Serverless API Security Best Practices

Serverless functions run in ephemeral environments, requiring different security approaches. Learn how to properly manage secrets and secure endpoints in serverless architectures.

Environment Variables in Serverless

Most serverless platforms support environment variables for configuration. However, the approach differs by provider.

AWS Lambda

• Use Parameter Store for sensitive values
• Encrypt environment variables with KMS
• Never log environment variables
• Use layers for shared secrets

Vercel

• Project settings → Environment Variables
• 区分开发、预览、生产环境
• 自动注入到函数环境
• 不暴露在客户端 bundle

Netlify

• Site settings → Environment Variables
• Netlify Identity for user authentication
• Edge functions support

Function Endpoint Security

• Use API keys or JWT for authentication
• Implement CORS properly
• Add rate limiting
• Validate all inputs
• Enable request logging

Cold Start Considerations

Avoid fetching secrets on every invocation. Cache credentials in memory or use connection pooling. Initialize external clients outside the handler function.