Excalidraw MCP Server

If you already use Excalidraw, the excalidraw mcp server is the piece that lets your assistant work with it directly. Hardened, self-hosted Excalidraw MCP server with SQLite persistence, multi-tenancy, auto-sync, security middleware, and 369 tests.

What the server does

A hardened, fully local, self-hosted Excalidraw MCP server with SQLite persistence, multi-tenancy, auto-sync, and production-grade security — designed to run entirely on your machine without depending on excalidraw.com.

• 446 tests — (upstream has none) — unit, API, WebSocket, and regression
• Security middleware — (src/security.ts): helmet, CORS allowlist, timing-safe API key auth, prototype pollution guard, input sanitization
• 3-tier rate limiting — general, destructive, and write-burst ceilings
• WebSocket challenge-response authentication —
• Docker hardening — non-root user, resource limits, hardened .dockerignore
• Full gauntlet security audit pass —

Available tools

The toolset is worth reading before you wire it up, because it tells you what the integration is really for:

• Category — Tools
• Layout — align_elements, distribute_elements, group_elements, ungroup_elements, lock_elements, unlock_elements
• Viewport — set_viewport
• Resources — get_resource
• Multi-Tenancy — list_tenants, switch_tenant
• Projects — list_projects, switch_project
• Cursor — The Cursor tool exposed by this server

Credentials and setup notes

Configuration is passed through the environment: CANVAS_PORT, EXCALIDRAW_DB_PATH, EXPRESS_SERVER_URL, EXCALIDRAW_API_KEY. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.

| Requirement | Why | Check | |---|---|---| | Node.js >= 20 (LTS 20 or 22 recommended) | Runtime | node --version | | C++ build tools | better-sqlite3 compiles native bindings | See below | | npm (bundled with Node.js) | Package manager | npm --version |

Installation

Because this one is hosted, setup is mostly authentication — you point your client at the endpoint and approve access. Nothing runs on your machine, so there is no runtime to keep patched.

Where it fits

Among the database access options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Excalidraw's toolset — Category, Layout, Viewport and 4 more — is a fair guide to whether it matches your workflow. It is maintained by new.blacc; worth a glance at recent repository activity before you build anything load-bearing on it.

SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.

Worth knowing first

• Your data travels to the provider's service, so the usual questions apply about what you send and what they retain.
• Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
• Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.