- Update lastSyncedElementsRef on every WS-applied scene change so
auto-sync does not revert MCP writes back to stale browser state
- Fix labeled container updates (rect/ellipse/diamond/arrow) to use
convertToExcalidrawElements with bound-text ID transplant, preventing
text clipping and empty labels after update
- Fix standalone text element updates to write into text/originalText
so Excalidraw renders the new value immediately
- Fix convertTextToLabel to handle arrows and empty string text values
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Deletions made in the UI were silently lost on page reload because the sync
baseline (lastSyncedElementsRef) was never populated after initial load,
making the delta algorithm unable to detect removed elements. Additionally,
import_scene and restore_snapshot used a non-atomic clear+create pattern
that could permanently lose all canvas data if the batch create failed
after clearing, and duplicate_elements copied stale binding references
pointing to original element IDs instead of remapped duplicates.
🔧 Sync baseline restoration:
- Populate deletion-detection baseline on every server-to-client data path
(page load, delta resync, hello handshake, initial elements broadcast)
- Establish sync version and hash baselines to prevent phantom re-syncs
🛡️ Data-loss prevention:
- Backup current scene before destructive clear in replace-mode operations
- Atomic restore from backup when subsequent batch create fails
- Remap all binding references (start/end IDs, boundElements, containerId)
to new IDs during element duplication
✅ Comprehensive test coverage (154 new tests, 344 total):
- Delta sync flows including deletion persistence and bidirectional sync
- Multi-tenant element/sync/WebSocket isolation
- Arrow binding resolution across all shape types and edge cases
- MCP tool integration covering backup-restore and binding remapping
- Input validation and security boundary testing
- Frontend sync algorithm unit tests reproducing the exact regression
🎯 Eliminates the most critical data-integrity risks: deletions now
persist reliably, destructive operations are rollback-safe, and the
full test suite provides regression coverage for every sync path.
Fix 6 bugs discovered during MCP tool usage:
1. syncToCanvas error handling: Distinguish network errors (return null)
from API errors (re-throw with actual message). Fixes misleading
"HTTP server unavailable" on batch_create_elements.
2. USER_PREFS fallbacks: create_element and batch_create_elements now
apply fontFamily/roughness/fontSize/strokeWidth from preferences.json
when not explicitly provided by the caller.
3. Hello handshake: Frontend sends `hello` on tenant_switched and handles
`hello_ack`. Server resolves projectId from tenantId when absent.
Fixes WS connections being registered under wrong scope.
4. Serialized broadcasts: Add serializedBroadcastWithAck() that queues
broadcasts per tenant/project scope. Prevents race condition where
parallel MCP create_element calls produce overlapping WS messages
that clobber each other in the frontend.
5. Viewport screenshot: get_canvas_screenshot passes captureViewport=true,
frontend captures DOM canvas via toDataURL() instead of exportToBlob()
which always rendered the full scene bounding box.
6. Viewport animate:false: set_viewport uses animate:false for instant
positioning, preventing mid-animation screenshot captures.
Tests: 14 new tests (8 API, 6 WS) + 9 E2E specs covering all fixes.
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Implement a complete sync architecture overhaul (12 tasks) replacing the flat
WebSocket broadcast with scoped, acknowledged delivery:
**Backend (server.ts, db.ts, types.ts, index.ts):**
- Scoped connection registry: Map<tenant, Map<project, Set<ClientConnection>>>
- Hello handshake: WS clients identify tenant/project, server responds with scoped elements
- broadcastToScope() replaces global broadcast for element mutations
- broadcastWithAck() waits for browser ACK before returning syncedToCanvas status
- sync_version: monotonic counter per project, stamped on every mutation
- Delta sync v2: POST /api/elements/sync/v2 for incremental sync with version tracking
- GET /api/sync/version endpoint
- Honest syncedToCanvas + canvasStatus in all mutation responses
- Fixed silent try/catch in tenant switch verification
**Frontend (App.tsx):**
- ACK sending after every updateScene() with element verification
- Delta sync v2 integration in syncToBackend()
- Gap detection: triggers resync when sync_version gaps are detected
- lastSyncVersion tracking via refs + localStorage persistence
**Tests (40 new tests, 168 total):**
- db.test.ts: +11 tests for sync_version CRUD, scoping, getChangesSince
- ws.test.ts: +8 tests for hello handshake, scoped broadcast, ACK model
- api.test.ts: +10 tests for sync/v2, sync/version, canvasStatus responses
- helpers.test.ts: +11 tests for isImageElement, normalizeImageElement, restoreBindings
- canvas.spec.ts: +8 e2e tests including full ACK pipeline verification
- Fixed stale tenant state bug in api.test.ts beforeEach
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Establish comprehensive quality infrastructure for a project that previously
had zero tests, enabling confident refactoring and community contributions
with automated guardrails. Port upstream enhancements for font normalization,
image element support, and arrow binding preservation.
🏗️ Testing infrastructure:
- Unit tests for SQLite persistence layer and element validation helpers
- Integration tests for REST API, WebSocket broadcast, and arrow binding
- E2E tests with Playwright for canvas rendering and real-time sync
- Vitest + Playwright configuration with proper isolation
👷 CI/CD pipeline:
- Auto-versioning from conventional commits on push to main
- Auto-publish to NPM and Docker Hub on GitHub release
- Matrix testing across Node 18/20/22 with pinned dependencies
- Docker health check with diagnostic logging on failure
- Preserve rollup status checks for branch protection gates
📦 Developer experience:
- Interactive setup wizard for first-time configuration
- Canvas clear confirmation and scene description tools
- Frontend helpers extracted for testability
🔧 Upstream feature ports:
- Font family normalization (string names to numeric IDs)
- Image element support with file management API
- Arrow binding preservation through server round-trips
- Vite config fix for font subsetting worker chunk names
- Idempotent database initialization for standalone Docker mode
🐛 Docker fixes:
- Set EXCALIDRAW_DB_PATH in both Dockerfiles to writable /app/data/
- Make initDb() idempotent and closeDb() reset-safe for test isolation
🎯 Provides the safety net needed for rapid iteration — every PR is
validated across 120 test cases before merge, and releases are fully
automated from commit to published package.
Co-authored-by: sanjibdevnathlabs <devnath.sanjib@gmail.com>
Replace in-memory storage with SQLite (WAL mode), add workspace-based
multi-tenancy with auto-detection via server.listRoots(), and embed the
canvas server into the MCP process for single-process operation.
🔧 Core enhancements:
- SQLite persistence with versioning, element history, and search
- Multi-tenancy: isolated canvases per workspace (SHA-256 tenant IDs)
- Embedded canvas lifecycle (single node process starts MCP + canvas)
- Auto-sync with 3s debounce and manual override toggle
- Configurable canvas port via CANVAS_PORT env var
- 6 new MCP tools (search, history, tenants, projects)
- Workspace switcher UI with dropdown search
- Sync normalization to prevent bound-text breakage on reload
🐳 Docker & CI improvements:
- BuildKit cache mounts for faster npm installs across builds
- Skip native compilation in frontend-builder stage (--ignore-scripts)
- Build only linux/amd64 on PRs, multi-arch on push to main
- Docker Hub registry with proper build tools for better-sqlite3
- CI and Docker status check gates (github/ci-status-check, github/docker-build-check)
📦 Package & publishing:
- Renamed to @sanjibdevnath/mcp-excalidraw-local (v3.0.0)
- Updated npm-publish workflow for scoped package
- Updated bin entry, keywords, and files list
📝 Documentation:
- README with UI screenshots, architecture diagram, and full feature docs
- Updated agent skill with 32-tool cheatsheet and workflow playbooks
- Fork attribution and upstream comparison table
Co-authored-by: Cursor <cursoragent@cursor.com>
* feat: enhance Excalidraw MCP with advanced canvas toolkit features
- Rename skill to `excalidraw-skill` with expanded playbook and cheatsheet.
- Add new MCP tools for iterative refinement: `describe_scene` and `get_canvas_screenshot`.
- Implement layout tools (`align_elements`, `distribute_elements`) and `duplicate_elements`.
- Add file I/O support for `.excalidraw` JSON and image export (PNG/SVG).
- Introduce named snapshots for canvas state management.
- Add server-side element CRUD and WebSocket handlers for real-time sync.
- Normalize `points` format for arrows and lines.
* docs: update README with v2.0 features and official MCP comparison
* feat: implement arrow binding and edge-to-edge routing
* fix: enhance security with path sanitization and improve export error handling
* feat: add viewport control, design guide, and excalidraw.com URL export
* feat: enhance excalidraw.com export with proper scene formatting and labels
* feat(skill): add excalidraw-mcp skill with export/import helpers
* fix(skill): correct url trailing-slash normalization in scripts
* feat(skill): add create/update/delete helpers and document CRUD test
* docs: restructure README and document skill usage
* docs: make README skill guidance tool-agnostic and SEO-friendly
* docs: add Claude Code skill installation instructions
* feat: Introduce skill creation tools and an agent-browser skill with templates and reference documentation.
* fix(frontend): keep server element ids for WS updates
Ensure WS delete/update events match scene element IDs by disabling ID regeneration when converting server payloads.
* feat: Add Zod library and OpenCode AI SDK dependencies, and introduce new Excalidraw skill scripts for element deletion and health checks.
* chore: Install project dependencies including Zod and OpenCode AI SDK, and add an Excalidraw reference cheatsheet.
---------
Co-authored-by: YC Lin <yclin@YCdeMacBook-Air.local>
- Replace all `any` types with proper Excalidraw types
- Add proper type imports from @excalidraw/excalidraw
- Improve MermaidConversionResult interface with ExcalidrawElement[] and BinaryFiles
- Add mermaidDiagram and config fields to WebSocketMessage interface
- Remove unused ElementBinding interface
- Remove all `as any` type casts throughout App.tsx
- Fix Vite security vulnerability (1 of 6 moderate vulns)
Changes:
- frontend/src/App.tsx: Restored proper TypeScript types, removed 12+ `as any` casts
- frontend/src/utils/mermaidConverter.ts: Added proper return types
- package-lock.json: Updated vite to fix security issue
Remaining security issues:
- 5 moderate vulnerabilities from @excalidraw/mermaid-to-excalidraw dependencies
- These are upstream issues in dompurify, nanoid, and mermaid packages
- No fixes available without major version upgrades
- Risk is acceptable for this use case (diagram rendering)
- Add WebSocket message handler for mermaid_convert type
- Make handleWebSocketMessage async to support conversion
- Add automatic backend sync after diagram generation
- Integrate convertMermaidToExcalidraw utility
- Remove test button and handleMermaidTest function
- Fix: Add missing Excalidraw CSS import for proper UI rendering
- Enhance server endpoint with WebSocket broadcast support
- Add mermaid_convert to WebSocketMessageType union
- Updated package.json to point to compiled TypeScript files in the dist directory.
- Improved TypeScript configuration with stricter type checks and removed JavaScript support.
- Migrated frontend entry point to TypeScript and added a new App component with enhanced functionality.
- Implemented a new server structure with TypeScript, including WebSocket support and improved element management.
- Updated README to reflect changes in architecture and usage instructions.
- Added comprehensive type definitions for Excalidraw elements and server responses.
- Fix MCP server update_element method parameter parsing issue
- Add comprehensive delete operation debugging and validation
- Implement frontend sync button with real-time status feedback
- Add elements sync API endpoint (/api/elements/sync) for manual synchronization
- Enhance WebSocket message handling with proper element validation
- Add binding validation and cleanup for Excalidraw elements
- Improve error handling and logging throughout the sync process
- Add sync status tracking and user feedback in the UI
- Update .gitignore to include additional build artifacts, logs, and editor files
- Modify package.json scripts for improved development workflow and remove unused scripts
- Change Vite output directory to 'dist' for consistency
- Simplify App.jsx by removing unused state and functions, enhancing readability
- Adjust server.js to serve static files from the new 'dist' directory
- Add React frontend with Excalidraw integration (App.jsx, main.jsx)
- Add Express server with MCP protocol support (server.js)
- Update CLI with new functionality (cli.js)
- Add Vite configuration for frontend build
- Update package.json with new dependencies
- Add public assets and build files
- Update .gitignore to exclude build artifacts
