Pencil: a design canvas that lives in your repo
I am not a designer. I am a PHP developer who builds Drupal themes anyway, which means every design tool I've ever used felt like visiting someone else's house. Pencil is the first one in a while that feels like it was built for people like me — because the design file is JSON, it lives in the repo, and my coding agent can edit it.
What Pencil actually is
Pencil (pencil.dev) is an AI-native design tool from Tom Krcha — the guy behind Adobe XD, later Around (acquired by Miro) and Alter (acquired by Google), now building under a company that appears to be called High Agency, Inc. It launched in late January 2026 and reportedly passed 100,000 users shortly after.
The pitch is a Figma-like canvas that runs as a desktop app or directly inside your IDE (VS Code, Cursor and friends). Designs are stored as .pen files — per the docs and every review I read, pure JSON — sitting in your workspace next to your application code. It ships with UI kits like shadcn/ui, so generated screens don't start from a blank rectangle.
The MCP server is the real product
Here's the part that got my attention. Pencil runs a local MCP server — no cloud dependency for design operations — that exposes the canvas to AI coding agents: Claude Code, Cursor, Windsurf, Codex CLI, Claude Desktop and others. The docs list tools like batch_design (create and modify elements), batch_get (read and search the file), get_screenshot, snapshot_layout and get_variables for design tokens.
So instead of an agent hallucinating a layout in CSS, you can literally prompt it to draw first. Better Stack's walkthrough uses exactly this kind of command:
claude 'Design a dashboard in the "Step 3 Frame" for a rover
management platform using the components.
- add a sidebar for navigation
- add rover stats and a table with available rovers for rent
use the pencil mcp server'The agent builds the design on the canvas, you nudge things around by hand in the inspector, then prompt it again to generate the actual HTML/CSS/JS (or, in my case eventually, Twig) from the .pen file. There's a genuinely fun demo of this — six agents designing an app on one canvas simultaneously — in Peter Yang's interview with Krcha:
Pencil treats design the way we already treat everything else: as a file in the repo that an agent can diff and edit.
Why that matters for a non-designer
My usual workflow is: client sends a vague screenshot, I squint, I write Twig and CSS, we iterate in production-ish. A canvas that my agent can read and write means the "squint" step becomes an artifact — versioned, reviewable, regeneratable. And because the file format is JSON rather than a proprietary blob behind a SaaS login, it fits how a one-person shop actually works.
Pricing helps too: Pencil is free during early access, with no listed limitations. The founders have been open that free is not a business model, so expect that to change. Note the hidden cost though — the AI half of the workflow needs your own agent subscription, e.g. Claude Code from roughly $20/month.
The caveats (there are real ones)
This is early software and the reviews don't hide it:
- No two-way sync. Unlike Lovable or v0, changing the design doesn't update your code automatically — you have to prompt the agent to re-sync. Design and code can drift.
- Desktop only (macOS and Linux per reviews), no browser version, and no real multiplayer collaboration yet — this is a solo/dev tool, not a Figma replacement for a design team.
- Not open source. The
.penformat is open JSON, but the app's source is "not yet public" per the docs. An open-source clone, OpenPencil, has already shown up on Hacker News, which tells you how much appetite there is. - Rough edges. Multiple reviewers describe it as young and occasionally fiddly. Fair — it's months old.
My plan: point it at a Drupal theme, let Claude Code sketch a content-type layout on the canvas, and see whether the generated markup survives contact with Twig. If it does, that's a genuinely new step in my toolchain. If not, well — it's free, and the file was just JSON anyway.