01 - Tools

Requirements

Your AI coding tool needs three things:

• Plan mode - Separate thinking from writing. You align on the approach before code is produced.
• LSP integration - The model sees type errors, completions, and diagnostics. Same information your editor has.
• Conversation forking - Explore an alternative without losing your current thread.

Two tools check all boxes:

1. OpenCode - Open source, any model. My preference.
2. Claude Code - Anthropic’s CLI.

OpenCode Setup

Install OpenCode, then update ~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "model": "openai/gpt-5.3-codex",
  "tui": {
    "scroll_speed": 3,
    "scroll_acceleration": {
      "enabled": true
    },
    "diff_style": "auto"
  },
  "tools": {
    "lsp": true
  },
  "mcp": {
    "context7": {
      "type": "remote",
      "url": "https://mcp.context7.com/mcp",
      "headers": {
        "CONTEXT7_API_KEY": "{env:CONTEXT7_API_KEY}"
      }
    },
    "playwright": {
      "type": "local",
      "enabled": true,
      "command": [
        "bunx",
        "@playwright/mcp@latest"
      ]
    }
  }
}

Add env vars to your .bashrc, .zshrc, or config.fish (if you are one of those guys):

export OPENCODE_EXPERIMENTAL_LSP_TOOL=true
export CONTEXT7_API_KEY=<your-key-here>

Get a Context7 API key at context7.com.

On first run, OpenCode prompts for a provider. Pick either OpenAI or Anthropic. I personally recommend Codex-5.3 for coding because he does what I say (heisenberg, BB), and Claude for creative writing or design experimentation because it’s like a kid wanting to do everything on the first shot and try creative stuff.

What’s an LSP? It’s how your IDE understands autocompletion and syntax. The model gets the same type information and diagnostics your editor does - real errors, not hallucinated ones. Watch this explainer by TJ DeVries if unfamiliar.

MCP Servers

The config above includes two MCP servers:

• Context7 - Documentation lookup. The model queries real, up-to-date library docs instead of hallucinating APIs from training data. This is non-negotiable - without it, the model invents function signatures that don’t exist.
• Playwright - Browser automation. Takes screenshots of UI changes for visual verification. More on this in the UI appendix.

You can add more MCP servers as needed. The point is: give the model access to real data sources instead of letting it guess.

Keep it lean. Every MCP server or Skill you add bloats the system prompt and eats into the model’s context window. The more you pile on, the dumber the model gets - less room to actually reason about your problem. Only keep what you actively use. If you’re not using it, rip it out.