Your AIStart with what you use.
Give the AI you already use a project with persistent memory, tasks, files and tools. Start with one connection and work the way you prefer.
Megastructure Arc
Your AI workstation.
Plug in the AI you use. Keep the knowledge you build.
Keep your project’s files, tasks, decisions and memory together on your computer. Work with the AI you already use, and bring in other models when you need them.
$199 once. No Arc subscription. Every Arc update included. 30-day money-back guarantee.
For Windows 10/11 and Apple Silicon Macs
Use your existing AI accounts or connect your own models. Hosted AI usage is billed separately by your provider.
Own your workflow.
Connect a tool you already use, run a model on your computer or use an API provider. Start with one. Add or change connections when you need to.
Your existing AI tools
Use supported tools with their existing accounts and subscriptions.
- Claude Code
- Codex
- Cursor
- Gemini CLI
More AI tools
- Claude Cowork
- OpenCode
- Grok Build
- Muse Code
- Hermes Agent manual MCP setup
- Other MCP-capable tools
Local models
Run a compatible model on your computer or connect a model server you control.
- GGUF
- llama.cpp
- LM Studio
- Ollama
More local model options
- DwarfStar
- OpenAI-compatible servers
API providers
Connect hosted models with your own provider keys.
- OpenAI
- Anthropic
- Google Gemini
- OpenRouter
More API providers
- xAI Grok
- DeepSeek
- Meta
- Mistral
- Groq
- Together AI
- Fireworks AI
- Cerebras
- NVIDIA NIM
- Hugging Face
- Qwen / DashScope
- GLM / Zhipu BigModel
- Kimi / Moonshot
- MiniMax
- Doubao / Volcengine Ark
- SiliconFlow
- Custom OpenAI-compatible APIs
One AI, or more when you need them.
Arc provides the place, tools and project structure. Work with one AI, switch tools or bring several into the same room to share tasks, work in parallel and review results. Your project’s memory and decisions stay in Arc.
API usage is billed by your provider. Model support depends on tool-use capabilities and available resources.
Third-party names are trademarks of their owners; compatibility does not imply endorsement.
A place for every project.
Your AI
Your workBuild on what you learn.
Keep your project’s decisions, skills and memory beyond a single session. Come back to the work with its context in one place, on your computer.
Your choiceChange tools. Keep the project.
Bring in other models or AI tools whenever the work calls for them. Share tasks, ask for another perspective or hand work over with the project context available.
Make room for your next project.
- 1Buy & install Arc
- 2Connect your AI
- 3Start your project
Arc in action
Start here shows what to do next
- Your agent says which room it joined
- Next steps for your first hour
One purchase. Your workstation.
Megastructure Arc Professional
Your AI workstation.
$199 USD · one-time purchase
Keep the knowledge you build, even when you change AI tools.
Buy Arc — $199 onceYour license key and download link arrive by email. Install on your computer when you’re ready.
Included with your purchase
- Keep project memory, tasks, decisions and files together
- Work with your existing AI tools, local models or API providers
- Use Arc on up to 5 of your own computers
- Personal and commercial use — what you build is yours
- Every Arc update included, with no Arc subscription
For Windows 10/11 and Apple Silicon Macs.
Use your existing AI accounts or connect your own models. Hosted AI usage is billed separately by your provider.
Secure checkout through Lemon Squeezy, a Stripe company and our merchant of record. Pay by card or PayPal; available wallets and local payment methods appear at checkout. Prices in USD; applicable taxes are calculated at checkout.
Buying for a team? Megastructure Arc Enterprise
Contact us for volume licensing and options for your organization.
enterprise@megastructure.aiA few practical questions.
Can I start with just one AI?
Yes. Connect a supported AI tool you already use, or choose a local model or API connection. Arc gives your work a project with memory, tasks, decisions and files. You can keep using one AI for as long as it suits you.
Do I have to work inside the Arc app?
You can work in Arc or keep using a connected tool such as Claude Code, Codex or Cursor. That tool can read and update the Arc project through its connection. The project record stays in Arc, whichever interface you use.
What happens when I change models or tools?
Your Arc project’s memory, decisions, tasks and saved work remain available. Connect another supported tool or model to the project so it can use that context. Each connection still has its own capabilities and access settings.
What stays on my computer?
Arc stores rooms, messages, tasks, decisions and artifacts in a local database on your computer. If you use a hosted model or an external AI tool, the context you send through that connection is handled by its provider. Read the privacy policy for details.
Does Arc include AI model usage?
Your purchase covers the Arc desktop app and its updates. Connected tools use your existing accounts or subscriptions. Hosted models use your own API keys, with usage billed by the provider. Compatible local models do not need a hosted model subscription.
Which computers does Arc support?
Windows 10 or 11 (64-bit), and macOS 11 or later on Apple Silicon. Intel Macs and Linux are not supported. See the installation guide for setup.
What if Arc is not right for me?
Arc has a 30-day money-back guarantee. The full terms are in the refund policy.
Your AI workstation. Bring your AI. Elevate your work.
Buy Megastructure Arc — $199