AI coding agents have crossed a threshold. They're no longer just autocomplete on steroids. Tools like Claude Code can plan, write, and edit code across an entire project with minimal hand-holding. For developers who haven't tried them yet, or for non-developers who've heard the hype and want to understand what's real, this guide is a grounded starting point.

This is the first article in the Getting Started with AI Agents series. We're starting with Claude Code because it's become one of the most-discussed tools in the developer community over the past six months, and because it represents a genuinely different mental model from editor-embedded AI tools like Cursor or GitHub Copilot.

What Is Claude Code, Actually?

Claude Code is a command-line AI coding agent built by Anthropic. You run it in your terminal. It reads your codebase, follows instructions in natural language, and makes changes to files directly.

That last part is what makes it different. Most AI coding tools are assistants: they suggest code, you accept or reject it, you copy-paste. Claude Code is more like an agent: you give it a task, it figures out the steps, and it does them. You review the results.

A simple example: you might tell Claude Code "add input validation to all the form fields in the checkout flow" and it will find the relevant files, understand the existing patterns, and make the changes, showing you what it did before asking you to confirm.

More complex example: "set up a new Next.js project with TypeScript, Tailwind, and a basic authentication flow using next-auth" and it will scaffold the whole thing, install dependencies, and configure the files.

It runs in your terminal, works on your local files, and requires an Anthropic API account for the underlying Claude model access.

Before You Install: What You Need

Required:

Helpful but not required:

Not required:

Installing Claude Code

Open your terminal and run:

`` npm install -g @anthropic-ai/claude-code ``

This installs Claude Code globally. Once installed, you can run claude from any directory.

Set your API key:

`` export ANTHROPIC_API_KEY=your-key-here ``

Get your API key from the Anthropic console. To make this permanent (so you don't have to set it each session), add that line to your shell config file (~/.zshrc on Mac with zsh, ~/.bashrc on Linux with bash).

Verify the installation:

`` claude --version ``

If you see a version number, you're ready.

Your First Session

Navigate to a project folder in your terminal. If you don't have one, create a test folder:

`` mkdir my-test-project cd my-test-project ``

Start Claude Code:

`` claude ``

You'll see a prompt. Try something simple to start:

`` > Create a README.md that describes a simple to-do list app ``

Claude Code will create the file and show you what it wrote. You can then ask it to change things, ask questions about what it did, or give it a new task.

For a real project: navigate to your actual project directory and give it something real. The more context it has (existing code to reference), the better the results.

Understanding the Permission Model

This is the part most beginners skip and then wonder why something unexpected happened.

Claude Code has three layers of behavior:

Read-only mode (default for exploration): Claude Code can read your files and explain what it sees but won't modify anything. Useful when you want to understand code before letting it make changes.

Edit mode: Claude Code proposes edits and shows you a diff before applying. You approve each change. This is the default for most coding tasks and the right starting point.

Auto mode: Claude Code makes changes without asking for approval on each step. Useful for well-defined tasks where you trust the direction. Riskier for complex changes.

You can control this with flags or via settings. For beginners: stick to the default edit mode. Review every diff. The speed benefit of auto mode isn't worth the debugging overhead until you understand how Claude Code reasons about your codebase.

The practical rule: If you wouldn't let a junior developer make this change unsupervised, don't let Claude Code do it in auto mode.

What Claude Code Is Good At

Boilerplate and scaffolding: Setting up project structure, creating configuration files, adding standard patterns. This is where AI agents save the most time with the least risk.

Adding features with clear requirements: "Add a search bar that filters the tool list by name" is a well-specified task. Claude Code handles these well when the codebase is readable and the requirement is concrete.

Refactoring with clear direction: "Rename all instances of userId to user_id across the project" or "convert this class component to a functional component" are mechanical tasks that Claude Code executes reliably.

Writing tests for existing code: Paste a function and ask for tests. The output is usually 80-90% correct and saves significant time even with editing required.

Debugging with stack traces: Paste an error, ask what's wrong. Claude Code is good at reading stack traces and identifying likely causes.

Explaining unfamiliar code: Navigate to a codebase you've never seen and ask Claude Code to explain what a particular module does. This is genuinely useful for onboarding.

What Claude Code Struggles With

Vague requirements: "Make this better" produces mediocre results. The more specific the instruction, the better the output.

Very large codebases without context: Claude Code has a context window limit. In a massive codebase, it may not have access to all the relevant files at once. You may need to point it to specific files.

Novel architecture decisions: Claude Code is trained on patterns that exist. For genuinely novel system design, it will produce something that looks right but may not be the best approach for your specific constraints. Use it as a starting point, not a final answer.

Tasks requiring real-world state: "Check if the API is down and fix it" is not a Claude Code task. It works on files, not live systems.

Real Use Cases from the Community

The developer community has been sharing how they're actually using Claude Code. Some patterns that come up repeatedly:

Solo developers building faster: Indie developers report using Claude Code to ship features they'd normally skip because the implementation time wasn't worth it. Not writing full apps from scratch, but adding the 20% of features that would have taken 80% of the time.

Non-developers building tools for themselves: People with domain expertise but limited coding background are using Claude Code to build internal tools: data pipelines, simple web apps, automation scripts. The workflow is iterative: ask for something, review it, ask for changes, repeat.

Code review and cleanup: Some developers use Claude Code as a second pass before submitting PRs. "Review this diff and flag anything that looks wrong" surfaces issues that were invisible after staring at the code for hours.

Dealing with unfamiliar languages: Working in a language you know less well? Claude Code handles the syntax and idioms while you focus on the logic.

Pricing and Costs

Claude Code uses your Anthropic API credits. Pricing is based on tokens (roughly, the amount of text processed).

For typical development use, expect:

The main cost driver is context size. Large codebases passed to Claude on every message get expensive quickly. Use the /compact command to compress conversation history when sessions get long.

There is no fixed subscription for Claude Code itself. You pay for what you use via API credits.

Tips for Better Results

Be specific about what you want: "Refactor the authentication module to use JWT instead of sessions, keeping the existing test suite passing" is a much better prompt than "improve the auth code."

Use git. Before any significant Claude Code session, make sure you're on a clean commit. If something goes wrong, you can revert. Claude Code can also help you write the commit message after.

Review every diff. It takes 30 seconds to read a diff and understand what changed. Build this habit early. The bugs that slip through are almost always the ones you accepted without reading.

Start small on new projects. Give Claude Code a small, well-defined task first. See how it reasons about your codebase. Build trust through small wins before letting it touch critical paths.

Use /help inside the session. The built-in help covers commands and options you'd otherwise miss.

Next Steps

Once you're comfortable with the basics, the next articles in this series cover:

For now, the best way to learn is to use it on something real. Pick a small, low-stakes task in a project you care about, and run a session. The gap between "reading about AI agents" and "having done it" closes fast once you try it.

This is the first article in the Getting Started with AI Agents series on Solaire Tools.