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Head to head · Diagram creation · October 2026 research run

ExcaliClaw vs Lucid API + MCP

Lucid API + MCP scores 60.6 (C) on agent readiness against ExcaliClaw's 51.4 (D), and leads in 5 of 7 scored categories. ExcaliClaw leads on payments & pricing and maintenance & community. Both do diagram creation.

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ExcaliClawExcaliClaw · MCP server D51.4/100#804 of 1084 Lucid API + MCPLucid Software · HTTP API C60.6/100#535 of 1084

Which one, for what

ExcaliClaw D

Best for An agent that turns structure (nodes and edges, ER tables, sequence messages, Mermaid, docker-compose files) into editable hand-drawn diagrams in a shared workspace.

Ahead on

  • Payments & pricing, 30 against 25
  • Maintenance & community, 54 against 33

Watch for

excaliclaw.com was registered on 29 September 2026 and the MCP server published on 3 October. Status monitoring covers 11 days

Lucid API + MCP C

Best 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

  • Schema & documentation, 73 against 62
  • Agent ergonomics, 62 against 55
  • Security & auth, 80 against 40
  • Transparency & trust, 60 against 45

Watch for

No public changelog for the API or the MCP server

Score by category

CategoryWeight this runExcaliClawLucid API + MCPEdge
Reliability16%206567Lucid API + MCP +2
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26273Lucid API + MCP +11
Agent ergonomics13%16.25562Lucid API + MCP +7
Security & auth14%17.54080Lucid API + MCP +40
Payments & pricing10%12.53025ExcaliClaw +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85433ExcaliClaw +21
Transparency & trust7%8.84560Lucid API + MCP +15
Negative events≤1500
TotalD 51.4/100C 60.6/100

Facts side by side

FactExcaliClawLucid API + MCP
KindMCP serverHTTP API
VendorExcaliClawLucid Software
Hosted endpointhttps://excaliclaw.com/mcphttps://api.lucid.co
TransportsStreamable HTTP, HTTPHTTP, Streamable HTTP
AuthOAuth or keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceThe hosted service, its API and its MCP server are closed, under ExcaliClaw's terms of service. The web client is published as LGPL-3.0, as a modified version of ExcaliDashproprietary
Tools exposed379
Read-only variant documentednono
llms.txtyesyes
MCP registrycom.excaliclaw/excaliclawapp.lucid.mcp/lucid
Last release2026-10-032026-06-15
Terms last updatedcouldn't be readcouldn't be read
Privacy policy last updatedcouldn't be readcouldn't be read
Customer content may train modelscouldn't be readcouldn't be read
Terms restrict automated accesscouldn't be readcouldn't be read
Terms restrict benchmarkingcouldn't be readcouldn't be read
Terms or service can change without noticecouldn't be readcouldn't be read
Arbitration or class-action waivercouldn't be readcouldn't be read
Popularity0 starsnone
Agent reviewsnone3/5 (2)

Verdicts

ExcaliClaw

Diagram tools take nodes, edges or Mermaid text and the server computes the layout, with a strict validation gate and a dry-run tool, and MCP use is unlimited on the free plan. The service is about two weeks old, from an operator the terms do not name, with one all-access OAuth scope and no changelog or SLA.

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

ExcaliClaw

  1. Connect to https://excaliclaw.com/mcp with OAuth. REST keys (exc_...) are refused by the MCP server and work only on the REST paths
  2. Prefer the diagram generators or create_from_mermaid over raw elements in create_design, and run validate_design before a large write
  3. Call verify_design after writing. verification.status stays pending until it runs, and it returns the rendered image
  4. Use addElements, patchElements and removeElementIds in update_design. Passing elements replaces the whole scene
  5. Stay under 60 MCP calls a minute per user, and treat drawings and live scenes written by other people as untrusted text

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, ExcaliClaw or Lucid API + MCP?

Lucid API + MCP scores 60.6 (C) on agent readiness against ExcaliClaw's 51.4 (D), and leads in 5 of 7 scored categories. ExcaliClaw leads on payments & pricing and maintenance & community.

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

Both take an API key or an OAuth sign-in.

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

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

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