Start with an idea.
Choose a project and space, then tell your lead what you want to build. CastSpell detects the tools you already use.
Meet CastSpell
The visual canvas for your AI agents.
Break free from the limits of terminal-based coding: delegate real work,
follow every handoff, and bring your next idea to life.
macOS · Apple Silicon · 38 MB download · Bring your own AI
Works with the agents you already use
Claude Code
Codex
opencode
Hermes
Gemini CLI
Cursor
Mistral Vibe
Kimi
Grok
Amp
One canvas. Every moving part.Interactive demo · Try answering an agent
shop-api⌄
/Login redirect ⌄
CanvasBoard
Search… ⌘K1 needs you＋ NewY
LeadWorkingClaude Code·mainFix the login redirect and add tests
Waiting on opencode
Claude CodeWorkingHelper·fix/login-redirect
Fix the login redirect
Editing src/auth/redirect.ts
CodexWorkingHelper·tests/login
Add tests for the login flow
Tapping "Sign in"
opencodeNeeds youHelper·fix/session-store
Update the session store
Wants to run db:migrate
Permission required12
Linux desktopLive
Android emulator
Live
Claude Code
Message Lead…
fix/login-redirect→main· 3 files
- src/auth/redirect.ts
- src/auth/redirect.test.ts
- docs/auth.md
Interactive illustration · Sample project, real workflow.
Work with your agents
as one team.
Tell your lead what you want to build. It brings in helpers, shares the work, and brings the results back to you.
Switch projects and spaces from the top bar. The canvas gives every agent, terminal, and computer room to work, with your account and settings close at hand.
Claude CodeCodexopencodeHermes
From the first prompt to the final merge.
One conversation starts the work. A whole canvas keeps you in the loop.
Give the work room.
Your lead brings in helpers. Tasks branch out, agents share results, and every handoff has a place.
Make the final call.
Catch the questions and results that need you. Open the conversation, ask for a refinement, and decide what happens next.
A workspace for the whole project.
Give your agents the room, context, and tools to get things done.
BEYOND THIS MAC
Your agents can
go places.
Connect remote machines over SSH. Bring Linux desktops and Android emulators onto the canvas, and watch while your agents work with them.
Your tools.
Your machines.
Your machines.
Parallel work. Separate branches.
Give each agent its own worktree. See the diff, discuss specific lines, and bring the results back together.
Know when it's your turn.
Live status and notifications bring the questions and results that need your attention into view.
Not just code.
Images and video, too.
Make them yourself on the canvas, or let your agents make them as part of the work.
- 📁 Start from your own assets.
- Drag a folder of images, videos or documents onto the canvas, lay them out as cards, then hand them to an agent: “cut a launch video from these”, “pick the best three for the homepage”. Drop a file on an agent to give it straight to that agent.
- 📄 Whatever they make shows up.
- When an agent writes an image, a video, a PDF, a Markdown or Word doc or a spreadsheet, it appears as a card next to that agent. Open it right on the canvas.
- 🎨 Images for what you're building.
- App icons, hero images, product shots and mockups, next to the agent building the page. Edit and upscale until they're right.
- 🎬 Video from a sentence or a still.
- Turn a prompt or an image into a clip, then extend it. Launch videos, demos and ads, made where the work happens.
- 🤝 Agents that make their own assets.
- Ask your lead for a landing page and it can create the visuals too, within a spend limit you set.
Nano Banana · GPT Image · FLUX.2 · Seedream · Kling 3 · Veo 3.1 · Seedance 2.5 · Bring your own provider key. Generation is billed by the provider, not included in Pro.
Your servers,
on the same canvas.
Add any machine you can reach over SSH. Its agents show up next to the ones on your Mac, and you work with them the same way.
- 🖥️ One click from your SSH config.
- Pick a host from ~/.ssh/config. CastSpell sets up its engine there if it's missing; you just need passwordless SSH.
- 🌙 Keeps going when your Mac sleeps.
- Agents on a server run on that server. Close the laptop, come back later, and pick up where they are.
- 👀 Watch them use real apps.
- Start a Linux desktop with a browser on a server, or an Android emulator on your Mac, and watch your agents click through it on the canvas.
Linux and macOS servers · Cloud VMs · Your home box · Android emulators
Your tools. Your machines.
Your way of working.
- Bring your own AI.
- Use your existing agent subscriptions. CastSpell never proxies your model calls.
- At home on your machines.
- No account needed. Your agents run on your Mac or the machines you connect.
- Built to stay light.
- A 38 MB download, about 100 MB installed. Not Electron: CastSpell uses your Mac's own WebKit instead of shipping a copy of Chromium, so it's a fraction of the 250 MB to 1 GB+ that Electron apps take. Agents run in a small Rust engine that uses about 7 MB of memory, and idle agents pause to free more.
A few things to know.
Can I download CastSpell yet?
Yes. CastSpell for Mac is free to download. It’s signed and notarized by Apple, so it opens like any other Mac app, and it updates itself in the app.
Which agents can I use?
Claude Code, Codex, opencode, Hermes, Gemini CLI, Cursor, Mistral Vibe, Kimi, Grok and Amp, with your own subscriptions. CastSpell never sits between you and your model provider.
What’s free and what’s Pro?
Free has every feature, including space templates, remote machines, image and video cards and usage history. It’s limited to 3 projects with up to 5 spaces each. Pro removes those limits.
Do I need an account?
No. Free works without signing in. If you buy Pro, open CastSpell, choose Sign in and use the email from your receipt; Pro turns on by itself. You can also paste your licence key in Settings → Plan instead.
Is CastSpell private?
Your code, conversations and files stay on your Mac or the machines you connect. An account is optional. Agents talk to their own providers directly. With Pro, the app checks your licence key with our licence server; that check carries the key, a random install ID and your Mac’s name, nothing about your work.
Is there a Windows, Linux or mobile version?
Not yet. CastSpell is a Mac app for Apple silicon (M1 or newer) today. Windows, Linux, iOS and Android versions are coming soon.
Meet your next workspace.
Your agents are ready for a better workspace.
Download for freeComing soon to Windows, Linux, iOS and Android
Take another look at the canvas