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GUI Clients

OpenCode isn't just a TUI. The agent itself is a server running in the background on your machine, and the TUI is just a client that connects to it. And OpenCode ships three types of clients:

The TUI, which is the opencode command you already know.
The Web UI, which runs in your browser.
The Desktop App, which is a native app for macOS, Windows, and Linux.

The Web UI

To use OpenCode in the browser, just generate a pairing link with the pair command:

opencode pair

This starts the shared background service if it wasn't already running, and gives you a link to open:

It can be configured to include a QR code in case you want to open it on your phone... more on that later.

You can stop the background server with opencode service stop, but I recommend just leaving it on even when you're not actively using OpenCode – it's lightweight and means your next session will start instantly.

The Desktop App

OpenCode Desktop is a native app for Linux, macOS, and Windows. We won't be using it in this course, but it's good to know it exists.

It renders the same interface as the web UI, and it connects to the same background service. It allows for the things a browser tab isn't allowed to do:

Native file and folder pickers
Pasting screenshots straight from the clipboard
Dragging in a file so the agent gets its real path
"Reveal in Finder" (or the equivalent on Windows or Linux) and one-click open in VS Code, Cursor, Zed, or Ghostty
Auto-updates, instead of re-running the install script

Picking a Client

Client	Good at	Tradeoff
TUI (`opencode`)	Scripting, automation, SSH, speed	Weakest for large diffs or anything overly visual
Web UI (`opencode pair`)	Reachable from your phone, comfortable review UI	The browser can't touch your filesystem natively
Desktop	Native file handling and editor handoff, auto-updates	Doesn't run on a phone or in a terminal

I use all 3: TUI for code-heavy work. Web for mobile. Desktop (very occasionally) for tasks that require native file handling or lots of images.

Assignment

Use the Web UI to add a SlopLang example that prints the result of (1 + 2) * 3 (notice we added some parentheses!).

Run opencode pair and follow the displayed link.
Under "Projects," open the Sloperator repo. If it isn't listed, click the folder icon and select your project directory.
Check the model selector before sending your first prompt. Select DeepSeek V4.1 Flash Free (or your preferred model from earlier). The Web UI may start with a different model selected than the TUI.
Tell the agent to create a new examples/grouping.slop file that prints the result of (1 + 2) * 3.
Review the file, then have the agent run it, along with uv run pytest tests/test_examples.py -q. Confirm that the program prints 9 and the tests pass.

In the web UI, tell OpenCode to run and submit the CLI tests from the project root.