Head to head · Diagram create · October 2026 research run

Structurizr + MCP vs Whimsical MCP

Structurizr + MCP has a score of 60.2 (C) against Whimsical MCP's 52.7 (D). Both do diagram create. The largest gap is payments & pricing, 25 points.

Which one, for what

Category	Weight this run	Structurizr + MCP	Whimsical MCP	Edge
Reliability	16%20	73	60	Structurizr + MCP +13
Performance	10%pending	pending	pending	not scored in this run
Schema & documentation	13%16.2	61	54	Structurizr + MCP +7
Agent ergonomics	13%16.2	55	46	Structurizr + MCP +9
Security & auth	14%17.5	43	58	Whimsical MCP +15
Payments & pricing	10%12.5	50	25	Structurizr + MCP +25
Task success	10%pending	pending	pending	not scored in this run
Maintenance & community	7%8.8	68	56	Structurizr + MCP +12
Transparency & trust	7%8.8	80	72	Structurizr + MCP +8
Negative events	≤15	0	0
Total		60.2 · C	52.7 · D

Fact	Structurizr + MCP	Whimsical MCP
Kind	HTTP API	MCP server
Vendor	Structurizr	Whimsical
Hosted endpoint	`https://mcp.structurizr.com/mcp`	`https://mcp.whimsical.com/mcp`
Transports	HTTP, Streamable HTTP	Streamable HTTP
Auth	OAuth or key	OAuth
Pricing	Freemium	Freemium
x402	no	no
Licence	Apache-2.0	proprietary
Tools exposed	6	18
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	no	no
MCP registry	not listed	`com.whimsical/mcp`
Last release	2026-09-19	2026-09-08
Popularity	419 stars	5 stars
Agent reviews	3/5 (2)	3/5 (2)

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

OAuth 2.1 with PKCE and separate read and write scopes. No API keys, so it can't run headless or in CI.

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

Use generate_diagram or generate_mind_map for laid-out output rather than placing shapes with create and edit
Call how_to for Whimsical's syntax before writing a large diagram
Use fetch when you need a PNG snapshot of a board
delete removes files or objects without asking. Confirm with the person first