1" parent="1">
     <mxGeometry x="140" y="40" width="180" height="60" as="geometry"/>
   </mxCell>
 
@@ -374,12 +391,16 @@ export const CACHED_EXAMPLE_RESPONSES: CachedResponse[] = [
 
   <mxCell id="12" value="Repair lamp" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#99ff99;strokeColor=#000000;strokeWidth=2;fontSize=18;fontStyle=0;" vertex="1" parent="1">
     <mxGeometry x="130" y="650" width="200" height="60" as="geometry"/>
-  </mxCell>`,
+  </mxCell>
+</root>`,
     },
     {
         promptText: "Summarize this paper as a diagram",
         hasImage: true,
-        xml: `<mxCell id="title_bg" parent="1"
+        xml: `            <root>
+                <mxCell id="0" />
+                <mxCell id="1" parent="0" />
+                <mxCell id="title_bg" parent="1"
                     style="rounded=1;whiteSpace=wrap;html=1;fillColor=#1a237e;strokeColor=none;arcSize=8;"
                     value="" vertex="1">
                     <mxGeometry height="80" width="720" x="40" y="20" as="geometry" />
@@ -730,12 +751,18 @@ export const CACHED_EXAMPLE_RESPONSES: CachedResponse[] = [
                     value="Foundational technique for modern LLM reasoning - inspired many follow-up works including Self-Consistency, Tree-of-Thought, etc."
                     vertex="1">
                     <mxGeometry height="55" width="230" x="530" y="600" as="geometry" />
-                </mxCell>`,
+                </mxCell>
+            </root>`,
     },
     {
         promptText: "Draw a cat for me",
         hasImage: false,
-        xml: `<mxCell id="2" value="" style="ellipse;whiteSpace=wrap;html=1;aspect=fixed;fillColor=#FFE6CC;strokeColor=#000000;strokeWidth=2;" vertex="1" parent="1">
+        xml: `<root>
+  <mxCell id="0"/>
+  <mxCell id="1" parent="0"/>
+
+
+  <mxCell id="2" value="" style="ellipse;whiteSpace=wrap;html=1;aspect=fixed;fillColor=#FFE6CC;strokeColor=#000000;strokeWidth=2;" vertex="1" parent="1">
     <mxGeometry x="300" y="150" width="120" height="120" as="geometry"/>
   </mxCell>
 
@@ -875,7 +902,9 @@ export const CACHED_EXAMPLE_RESPONSES: CachedResponse[] = [
         <mxPoint x="235" y="290"/>
       </Array>
     </mxGeometry>
-  </mxCell>`,
+  </mxCell>
+
+</root>`,
     },
 ]
 

lib/system-prompts.ts

@@ -104,21 +104,22 @@ When using edit_diagram tool:
 
 ## Draw.io XML Structure Reference
 
-**IMPORTANT:** You only generate the mxCell elements. The wrapper structure and root cells (id="0", id="1") are added automatically.
-
-Example - generate ONLY this:
+Basic structure:
 \`\`\`xml
-<mxCell id="2" value="Label" style="rounded=1;" vertex="1" parent="1">
-  <mxGeometry x="100" y="100" width="120" height="60" as="geometry"/>
-</mxCell>
+<mxGraphModel>
+  <root>
+    <mxCell id="0"/>
+    <mxCell id="1" parent="0"/>
+  </root>
+</mxGraphModel>
 \`\`\`
+Note: All other mxCell elements go as siblings after id="1".
 
 CRITICAL RULES:
-1. Generate ONLY mxCell elements - NO wrapper tags (<mxfile>, <mxGraphModel>, <root>)
-2. Do NOT include root cells (id="0" or id="1") - they are added automatically
-3. ALL mxCell elements must be siblings - NEVER nest mxCell inside another mxCell
-4. Use unique sequential IDs starting from "2"
-5. Set parent="1" for top-level shapes, or parent="<container-id>" for grouped elements
+1. Always include the two root cells: <mxCell id="0"/> and <mxCell id="1" parent="0"/>
+2. ALL mxCell elements must be DIRECT children of <root> - NEVER nest mxCell inside another mxCell
+3. Use unique sequential IDs for all cells (start from "2" for user content)
+4. Set parent="1" for top-level shapes, or parent="<container-id>" for grouped elements
 
 Shape (vertex) example:
 \`\`\`xml
@@ -132,90 +133,12 @@ Connector (edge) example:
 <mxCell id="3" style="endArrow=classic;html=1;" edge="1" parent="1" source="2" target="4">
   <mxGeometry relative="1" as="geometry"/>
 </mxCell>
-
-### Edge Routing Rules:
-When creating edges/connectors, you MUST follow these rules to avoid overlapping lines:
-
-**Rule 1: NEVER let multiple edges share the same path**
-- If two edges connect the same pair of nodes, they MUST exit/enter at DIFFERENT positions
-- Use exitY=0.3 for first edge, exitY=0.7 for second edge (NOT both 0.5)
-
-**Rule 2: For bidirectional connections (A↔B), use OPPOSITE sides**
-- A→B: exit from RIGHT side of A (exitX=1), enter LEFT side of B (entryX=0)
-- B→A: exit from LEFT side of B (exitX=0), enter RIGHT side of A (entryX=1)
-
-**Rule 3: Always specify exitX, exitY, entryX, entryY explicitly**
-- Every edge MUST have these 4 attributes set in the style
-- Example: style="edgeStyle=orthogonalEdgeStyle;exitX=1;exitY=0.3;entryX=0;entryY=0.3;endArrow=classic;"
-
-**Rule 4: Route edges AROUND intermediate shapes (obstacle avoidance) - CRITICAL!**
-- Before creating an edge, identify ALL shapes positioned between source and target
-- If any shape is in the direct path, you MUST use waypoints to route around it
-- For DIAGONAL connections: route along the PERIMETER (outside edge) of the diagram, NOT through the middle
-- Add 20-30px clearance from shape boundaries when calculating waypoint positions
-- Route ABOVE (lower y), BELOW (higher y), or to the SIDE of obstacles
-- NEVER draw a line that visually crosses over another shape's bounding box
-
-**Rule 5: Plan layout strategically BEFORE generating XML**
-- Organize shapes into visual layers/zones (columns or rows) based on diagram flow
-- Space shapes 150-200px apart to create clear routing channels for edges
-- Mentally trace each edge: "What shapes are between source and target?"
-- Prefer layouts where edges naturally flow in one direction (left-to-right or top-to-bottom)
-
-**Rule 6: Use multiple waypoints for complex routing**
-- One waypoint is often not enough - use 2-3 waypoints to create proper L-shaped or U-shaped paths
-- Each direction change needs a waypoint (corner point)
-- Waypoints should form clear horizontal/vertical segments (orthogonal routing)
-- Calculate positions by: (1) identify obstacle boundaries, (2) add 20-30px margin
-
-**Rule 7: Choose NATURAL connection points based on flow direction**
-- NEVER use corner connections (e.g., entryX=1,entryY=1) - they look unnatural
-- For TOP-TO-BOTTOM flow: exit from bottom (exitY=1), enter from top (entryY=0)
-- For LEFT-TO-RIGHT flow: exit from right (exitX=1), enter from left (entryX=0)
-- For DIAGONAL connections: use the side closest to the target, not corners
-- Example: Node below-right of source → exit from bottom (exitY=1) OR right (exitX=1), not corner
-
-**Before generating XML, mentally verify:**
-1. "Do any edges cross over shapes that aren't their source/target?" → If yes, add waypoints
-2. "Do any two edges share the same path?" → If yes, adjust exit/entry points
-3. "Are any connection points at corners (both X and Y are 0 or 1)?" → If yes, use edge centers instead
-4. "Could I rearrange shapes to reduce edge crossings?" → If yes, revise layout
-
-
 \`\`\`
 
-`
-
-// Style instructions - only included when minimalStyle is false
-const STYLE_INSTRUCTIONS = `
 Common styles:
 - Shapes: rounded=1 (rounded corners), fillColor=#hex, strokeColor=#hex
 - Edges: endArrow=classic/block/open/none, startArrow=none/classic, curved=1, edgeStyle=orthogonalEdgeStyle
 - Text: fontSize=14, fontStyle=1 (bold), align=center/left/right
-`
-
-// Minimal style instruction - skip styling and focus on layout (prepended to prompt for emphasis)
-const MINIMAL_STYLE_INSTRUCTION = `
-## ⚠️ MINIMAL STYLE MODE ACTIVE ⚠️
-
-### No Styling - Plain Black/White Only
-- NO fillColor, NO strokeColor, NO rounded, NO fontSize, NO fontStyle
-- NO color attributes (no hex colors like #ff69b4)
-- Style: "whiteSpace=wrap;html=1;" for shapes, "html=1;endArrow=classic;" for edges
-- IGNORE all color/style examples below
-
-### Container/Group Shapes - MUST be Transparent
-- For container shapes (boxes that contain other shapes): use "fillColor=none;" to make background transparent
-- This prevents containers from covering child elements
-- Example: style="whiteSpace=wrap;html=1;fillColor=none;" for container rectangles
-
-### Focus on Layout Quality
-Since we skip styling, STRICTLY follow the "Edge Routing Rules" section below:
-- SPACING: Minimum 50px gap between all elements
-- NO OVERLAPS: Elements and edges must never overlap
-- Follow ALL 7 Edge Routing Rules for arrow positioning
-- Use waypoints to route edges AROUND obstacles
-- Use different exitY/entryY values for multiple edges between same nodes
 
 `
 
@@ -228,30 +151,34 @@ const EXTENDED_ADDITIONS = `
 ### display_diagram Details
 
 **VALIDATION RULES** (XML will be rejected if violated):
-1. Generate ONLY mxCell elements - wrapper tags and root cells are added automatically
-2. All mxCell elements must be siblings - never nested inside other mxCell elements
-3. Every mxCell needs a unique id attribute (start from "2")
-4. Every mxCell needs a valid parent attribute (use "1" for top-level, or container-id for grouped)
-5. Edge source/target attributes must reference existing cell IDs
-6. Escape special characters in values: &lt; for <, &gt; for >, &amp; for &, &quot; for "
+1. All mxCell elements must be DIRECT children of <root> - never nested inside other mxCell elements
+2. Every mxCell needs a unique id attribute
+3. Every mxCell (except id="0") needs a valid parent attribute referencing an existing cell
+4. Edge source/target attributes must reference existing cell IDs
+5. Escape special characters in values: &lt; for <, &gt; for >, &amp; for &, &quot; for "
+6. Always start with the two root cells: <mxCell id="0"/><mxCell id="1" parent="0"/>
 
-**Example with swimlanes and edges** (generate ONLY this - no wrapper tags):
+**Example with swimlanes and edges** (note: all mxCells are siblings under <root>):
 \`\`\`xml
-<mxCell id="lane1" value="Frontend" style="swimlane;" vertex="1" parent="1">
-  <mxGeometry x="40" y="40" width="200" height="200" as="geometry"/>
-</mxCell>
-<mxCell id="step1" value="Step 1" style="rounded=1;" vertex="1" parent="lane1">
-  <mxGeometry x="20" y="60" width="160" height="40" as="geometry"/>
-</mxCell>
-<mxCell id="lane2" value="Backend" style="swimlane;" vertex="1" parent="1">
-  <mxGeometry x="280" y="40" width="200" height="200" as="geometry"/>
-</mxCell>
-<mxCell id="step2" value="Step 2" style="rounded=1;" vertex="1" parent="lane2">
-  <mxGeometry x="20" y="60" width="160" height="40" as="geometry"/>
-</mxCell>
-<mxCell id="edge1" style="edgeStyle=orthogonalEdgeStyle;endArrow=classic;" edge="1" parent="1" source="step1" target="step2">
-  <mxGeometry relative="1" as="geometry"/>
-</mxCell>
+<root>
+  <mxCell id="0"/>
+  <mxCell id="1" parent="0"/>
+  <mxCell id="lane1" value="Frontend" style="swimlane;" vertex="1" parent="1">
+    <mxGeometry x="40" y="40" width="200" height="200" as="geometry"/>
+  </mxCell>
+  <mxCell id="step1" value="Step 1" style="rounded=1;" vertex="1" parent="lane1">
+    <mxGeometry x="20" y="60" width="160" height="40" as="geometry"/>
+  </mxCell>
+  <mxCell id="lane2" value="Backend" style="swimlane;" vertex="1" parent="1">
+    <mxGeometry x="280" y="40" width="200" height="200" as="geometry"/>
+  </mxCell>
+  <mxCell id="step2" value="Step 2" style="rounded=1;" vertex="1" parent="lane2">
+    <mxGeometry x="20" y="60" width="160" height="40" as="geometry"/>
+  </mxCell>
+  <mxCell id="edge1" style="edgeStyle=orthogonalEdgeStyle;endArrow=classic;" edge="1" parent="1" source="step1" target="step2">
+    <mxGeometry relative="1" as="geometry"/>
+  </mxCell>
+</root>
 \`\`\`
 
 ### append_diagram Details
@@ -259,9 +186,9 @@ const EXTENDED_ADDITIONS = `
 **WHEN TO USE:** Only call this tool when display_diagram output was truncated (you'll see an error message about truncation).
 
 **CRITICAL RULES:**
-1. Do NOT include any wrapper tags - just continue the mxCell elements
+1. Do NOT start with <mxGraphModel>, <root>, or <mxCell id="0"> - they already exist in the partial
 2. Continue from EXACTLY where your previous output stopped
-3. Complete the remaining mxCell elements
+3. End with the closing </root> tag to complete the diagram
 4. If still truncated, call append_diagram again with the next fragment
 
 **Example:** If previous output ended with \`<mxCell id="x" style="rounded=1\`, continue with \`;" vertex="1">...\` and complete the remaining elements.
@@ -335,6 +262,53 @@ If edit_diagram fails with "pattern not found":
 
 
 
+### Edge Routing Rules:
+When creating edges/connectors, you MUST follow these rules to avoid overlapping lines:
+
+**Rule 1: NEVER let multiple edges share the same path**
+- If two edges connect the same pair of nodes, they MUST exit/enter at DIFFERENT positions
+- Use exitY=0.3 for first edge, exitY=0.7 for second edge (NOT both 0.5)
+
+**Rule 2: For bidirectional connections (A↔B), use OPPOSITE sides**
+- A→B: exit from RIGHT side of A (exitX=1), enter LEFT side of B (entryX=0)
+- B→A: exit from LEFT side of B (exitX=0), enter RIGHT side of A (entryX=1)
+
+**Rule 3: Always specify exitX, exitY, entryX, entryY explicitly**
+- Every edge MUST have these 4 attributes set in the style
+- Example: style="edgeStyle=orthogonalEdgeStyle;exitX=1;exitY=0.3;entryX=0;entryY=0.3;endArrow=classic;"
+
+**Rule 4: Route edges AROUND intermediate shapes (obstacle avoidance) - CRITICAL!**
+- Before creating an edge, identify ALL shapes positioned between source and target
+- If any shape is in the direct path, you MUST use waypoints to route around it
+- For DIAGONAL connections: route along the PERIMETER (outside edge) of the diagram, NOT through the middle
+- Add 20-30px clearance from shape boundaries when calculating waypoint positions
+- Route ABOVE (lower y), BELOW (higher y), or to the SIDE of obstacles
+- NEVER draw a line that visually crosses over another shape's bounding box
+
+**Rule 5: Plan layout strategically BEFORE generating XML**
+- Organize shapes into visual layers/zones (columns or rows) based on diagram flow
+- Space shapes 150-200px apart to create clear routing channels for edges
+- Mentally trace each edge: "What shapes are between source and target?"
+- Prefer layouts where edges naturally flow in one direction (left-to-right or top-to-bottom)
+
+**Rule 6: Use multiple waypoints for complex routing**
+- One waypoint is often not enough - use 2-3 waypoints to create proper L-shaped or U-shaped paths
+- Each direction change needs a waypoint (corner point)
+- Waypoints should form clear horizontal/vertical segments (orthogonal routing)
+- Calculate positions by: (1) identify obstacle boundaries, (2) add 20-30px margin
+
+**Rule 7: Choose NATURAL connection points based on flow direction**
+- NEVER use corner connections (e.g., entryX=1,entryY=1) - they look unnatural
+- For TOP-TO-BOTTOM flow: exit from bottom (exitY=1), enter from top (entryY=0)
+- For LEFT-TO-RIGHT flow: exit from right (exitX=1), enter from left (entryX=0)
+- For DIAGONAL connections: use the side closest to the target, not corners
+- Example: Node below-right of source → exit from bottom (exitY=1) OR right (exitX=1), not corner
+
+**Before generating XML, mentally verify:**
+1. "Do any edges cross over shapes that aren't their source/target?" → If yes, add waypoints
+2. "Do any two edges share the same path?" → If yes, adjust exit/entry points
+3. "Are any connection points at corners (both X and Y are 0 or 1)?" → If yes, use edge centers instead
+4. "Could I rearrange shapes to reduce edge crossings?" → If yes, revise layout
 
 ## Edge Examples
 
@@ -388,16 +362,12 @@ const EXTENDED_PROMPT_MODEL_PATTERNS = [
 ]
 
 /**
- * Get the appropriate system prompt based on the model ID and style preference
+ * Get the appropriate system prompt based on the model ID
  * Uses extended prompt for Opus 4.5 and Haiku 4.5 which have 4000 token cache minimum
  * @param modelId - The AI model ID from environment
- * @param minimalStyle - If true, removes style instructions to save tokens
  * @returns The system prompt string
  */
-export function getSystemPrompt(
-    modelId?: string,
-    minimalStyle?: boolean,
-): string {
+export function getSystemPrompt(modelId?: string): string {
     const modelName = modelId || "AI"
 
     let prompt: string
@@ -418,15 +388,5 @@ export function getSystemPrompt(
         prompt = DEFAULT_SYSTEM_PROMPT
     }
 
-    // Add style instructions based on preference
-    // Minimal style: prepend instruction at START (more prominent)
-    // Normal style: append at end
-    if (minimalStyle) {
-        console.log(`[System Prompt] Minimal style mode ENABLED`)
-        prompt = MINIMAL_STYLE_INSTRUCTION + prompt
-    } else {
-        prompt += STYLE_INSTRUCTIONS
-    }
-
     return prompt.replace("{{MODEL_NAME}}", modelName)
 }

lib/utils.ts

@@ -29,38 +29,6 @@ const STRUCTURAL_ATTRS = [
 /** Valid XML entity names */
 const VALID_ENTITIES = new Set(["lt", "gt", "amp", "quot", "apos"])
 
-// ============================================================================
-// mxCell XML Helpers
-// ============================================================================
-
-/**
- * Check if mxCell XML output is complete (not truncated).
- * Complete XML ends with a self-closing tag (/>) or closing mxCell tag.
- * Also handles function-calling wrapper tags that may be incorrectly included.
- * @param xml - The XML string to check (can be undefined/null)
- * @returns true if XML appears complete, false if truncated or empty
- */
-export function isMxCellXmlComplete(xml: string | undefined | null): boolean {
-    let trimmed = xml?.trim() || ""
-    if (!trimmed) return false
-
-    // Strip Anthropic function-calling wrapper tags if present
-    // These can leak into tool input due to AI SDK parsing issues
-    // Use loop because tags are nested: </mxCell></mxParameter></invoke>
-    let prev = ""
-    while (prev !== trimmed) {
-        prev = trimmed
-        trimmed = trimmed
-            .replace(/<\/mxParameter>\s*$/i, "")
-            .replace(/<\/invoke>\s*$/i, "")
-            .replace(/<\/antml:parameter>\s*$/i, "")
-            .replace(/<\/antml:invoke>\s*$/i, "")
-            .trim()
-    }
-
-    return trimmed.endsWith("/>") || trimmed.endsWith("</mxCell>")
-}
-
 // ============================================================================
 // XML Parsing Helpers
 // ============================================================================
@@ -214,13 +182,6 @@ export function convertToLegalXml(xmlString: string): string {
             )
         }
 
-        // Fix unescaped & characters in attribute values (but not valid entities)
-        // This prevents DOMParser from failing on content like "semantic & missing-step"
-        cellContent = cellContent.replace(
-            /&(?!(?:lt|gt|amp|quot|apos|#[0-9]+|#x[0-9a-fA-F]+);)/g,
-            "&amp;",
-        )
-
         // Indent each line of the matched block for readability.
         const formatted = cellContent
             .split("\n")
@@ -236,17 +197,13 @@ export function convertToLegalXml(xmlString: string): string {
 
 /**
  * Wrap XML content with the full mxfile structure required by draw.io.
- * Always adds root cells (id="0" and id="1") automatically.
- * If input already contains root cells, they are removed to avoid duplication.
- * LLM should only generate mxCell elements starting from id="2".
- * @param xml - The XML string (bare mxCells, <root>, <mxGraphModel>, or full <mxfile>)
- * @returns Full mxfile-wrapped XML string with root cells included
+ * Handles cases where XML is just <root>, <mxGraphModel>, or already has <mxfile>.
+ * @param xml - The XML string (may be partial or complete)
+ * @returns Full mxfile-wrapped XML string
  */
 export function wrapWithMxFile(xml: string): string {
-    const ROOT_CELLS = '<mxCell id="0"/><mxCell id="1" parent="0"/>'
-
-    if (!xml || !xml.trim()) {
-        return `<mxfile><diagram name="Page-1" id="page-1"><mxGraphModel><root>${ROOT_CELLS}</root></mxGraphModel></diagram></mxfile>`
+    if (!xml) {
+        return `<mxfile><diagram name="Page-1" id="page-1"><mxGraphModel><root><mxCell id="0"/><mxCell id="1" parent="0"/></root></mxGraphModel></diagram></mxfile>`
     }
 
     // Already has full structure
@@ -259,20 +216,9 @@ export function wrapWithMxFile(xml: string): string {
         return `<mxfile><diagram name="Page-1" id="page-1">${xml}</diagram></mxfile>`
     }
 
-    // Has <root> wrapper - extract inner content
-    let content = xml
-    if (xml.includes("<root>")) {
-        content = xml.replace(/<\/?root>/g, "").trim()
-    }
-
-    // Remove any existing root cells from content (LLM shouldn't include them, but handle it gracefully)
-    // Use flexible patterns that match both self-closing (/>) and non-self-closing (></mxCell>) formats
-    content = content
-        .replace(/<mxCell[^>]*\bid=["']0["'][^>]*(?:\/>|><\/mxCell>)/g, "")
-        .replace(/<mxCell[^>]*\bid=["']1["'][^>]*(?:\/>|><\/mxCell>)/g, "")
-        .trim()
-
-    return `<mxfile><diagram name="Page-1" id="page-1"><mxGraphModel><root>${ROOT_CELLS}${content}</root></mxGraphModel></diagram></mxfile>`
+    // Just <root> content - extract inner content and wrap fully
+    const rootContent = xml.replace(/<\/?root>/g, "").trim()
+    return `<mxfile><diagram name="Page-1" id="page-1"><mxGraphModel><root>${rootContent}</root></mxGraphModel></diagram></mxfile>`
 }
 
 /**
@@ -823,8 +769,6 @@ function checkNestedMxCells(xml: string): string | null {
  * @returns null if valid, error message string if invalid
  */
 export function validateMxCellStructure(xml: string): string | null {
-    console.time("perf:validateMxCellStructure")
-    console.log(`perf:validateMxCellStructure XML size: ${xml.length} bytes`)
     // Size check for performance
     if (xml.length > MAX_XML_SIZE) {
         console.warn(
@@ -834,18 +778,10 @@ export function validateMxCellStructure(xml: string): string | null {
 
     // 0. First use DOM parser to catch syntax errors (most accurate)
     try {
-        console.time("perf:validate-DOMParser")
         const parser = new DOMParser()
         const doc = parser.parseFromString(xml, "text/xml")
-        console.timeEnd("perf:validate-DOMParser")
         const parseError = doc.querySelector("parsererror")
         if (parseError) {
-            const actualError = parseError.textContent || "Unknown parse error"
-            console.log(
-                "[validateMxCellStructure] DOMParser error:",
-                actualError,
-            )
-            console.timeEnd("perf:validateMxCellStructure")
             return `Invalid XML: The XML contains syntax errors (likely unescaped special characters like <, >, & in attribute values). Please escape special characters: use &lt; for <, &gt; for >, &amp; for &, &quot; for ". Regenerate the diagram with properly escaped values.`
         }
 
@@ -854,7 +790,6 @@ export function validateMxCellStructure(xml: string): string | null {
         for (const cell of allCells) {
             if (cell.parentElement?.tagName === "mxCell") {
                 const id = cell.getAttribute("id") || "unknown"
-                console.timeEnd("perf:validateMxCellStructure")
                 return `Invalid XML: Found nested mxCell (id="${id}"). Cells should be siblings, not nested inside other mxCell elements.`
             }
         }
@@ -868,18 +803,12 @@ export function validateMxCellStructure(xml: string): string | null {
 
     // 1. Check for CDATA wrapper (invalid at document root)
     if (/^\s*<!\[CDATA\[/.test(xml)) {
-        console.timeEnd("perf:validateMxCellStructure")
         return "Invalid XML: XML is wrapped in CDATA section - remove <![CDATA[ from start and ]]> from end"
     }
 
     // 2. Check for duplicate structural attributes
-    console.time("perf:checkDuplicateAttributes")
     const dupAttrError = checkDuplicateAttributes(xml)
-    console.timeEnd("perf:checkDuplicateAttributes")
-    if (dupAttrError) {
-        console.timeEnd("perf:validateMxCellStructure")
-        return dupAttrError
-    }
+    if (dupAttrError) return dupAttrError
 
     // 3. Check for unescaped < in attribute values
     const attrValuePattern = /=\s*"([^"]*)"/g
@@ -887,67 +816,44 @@ export function validateMxCellStructure(xml: string): string | null {
     while ((attrValMatch = attrValuePattern.exec(xml)) !== null) {
         const value = attrValMatch[1]
         if (/</.test(value) && !/&lt;/.test(value)) {
-            console.timeEnd("perf:validateMxCellStructure")
             return "Invalid XML: Unescaped < character in attribute values. Replace < with &lt;"
         }
     }
 
     // 4. Check for duplicate IDs
-    console.time("perf:checkDuplicateIds")
     const dupIdError = checkDuplicateIds(xml)
-    console.timeEnd("perf:checkDuplicateIds")
-    if (dupIdError) {
-        console.timeEnd("perf:validateMxCellStructure")
-        return dupIdError
-    }
+    if (dupIdError) return dupIdError
 
     // 5. Check for tag mismatches
-    console.time("perf:checkTagMismatches")
     const tagMismatchError = checkTagMismatches(xml)
-    console.timeEnd("perf:checkTagMismatches")
-    if (tagMismatchError) {
-        console.timeEnd("perf:validateMxCellStructure")
-        return tagMismatchError
-    }
+    if (tagMismatchError) return tagMismatchError
 
     // 6. Check invalid character references
     const charRefError = checkCharacterReferences(xml)
-    if (charRefError) {
-        console.timeEnd("perf:validateMxCellStructure")
-        return charRefError
-    }
+    if (charRefError) return charRefError
 
     // 7. Check for invalid comment syntax (-- inside comments)
     const commentPattern = /<!--([\s\S]*?)-->/g
     let commentMatch
     while ((commentMatch = commentPattern.exec(xml)) !== null) {
         if (/--/.test(commentMatch[1])) {
-            console.timeEnd("perf:validateMxCellStructure")
             return "Invalid XML: Comment contains -- (double hyphen) which is not allowed"
         }
     }
 
     // 8. Check for unescaped entity references and invalid entity names
     const entityError = checkEntityReferences(xml)
-    if (entityError) {
-        console.timeEnd("perf:validateMxCellStructure")
-        return entityError
-    }
+    if (entityError) return entityError
 
     // 9. Check for empty id attributes on mxCell
     if (/<mxCell[^>]*\sid\s*=\s*["']\s*["'][^>]*>/g.test(xml)) {
-        console.timeEnd("perf:validateMxCellStructure")
         return "Invalid XML: Found mxCell element(s) with empty id attribute"
     }
 
     // 10. Check for nested mxCell tags
     const nestedCellError = checkNestedMxCells(xml)
-    if (nestedCellError) {
-        console.timeEnd("perf:validateMxCellStructure")
-        return nestedCellError
-    }
+    if (nestedCellError) return nestedCellError
 
-    console.timeEnd("perf:validateMxCellStructure")
     return null
 }
 
@@ -1151,56 +1057,12 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
     // This handles both opening and closing tags
     const hasCellTags = /<\/?Cell[\s>]/i.test(fixed)
     if (hasCellTags) {
-        console.log("[autoFixXml] Step 8: Found <Cell> tags to fix")
-        const beforeFix = fixed
         fixed = fixed.replace(/<Cell(\s)/gi, "<mxCell$1")
         fixed = fixed.replace(/<Cell>/gi, "<mxCell>")
         fixed = fixed.replace(/<\/Cell>/gi, "</mxCell>")
-        if (beforeFix !== fixed) {
-            console.log("[autoFixXml] Step 8: Fixed <Cell> tags")
-        }
         fixes.push("Fixed <Cell> tags to <mxCell>")
     }
 
-    // 8b. Remove non-draw.io tags (LLM sometimes includes Claude's function calling XML)
-    // Valid draw.io tags: mxfile, diagram, mxGraphModel, root, mxCell, mxGeometry, mxPoint, Array, Object
-    const validDrawioTags = new Set([
-        "mxfile",
-        "diagram",
-        "mxGraphModel",
-        "root",
-        "mxCell",
-        "mxGeometry",
-        "mxPoint",
-        "Array",
-        "Object",
-        "mxRectangle",
-    ])
-    const foreignTagPattern = /<\/?([a-zA-Z][a-zA-Z0-9_]*)[^>]*>/g
-    let foreignMatch
-    const foreignTags = new Set<string>()
-    while ((foreignMatch = foreignTagPattern.exec(fixed)) !== null) {
-        const tagName = foreignMatch[1]
-        if (!validDrawioTags.has(tagName)) {
-            foreignTags.add(tagName)
-        }
-    }
-    if (foreignTags.size > 0) {
-        console.log(
-            "[autoFixXml] Step 8b: Found foreign tags:",
-            Array.from(foreignTags),
-        )
-        for (const tag of foreignTags) {
-            // Remove opening tags (with or without attributes)
-            fixed = fixed.replace(new RegExp(`<${tag}[^>]*>`, "gi"), "")
-            // Remove closing tags
-            fixed = fixed.replace(new RegExp(`</${tag}>`, "gi"), "")
-        }
-        fixes.push(
-            `Removed foreign tags: ${Array.from(foreignTags).join(", ")}`,
-        )
-    }
-
     // 9. Fix common closing tag typos
     const tagTypos = [
         { wrong: /<\/mxElement>/gi, right: "</mxCell>", name: "</mxElement>" },
@@ -1266,98 +1128,6 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
         }
     }
 
-    // 10b. Remove extra closing tags (more closes than opens)
-    // Need to properly count self-closing tags (they don't need closing tags)
-    const tagCounts = new Map<
-        string,
-        { opens: number; closes: number; selfClosing: number }
-    >()
-    // Match full tags to detect self-closing by checking if ends with />
-    const fullTagPattern = /<(\/?[a-zA-Z][a-zA-Z0-9]*)[^>]*>/g
-    let tagCountMatch
-    while ((tagCountMatch = fullTagPattern.exec(fixed)) !== null) {
-        const fullMatch = tagCountMatch[0] // e.g., "<mxCell .../>" or "</mxCell>"
-        const tagPart = tagCountMatch[1] // e.g., "mxCell" or "/mxCell"
-        const isClosing = tagPart.startsWith("/")
-        const isSelfClosing = fullMatch.endsWith("/>")
-        const tagName = isClosing ? tagPart.slice(1) : tagPart
-
-        let counts = tagCounts.get(tagName)
-        if (!counts) {
-            counts = { opens: 0, closes: 0, selfClosing: 0 }
-            tagCounts.set(tagName, counts)
-        }
-        if (isClosing) {
-            counts.closes++
-        } else if (isSelfClosing) {
-            counts.selfClosing++
-        } else {
-            counts.opens++
-        }
-    }
-
-    // Log tag counts for debugging
-    for (const [tagName, counts] of tagCounts) {
-        if (
-            tagName === "mxCell" ||
-            tagName === "mxGeometry" ||
-            counts.opens !== counts.closes
-        ) {
-            console.log(
-                `[autoFixXml] Step 10b: ${tagName} - opens: ${counts.opens}, closes: ${counts.closes}, selfClosing: ${counts.selfClosing}`,
-            )
-        }
-    }
-
-    // Find tags with extra closing tags (self-closing tags are balanced, don't need closing)
-    for (const [tagName, counts] of tagCounts) {
-        const extraCloses = counts.closes - counts.opens // Only compare opens vs closes (self-closing are balanced)
-        if (extraCloses > 0) {
-            console.log(
-                `[autoFixXml] Step 10b: ${tagName} has ${counts.opens} opens, ${counts.closes} closes, removing ${extraCloses} extra`,
-            )
-            // Remove extra closing tags from the end
-            let removed = 0
-            const closeTagPattern = new RegExp(`</${tagName}>`, "g")
-            const matches = [...fixed.matchAll(closeTagPattern)]
-            // Remove from the end (last occurrences are likely the extras)
-            for (
-                let i = matches.length - 1;
-                i >= 0 && removed < extraCloses;
-                i--
-            ) {
-                const match = matches[i]
-                const idx = match.index ?? 0
-                fixed = fixed.slice(0, idx) + fixed.slice(idx + match[0].length)
-                removed++
-            }
-            if (removed > 0) {
-                console.log(
-                    `[autoFixXml] Step 10b: Removed ${removed} extra </${tagName}>`,
-                )
-                fixes.push(
-                    `Removed ${removed} extra </${tagName}> closing tag(s)`,
-                )
-            }
-        }
-    }
-
-    // 10c. Remove trailing garbage after last XML tag (e.g., stray backslashes, text)
-    // Find the last valid closing tag or self-closing tag
-    const closingTagPattern = /<\/[a-zA-Z][a-zA-Z0-9]*>|\/>/g
-    let lastValidTagEnd = -1
-    let closingMatch
-    while ((closingMatch = closingTagPattern.exec(fixed)) !== null) {
-        lastValidTagEnd = closingMatch.index + closingMatch[0].length
-    }
-    if (lastValidTagEnd > 0 && lastValidTagEnd < fixed.length) {
-        const trailing = fixed.slice(lastValidTagEnd).trim()
-        if (trailing) {
-            fixed = fixed.slice(0, lastValidTagEnd)
-            fixes.push("Removed trailing garbage after last XML tag")
-        }
-    }
-
     // 11. Fix nested mxCell by flattening
     // Pattern A: <mxCell id="X">...<mxCell id="X">...</mxCell></mxCell> (duplicate ID)
     // Pattern B: <mxCell id="X">...<mxCell id="Y">...</mxCell></mxCell> (different ID - true nesting)
@@ -1567,26 +1337,16 @@ export function validateAndFixXml(xml: string): {
 
     // Try to fix
     const { fixed, fixes } = autoFixXml(xml)
-    console.log("[validateAndFixXml] Fixes applied:", fixes)
 
     // Validate the fixed version
     error = validateMxCellStructure(fixed)
-    if (error) {
-        console.log("[validateAndFixXml] Still invalid after fix:", error)
-    }
 
     if (!error) {
         return { valid: true, error: null, fixed, fixes }
     }
 
-    // Still invalid after fixes - but return the partially fixed XML
-    // so we can see what was fixed and what error remains
-    return {
-        valid: false,
-        error,
-        fixed: fixes.length > 0 ? fixed : null,
-        fixes,
-    }
+    // Still invalid after fixes
+    return { valid: false, error, fixed: null, fixes }
 }
 
 export function extractDiagramXML(xml_svg_string: string): string {

package.json

@@ -1,6 +1,6 @@
 {
     "name": "next-ai-draw-io",
-    "version": "0.4.1",
+    "version": "0.4.0",
     "license": "Apache-2.0",
     "private": true,
     "scripts": {