What Castforge is
Castforge is a desktop app that puts AI coding agents to work on your projects, on a live board you can watch. Instead of juggling separate command-line tools for GitHub Copilot, Claude, OpenAI Codex, Google Gemini, Cursor, and the rest, you connect the AI you already have access to and drive it all from one window.
The core idea: sign in for free, connect with an AI subscription you already pay for, and just start coding. There are no API keys to manage and no per-token billing to worry about. The lowest-friction start is a free GitHub Copilot sign-in. (If you prefer, you can bring your own API key or run a local model instead, which is covered in the connecting agents guide.)
Who it is for
Castforge is built for developers who already use AI coding tools and want a polished workspace on top of them. You do not need to be an expert. The setup takes about two minutes, and you describe a task in plain language and watch the agent build.
System requirements
- Windows is the supported platform right now. There is no macOS or Linux build yet.
- A Windows 10 or Windows 11 machine.
- An internet connection for sign-in and for the AI agents to run.
- At least one AI agent command-line tool installed (Castforge checks for this during setup and helps you install it if it is missing). See the connecting agents guide for details.
If you are on macOS or Linux, Castforge will not run today. Keep an eye on the website for future platform support.
Downloading and installing
- Go to castforge.ai and download the Windows installer.
- Run the downloaded installer (a file named like
Castforge_<version>_x64-setup.exe). - Follow the prompts to finish installation. Castforge installs as a normal desktop app and adds itself to your Start menu.
- Launch Castforge from the Start menu or the desktop shortcut.
A note on the security warning
Castforge is a newer app, so Windows SmartScreen may show a caution screen the first time you run the installer. If you downloaded it from castforge.ai, you can choose "More info" and then "Run anyway" to continue. This warning fades as more people install the app over time.
First launch and the setup flow
The very first time you open Castforge on a machine, it walks you through a short setup flow. There are five steps, shown as a progress strip across the top:
- Account
- Welcome
- Connect
- Install
- Project
You can always tell where you are by the highlighted step in the strip.
Step 1: Your Castforge account
Setup starts by asking you to sign in or create a free Castforge account. This step is required and cannot be skipped, because your account keeps your projects, settings, and subscription in sync on this machine.
Castforge uses passwordless, magic-link sign-in. There is no password to create or remember.
To sign in:
- Click "Sign in or create account".
- In the dialog that appears, type your email address and click "Send magic link". Castforge opens your web browser to finish the request.
- Check your email inbox for a message from Castforge with a sign-in link.
- Click the link in that email. If you are new, your account is created on the spot.
- Castforge detects the completed sign-in automatically. The "Continue" button activates, and setup moves you forward to the Welcome step.
A few things worth knowing about the magic link:
- The link is one-time use. Once you click it and sign in, it is spent.
- It expires after about 60 minutes. If too much time passes, request a fresh one.
- Open the link on the same machine where you are running Castforge. The sign-in is tied to that machine's browser session, so clicking it on a phone or a different computer will not complete the sign-in in the app.
- If the email does not arrive, use the "Resend magic link" option in the sign-in dialog. Also check your spam folder.
- Your Castforge account is separate from your agent connections (GitHub Copilot, Claude, Codex, Gemini, and the rest). Castforge never sees your AI provider credentials.
No credit card is required to create an account.
Step 2: Welcome
This is a brief introduction screen. It shows the journey ahead: connect your AI, describe a task, and watch it build. Click "Get started" to continue.
Step 3: Connect an agent
Here you connect the AI agent Castforge will use. You can connect for free, use a subscription you already pay for, or paste your own API key. This step is covered in depth in the connecting agents guide. In short:
- Pick the recommended free path (a free GitHub Copilot sign-in), use a subscription, or bring your own key.
- You only need to connect one agent to start. You can add more later.
When an agent is connected, setup moves on to the Install check.
Step 4: Install check
Each agent runs through its own command-line tool on your machine. On this step, Castforge checks whether that tool is already installed.
- If the tool is found, you see a confirmation that you are already set up. Click "Continue".
- If the tool is missing, Castforge shows you exactly how to install it, including a command you can copy and, for some agents, an "Install for me" button. You can also choose "I'll install it later" and proceed anyway.
This step never traps you. Whether the tool is present or not, you can move forward to creating your project.
Step 5: Your first project
The final step launches the New Project wizard so you can create your first project. See "Creating your first project" below for the full walkthrough. When the project is created, you land directly inside it, ready to work, and setup is complete.
The "Skip setup" option
If you would rather explore Castforge before finishing setup, there is a "Skip setup" link in the top-right of the setup window's progress strip.
Note: Skip setup is a general-availability affordance. It is hidden in alpha and tester builds, so if you are on an early build you may not see it and will finish the guided steps instead.
When you click it, Castforge asks you to confirm. Choosing "Skip setup" takes you straight to the Castforge home screen instead of finishing the guided steps. Note that the account step itself is the one part you cannot skip past; the skip option applies to the rest of the flow.
Skipping is not permanent. You can re-run the setup tour any time from Settings, under About, using the "Replay onboarding tour" option. And you can connect agents and create projects from inside the app whenever you are ready.
What returning users see
The guided setup only runs on a true first launch on a machine. After that:
- If you already have projects, Castforge opens straight to your home screen with your projects, skipping setup entirely.
- If you are already signed in and you re-enter the setup flow for any reason, the account step recognizes you and advances automatically, so you are never asked to sign in twice.
- If you have used Castforge before but deleted all your projects, you land on the home screen's empty state rather than being thrown back into the setup wizard.
Creating your first project
Whether you reach it at the end of setup or start it later from the home screen, the New Project wizard is how you create a project. It has a few steps along a left-hand rail (Setup, the team, charters, display mode, and review), and everything you choose is editable later from project settings.
On the first step (Setup), you give the project a name and pick a starting point. There are four ways to begin:
- Blank project. Start from an empty workspace. Castforge scaffolds a fresh folder for you.
- From a template. Choose a curated starter pack with a guided walkthrough.
- From a Git repo. Paste a repository URL and Castforge clones it for you to work on.
- Open existing folder. Adopt a folder that is already on your machine. Castforge opens a folder picker and works with that folder in place.
The Setup step also lets you pick a project type: Web app (the default) or Unreal Engine. This sets which surface the project opens to later, and you can change it any time from project settings.
For blank and template projects, Castforge can also set up a Git repository and shared agent context files for you (these toggles are on by default), and optionally publish to a private GitHub repository if you have GitHub connected.
To finish:
- Name your project and pick a starting point.
- Click "Continue" to move through the remaining steps, or jump straight to Review.
- On the Review step, click "Create project".
Castforge creates the project and drops you right into it.
Choosing a location
By default, new projects are created under your Documents folder, in a "CastforgeProjects" subfolder. You can change the location with the "Browse..." button on the Setup step.
What's next
- Connecting agents. Learn the three ways to connect (free sign-in, your subscription, or your own API key), how to switch your active agent, and how to set a different agent per project. See the connecting agents guide.
- Run your first task. Inside a project, describe what you want in plain language and watch the agent work on the live board.
- Manage your account. Visit your account dashboard at castforge.ai to see your plan, connections, and settings.
Common questions
Do I need a credit card to use Castforge? No. Creating a Castforge account requires no card, and the recommended way to connect an agent is free.
Is there a password to remember? No. Castforge uses magic-link sign-in. You type your email, click the link Castforge sends you, and you are in.
My magic link is not working. What do I do? The link is single-use and expires after about 60 minutes, and it must be opened on the same machine where Castforge is running. If it has expired or you clicked it elsewhere, request a fresh one with "Resend magic link" and click the new link on the same computer.
Can I use Castforge on a Mac or on Linux? Not yet. Castforge is Windows-only for now.
Can I skip the setup and just look around? Yes, with the "Skip setup" link in the top-right of the setup window, except for the account sign-in, which is required. Skip setup is a general-availability affordance and is hidden in alpha and tester builds, so on an early build you may not see it. You can replay the setup tour later from Settings, under About.
I deleted all my projects. Will Castforge make me redo setup? No. Once you have completed setup once on a machine, emptying your project list takes you to the home screen's empty state, not back into the wizard.
Do I have to connect an agent during setup? You connect one to finish setup naturally, but the Install step lets you proceed even if the tool is not installed yet, and you can connect agents from inside the app at any time.