If you tried to run OpenCode on an older Windows machine, you may have hit this:

this CPU is missing SSE4.2 support, which Bun requires

The standard Windows binary is compiled with Bun, and Bun won't start on CPUs without SSE4.2. Nothing is wrong with your computer. The runtime just refuses to launch.

So We made a build of OpenCode v2.2.6 packaged as a Node.js executable. The Bun CPU check never runs.

OpenCode running

Repo: (https://github.com/foxauraai/opencode-node/)

What you get

  • A ready-to-use zip for Windows x64 (OpenCode v2.2.6)
  • No installation. Node.js is already inside the package
  • Setup with Command Prompt only

Install and run

  1. Download the zip from the Releases page and extract it, for example to C:\opencode.
  2. Open Command Prompt and run: 
cd /d C:\opencode\cli-node-windows-x64 OpenCode.bat

Any arguments you add after OpenCode.bat are passed to the program.

What's in the folder 

cli-node-windows-x64/ ├─ OpenCode.bat <- launcher, run this ├─ package.json └─ bin/ ├─ opencode2-node.exe <- the app (Node executable, ~187 MB) └─ photon_rs_bg.wasm <- needed by the app

OpenCode.bat is a one-line launcher that starts bin\opencode2-node.exe. Keep both files in bin\ together.

Run it from any folder

To run it as just OpenCode.bat from anywhere, add C:\opencode\cli-node-windows-x64 to your user PATH in Edit the system environment variables, then open a new Command Prompt.

Limits

  • This removes the Bun CPU requirement, not every requirement. Windows and your CPU still need to meet the basic requirements for modern 64-bit programs, and I haven't tested every older processor.
  • It's an unofficial build, not affiliated with the OpenCode project.

If it doesn't start on your machine, open an issue with your CPU model, Windows version, and the full error text.

👉 Download and instructions