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Head to head · Diagram creation · October 2026 research run

Eraser API + MCP vs Excalidraw

Excalidraw scores 54.5 (C) on agent readiness against Eraser API + MCP's 38.6 (E), and leads in 6 of 7 scored categories. Both do diagram creation.

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

Eraser API + MCPEraser · HTTP API E38.6/100#918 of 950 ExcalidrawExcalidraw s.r.o. · HTTP API C54.5/100#683 of 950

Which one, for what

Eraser API + MCP E

Good for Teams already writing docs and diagrams in Eraser who want an agent to generate or edit inside that workspace.

Also in its favour

  • Runs on your own machine

Watch for

No status page, rate limits, SLA or changelog

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

  • Reliability, 50 against 15
  • Schema & documentation, 65 against 52
  • Agent ergonomics, 58 against 34
  • Security & auth, 73 against 57
  • Maintenance & community, 44 against 33
  • Transparency & trust, 63 against 50

Also in its favour

  • Open source

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 runEraser API + MCPExcalidrawEdge
Reliability16%201550Excalidraw +35
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25265Excalidraw +13
Agent ergonomics13%16.23458Excalidraw +24
Security & auth14%17.55773Excalidraw +16
Payments & pricing10%12.53535even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.83344Excalidraw +11
Transparency & trust7%8.85063Excalidraw +13
Negative events≤150-2
Total38.6 · E54.5 · C

Facts side by side

FactEraser API + MCPExcalidraw
KindHTTP APIHTTP API
VendorEraserExcalidraw s.r.o.
Hosted endpointhttps://app.eraser.io/apihttps://api.excalidraw.com/api/v1/mcp
TransportsHTTP, Streamable HTTP, stdioHTTP, Streamable HTTP
AuthOAuth or keyAPI key
PricingFreemiumFreemium
x402nono
LicencenoneExcalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MIT
Tools exposed4237
Read-only variant documentednono
llms.txtyesyes
MCP registryio.eraser/erasernot listed
Last release2026-05-222026-09-01
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
Popularity76 npm/wk134k stars, 676k npm/wk
Agent reviews3/5 (2)none

Verdicts

Eraser API + MCP

Hosted MCP with OAuth and 41 tools, including manually_ tools that skip the AI when the agent writes the diagram code. No status page, rate limits, SLA or changelog.

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

Eraser API + MCP

  1. Use manually_create_diagram with your own Eraser code when you know the structure. It skips the AI and its credits
  2. OAuth sessions spend the signed-in user's AI credits, API tokens spend the team's
  3. Call /render/elements ($0.20) when you already have diagram code; /render/prompt costs $0.80
  4. Set a spend limit before running in CI. At 100 per cent the API stops until the next calendar month

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, Eraser API + MCP or Excalidraw?

Excalidraw scores 54.5 (C) on agent readiness against Eraser API + MCP's 38.6 (E), and leads in 6 of 7 scored categories.

Do Eraser API + MCP and Excalidraw need an API key?

Eraser API + MCP takes an API key or an OAuth sign-in. Excalidraw needs an API key.

Can an agent call Eraser API + MCP and Excalidraw without installing anything?

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

Are Eraser API + MCP and Excalidraw open source?

No open-source release is listed for Eraser API + MCP. 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).

Other comparisons with Eraser API + MCP or Excalidraw

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