Open source · BYOK · Web + desktop
One open canvas.
Every format.
Describe a page, a prototype, a brand board. Get live variations as movable frames. Remix, export, or let your agent drive.
If you can describe it,
it fits on the canvas.
One prompt in, live variations out. Pages, prototypes, decks, brand boards, social cards, and the formats nobody has named yet.
“A landing page for a sourdough bakery — warm hero with a tagline, a three-item bread menu with prices, a short story section, and a footer with hours and address.”
“A fleet-tracking dashboard with a dark sidebar, four KPI cards, a route-status table, and a small map panel.”
“A 1200x628 launch announcement card for a minimal note-taking app called Jot — bold headline, one screenshot mockup, release date.”
“A pitch-deck cover slide for a warehouse-robotics startup — big title, one-line thesis, team row, and a contact footer.”
And everything else
Docs, wireframes, email templates, moodboards, social assets. The canvas does not care about the format. Describe the frame you want and take the take you like.
Real output, not mockups
Every frame on this page came out of the app you can open right now, prompts included.
Start from a prompt,
not a blank page.
Bring your own key, pick a preset, generate. Nothing to install.
A landing page for a sourdough bakery — warm hero with a tagline, a three-item bread menu with prices, a short story section, and a footer with hours and address.
A fleet-tracking dashboard with a dark sidebar, four KPI cards, a route-status table, and a small map panel.
A 1200x628 launch announcement card for a minimal note-taking app called Jot — bold headline, one screenshot mockup, release date.
A pitch-deck cover slide for a warehouse-robotics startup — big title, one-line thesis, team row, and a contact footer.
1Paste a key
Anthropic or any OpenAI-compatible endpoint. One field, done.
2Pick a preset
UI/UX, marketing, brand, deck, email. Or write your own system prompt.
3Generate
Compare the takes side by side on one canvas. Remix the winner.
Your key never leaves your browser. No account, no proxy, nothing stored server side.
Open the demoA canvas your agents
can drive.
The calca CLI ships the canvas as MCP tools. One install and your agent can read a board, stage edits under a lease, and rearrange frames — no screenshots, no copy-paste. Open source, every layer.
One command to install, then your agent works the board directly.