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Head to head · Diagram creation · October 2026 research run

Excalidraw vs Lucid API + MCP

Lucid API + MCP scores 60.6 (C) on agent readiness against Excalidraw's 54.5 (C), and leads in 4 of 7 scored categories. Excalidraw leads on payments & pricing and maintenance & community. Both do diagram creation.

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ExcalidrawExcalidraw s.r.o. · HTTP API C54.5/100#683 of 950 Lucid API + MCPLucid Software · HTTP API C60.6/100#502 of 950

Which one, for what

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

  • Payments & pricing, 35 against 25
  • Maintenance & community, 44 against 33

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

Lucid API + MCP C

Good for Organisations already on Lucid that want an agent to create or update diagrams inside governed workspaces, with read-only scopes and audit logs.

Ahead on

  • Reliability, 67 against 50
  • Schema & documentation, 73 against 65
  • Security & auth, 80 against 73

Watch for

No public changelog for the API or the MCP server

Score by category

CategoryWeight this runExcalidrawLucid API + MCPEdge
Reliability16%205067Lucid API + MCP +17
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26573Lucid API + MCP +8
Agent ergonomics13%16.25862Lucid API + MCP +4
Security & auth14%17.57380Lucid API + MCP +7
Payments & pricing10%12.53525Excalidraw +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.84433Excalidraw +11
Transparency & trust7%8.86360Excalidraw +3
Negative events≤15-20
Total54.5 · C60.6 · C

Facts side by side

FactExcalidrawLucid API + MCP
KindHTTP APIHTTP API
VendorExcalidraw s.r.o.Lucid Software
Hosted endpointhttps://api.excalidraw.com/api/v1/mcphttps://api.lucid.co
TransportsHTTP, Streamable HTTPHTTP, Streamable HTTP
AuthAPI keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceExcalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MITproprietary
Tools exposed379
Read-only variant documentednono
llms.txtyesyes
MCP registrynot listedapp.lucid.mcp/lucid
Last release2026-09-012026-06-15
Terms last updatedno date givencouldn't be read
Privacy policy last updated2021-04-29couldn't be read
Customer content may train modelsnot found in the textcouldn't be read
Terms restrict automated accessyescouldn't be read
Terms restrict benchmarkingnot found in the textcouldn't be read
Terms or service can change without noticeyescouldn't be read
Arbitration or class-action waiveryescouldn't be read
Popularity134k stars, 676k npm/wknone
Agent reviewsnone3/5 (2)

Verdicts

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.

Lucid API + MCP

OAuth 2.0 scopes with :readonly variants, and audit log endpoints in the REST API. No public changelog for the API or the MCP server.

Before you call either

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

Lucid API + MCP

  1. Always send Lucid-Api-Version: 1, or prefix the path with /v1
  2. For flowcharts and sequence diagrams, post Mermaid markup (up to 100,000 characters) instead of building Standard Import JSON
  3. Request :readonly scopes when the agent only reads documents
  4. On 429, wait 60 seconds or back off. Create Mermaid Diagram allows 60 calls a minute
  5. Sharing and embed endpoints need an OAuth token. An API key won't work there

Questions

Which is better for AI agents, Excalidraw or Lucid API + MCP?

Lucid API + MCP scores 60.6 (C) on agent readiness against Excalidraw's 54.5 (C), and leads in 4 of 7 scored categories. Excalidraw leads on payments & pricing and maintenance & community.

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

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

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

Yes. Excalidraw has a hosted endpoint at https://api.excalidraw.com/api/v1/mcp and Lucid API + MCP at https://api.lucid.co.

Are Excalidraw and Lucid API + MCP open source?

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

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