What Is Claude Code? How to Install and Use It

What is Claude Code and what does it do?

What is Claude Code? Claude Code is an agentic AI coding tool from Anthropic that reads your codebase, edits files, runs commands, and connects to your development tools. It runs in the terminal, in IDE extensions, in a desktop app, and in the browser. You describe the goal, and it plans and carries out the steps with your permission.

In this guide, we at Talha Aslan and team explain the tool based on our hands-on experience. First, we cover the concept. Then we walk through the install logic, the first session, the project instruction file, and the permission model. As a result, you can decide whether it fits your workflow.

One thing is worth saying up front. Claude Code is not a chat window. Its key difference is that it works with real files inside a project folder on your machine. Therefore it brings responsibility as well as speed, so please do not skip the security section.

What is Claude Code in simple terms?

Put simply, Claude Code is like an experienced helper developer who sits inside your project. You say, "find and fix the bug in the login form." It opens files, reads the relevant code, proposes a plan, makes the change, and runs the tests. Still, it checks in with you at each critical step.

A chat-based AI, on the other hand, only sees the code you paste into it. For example, to explain a bug that spans three files, you have to copy each file by hand. Claude Code explores the folder on its own. In other words, you do not carry the context; the tool gathers it.

In short, a chat tool is a consultant. Claude Code is a teammate who sits at your desk and uses the keyboard with your approval. That difference in authority explains both its power and the parts that need care.

How does Claude Code work?

Claude Code works in an agent loop. You give it a task in plain language. Then it inspects the environment and uses tools such as file reading, search, editing, and shell commands. It sees the result of each step and picks the next one based on that result.

1. Understand the task and ask for clarity if needed.
2. Find and read the relevant files.
3. Plan an approach.
4. Make the change, or request permission to run a command.
5. Verify the result, for example by running tests.
6. Summarize the work for you.

Anthropic's Claude models power this loop. The specific model and version change over time, so check Anthropic's official documentation for current details. How much text the model can consider at once relates to the context window, and you will notice that limit in long sessions.

Also keep in mind that the tool does not just produce text. It takes real actions. Therefore you should review its output as a change that already happened, not as a suggestion.

Where does Claude Code run?

According to Anthropic's official overview, Claude Code runs on several surfaces that all connect to the same engine. As a result, your project instruction file, settings, and connections stay shared across them.

• Terminal (CLI): the most complete surface, where you manage the whole project from the command line.
• IDE extensions: extensions for VS Code and JetBrains IDEs with inline diff views.
• Desktop app: visual diff review and several sessions side by side.
• Web: start long tasks in the browser with no local setup.

The docs also cover integrations with CI pipelines and team chat. However, this guide focuses on the terminal, because that is where the tool's logic is easiest to see. If you are curious about an editor-first approach, our Cursor AI guide covers that side in depth.

How do you install Claude Code?

The install logic is simple. You install the tool, open a project folder in your terminal, and start it. The official docs recommend a native install script for macOS, Linux, and WSL. They also list separate PowerShell and CMD options for Windows.

1. Open the official setup page and copy the command for your operating system.
2. On macOS, you can also use Homebrew with brew install --cask claude-code.
3. When the install finishes, open a new terminal window and run claude --version to see a version number.
4. If the command is not found, the install folder is not on your PATH yet. The official troubleshooting page covers this case.

The native install updates itself in the background. Homebrew and WinGet installs do not, so you upgrade them yourself. Commands can change over time. That is why we suggest you always copy them from the official setup docs, not from our article.

On the account side, most surfaces need a Claude subscription or an Anthropic Console account. Plans and prices change, so check the current value on Anthropic's official pricing page.

How do you start your first session?

To start your first session, move into your project folder in the terminal and type claude. The tool asks you to log in on first use. After that, it uses the project folder as its context.

For your first task, we suggest exploration rather than changes. For example, ask it to summarize the project structure and find the entry points and test command. That way you see how the tool understands the project, and you can correct any wrong assumption early.

Next, continue with a small, reversible task. Fixing a typo or adding a test to a single function makes a good start. Moreover, if Git tracks your project, you can undo any change easily. For the basics, see our Git and GitHub guide.

In short, the goal of the first session is trust, not speed. Seeing how the tool reasons and asks for permission saves you time on larger tasks later.

What does a good Claude Code workflow look like?

In our experience, the most productive workflow has four stages: explore, plan, implement, and verify. This order ties the tool's speed to a controlled process.

1. Explore: have it read the relevant files and describe current behavior.
2. Plan: ask for an approach before any change and review it.
3. Implement: let it apply the approved plan in small steps.
4. Verify: have it run the tests, the build, or the app itself.

Be concrete when you describe a task. Instead of "make the site faster," say "add lazy loading to images on the product list page and keep the existing tests passing." The second request gives a far more accurate result.

The tool also runs non-interactively on the command line. For example, you can pipe log output into it and ask for a summary. That said, we suggest you set up this kind of automation only after you know the tool well in interactive use.

What is the CLAUDE.md project instruction file?

CLAUDE.md is a Markdown file you place in your project root. Claude Code reads it at the start of every session. According to the official memory docs, you use it for coding standards, architecture decisions, preferred libraries, and review checklists.

In other words, you write these rules once instead of repeating them each session. For example, rules like "run tests with this command," "do not touch this folder," or "use existing design components on new pages" belong in this file.

• Keep it short and in bullet points.
• Add project-specific commands for setup, tests, and builds.
• State clear prohibitions, such as never touching production config.
• Commit the shared file to version control for the team.

The docs also mention auto memory, where the tool saves learnings across sessions. Still, CLAUDE.md remains the place for durable, team-wide rules. To keep the file lean, you can check its length with our word counter. A shorter file also uses context more efficiently.

How do Claude Code permissions and security work?

Claude Code uses a tiered permission system. According to the official permissions docs, read-only actions such as file reads and search need no approval within the working directory. Shell commands and file edits, by contrast, wait for your approval by default.

The approval prompt shows what the tool is about to do, and you allow or deny it. You can also define allow and deny rules in settings files. That way you permanently allow certain commands and fully block the ones you consider risky.

• Keep the default behavior and read every change.
• Add allow rules for safe commands you use often.
• Block access to files with secrets through deny rules.
• Commit shared settings to version control in team setups.

When the tool reads outside content, hidden instructions in that content can pose a risk. We explain this attack type in our prompt injection guide. Therefore, be careful with unfamiliar repos and pages, and do not loosen permissions.

Why does planning matter in Claude Code?

Planning means the tool shows you what it will do before it changes anything. On large tasks, this step prevents wasted effort in the wrong direction. The Claude Code docs present plan review as its own way of working.

For example, say you want to refactor a payment module. If you start without a plan, the tool may touch dozens of files. During planning, however, you see which files will change, the order, and the risks. You fix anything you dislike before a single line of code exists.

Reviewing the plan against your CLAUDE.md rules also keeps things consistent. If the plan breaks a rule, you notice right away. In short, the plan bridges speed and control, so we suggest you never skip it on production projects.

Another benefit is learning. Because the tool explains its reasoning, reading its plans teaches you the structure of a new codebase quickly.

How do you extend Claude Code with MCP, skills, and hooks?

Claude Code is not limited to local files. It has three main ways to extend it: MCP for outside data, skills for repeatable workflows, and hooks for automatic checks.

• MCP: the Model Context Protocol is an open standard that connects AI tools to outside sources. See our MCP guide for details.
• Skills: instruction sets that package workflows your team repeats.
• Hooks: shell commands that run before or after the tool's actions, such as formatting after every edit.

These extensions are powerful. However, each one widens the tool's reach. So before you add an MCP server, check its source, which data it accesses, and who maintains it.

For instance, if your project handles event notifications from a payment provider, add a few short rules to CLAUDE.md based on the concepts in our webhook guide. That helps the tool understand the notification logic correctly.

What is the difference between a terminal agent, an IDE assistant, and a chat interface?

AI coding tools fall roughly into three groups. The table below summarizes the differences at a conceptual level. It does not crown any specific product.

This table also answers "what is Claude Code" by category: it belongs to the terminal agent group. In practice, most developers use all three. For example, they use chat for ideas, an IDE assistant while typing, and a terminal agent for multi-file edits.

What is Claude Code not good at, and what are the risks?

Any honest answer to what is Claude Code includes its limits. Knowing them keeps expectations realistic and keeps faulty changes out of production.

• The tool can make mistakes, so you must read and test its code.
• Context fills up in very long sessions, and earlier details fade.
• Vague task descriptions lead to broad changes you did not expect.
• Loose permission settings raise the risk of unwanted commands.
• Files with secrets and personal data need extra protection.

For that reason, treat the tool as a supervised helper, not a system you hand responsibility to. We also discuss the upsides and traps of fast AI prototyping in our vibe coding guide.

Watch the cost side too. Usage counts toward your account or subscription. Plan limits and prices change, so check the current value on Anthropic's official page.

Which real scenarios does Claude Code help with?

The scenarios below are example scenarios based on use cases in the official docs. None of them is a guaranteed outcome, and results vary with your project.

• Writing tests: it writes tests for a weakly covered module, runs them, and fixes failures.
• Debugging: you paste an error, and it traces the root cause through the codebase.
• Commits and PRs: it saves changes with a descriptive message.
• Text processing: it explains a complex validation rule, such as what a regular expression matches, step by step.
• Configuration: it finds indentation errors in CI or Docker files.

As an example scenario, picture a small online store. The developer describes a product filter bug. The tool finds the relevant query, proposes a fix, and runs the existing tests. Still, the developer makes the final call and handles the release.

How do you debug with Claude Code?

Debugging is one of the areas where the tool saves the most time. According to the official docs, when you paste an error message or describe a symptom, it traces the issue through the codebase, looks for the root cause, and proposes a fix.

Good results, however, need good input. Give it the full error message, the steps that trigger it, and the behavior you expect. For example, "the signup form shows a blank page on submit, and the browser console shows this error" works much faster than "the form is broken."

1. Write the steps to reproduce the bug.
2. Add the full error output and related log lines.
3. Ask the tool to list likely causes first.
4. Let it apply the fix and repeat the same steps.
5. Have it add a test so the bug does not return.

As an example scenario, consider a Python project where a module cannot be found. The tool checks the virtual environment and the dependency list. Often it traces the problem to the wrong environment. For a detailed fix, see our ModuleNotFoundError guide.

Moreover, the tool explains why the bug happened, not just how to fix it. Reading that explanation helps you spot similar bugs yourself later.

How does Claude Code fit into a Git workflow?

People who ask what Claude Code is often wonder about version control as well. The tool works with Git directly. According to the official docs, it stages changes, writes descriptive commit messages, creates branches, and opens pull requests. That saves time, but keeping your history clean is still your job.

We suggest this setup. Open a separate branch for each task, run the tool on that branch, and read the diff yourself before you merge. As a result, the main branch stays clean, and you can revert a bad change in one move.

• Use one branch per task.
• Approve the content even when the tool writes the commit message.
• Check its suggestions line by line during merge conflicts.
• Trigger the push to the remote yourself, on purpose.

For example, when two developers touch the same file, the tool helps resolve the conflict. Still, the person who knows the business logic should decide which lines stay. For the basics, see our guide on resolving merge conflicts.

How do you manage context in long sessions?

In a long session, the tool tries to carry the whole conversation and every file it read. As context nears its limit, earlier details get summarized or fade. That is why long sessions sometimes produce inconsistent results.

The practical fix is simple: run unrelated tasks in separate sessions. For instance, after you finish a bug fix, clear the session before you start a new feature. That way the tool does not mix details from the old task into the new one.

Also, keep durable knowledge in CLAUDE.md rather than in the chat. Even after a session ends, the tool reads that file again at the next start. Consequently, the "I told you last time" problem mostly goes away.

Keep task descriptions short as well. Long, padded explanations fill the context and bury the detail that matters. For the theory behind this, our context engineering guide helps.

When does non-interactive mode and automation make sense?

Claude Code follows the Unix philosophy and works alongside other command line tools. The official docs show examples such as piping log output into it, or running translation and code review in CI.

This kind of use can skip some of the approval prompts you see in interactive sessions. Therefore, we suggest automation only for well-defined, bounded, and reversible jobs.

1. Try the task by hand in interactive mode a few times first.
2. Limit the tool's rights to the narrowest scope the task needs.
3. Send the output to a pull request for review, not straight to production.
4. Keep logs so you can trace unexpected behavior later.

As an example scenario, picture a nightly job that checks for dependency updates. The tool prepares the updates and opens a pull request. Then a team member decides on the merge in the morning. In short, automation adds speed, while the decision stays with a person.

How do teams share Claude Code settings?

Claude Code keeps settings at several levels: personal user settings, shared project settings, and policies that organizations manage. The official permissions docs explain that you can check settings into version control to share them with every developer, and each developer can still customize their own.

This structure keeps a team consistent. For example, you allow the test command for everyone and block the deploy command for everyone. A new developer then works inside the same safety frame from day one.

• Keep shared rules in the repo with the project.
• Do not mix personal preferences into the shared file.
• Set organization policies together with your IT team.
• Send settings changes through code review too.

A shared CLAUDE.md and shared permission settings also complement each other. One explains how the tool should behave, and the other limits what it can do. When you set up both, the tool works consistently and safely.

What should businesses check before adopting Claude Code?

A team or business should run through a short checklist before adopting the tool. It cuts security and consistency problems from the start.

• Is it clear which repos allow the tool and which do not?
• Are shared permission settings and deny rules in place?
• Are secrets kept outside the repo?
• Does CLAUDE.md reflect team standards?
• Does code review cover AI-generated changes as well?
• Who owns usage costs and account management?

If your project handles personal data, review your privacy obligations as well. This article is not legal advice, so consult a qualified advisor when needed. Strong passwords and key management are also basic hygiene. To generate a secure password quickly, try our password generator.

When is it better to work with a software team?

In the hands of an experienced developer, Claude Code is a strong accelerator. However, architecture decisions, security review, and long-term maintenance still need human ownership. Consequently, as your project grows, treating the tool as the whole solution becomes risky.

For example, if you are building a platform with payments, accounts, and personal data, getting the architecture right early costs far less than fixing it later. In our custom software development work, we use AI tools too, under supervision.

On the other hand, a coding tool and business process automation are different needs. If you want to automate business workflows with AI, our AI automation services are a better starting point.

Who is Claude Code a good fit for?

To sum up, the practical answer to "what is Claude Code" is this: a coding agent that works with real files in your project folder, with your permission. It delivers the most value to developers who are comfortable in the terminal, describe tasks clearly, and take time to review changes.

It can also teach beginners a lot. Still, accepting code you do not understand does harm over time. So start with small tasks, create your CLAUDE.md, keep permissions tight, and always return to Anthropic's official docs for setup and current features.

That way, the tool becomes a teammate who raises your speed and leaves control with you. If you have questions, Talha Aslan and team are here to help with your software and AI projects.