MCP

Generate architecture diagrams from Cursor.

Stay in the editor, get a diagram a solver arranged.

Download for macOS
v0.1.33 · .dmg · Apple Silicon & Intel
Signed & notarized by Apple · opens without a Gatekeeper warning
sha256 698955a0187bc039f4c74f5d05a9f10fbb27376a45788a0a241d1326b73873c7
Download for Windows instead
$curl -fsSL https://lucidtrain.com/install.sh | sh

Cursor supports stdio MCP servers, so adding Lucid Train makes its diagram tools available inside the editor. Cursor reads the repository and produces a semantic graph of components and edges; the ELK layout engine computes the positions. The result is an architecture diagram with tier bands and real service icons, generated without leaving the editor and without the model placing anything itself.

Adding the server

Cursor takes stdio MCP servers as a command with arguments in its MCP settings. Once added, the diagram tools appear to the agent alongside its built-in ones and can be called during an ordinary session.

What you get that a chat answer does not give you

A laid-out diagram rather than syntax you then have to render. Tier bands that make dependency direction visible, bundled service logos rendered offline, orthogonal edge routing, and node states that can mark a single point of failure. The model contributes the structure; the solver contributes the arrangement.

Transport

Connections are stdio: the server runs as a local child process with piped stdin and stdout. Remote HTTP and SSE servers appear in the Connectors tab's registry search but cannot be connected, and that is a real limit rather than a configuration step you are missing. A remote server needs a local stdio bridge in front of it.

Cursor as an engine instead

The relationship also runs the other way: Lucid Train drives Cursor's agent as one of four interchangeable execution engines, so you can design the architecture on the canvas and have Cursor implement against the resulting specification. Which direction is better depends on whether the visual or the editor is where you want to sit.

MCP configuration

shell
$ {
$ "mcpServers": {
$ "lucid": { "command": "lucid-train", "args": ["mcp"] }
$ }
$ }
FAQ

Questions

Does Cursor support MCP servers?

Yes, over stdio, configured as a command with arguments. Lucid Train's server is added the same way as any other.

Can Cursor draw architecture diagrams without this?

It can write Mermaid or another text format into a file. What it cannot do is lay out a diagram with a constraint solver or attach real service icons.

Is the CLI free?

Yes, free and open source, and it is what provides the MCP server. The desktop app is separate.

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