12 - Claude Code CLI: Essential Commands and Configuration

# Global installation
npm install -g @anthropic-ai/claude-code

# Verify installation
claude --version

# First launch and authentication
claude

# Update to the latest version
npm update -g @anthropic-ai/claude-code

# macOS and Linux
curl -fsSL https://cli.anthropic.com/install.sh | sh

# Verify that the binary is in the PATH
which claude
# Expected output: /usr/local/bin/claude

# First run
claude

# Add the official Anthropic tap
brew tap anthropics/claude-code

# Installation
brew install claude-code

# Update
brew upgrade claude-code

# Verify version
claude --version

# Step 1: Install WSL2 (if not already installed)
wsl --install

# Step 2: Open the WSL terminal (Ubuntu)
wsl

# Step 3: Install Node.js in WSL
curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt-get install -y nodejs

# Step 4: Install Claude Code
npm install -g @anthropic-ai/claude-code

# Step 5: Verify
claude --version

# Alternative: Direct installation from PowerShell
# (Requires Node.js installed on Windows)
npm install -g @anthropic-ai/claude-code

# Method 1: Environment variable (current session)
export ANTHROPIC_API_KEY="sk-ant-api03-xxxxx"

# Method 2: .env file in the project root
echo 'ANTHROPIC_API_KEY=sk-ant-api03-xxxxx' >> .env

# Method 3: Permanent configuration in .bashrc or .zshrc
echo 'export ANTHROPIC_API_KEY="sk-ant-api03-xxxxx"' >> ~/.zshrc
source ~/.zshrc

# Verify authentication
claude --print-auth-status

# Activate Plan Mode with Shift+Tab+Tab, then type the prompt:
> Add email validation to the registration form

# Claude responds with a plan:
# Execution Plan:
# 1. Read src/app/auth/register.component.ts
# 2. Read src/app/auth/register.component.html
# 3. Add email validator to the FormGroup
# 4. Add error message in the template
# 5. Add tests for email validation
# 6. Update the validation service
#
# Files involved: 4
# Operations: 6
#
# Proceed? [y/n]

# Pattern 1: Context reset for a new task
/clear
/add-dir ./src/features/new-feature
Implement the UserProfile component following existing patterns

# Pattern 2: Status check before critical operations
/status
/permissions
Execute the refactoring of the payment module

# Pattern 3: Model switch for specific tasks
/model claude-sonnet-4-20250514    # For quick and frequent tasks
Generate boilerplate tests for all services
/model claude-opus-4-20250514      # For complex tasks
Analyze the architecture and propose improvements

# Pattern 4: Debug MCP connections
/mcp
# Verify that the required servers are connected
# before executing tasks that require them

# Complete Code Review

Perform a thorough code review of the modified files.

## Checklist
1. Verify the logical correctness of the code
2. Check naming conventions and consistency
3. Identify potential bugs or edge cases
4. Verify error handling
5. Check test coverage
6. Evaluate performance and scalability

## Output
Produce a structured report with:
- **Severity**: Critical / Major / Minor / Suggestion
- **File and line**: Precise reference
- **Issue**: Clear description
- **Solution**: Proposed fix with code

# Pre-Deploy Verification

Before proceeding with the deploy, check:

1. Run `npm run build` and verify there are no errors
2. Run `npm test` and verify all tests pass
3. Check that no console.log statements remain in the code
4. Verify that environment variables are configured
5. Check that the .env.production file is up to date
6. Verify the version in package.json

Report the status of each point with a checkmark.

{
  "permissions": {
    "deny": [
      "Bash(rm -rf /*)",
      "Bash(sudo *)",
      "Bash(chmod 777 *)",
      "Write(~/.ssh/*)",
      "Write(~/.aws/*)"
    ]
  },
  "security": {
    "max_file_size_bytes": 10485760,
    "blocked_domains": ["*.internal.company.com"],
    "require_approval_for_network": true
  },
  "model": {
    "default": "claude-sonnet-4-20250514",
    "allowed": ["claude-sonnet-4-20250514", "claude-opus-4-20250514"]
  }
}

{
  "permissions": {
    "allow": [
      "Bash(npm run test:watch)",
      "Bash(npm run dev)",
      "Bash(docker compose up -d)"
    ]
  },
  "preferences": {
    "model": "claude-opus-4-20250514",
    "theme": "dark",
    "auto_approve_reads": true
  }
}

{
  "permissions": {
    "allow": [
      "Bash(npm run *)",
      "Bash(mvn *)",
      "Bash(gradle *)",
      "Bash(git status)",
      "Bash(git diff *)",
      "Bash(git log *)",
      "Read(*)",
      "Write(src/**/*)"
    ],
    "deny": [
      "Bash(git push --force *)",
      "Bash(git reset --hard *)",
      "Bash(rm -rf *)",
      "Write(.env*)",
      "Write(**/credentials*)",
      "Write(**/secrets*)"
    ]
  },
  "context": {
    "include_patterns": ["src/**/*.ts", "src/**/*.html", "src/**/*.css"],
    "exclude_patterns": ["node_modules/**", "dist/**", ".angular/**"]
  }
}

{
  "permissions": {
    "allow": [
      "Bash(ls *)",
      "Bash(cat *)",
      "Bash(which *)",
      "Bash(node --version)",
      "Read(*)"
    ]
  },
  "preferences": {
    "model": "claude-sonnet-4-20250514",
    "auto_approve_reads": true,
    "verbose_output": false,
    "language": "it"
  }
}

{
  "permissions": {
    "allow": [
      "Bash(npm run *)",
      "Bash(npm test *)",
      "Bash(npm install *)",
      "Bash(npx *)",
      "Bash(git status)",
      "Bash(git diff *)",
      "Bash(git log *)",
      "Bash(git branch *)",
      "Bash(git checkout *)",
      "Bash(git add *)",
      "Bash(git commit *)",
      "Bash(tsc *)",
      "Bash(ng *)",
      "Bash(mvn *)",
      "Bash(gradle *)",
      "Bash(python -m pytest *)",
      "Bash(docker compose *)",
      "Bash(curl *)",
      "Read(*)",
      "Write(src/**/*)",
      "Write(tests/**/*)",
      "Write(docs/**/*)"
    ],
    "deny": [
      "Write(.env*)",
      "Write(**/*.pem)",
      "Write(**/*.key)",
      "Write(**/credentials*)",
      "Write(**/secrets*)",
      "Write(~/.ssh/*)",
      "Write(~/.aws/*)",
      "Bash(rm -rf *)",
      "Bash(sudo *)",
      "Bash(chmod 777 *)",
      "Bash(git push --force *)",
      "Bash(git reset --hard *)"
    ]
  }
}

{
  "permissions": {
    "allow": [
      "Read(src/**/*)",
      "Read(tests/**/*)",
      "Read(docs/**/*)",
      "Bash(git status)",
      "Bash(git diff *)",
      "Bash(git log *)"
    ],
    "deny": [
      "Write(*)",
      "Bash(npm install *)",
      "Bash(npx *)",
      "Bash(curl *)",
      "Bash(wget *)",
      "Bash(ssh *)",
      "Bash(scp *)",
      "Bash(nc *)",
      "Bash(git push *)",
      "Bash(git commit *)",
      "Bash(docker *)",
      "Bash(sudo *)",
      "Bash(rm *)",
      "Bash(mv *)",
      "Bash(cp *)"
    ]
  },
  "security": {
    "require_approval_for_all_writes": true,
    "require_approval_for_network": true,
    "audit_log": true,
    "max_file_modifications_per_session": 10
  }
}

# Basic syntax
claude --print "Analyze the code in src/ and report issues" --output-format json

# With iteration limit
claude --print "Run tests and fix failures" \
  --output-format json \
  --max-iterations 10

# With specific model
claude --print "Generate API documentation" \
  --output-format json \
  --model claude-sonnet-4-20250514

# With explicit permissions
claude --print "Format all TypeScript files" \
  --output-format json \
  --allowedTools "Bash(npx prettier --write src/**/*.ts)" \
  --allowedTools "Read(*)"

name: Claude Code Review

on:
  pull_request:
    types: [opened, synchronize]

jobs:
  review:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - uses: actions/setup-node@v4
        with:
          node-version: '20'

      - name: Install Claude Code
        run: npm install -g @anthropic-ai/claude-code

      - name: Run Code Review
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
        run: |
          DIFF=$(git diff origin/main...HEAD)
          claude --print "Analyze the following diff and provide a code review:
          $DIFF

          Output format:
          - Severity: Critical/Major/Minor
          - File and line
          - Issue
          - Proposed solution" \
            --output-format json \
            --max-iterations 5 > review.json

      - name: Post Review Comment
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const review = JSON.parse(fs.readFileSync('review.json', 'utf8'));
            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
              body: review.result
            });

#!/bin/bash
# Script for automatic lint error fixing

echo "=== Claude Code Auto-Fix ==="
echo "Analyzing lint errors..."

# Run lint and capture errors
LINT_OUTPUT=$(npm run lint 2>&1 || true)

if [ -z "$LINT_OUTPUT" ]; then
  echo "No errors found!"
  exit 0
fi

echo "Errors found. Starting Claude Code for correction..."

claude --print "Fix the following lint errors:
$LINT_OUTPUT

Rules:
- Fix only the reported errors
- Do not modify the code logic
- Maintain the existing style" \
  --output-format json \
  --max-iterations 15 \
  --allowedTools "Read(src/**/*)" \
  --allowedTools "Write(src/**/*)" \
  --allowedTools "Bash(npm run lint)"

echo "Fix completed. Final verification..."
npm run lint

# Check the installed version
claude --version

# Check authentication status
claude --print-auth-status

# Start in verbose debug mode
claude --verbose

# Check the active configuration
claude --print "Show the active configuration" --output-format json

# Complete configuration reset
rm -rf ~/.claude/settings.json
claude  # Recreates the default configuration

# Verify API connectivity
curl -s https://api.anthropic.com/v1/messages \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2024-01-01" \
  -H "content-type: application/json" \
  -d '{"model":"claude-sonnet-4-20250514","max_tokens":10,"messages":[{"role":"user","content":"test"}]}'

# 1. Enter the project directory
cd ~/projects/my-app

# 2. Launch Claude Code
claude

# 3. Check the repository status
> !git status
> !git log --oneline -5

# 4. Load the context for the current task
> @src/features/user-profile/
> I'm working on the user-profile feature.
> What has been done so far and what remains to be implemented?

# 5. Activate Plan Mode for the first task
> [Shift+Tab+Tab] Implement the profile form validation

# Feature implementation
> Implement the EditProfile component with a reactive form
> Use Angular validators for email, phone, and name
> Follow existing patterns in src/features/auth/

# Testing
> Generate unit tests for EditProfileComponent
> Cover the cases: valid form, invalid email, submit and cancel

# Code review
> /review   # Use the custom command created earlier

# Commit
> !git add -A
> !git commit -m "feat(user-profile): add edit profile form with validation"

# Move to the next task
> /clear
> @src/features/notifications/
> Implement the push notification system

{
  "permissions": {
    "allow": [
      "Read(*)",
      "Write(packages/*/src/**/*)",
      "Write(packages/*/tests/**/*)",
      "Bash(npm run -w packages/* *)",
      "Bash(npx turbo run *)",
      "Bash(git *)"
    ],
    "deny": [
      "Write(packages/*/node_modules/**)",
      "Write(packages/*/.env*)",
      "Bash(rm -rf *)",
      "Bash(sudo *)"
    ]
  },
  "context": {
    "include_patterns": [
      "packages/*/src/**/*.ts",
      "packages/*/package.json",
      "turbo.json",
      "package.json"
    ],
    "exclude_patterns": [
      "**/node_modules/**",
      "**/dist/**",
      "**/.turbo/**"
    ]
  }
}