Table of Contents
Best Practices for Securing API Keys on Server-Side for Claude?
Secure your Claude API key by storing it exclusively on your server inaccessible to users, avoiding client-side exposure in JavaScript or mobile apps to prevent leaks, abuse, and unexpected charges in web applications.
Question
You’re building a web app that talks to Claude. Where should you store your API key?
A. In your mobile app that users install
B. In a text file on the user’s computer
C. On your server that users can’t access
D. In your JavaScript code that users download
Answer
C. On your server that users can’t access
Explanation
Storing the Claude API key on your server ensures it remains secure from client-side exposure, as web apps involve frontend code (like JavaScript) that users download and can inspect via browser tools, making keys in options A and D easily extractable by malicious users for unauthorized API abuse and billing charges. Server-side storage allows your backend to authenticate requests to Claude’s API on behalf of the frontend, using secure environment variables or secret managers (e.g., AWS Secrets Manager) without ever transmitting the key to the client. Options A and B risk local user access or device compromise, while D violates core web security principles; this backend-proxy pattern is standard for all third-party APIs to prevent key leakage and enforce rate limiting or validation.