Overview

The Claude Code CLI (Command Line Interface) is the primary way to interact with Claude Code. It provides powerful options for running queries, managing sessions, configuring models, and integrating Claude into your development workflows.

A CLI is a text-based interface where you type commands instead of clicking buttons. If you've ever used a terminal or command prompt, you've used a CLI. Claude Code runs entirely in your terminal — there's no separate app to install or browser tab to open. You launch it, give it instructions, and it reads, writes, and runs code right alongside you.

Why the CLI Matters

The CLI gives you fine-grained control over how Claude Code behaves. You can pass flags to change the model, set output formats, pipe input from other commands, and run Claude Code non-interactively in scripts. This flexibility makes it useful for quick one-off questions, long coding sessions, and automated CI/CD pipelines alike.

Common Commands to Know

Here are the commands you'll use most often:

claude                  # Start an interactive session
claude "fix the bug"    # Run a one-shot prompt
claude --model sonnet   # Use a specific model
claude --help           # See all available options
claude config           # View or change settings

You can also pipe content directly into Claude Code:

cat error.log | claude "explain this error"

This sends the contents of error.log as context, so Claude can analyze it without you copying and pasting.

Key Takeaway

The CLI is your control panel for everything Claude Code does. Learning a handful of flags and commands unlocks faster workflows, automation options, and deeper customization. The lessons in this module walk through each area — configuration files, model selection, session management, and more — so you know exactly what's available.