Trying to install OpenCode AI on Windows but getting errors like this?

Invoke-WebRequest : A parameter cannot be found that matches parameter name 'fsSL'

or:

The '<' operator is reserved for future use.

Don’t worry — this issue usually happens because the installation command is designed for Linux/macOS terminals, not the default Windows PowerShell.

In this guide, you’ll learn:

  • Why the error happens
  • How to install Git Bash on Windows
  • How to properly install OpenCode AI
  • Common troubleshooting tips

Why Does OpenCode AI Fail in PowerShell?

The official OpenCode AI installation command is:

curl -fsSL https://opencode.ai/install | bash

This command works normally on:

  • Linux
  • macOS
  • WSL
  • Git Bash

The problem is that on Windows PowerShell, curl is not the real Linux curl command. It’s actually an alias for:

Invoke-WebRequest

As a result, PowerShell tries to interpret Linux shell syntax as PowerShell syntax, which causes installation errors.

Solution: Install Git Bash First

The easiest solution is using Git Bash.

Git Bash provides a lightweight Linux-like terminal environment on Windows, allowing commands like curl, bash, and shell scripts to run properly.

Step 1 — Download Git Bash

To get Git Bash, install Git for Windows first.

Download it here:

Git for Windows

Step 2 — Install Git Bash

Run the Git for Windows installer.

For most users, the default installation settings are perfectly fine.

After installation:

  • restart your terminal
  • or restart VS Code if it’s currently open

Step 3 — Open Git Bash

There are several ways to open Git Bash.

Method 1 — From the Start Menu

Press:

Windows Key

Then search for:

Git Bash

Open the application.

Method 2 — Right Click Inside Your Project Folder

Inside your project folder:

  • right click
  • select:
Open Git Bash here

This is usually the fastest workflow for development.

Step 4 — Install OpenCode AI

Once Git Bash is open, run the following command:

curl -fsSL https://opencode.ai/install | bash

Since the command is now running inside Git Bash, the installation process should work correctly.

How to Verify the Installation

After installation, run:

opencode --version

If you see a version number, OpenCode AI has been installed successfully.

Common Troubleshooting

1. curl: command not found

Git Bash usually includes curl by default.

If the error still appears:

  • reinstall Git for Windows
  • make sure Git Bash components are included

2. bash: command not found

This usually means the command is still running inside:

  • PowerShell
  • CMD

Make sure you are using Git Bash.

You can identify Git Bash if the terminal shows:

MINGW64

inside the terminal window.

3. opencode: command not found

Try:

  • closing Git Bash
  • opening the terminal again
  • rerunning the installation command

4. Node.js Not Installed

Some AI development tools require Node.js.

Check your Node.js version with:

node -v

If Node.js is missing, install it from:

Node.js Official Website

Bonus: Use Git Bash in VS Code

If you use Visual Studio Code, you can make Git Bash your default terminal.

Open the Command Palette:

Ctrl + Shift + P

Search for:

Terminal: Select Default Profile

Select:

Git Bash

From now on, VS Code terminals will automatically use Git Bash.

Fix PATH Environment on Windows

Sometimes after installation, the opencode command is not recognized in Terminal or PowerShell.

If you see an error like this:

'opencode' is not recognized

it means the PATH environment variable has not been added yet.

How to Add OpenCode to PATH

Open:

Environment Variables

Then edit:

Path

Add the following directory:

C:\Users\USERNAME\.opencode\bin

Replace USERNAME with your Windows username.

After that:

  • Click OK
  • Restart Terminal or VSCode
  • Run the command again:
opencode

Final Thoughts

Most OpenCode AI installation errors on Windows are caused by running Linux commands directly inside PowerShell.

The easiest and safest solution is:

  1. Install Git Bash
  2. Run the OpenCode AI installer from Git Bash

Once Git Bash is ready, installing OpenCode AI becomes much smoother and avoids most terminal compatibility issues.