* feat(session): add chat session history with IndexedDB storage
- Add session-storage.ts with IndexedDB wrapper using idb library
- Add use-session-manager.ts hook for session state management
- Add session-history-dropdown.tsx for session selection UI
- Integrate session system into chat-panel.tsx
- Auto-generate session titles from first user message
- Auto-save sessions on message completion
- Support session switching, deletion, and creation
- Migrate existing localStorage data to IndexedDB
- Add i18n translations for session history UI
* feat(session): improve history dropdown and persist diagram history
- Add time-based grouping (Today, Yesterday, This Week, Earlier)
- Add thumbnail previews using Next.js Image component
- Add staggered entrance animations with fade-in effects
- Improve active session indicator with left border accent
- Fix scrolling by using native overflow instead of ScrollArea
- Persist diagram version history to IndexedDB sessions
- Remove redundant diagram XML from localStorage
- Add i18n strings for time group labels (en, ja, zh)
* fix(session): prevent data loss on theme change and tab close
- Add isDrawioReady effect to restore diagram after DrawIO remount
- Add visibilitychange handler to save session when page becomes hidden
- Fix missing currentSessionId in saveCurrentSession dependency array
- Remove unused sanitizeMessages import from use-session-manager
* fix(session): fix diagram save and migration data loss bugs
- Add diagramHistory to save effect dependency array so diagram-only
edits trigger saves (previously only message changes did)
- Destructure stable sessionManager values to prevent unnecessary
effect re-runs on every render
- Add try-catch wrapper around debounced async save operation
- Make saveSession() return boolean to indicate success/failure
- Verify IndexedDB write succeeded before deleting localStorage data
during migration (prevents data loss if write silently fails)
- Keep localStorage data for retry if migration fails instead of
marking as complete anyway
* refactor(session): extract helpers to reduce code duplication
- Add syncUIWithSession helper to consolidate 4 duplicate UI sync blocks
- Add buildSessionData helper to consolidate 4 duplicate save logic blocks
- Remove unused saveTimeoutRef and its cleanup effect
- Net reduction of ~80 lines of duplicate code
* style(ui): improve history dropdown and delete dialog styling
- Change destructive color from coral to muted rose for refined look
- Make session history panel taller (400px fixed height)
- Fix popover alignment to prevent truncation
- Style delete button with soft red outline instead of solid fill
- Make delete dialog more compact (max-w-sm)
* fix(session): reset refs on new chat and show recent sessions
- Fix cached example diagrams not displaying after creating new session
- Reset previousXML, lastProcessedXmlRef and processedToolCalls when
messages become empty (new chat or session switch)
- Add recent chats section in empty chat state with collapsible examples
- Pass sessions and onSelectSession to ChatMessageDisplay
- Add loadedMessageIdsRef to skip animations on session restore
- Add debug console.log for diagram processing flow
* feat(session): add search bar and improve history UI
- Remove session history dropdown, use main panel instead
- Add search bar to filter history chats by title
- Show minutes (Xm ago) instead of "Just now" for recent sessions
- Scroll to top when switching to new/empty chat
- Remove title truncation limit for better searchability
- Remove debug console.log statements
* refactor: remove redundant code and fix nested button hydration error
- Remove unused 'sessions' from deleteSession dependency array
- Remove unused 'switchedTo' variable and simplify return type
- Remove unused 'restoredMessageIdsRef' (always empty)
- Fix nested button hydration error by using div with role=button
- Simplify handleDeleteSession callback
* fix(session): fix migration bug, improve metadata perf, truncate titles
- Fix migration retry loop when localStorage has empty array
- Use cursor-based iteration for getAllSessionMetadata
- Truncate session titles to 100 chars with ellipsis
* refactor: remove dead code and extract diagram length constant
- Remove unused exports: getAllSessions, createNewSession, updateSessionTitle
- Remove write-only CURRENT_SESSION_KEY and all localStorage calls
- Remove dead messagesEndRef and unused scroll effect
- Extract magic number 300 to MIN_REAL_DIAGRAM_LENGTH constant
- Add isRealDiagram() helper function for semantic clarity
* fix(edit_diagram): implement cascade delete for children and edges
- Add automatic cascade deletion when deleting a cell
- Recursively delete all child cells (parent attribute references)
- Delete all edges referencing deleted cells (source/target)
- Skip silently if cell already deleted (handles AI redundant ops)
- Update prompts to inform AI about cascade behavior
Fixes#450
* fix: add root cell protection and sync MCP server cascade delete
- Add protection for root cells '0' and '1' to prevent full diagram wipe
- Sync MCP server with main app's cascade delete logic
- Both lib/utils.ts and packages/mcp-server now have identical delete behavior
* chore(mcp): bump version to 0.1.9
* fix(cascade-delete): recursively collect edge children (labels)
- Change from cellsToDelete.add(edgeId) to collectDescendants(edgeId)
- Fixes orphaned edge labels causing draw.io to crash/clear canvas
- Edge labels (parent=edgeId) are now deleted with their parent edge
Fixes#374 - Models were confused by the `type` field name and sent
`operation` instead. This change:
- Renames DiagramOperation.type to DiagramOperation.operation across
all files (MCP server, web app, hooks, components, system prompts)
- Adds JSON examples in tool descriptions to show correct format
- Updates all test data to use the new field name
Affected files:
- lib/utils.ts
- app/api/chat/route.ts
- hooks/use-diagram-tool-handlers.ts
- components/chat-message-display.tsx
- lib/system-prompts.ts
- packages/mcp-server/src/diagram-operations.ts
- packages/mcp-server/src/index.ts
- scripts/test-diagram-operations.mjs
MCP server version bumped to 0.1.6
- Add HTML escaping (<, >) in convertToLegalXml for attribute values
- Update isMxCellXmlComplete to handle any LLM provider's wrapper tags
- Add wrapper tag stripping in wrapWithMxFile for DeepSeek/Anthropic tags
- Update autoFixXml to escape both < and > in attribute values
Fixes 'Malformed XML detected in final output' error when AI generates
diagrams with HTML content in value attributes like <b>Title</b>.
- Add extractCompleteMxCells() to extract only complete mxCell elements from partial XML
- Remove useEffect cleanup that was killing debounce timeouts on every re-render
- Wrap XML in <root> tags for proper DOMParser validation
Previously, diagrams only rendered after ALL XML finished streaming because:
1. useEffect cleanup cleared the 150ms debounce timeout on every message change
2. DOMParser rejected partial XML like '<mxCell id="2" value="...' (incomplete)
Now each complete mxCell renders progressively as it finishes streaming.
* feat(mcp): add XML validation and auto-fix to MCP server
- Add xml-validation.ts with validateAndFixXml function
- Integrate validation into display_diagram tool (fails if unfixable)
- Integrate validation into edit_diagram tool (auto-fix each operation)
- Fix bug: typo fixes now run before foreign tag removal
- Fix bug: use before/after comparison instead of regex .test()
* style: auto-format with Biome
* chore(mcp): bump version to 0.1.3
---------
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
* refactor: replace text-based edit_diagram with ID-based operations
- Add applyDiagramOperations() function using DOMParser for ID lookup
- New schema: operations array with type (update/add/delete), cell_id, new_xml
- Update chat-panel.tsx handler for new operations format
- Update OperationsDisplay component to show operation type and cell_id
- Simplify system prompts with new ID-based examples
- Add ID validation for add operations
- Add warning for edges referencing deleted cells
* fix: add ID validation to update operation and remove dead code
- Add ID mismatch validation to update operation (consistency with add)
- Remove orphaned replaceXMLParts function (~300 lines of dead code)
- Update cell_id schema description for clarity
- Add unit tests for applyDiagramOperations (11 tests)
* feat: add minimal style mode toggle for faster diagram generation
- Add Minimal/Styled toggle switch in chat input UI
- When enabled, removes color/style instructions from system prompt
- Faster generation with plain black/white diagrams
- Improves XML auto-fix: handle foreign tags, extra closing tags, trailing garbage
- Fix isMxCellXmlComplete to strip Anthropic function-calling wrappers
- Add debug logging for truncation detection diagnosis
* fix: prevent false XML parse errors during streaming
- Escape unescaped & characters in convertToLegalXml() before DOMParser validation
- Only log console.error for final output, not during streaming updates
- Prevents Next.js dev mode error overlay from showing for expected streaming states
* refactor: simplify LLM XML format to output bare mxCells only
- Update wrapWithMxFile() to always add root cells (id=0, id=1) automatically
- LLM now generates only mxCell elements starting from id=2 (no wrapper tags)
- Update system prompts and tool descriptions with new format instructions
- Update cached responses to remove root cells and wrapper tags
- Update truncation detection to check for complete mxCell endings
- Update documentation in xml_guide.md
* fix: address PR review issues for XML format refactor
- Fix critical bug: inconsistent truncation check using old </root> pattern
- Fix stale error message referencing </root> tag
- Add isMxCellXmlComplete() helper for consistent truncation detection
- Improve regex patterns to handle any attribute order in root cells
- Update wrapWithMxFile JSDoc to document root cell removal behavior
* fix: handle non-self-closing root cells in wrapWithMxFile regex
* feat: support minimax model with XML wrapping fix
- Add wrapWithMxFile utility to properly wrap XML for draw.io
- Fix 'Not a diagram file' error when model generates raw <root> XML
- Add supportsPromptCaching check for conditional caching
- Only enable Bedrock prompt caching for Claude models
* docs: update model mention to minimax-m2 across About pages and READMEs
- Update tooltip in chat-panel.tsx to mention minimax-m2 model change
- Update English, Chinese, and Japanese About pages with model change info
- Update English, Chinese, and Japanese READMEs with demo site model note
---------
Co-authored-by: dayuan.jiang <jiangdy@amazon.co.jp>
- Save and restore chat messages, XML snapshots, session ID, and diagram XML to localStorage
- Restore diagram when DrawIO becomes ready (using new onLoad callback)
- Change close protection default to false since auto-save handles persistence
- Clear localStorage when clearing chat
- Handle edge cases: undefined edit fields, empty chartXML, missing access code header
- Add validation for orphaned mxPoint elements in validateMxCellStructure()
- Add cleanup of orphaned mxPoint elements in convertToLegalXml()
- Orphaned mxPoints cause 'Could not add object mxPoint' errors in draw.io
- mxPoint elements must have 'as' attribute or be inside <Array as="points">
Co-authored-by: dayuan.jiang <jiangdy@amazon.co.jp>
- Add 6th strategy: match by value attribute (label text)
- Add 7th strategy: normalized whitespace match
- Remove lastProcessedIndex tracking - always search from beginning
- Pairs may not be in document order, so sequential tracking was unreliable
Co-authored-by: dayuan.jiang <jiangdy@amazon.co.jp>
- Add Biome as formatter and linter (replaces Prettier)
- Configure Husky + lint-staged for pre-commit hooks
- Add VS Code settings for format on save
- Ignore components/ui/ (shadcn generated code)
- Remove semicolons, use 4-space indent
- Reformat all files to new style
- Update log-feedback API to find existing chat trace by sessionId and attach score to it
- Update log-save API to create span on existing chat trace instead of standalone trace
- Add thumbs up/down feedback buttons on assistant messages
- Add message regeneration and edit functionality
- Add save dialog with format selection (drawio, png, svg)
- Pass sessionId through components for Langfuse linking
- Extract system prompts to dedicated lib/system-prompts.ts module
- Add extended system prompt (~4000 tokens) for models with higher cache minimums (Opus 4.5, Haiku 4.5)
- Clean up debug logs while preserving informational and cache-related logs
- Improve code formatting and organization in chat route
- Add essential draw.io XML structure rules to system prompt
- Include critical rules about mxCell nesting (all must be direct children of root)
- Add shape/vertex and connector/edge examples with proper structure
- Improve tool description for display_diagram with validation rules
- Update xml_guide.md with better swimlane examples showing flat structure
- Add client-side XML validation to catch nested mxCell errors early
Helps address issues #40 (local Ollama models not working) and #39 (mxCell nesting errors)
- Add formatXML function to format single-line XML with proper indentation
- Format chartXml after fetching to ensure consistency
- Update replaceXMLParts to handle single-line XML with substring fallback
- Improve edit_diagram tool guidance with SEARCH/REPLACE best practices
- Add concrete examples to help AI use minimal, targeted edits
