Claude Code

Claude Code Security Best Practices

Use Claude Code safely with these essential security practices. From permission management to safe AI-assisted coding.

Verify your app follows these best practices automatically.

Claude Code brings powerful AI assistance to your terminal, but working with AI in the command line requires security awareness. These practices help you use Claude Code safely.

Quick Wins

Set restrictive permission mode for sensitive projects
Create .claudeignore with .env* pattern
Keep code in version control for easy rollback
Review shell commands before execution
Audit any MCP servers you've installed

Security Best Practices

#1Use Permission Tiers Appropriately

critical

Claude Code has permission levels from 'ask' to 'auto'. Use restrictive permissions for sensitive operations.

Implementation

Keep default 'ask' mode for unknown projects, only enable 'auto' for trusted operations

#2Never Share Real Credentials in Prompts

critical

Prompts and context are sent to Anthropic. Never include real API keys, passwords, or secrets.

Implementation

Use placeholder values in prompts, configure real secrets via environment variables

#3Review All File Modifications

critical

Claude Code can modify files. Always review proposed changes before accepting, especially for security-critical code.

Implementation

Use git to track changes, review diffs before accepting modifications

#4Configure .claudeignore for Sensitive Files

high

Exclude sensitive files from Claude's context using .claudeignore.

Implementation

Add .env*, credentials/, secrets/, and private configs to .claudeignore

#5Audit Shell Commands Before Execution

high

Claude Code can run shell commands. Review all commands before allowing execution.

Implementation

Use 'ask' permission mode, read commands carefully before approving

#6Use MCP Servers Carefully

medium

MCP servers extend Claude's capabilities but can access your system. Only use trusted MCP servers.

Implementation

Review MCP server source code before installation, monitor active servers

Common Mistakes to Avoid

Using 'auto' mode on unfamiliar projects

Why it's dangerous:

AI can execute harmful commands without review

How to fix:

Start with 'ask' mode, only escalate for trusted operations

Including real secrets in prompts

Why it's dangerous:

Prompts are sent to Anthropic's servers

How to fix:

Use placeholder values, configure secrets via environment variables

Auto-accepting file modifications

Why it's dangerous:

AI may introduce bugs or security vulnerabilities

How to fix:

Review all changes in git diff before accepting

Verify Your Claude Code App Security

Following best practices is the first step. Verify your app is actually secure with a comprehensive security scan.

Get Starter Scan

Frequently Asked Questions

Is Claude Code safe to use?

Yes, with proper precautions. Use appropriate permission levels, don't share real credentials, and review all file modifications and commands before accepting.

Does Claude Code send my code to Anthropic?

Yes, code context is sent to Anthropic for AI processing. Use .claudeignore to exclude sensitive files. Review Anthropic's privacy policy for data handling details.

Can Claude Code run dangerous commands?

Only if you approve them. Use 'ask' mode to review all commands before execution. Never blindly approve shell commands, especially rm, chmod, or network operations.

Last updated: January 2026