How To Use Claude Code? Step By Step Guide

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Claude Code is an advanced agentic AI assistant developed by Anthropic designed to operate directly within your local codebase. Unlike standard AI autocomplete tools that suggest code line by line, Claude Code functions as an autonomous agent. It reads full directories, processes multi file context, plans out changes, runs terminal commands, executes tests, and handles Git version control.

Powered by flagship models like Claude 3.5 Sonnet and Claude Opus, Claude Code is fully accessible across terminal CLIs, the desktop app, VS Code, JetBrains IDEs, and the web. Traditional AI tools act as junior assistants providing code completions. Claude Code is an execution engine. You provide a high level goal in natural language, and it performs a continuous gather context -> take action -> verify results loop until the job is complete.

Core Technical Capabilities

• Full Codebase Comprehension: Maps file structures, traces dependencies, and reads multiple files simultaneously to build mental context.
• Autonomous Terminal Execution: Runs build commands, manages server logs, and executes test suites locally.
• Advanced Version Control: Stages changes, writes detailed commit messages, switches branches, and opens pull requests.
• Dynamic Workflows & Subagents: Uses parallel processing layers via Dynamic Workflows to delegate smaller subtasks to subagents.
• Model Context Protocol (MCP): Connects seamlessly to external developer data sources like Slack, Jira, or Google Drive via MCP Standards.

By default, Claude Code functions on a cautious permission model. It provides visual diffs showing exactly what it intends to change and waits for your confirmation before touching files or running sensitive commands.

How To Use Claude Code? Beginner’s Guide

Step 1: Meet the Prerequisites

Ensure your local system has the following core developer components installed:

• Node.js: Verify installation by running node -v in your terminal.
• Git: Essential for local sessions and workspace management.
• An active account: A Claude Pro/Max subscription plan or an Anthropic Console API account with pre paid token credits.

Step 2: Install Claude Code

Open your system’s Command Prompt, PowerShell, or Terminal window. Paste the following package manager command and hit Enter:

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

Verify success by checking the version:

claude --version

Step 3: Authenticate Your Workspace

Navigate to your specific coding project directory using your terminal:

cd path/to/your/project-folder

Initiate the tool by typing:

claude

Your default browser will open automatically. Log in using your Claude credentials to link your subscription plan.

Step 4: Mastering the Workflow

When working on new features or complex bugs, use this industry standard three tier execution loop:

1. Research (Plan Mode): Double tap Shift+Tab to toggle into Plan Mode. Ask informational questions without allowing Claude to write files:
   “Explain the current authentication flow and folder structure.”
2. Draft a Strategy: While still in Plan Mode, request a step by step implementation blueprint:
   “Create a plan to add email validation to our signup page.”
3. Execute (Normal Mode): Toggle back to Normal Mode. Tell Claude to proceed with the action:
   “Implement the plan. Run tests afterward to ensure it passes.”

Step 5: Save & Commit

Once you approve the generated changes, let Claude handle Git maintenance directly through the interactive shell session:

• “Review my current changes and commit them with a precise message.”

You can learn how to use agent teams in Claude Code to have multiple “Claudes” work on your project using step by step guide.

Essential Terminal Shortcuts & Commands

How to Use Claude Code for Technical Debugging?

Developers use Claude Code for technical debugging by transforming the traditional manual troubleshooting loop into an automated, conversational diagnostic session. Because it operates natively inside the terminal, it doesn’t just read the code; it interacts with your environment to isolate root causes.

Here is an analysis of how developers practically leverage Claude Code’s agentic loop to find and fix bugs, along with a step by step example workflow.

Key Debugging Strategies Used by Developers

Live Runtime Log Analysis

Instead of copy-pasting massive log dumps into a web browser, developers launch the app server or test suites inside Claude Code’s interactive environment. You can point Claude directly to terminal outputs or active files:

• “Watch the backend logs at /logs/server.log while I hit the login endpoint, and figure out why it returns a 500 error.”
• Claude will scan the stack trace, locate the throwing file, and identify the line of failure autonomously.

Test Driven Diagnostics

Developers frequently use Claude Code to fix failing tests by giving it execution authority.

• You can command: “Run the Vitest suite for the authentication module, analyze the failure, and fix the codebase until all tests pass green.”
• Claude will run the command, look at the error assertions, modify the necessary files, and re-run the tests to verify its own fix.

Trace-Route Code Exploration

When dealing with legacy or unfamiliar codebases, developers use Claude Code to trace bugs across multiple files. Because it maps dependencies, you can ask it to track the lifecycle of a variable or state change across the app architecture to spot where logic breaks down.

The Sandbox “Rewind” Safeguard

Debugging can often break other parts of an application. Developers freely let Claude experiment with aggressive bug fixes because of the built-in /rewind command. If Claude’s structural changes don’t work or cause a cascading failure, a simple /rewind reverts the directory exactly to its pre debugging state.

Step By Step Debugging Workflow Example

Here is how a developer uses the Three Tier Workflow to diagnose and repair a broken API route.

Step 1: Isolate the Issue (Plan Mode)

Double tap Shift+Tab to enter Plan Mode. This ensures Claude investigates without prematurely rewriting files. Feed it the error message:

(Plan Mode) Terminal output shows: "TypeError: Cannot read properties of undefined (reading 'map')" when calling /api/v1/users. Help me find where this originates.

Claude’s Action: It will use terminal commands to search the project for /api/v1/users, open the controller file, track down the variable utilizing .map(), and identify that the database query is returning undefined instead of an empty array.

Step 2: Formulate the Fix

Still in Plan Mode, ask Claude to outline its strategy to prevent side effects:

(Plan Mode) How do we fix this safely without breaking the frontend's expected data structure?

• Claude’s Action: It will suggest adding an optional chaining operator (?.), a fallback default array (|| []), and an explicit database try/catch block.

Step 3: Execute and Verify (Normal Mode)

Toggle back to Normal Mode (Shift+Tab) and instruct Claude to implement and verify:

Implement the fallback array fix, run the local build command, and execute the API test suite.

• Claude’s Action: It applies the code changes, displays a visual diff for your approval, runs your build tool (e.g., npm run build), and fires the local test suite to confirm the error is resolved.

Essential Debugging Prompts for Your Toolbox

• For Git Bisect / Regression Hunting:
  “This feature worked yesterday but is broken today. Look at my recent Git commits, check the files changed in the last 3 commits, and find what broke the cart calculation logic.”
• For Explaining Complicated Stack Traces:
  “Here is a Docker container crash log [paste log]. Inspect our internal config files and Dockerfile to determine if this is an environment variable issue or a network binding error.”
• For Memory Leaks / Performance Drops:
  “Analyze server.ts. Are there any unclosed database connections, dangling event listeners, or infinite loops causing this high CPU usage?”

How to Use Claude Code for Workflow Automation?

Claude Code automates complex engineering workflows by combining natural language instructions with autonomous shell execution, version control integration, and structural codebase knowledge. Unlike standard automation scripts that break when code structures change, Claude Code uses dynamic reasoning to adapt to your system’s current state.

Developers primarily automate tasks using two execution styles: One-Off Terminal Scripts (for instant workspace automation) or Custom Knowledge Files (for establishing long term, autonomous team pipelines).

Method 1: One-Off Terminal Automation (The claude “task” Syntax)

Instead of entering the interactive shell session, you can pass automation commands directly to Claude Code from your normal terminal. This allows you to chain commands or embed Claude directly into your existing shell scripts (.sh or .zshrc aliases).

Automated Code Reviews & Cleanup

You can automate compliance, formatting, and optimization passes over modified code:

claude "Review all staged Git changes against our style guide, fix formatting errors, and run tests."

Automated Dependency Management

Updating packages safely usually requires manual verification. Claude can automate the entire lifecycle:

claude "Check for outdated npm minor versions, update them one by one, run the test suite after each update, and revert if any test fails."

Automated Documentation Synchronization

Keep your project documentation accurate by automating updates directly from structural changes:

claude "Scan the `/src/routes` directory, identify any new API endpoints added, and update `API_README.md` to reflect them accurately."

Method 2: Long Term Workspace Automation (CLAUDE.md)

To enforce permanent, team-wide workflow automation guidelines, create a specialized configuration file named CLAUDE.md in the root directory of your project.

Claude Code searches for and reads this file automatically at the start of every session [1]. It uses these instructions to automate choices regarding testing frameworks, code formatting, and deployment protocols without needing repetitive prompting.

Recommended CLAUDE.md Automation Template

# Project Automation Guidelines

## Build & Test Automation
- Build command: `npm run build`
- Run single test file: `npm run test -- <file-path>`
- Run complete test suite: `npm run test:ci`

## Code Style Automation
- Formatting rule: Always run `npm run lint --fix` before completing any file edits.
- Types: Strictly enforce TypeScript types; never use `any`. Always use explicit return types.
- Components: Automate UI generation using TailwindCSS utility classes exclusively.

## Git & Deployment Workflows
- Branch naming: `feature/short-description` or `bugfix/short-description`.
- Commit format: Use conventional commits format (e.g., `feat(auth): add email verification`).
- Pull Requests: After solving an issue, autonomously switch to a new branch, commit the changes, and print a clear summary draft for the PR description.

Method 3: Integrating with CI/CD and Version Control Platforms

Because Claude Code supports the Model Context Protocol (MCP), you can automate workflows that bridge the gap between your local terminal and external cloud infrastructure.

Automated GitHub Issue Resolution

By hooking Claude Code into an MCP server for GitHub, you can automate tasks across cloud repositories:

claude "Fetch the latest unassigned issue labeled 'bug' from GitHub, write a local test file replicating the bug, fix the source code, and verify it passes."

CI/CD Pre flight Verification

You can automate complex pipeline verifications locally before pushing code to remote servers to save expensive CI/CD runner minutes:

claude "Build the local Docker container, verify the environment health check endpoint returns 200, clean up the container, and draft the git push command."

Core Safeguards for Secure Automation

To keep autonomous automation completely safe, apply these execution parameters:

• Prevent Loop Lock-ups: If writing an automation loop inside a bash script, always use a timeout or enforce Claude’s default user confirmation checks so it doesn’t execute infinitely.
• Isolate Experimental Scripts: Use Shift+Tab to move Claude into Plan Mode first when testing complex automation ideas [1]. This lets Claude print out the exact actions and commands it intends to run without executing them.
• The Panic Button: If an automated loop begins changing files or running scripts incorrectly, press Esc twice or type /rewind inside the active session to revert all changes immediately back to your clean Git snapshot.