How
MCP (official: remote https://mcp.excalidraw.com or local stdio, MCP Apps UI; community: stdio MCP 26 tools, CLI `npx -y mcp-excalidraw-server <cmd>`, REST API).
Excalidraw MCP (official MCP App + community mcp_excalidraw)
Agents draw, inspect and edit Excalidraw diagrams over MCP.
mcp.excalidraw.com ↗repo ↗docs ↗Community mcp_excalidraw (mcp-excalidraw-server) ↗Excalidraw ↗MCP Apps extension ↗
- license
- MIT · Official excalidraw-mcp README says MIT but the repo has no LICENSE file (GitHub reports no license). Community mcp_excalidraw is MIT with a LICENSE file. Excalidraw itself is MIT.
- language
- TypeScript
- backing
- Official: Excalidraw (company behind excalidraw.com; repo originated as antonpk1/excalidraw-mcp-app). Community: individual (yctimlin) with 25 contributors.
- stars
- 5,493 (as of 2026-10-09)
- downloads
- Community mcp-excalidraw-server: 5,145/week npm (2026-10-01..07). @excalidraw/excalidraw: 675,606/week npm. Official MCP is mainly used via the hosted remote endpoint (no download count).
- latest release
- v0.3.2, 2026-02-09
- first release
- 2026-02
borrow
Different medium, but its agent protocol details (cheat-sheet tool, checkpoint-relative patches, describe vs screenshot) are battle-tested patterns scene can copy.
Borrow from it: take a specific idea, API or format.
the steelman: the best honest case for it
Excalidraw over MCP is the cleanest proof that 'the picture is a JSON value' makes agents good at visual work. The official MCP App needed only two tools and a cheat-sheet to get agents in Claude, ChatGPT and VS Code drawing animated, hand-drawn diagrams inline, and its checkpoint plus delete-pseudo-element trick is a token-cheap patch protocol that even supports in-place animation. The community server goes all the way: 26 tools for per-element CRUD, layout, structured scene description and headless screenshots, so an agent draws, looks, fixes truncated labels and looks again; diagrams export as .excalidraw files into the repo. It is MIT, trivial to install, and actively used.
scores
| UI as data | 5 scene 5 | the diagram is entirely a JSON element list (it is a diagram, not an app UI) |
|---|---|---|
| Agent can drive it | 5 scene 5 | community server: create/change/operate a live canvas via MCP, CLI or REST |
| Agent can see it | 5 scene 5 | community: structured describe + rendered screenshot |
| Small, targeted edits | 5 scene 5 | community update_element by id; official only coarse checkpoint/delete |
| Time travel | 3 scene 0 | checkpoints/named snapshots the agent can restore; no history log or seek |
| Live data rate | 2 scene 5 | WebSocket sync of agent-paced edits; no data streams |
| Terminal native | 0 scene 5 | |
| Pixel graphics | 5 scene 4 | |
| Teaching | 2 scene 3 | |
| Maturity | 3 scene 1 | official widely reachable but dormant since March; community actively used (5k npm/week) |
| Openness | 4 scene 4 | MIT, controlled by a company (official) or one maintainer (community) |
Excalidraw MCP (official MCP App + community mcp_excalidraw) scene now scene planned
how agents use it
Wiring it in
One connector URL (official) or one `claude mcp add` / npx command (community).
Seeing the result
Official: none for the model beyond its own checkpoints. Community: describe_scene (structured) and get_canvas_screenshot (image).
Small edits
Official: coarse (restore checkpoint, delete by id, append). Community: per-element update by id, query by type/bbox/filter.
History
Official: checkpoints per create_view. Community: named snapshots save/list/restore. Excalidraw's own undo/redo is human-facing.
In short
The community server is a near-complete 'agent-editable live canvas' with structured and visual readback; the official one is a polished one-shot widget.
architecture
Official: an MCP Apps server with two tools, read_me (format cheat-sheet) and create_view (a JSON array of Excalidraw elements rendered into a ui:// iframe with draw-on animation and camera moves). It is a declarative re-send model: each create_view returns a checkpointId; later calls start with {type:'restoreCheckpoint', id} and add elements or {type:'delete', ids} pseudo-elements, and user edits in fullscreen are saved back to the checkpoint. Community: a local canvas server (Excalidraw web UI + REST + WebSocket sync) fronted by an MCP stdio server with 26 tools, a CLI with JSON in/out, and an agent skill; screenshots render headlessly since v2.1.
- Scene is a JSON array of elements with ids; .excalidraw files are portable artifacts
- Official tools: read_me, create_view; checkpoints + delete pseudo-elements; 'animation mode' (delete and replace in place with camera nudges)
- Community tools: create_element, get_element, update_element, delete_element, query_elements, batch_create_elements, duplicate_elements, align/distribute/group/ungroup/lock/unlock, describe_scene, get_canvas_screenshot, export_scene, import_scene, export_to_image, export_to_excalidraw_url, create_from_mermaid, clear_canvas, snapshot_scene, restore_snapshot, set_viewport, read_diagram_guide, get_resource
- Community readback: describe (structured text: ids, positions, labels, connections) and screenshot (PNG/SVG)
- Community state: in-memory by default, EXCALIDRAW_DATA_DIR for restart recovery; named snapshots
performance
No published numbers.
adoption and upkeep
Adoption
Official MCP App: 5.5k stars, 518 forks, works in Claude, ChatGPT, VS Code, Goose. Community server: 2.5k stars, actively released (v2.1.x, Oct 2026).
Maintainability
The official MCP App was a burst in February 2026; the community server is the actively maintained, more capable one.
Releases: Official: v0.1.0 2026-02-04 to v0.3.2 2026-02-09, then no releases; last push 2026-03-24. Community: v2.1.0 2026-10-03, v2.1.1 and v2.1.2 2026-10-04 · Contributors: Official: 5; community: 25 · Recent: Official: none since 2026-03-24. Community: 35 commits since 2026-07-11, pushed 2026-10-09 · Bus factor: low for both: official is a small widget side project; community is one main maintainer
weaknesses
- Diagrams, not application UIs: no input widgets, data binding or keyboard-driven apps
- Official server: model cannot see the canvas or user edits except via checkpoints; dormant since March 2026; no LICENSE file despite MIT claim
- Community server: in-memory by default; Mermaid conversion still needs a browser tab
- Web-only rendering; no terminal surface
- No real history log or replay, only snapshots
and thc-scene
Overlap
Whole surface as a JSON value, id-addressed element edits, structured plus rendered readback, snapshots, agent-driven animation and explanation.
What scene would be reinventing
Little for scene's core, but the community server's draw-look-fix loop and the official checkpoint/delete patch format are proven agent ergonomics scene should mirror rather than reinvent.
The gap it leaves
No terminal rendering, no app interactivity (keys, focus, lists), no live data sources, no hot-swap; scene is a running terminal application, not a diagram.
What to borrow
- A read_me / guide tool that returns the format cheat-sheet before first use
- Checkpoint ids returned from every push so the agent can say 'start from checkpoint X, delete ids a,b, add these' instead of resending
- describe_scene: a compact text description (ids, positions, labels, connections) distinct from the raw screen
- query_elements by type/bbox/filter for addressing scene nodes
- Named snapshots save/list/restore as a stopgap before full time travel
sources
- excalidraw/excalidraw-mcp README github.com
- excalidraw-mcp src/server.ts github.com
- yctimlin/mcp_excalidraw README github.com
- GitHub API repos/excalidraw/excalidraw-mcp api.github.com
- GitHub API repos/yctimlin/mcp_excalidraw api.github.com
- npm downloads mcp-excalidraw-server api.npmjs.org