Lucid Train vs pen.dev
Lucid Train
lucidtrain.compen.dev
pen.devSide by side
| Figure | Lucid Train | pen.dev |
|---|---|---|
| Price from | $2.50/mo | $16/mo |
| Free plan | Yes | Yes |
| Free trial | Yes | — |
| Open source | — | — |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | — | Yes |
| Plans published | 2 | 4 |
| Spec score · AI Wireframe Generators | 8.2 (#15) | 9.0 (#7) |
| Data handling | The software processes repository files locally, and prompts and code go directly to the chosen model provider or nowhere when local models are used. | Text AI requests using a user's own provider credentials go directly from the device to that provider, while hosted-model requests pass through High Agency infrastructure in real time. |
| Integrations | The Connectors tab lists GitHub, Vercel, Railway and Grafana and can install arbitrary stdio MCP servers. | Official documentation lists MCP integrations including Claude Code, Codex, Gemini CLI, Antigravity, OpenCode, Kiro, and Claude Desktop. |
| Product | Lucid Train draws architecture diagrams from a codebase and hands the diagram to a coding agent as a specification. | pen.dev describes itself as an agentic canvas for building software and a vector design tool integrated with development environments. |
Plans
In their own words
Lucid Train
Lucid Train is a desktop coding harness that draws architecture diagrams from a codebase and passes the diagram to a coding agent as a specification. The agent emits a semantic graph, and the ELK layout engine positions diagram elements and routes edges. Diagrams are Excalidraw scenes that can export to SVG and PNG or become Markdown specifications; Mermaid support and diagram import are also listed. Proposed edits appear as diffs, and commands use risk tiers, with catastrophic commands refused. Model options include local Ollama, OpenRouter, other OpenAI-compatible endpoints, and hosted cloud models. Repository files are processed locally; prompts and code go to the selected provider, or nowhere when using local models. The maker says it collects no telemetry, analytics, prompts, code, or usage data from local or bring-your-own-key sessions. API keys are stored locally or in the OS keychain. Connectors include GitHub, Vercel, Railway, and Grafana, plus arbitrary stdio MCP servers; remote HTTP and SSE servers cannot connect directly. The free CLI is open source. The native app costs $2.50 per month, billed $30 a year, and includes a 7-day free trial.
pen.dev
pen.dev is a canvas for building software and a vector design tool integrated with development environments. Its editor works with components, variables, themes, scripts and shaders, and can import Figma files and HTML. It can export to HTML, CSS and Tailwind, as well as PNG, JPEG, WEBP and PDF. Users can work with its integrated agent or connect external agents through MCP; the available plans specify how many agents can run in parallel. Documented integrations include Claude Code, Codex, Gemini CLI, Antigravity, OpenCode, Kiro and Claude Desktop. Integrated provider options include OpenAI, Anthropic, Google Gemini, Cursor, GitHub Copilot, xAI, OpenRouter and other API-key providers. Its.pen design file is open JSON with an open schema. Tools include a Chrome extension for importing webpages, IDE extensions and an npm-installed CLI requiring Node.js 22.19 or later. The pricing page says pen.dev stays free until plans launch. The Free plan is free; Pro is $16 a month; Ultra is $48 a month.