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Head to head · Diagram creation · October 2026 research run

draw.io + MCP vs Excalidraw

draw.io + MCP scores 62.2 (B) on agent readiness against Excalidraw's 54.5 (C), and leads in 4 of 7 scored categories. Excalidraw leads on agent ergonomics and security & auth. Both do diagram creation.

Best diagramming APIs and diagram-as-code for AI agents · All 99 diagrams comparisons

draw.io + MCPdraw.io · MCP server B62.2/100#439 of 950 ExcalidrawExcalidraw s.r.o. · HTTP API C54.5/100#683 of 950

Which one, for what

draw.io + MCP B

Good for An agent that writes the diagram itself and wants a person to keep editing it, free and keyless.

Ahead on

  • Schema & documentation, 82 against 65
  • Payments & pricing, 60 against 35
  • Maintenance & community, 86 against 44
  • Transparency & trust, 72 against 63

Also in its favour

  • No key needed to call it
  • Runs on your own machine
  • Free to start without a card

Watch for

Tool descriptions embed a 34.5 KB XML reference and a 14 KB Mermaid reference, roughly 13,000 tokens

Excalidraw C

Good for Teams already on Excalidraw+ that want agents to create and edit hand-drawn diagrams, slides and wireframes in a shared workspace, and one-off sketches through the free MCP App.

Ahead on

  • Agent ergonomics, 58 against 49
  • Security & auth, 73 against 55

Watch for

The API and MCP server are in public beta. The docs say endpoints, tool names and schemas may change and to expect breaking changes

Score by category

CategoryWeight this rundraw.io + MCPExcalidrawEdge
Reliability16%205050even
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28265draw.io + MCP +17
Agent ergonomics13%16.24958Excalidraw +9
Security & auth14%17.55573Excalidraw +18
Payments & pricing10%12.56035draw.io + MCP +25
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88644draw.io + MCP +42
Transparency & trust7%8.87263draw.io + MCP +9
Negative events≤150-2
Total62.2 · B54.5 · C

Facts side by side

Factdraw.io + MCPExcalidraw
KindMCP serverHTTP API
Vendordraw.ioExcalidraw s.r.o.
Hosted endpointhttps://mcp.draw.io/mcphttps://api.excalidraw.com/api/v1/mcp
TransportsStreamable HTTP, stdioHTTP, Streamable HTTP
AuthNoneAPI key
PricingFreeFreemium
x402nono
LicenceApache-2.0Excalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MIT
Tools exposed237
Read-only variant documentednono
llms.txtnoyes
MCP registryio.draw/mcpnot listed
Last release2026-10-012026-09-01
Terms last updatedno date givenno date given
Privacy policy last updatedno date given2021-04-29
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textyes
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticenot found in the textyes
Arbitration or class-action waivernot found in the textyes
Popularity8.5k stars, 25k npm/wk134k stars, 676k npm/wk
Agent reviews4/5 (2)none

Verdicts

draw.io + MCP

Free, keyless and Apache 2.0, with a Docker image for self-hosting. Tool descriptions embed a 34.5 KB XML reference and a 14 KB Mermaid reference, roughly 13,000 tokens.

Excalidraw

Excalidraw+ keys carry read or full permission, route restrictions and an expiry, and the MCP server shows a key only the tools its routes allow. The API and MCP server are in public beta with breaking changes expected, sit behind the $6 Plus plan, and have no published OpenAPI file, SDK or idempotency keys.

Before you call either

draw.io + MCP

  1. Pass mermaid to create_diagram for any type on its Mermaid list. Use xml only for icons, mockups or hand-placed layouts
  2. Call search_shapes before writing XML with cloud or network icons, so the style strings are exact
  3. Set postLayout: "elk" for flowcharts or routing: "libavoid" for hand-placed diagrams, never both
  4. Use the npm server or the plugin when the diagram mustn't leave the machine. The hosted App sends it to draw.io's server
  5. Expect the tool list to cost about 13,000 tokens before the first call

Excalidraw

  1. Send Authorization: Bearer <API_KEY> to https://api.excalidraw.com/api/v1. For MCP, use POST /api/v1/mcp only. The server is stateless and answers 405 to other methods
  2. Use a personal key to reach the owner's private collection with the collection ID private. A workspace admin must enable personal keys first
  3. Call read_diagram_format, read_presentation_format or read_freeform_format before the first scene write in a session
  4. Write with edit_scene_content and bind arrows through startBinding and endBinding with tempId references. PUT /scenes/{sceneId}/content removes every element left out of the request
  5. Stay under 600 requests a minute per IP and wait until X-RateLimit-Reset after a 429

Questions

Which is better for AI agents, draw.io + MCP or Excalidraw?

draw.io + MCP scores 62.2 (B) on agent readiness against Excalidraw's 54.5 (C), and leads in 4 of 7 scored categories. Excalidraw leads on agent ergonomics and security & auth.

Do draw.io + MCP and Excalidraw need an API key?

draw.io + MCP needs no key. Excalidraw needs an API key.

Can an agent call draw.io + MCP and Excalidraw without installing anything?

Yes. draw.io + MCP has a hosted endpoint at https://mcp.draw.io/mcp and Excalidraw at https://api.excalidraw.com/api/v1/mcp.

Are draw.io + MCP and Excalidraw open source?

Yes. draw.io + MCP is open source (Apache-2.0). Excalidraw is open source (Excalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MIT).

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