GroningenPHP - Spec-Driven Development: Setup

Setup ~15 min

You need two things: a coding agent (the tool in your terminal) and a model (the brain it talks to). Both can be completely free — no paid LLM subscription required.

The two layers: OpenCode is the free, open-source agent. It is model-agnostic, so you pick a free model provider below. Facilitators are here to help if anything gets stuck.

1 · Install OpenCode (the agent)

Pick your operating system.

Install OpenCode with the official script:
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```
curl -fsSL https://opencode.ai/install | bash
```
Prefer npm? npm install -g opencode-ai works too (needs Node.js 18+).
Restart your terminal, then confirm it is on your PATH:
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```
opencode --version
```
Install the file-tree plugin for terminal OpenCode:
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```
opencode plugin --global opencode-file-tree
```
Then restart OpenCode. The file tree appears in the sidebar.

Install OpenCode with Scoop (recommended) …
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```
scoop install opencode
```
… or with Chocolatey, or npm:
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```
choco install opencode
# or
npm install -g opencode-ai
```
No package manager? Grab the Windows binary from the releases page. Windows users often have the smoothest time inside WSL2 (Ubuntu) — if you use WSL, follow the Ubuntu tab instead.
Open a new terminal (PowerShell) and confirm:
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```
opencode --version
```
Install the file-tree plugin for terminal OpenCode:
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```
opencode plugin --global opencode-file-tree
```
Then restart OpenCode. The file tree appears in the sidebar.

Download the OpenCode GUI release for your OS from github.com/anomalyco/opencode/releases.
Pick the latest stable release. Download the Windows installer (.exe / .msi) or Linux package (.AppImage / .deb) matching your system.
Install and launch the app, then open your project folder in the GUI.
Connect a model provider inside the app (same as step 2 below: MiMo v2.6 Flash Free, Copilot, or Ollama).

2 · Connect a free model (the brain)

Choose one. Start with the default — the fallbacks are there if signup, connectivity, or your laptop get in the way.

Default

MiMo v2.6 Flash Free (Xiaomi) or Muse Spark 1.3 Free (Meta)

Best quality-for-effort: works out of the box in OpenCode, no API key needed.

Open OpenCode and run /models.
Pick your model.
Send a quick test prompt to confirm it responds.
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```
What model are you?
```

Fallback A

GitHub Copilot

Already have Copilot (free for students & OSS maintainers)? Zero setup.

In OpenCode run /connect, choose GitHub Copilot.
Open github.com/login/device and enter the code shown.
Run /models and pick a model.

Fallback B

Local model (Ollama)

Offline & no signup. Needs a capable laptop (~8 GB free RAM/VRAM).

Install Ollama, then pull a coding model:
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```
ollama pull qwen2.5-coder
```

Point OpenCode at it via opencode.json (OpenAI-compatible endpoint):

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                                {
                                  "$schema": "https://opencode.ai/config.json",
                                  "provider": {
                                    "ollama": {
                                      "npm": "@ai-sdk/openai-compatible",
                                      "name": "Ollama (local)",
                                      "options": { "baseURL": "http://localhost:11434/v1" },
                                      "models": { "qwen2.5-coder": { "name": "Qwen2.5 Coder" } }
                                    }
                                  }
                                }

Run /models and pick Qwen2.5 Coder.

3 · Readiness check

Navigate into any empty folder and start OpenCode:

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mkdir sdd-workshop && cd sdd-workshop
opencode

Type a message like "Say hello and tell me which model you are." and press Enter.

✅ You're ready when the agent replies in the terminal. Tip: press Tab to toggle Plan mode — you'll use it a lot today, because in spec-driven development we settle the plan before writing code.

Stuck? Grab a facilitator, or ask the agent itself to help debug the setup once it responds.

4 · Optional: Browser MCP plugin

Useful for browser automation, repeatable UI checks, and screenshots during verification.

Prerequisite: Node.js must be installed (Node 18+ recommended).
Install instructions: nodejs.org/en/download
Install the Browser MCP extension in Chrome or Edge:
browsermcp.io/install
Initialize the OpenCode plugin in your project:
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```
npx opencode-browser init
```
This updates opencode.json with the required plugin + MCP configuration.
Restart OpenCode, then run a quick browser task in chat (for example: "Open example.com and report the page title.").