2.1 Prerequisites#

• Node.js 18 or higher
• An Anthropic API Key (obtained at console.anthropic.com)

2.2 Global Installation#

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

Verify after installation:

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claude --version

2.3 Configuring the API Key#

Set the API Key as an environment variable:

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# macOS / Linux — add to ~/.bashrc or ~/.zshrc
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export ANTHROPIC_API_KEY="sk-ant-xxx"
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# Windows PowerShell
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$env:ANTHROPIC_API_KEY="sk-ant-xxx"

Or use Claude Code’s built-in login method:

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claude login

This will open a browser to guide you through OAuth authentication, with no need to manually handle the API Key.

2.4 Updating#

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

3.1 Starting#

Run in your project directory:

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claude

You will see an interactive terminal interface where you can communicate with Claude directly in natural language.

3.2 Common Commands#

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# Initialize the project config file (generates CLAUDE.md)
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claude init
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# View the current configuration
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claude config
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# Update to the latest version
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claude update

3.3 Typical Workflows#

Code Review

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> Review the changes on the current branch, focusing on security issues

Claude will read git diff, analyze the code changes, and point out potential security risks.

Bug Fixing

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> User reports a blank page after login; help me troubleshoot the cause

Claude will search for relevant files, inspect component logic, locate the problem, and fix it directly.

Feature Development

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> Add an API endpoint to retrieve a user's favorites list, including pagination

Claude will analyze the existing route structure and generate route definitions, controller logic, and database queries.

4.1 The CLAUDE.md File#

Create CLAUDE.md in the project root directory to tell Claude key information about the project:

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# Project Name
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## Tech Stack
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- Frontend: React 18 + TypeScript + Tailwind
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- Backend: Go + PostgreSQL
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- Deployment: Docker + K8s
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## Code Standards
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- Use Prettier for formatting, single quotes, no semicolons
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- Use PascalCase for component naming
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- Use kebab-case for API routes
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## Notes
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- Do not directly modify generated code files
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- Use Vitest for testing, do not use Jest

With this file in place, Claude will automatically load it on every startup, reducing repeated explanations.

4.2 Permission Control#

By default, Claude Code requests confirmation for sensitive operations (such as network requests and file writes). You can manage permission levels through /permissions.

4.3 Pipe Mode#

Claude also supports piped input, suitable for scripting scenarios:

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cat error.log | claude "Analyze these logs and identify the key errors"

4.4 Session Management#

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# Resume the previous session
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claude --continue
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# Continue with a specific session ID
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claude --resume <session-id>

6.1 Network Issues in China#

If you encounter network issues accessing the Anthropic API from China, you can:

• Use an API proxy address by setting the environment variable ANTHROPIC_BASE_URL
• Configure an HTTPS proxy: export HTTPS_PROXY=http://127.0.0.1:7890

6.2 Cost Control#

Claude Code consumes API tokens with every conversation. Suggestions for controlling costs:

• Set a maximum token limit in .claude/settings.json
• Use short sessions and promptly exit after completing tasks
• For simple questions, add comments directly in the code instead of starting a full session

6.3 Domestic Mirror Acceleration#

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# Use a domestic mirror when installing with npm
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npm install -g @anthropic-ai/claude-code --registry=https://registry.npmmirror.com