Table of contents
- 1. Install Claude Code on Your System
- 2. Authenticate Your Anthropic Account
- 3. Configure Billing and API Keys
- 4. Run Your First Interactive Session
- 5. Execute Single Commands Directly
- 6. Understand Agentic File Permissions
- 7. Run and Approve Terminal Commands
- 8. Configure System Settings and Preferences
- 9. Set Up Ignore Rules for Projects
- 10. Troubleshoot Common Installation Errors
- Frequently Asked Questions
Before installing anything, confirm your machine qualifies.
Claude Code runs on macOS 13.0 and later, Windows 10 version 1809 or newer, and several Linux distributions including Ubuntu 20.04 and later, Debian 10 and later, and Alpine Linux 3.19 and later.
You will need at least 4 GB of RAM, a 64 bit or ARM64 processor, and a working internet connection, since Claude Code needs network access to function at all.
Your shell needs to be Bash, Zsh, PowerShell, or CMD, which covers essentially every standard terminal setup across all three operating systems.
One additional tool called ripgrep handles search functionality, and it comes bundled automatically in nearly every installation method, so this rarely requires a separate step.
1. Install Claude Code on Your System
Install Claude Code to bring the reasoning power of Anthropic directly into your terminal.
This command line tool acts as an agentic assistant capable of reading files, running terminal commands, and editing code on your local computer.
Unlike web based interfaces, this tool runs locally and executes actions directly on your development environment.
To complete the installation, you need Node.js version 18 or higher.
Open your terminal and run the global package installation command.
npm install -g @anthropic-ai/claude-code
If your system requires administrator privileges for global npm packages, you may need to prefix this command with sudo on Unix based systems.
Once the installation process completes, you can verify the setup by typing the primary command in your terminal.
claude
This command initializes the tool and prepares it for its first run.
It will check your environment, verify dependencies, and prompt you to log in to your Anthropic account.
2. Authenticate Your Anthropic Account
After launching the command line tool, you must connect it to your Anthropic account to authenticate API calls.
The tool uses a browser based authentication flow that links your terminal session to your existing console account.
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When you run the launch command, a unique authentication link will appear in your terminal.
Copy this link and paste it into your web browser, or press the enter key if your terminal supports automatic link opening.
Log in to your Anthropic Console account if you are not already logged in.
You will see a confirmation screen asking you to authorize the command line utility.
Click the authorize button, and your browser will pass a secure token back to your terminal.
Your terminal will display a success message, indicating that the tool is ready to use.
3. Configure Billing and API Keys
Using this terminal tool incurs costs based on token consumption, which requires an active billing setup on the Anthropic Console.
The tool does not use standard personal API keys from your environment variables, instead, it manages its own secure session tokens through the web authentication process.
Navigate to the Anthropic Console in your web browser and click on the billing section.
Ensure you have a valid credit card on file or sufficient prepaid credits.
Since agentic tools can execute multiple API calls to solve complex tasks, setting up spend limits is highly recommended.
Within your console dashboard, set a daily or monthly budget threshold.
This safeguard ensures that the command line assistant will halt and warn you if your automated tasks consume more budget than expected.
4. Run Your First Interactive Session
Once authenticated, you can start using the assistant inside any project directory.
Navigate to the root directory of a project you want to work on and launch the interactive shell.
cd projects/my-web-app claude
The terminal will transform into an interactive chat interface.
You can now type natural language requests, ask questions about the codebase, or instruct the tool to perform specific development tasks.
Try a simple query to test the responsiveness.
Ask the assistant to explain the directory structure of your current project.
It will analyze the local files and output a clean, readable overview of your project architecture.
To exit the interactive session at any time, type exit or press control plus d.
5. Execute Single Commands Directly
You do not need to enter the interactive shell to use the assistant.
You can pass instructions directly from your standard shell prompt, which is ideal for quick tasks, script automation, or single edits.
To execute a one off task, pass your query as an argument after the main command.
claude "explain the purpose of src/index.js"
The utility will boot up, analyze the file, print the explanation directly to your standard output, and exit back to your shell prompt.
This allows you to chain the assistant with other command line utilities or run quick analysis jobs without leaving your primary terminal workflow.
6. Understand Agentic File Permissions
This tool operates as an agentic assistant, meaning it can create, read, update, and delete files on your system.
Before it performs any destructive action or edits a file, it will display a clear diff of the changes it proposes.
You must review these changes in the terminal.
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The tool will prompt you for permission before writing the changes to your hard drive.
You can approve the edit, reject it, or ask the tool to modify its approach.
For security reasons, do not run the tool with root or administrator privileges unless absolutely necessary.
Keep the tool focused on the specific project folder where you ran the command, preventing unintended modifications to your global system files.
7. Run and Approve Terminal Commands
In addition to editing files, the assistant can execute terminal commands such as running tests, installing npm packages, or starting local build servers.
When a task requires running a command, the tool will display the exact command it wants to execute.
You must manually approve the command execution by pressing y for yes or n for no.
This prevention mechanism keeps you in full control of your local environment.
If you are running a trusted, repetitive task and want to skip the manual approvals, you can use the auto approve flag.
Use this flag with caution, as it allows the AI to run commands and edit files without pausing for validation.
claude "fix failing tests" --auto-approve
8. Configure System Settings and Preferences
You can customize how the tool behaves by accessing its configuration settings.
These settings allow you to toggle features, change default models, or adjust terminal display preferences.
To view your current configuration, run the config command in your terminal.
claude config
To change a specific setting, pass the key and the value you wish to assign.
For example, you can toggle the verbose output mode or switch the primary model used for code analysis.
These configurations are saved locally in your user profile directory, ensuring they persist across different terminal sessions and projects.
9. Set Up Ignore Rules for Projects
By default, the assistant indexes files in your project directory to understand the context of your codebase.
To prevent the tool from reading sensitive files, build artifacts, or massive node modules, you should configure ignore patterns.
The tool automatically respects your existing gitignore file.
If you want to add specific exclusions just for the AI assistant without changing your git rules, create a new file named claudeignore in your project root directory.
Inside this file, list the directories or file extensions you want to exclude, using standard glob patterns.
This reduces token consumption, speeds up project indexing, and protects sensitive environment variables or credentials from being sent to the API.
10. Troubleshoot Common Installation Errors
If you encounter errors during the installation or initial launch, check your Node.js runtime environment first.
The tool requires an active LTS version of Node, and older runtimes will fail to parse modern JavaScript syntax used in the package.
If you see permission denied errors during npm install, avoid using sudo by configuring a local node version manager like nvm.
This allows you to install global packages without root access.
If the login screen fails to open in your browser, check your terminal link settings or manually copy the authentication URL.
If API connection errors persist, verify that your local network is not blocking traffic to the Anthropic API endpoints.
Frequently Asked Questions
What are the system requirements for running this tool?
You need a computer running macOS, Linux, or Windows with a terminal emulator.
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Node.js version 18 or higher must be installed on your system, along with npm or another compatible package manager.
Does this tool require an active internet connection?
Yes, the tool relies on the Anthropic cloud APIs to process queries, analyze code, and generate suggestions.
It cannot function offline, though it reads and writes files locally.
How much does it cost to use this command line tool?
The tool uses your Anthropic Console billing account.
You pay per token consumed during your sessions.
Because agentic workflows send code context back and forth, token usage can accumulate faster than typical chat interfaces.
Can I use this tool with repositories that are not managed by Git?
Yes, the tool works in any directory.
However, running it inside a Git repository is highly recommended, as it allows you to easily review file diffs, track changes, and revert edits if the tool makes an error.
Is my code used to train Anthropic models?
No, Anthropic does not use data submitted through its commercial API or developer tools to train its generative models, ensuring your proprietary code remains private.
