Claude Code CLI Commands I Wish I Had Known Sooner

I used Claude Code daily for months before realizing that claude --help hides many of its most useful capabilities. I kept restarting fresh sessions, repeatedly explaining the same project structure, simply because I did not know a better workflow existed. While debugging an unrelated issue, I discovered the full CLI reference: dozens of commands and flags that completely changed how I use the tool. In this article, I walk through the hidden features that mattered most in practice and how they can make Claude Code significantly more productive. 1. The First Thing That Changed: I Stopped Losing My Sessions 2. The One That Changed My Whole Working Day: Background Agents 3. The Flag I Should Have Learned on Day One 4. Where I Was Quietly Burning Money 5. The Setting I Had Wrong for Months 6. MCP From the Terminal 7. System Prompts: Append or Replace, and Why It Matters 8. When Something Breaks Note: This article skips installation and beginner setup. If you are new to Claude Code, start with Getting Started with Claude Code for installation and first-run setup, and Claude Code: Master it in 20 Minutes for a quick overview of the tool. Everything below focuses on…