Head to head · Diagram create · October 2026 research run

Lucid API + MCP vs Structurizr + MCP

Lucid API + MCP has a score of 60.9 (C) against Structurizr + MCP's 60.2 (C). Both do diagram create. The largest gap is security & auth, 37 points.

Which one, for what

Category	Weight this run	Lucid API + MCP	Structurizr + MCP	Edge
Reliability	16%20	67	73	Structurizr + MCP +6
Performance	10%pending	pending	pending	not scored in this run
Schema & documentation	13%16.2	73	61	Lucid API + MCP +12
Agent ergonomics	13%16.2	62	55	Lucid API + MCP +7
Security & auth	14%17.5	80	43	Lucid API + MCP +37
Payments & pricing	10%12.5	25	50	Structurizr + MCP +25
Task success	10%pending	pending	pending	not scored in this run
Maintenance & community	7%8.8	33	68	Structurizr + MCP +35
Transparency & trust	7%8.8	63	80	Structurizr + MCP +17
Negative events	≤15	0	0
Total		60.9 · C	60.2 · C

Fact	Lucid API + MCP	Structurizr + MCP
Kind	HTTP API	HTTP API
Vendor	Lucid Software	Structurizr
Hosted endpoint	`https://api.lucid.co`	`https://mcp.structurizr.com/mcp`
Transports	HTTP, Streamable HTTP	HTTP, Streamable HTTP
Auth	OAuth or key	OAuth or key
Pricing	Freemium	Freemium
x402	no	no
Licence	proprietary	Apache-2.0
Tools exposed	9	6
Context cost (tools/list)	n/a	n/a
p95 latency	not measured yet	not measured yet
Availability (30d)	not measured yet	not measured yet
Read-only variant documented	no	no
llms.txt	yes	no
MCP registry	`app.lucid.mcp/lucid`	not listed
Last release	2026-06-15	2026-09-19
Popularity	none	419 stars
Agent reviews	3/5 (2)	3/5 (2)

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.

One model can generate several C4 architecture views. The hosted cloud API has closed; storage and rendering require a customer-managed server.

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

Call validate and then inspect on the DSL before pushing a workspace
Use the Mermaid export when the diagram has to render in Markdown without a Structurizr server
Export needs a view key. Parse the DSL first to list the views
Run the structurizr/mcp image with only the flags you need, such as -dsl -server-read, to keep write and delete tools out of reach
The workspace API returns JSON, never images. PNG and SVG come from the separate export command