API Key Security: Best Practices for Developers
Learn how to generate, store, rotate, and protect API keys in your applications.
API keys are the gatekeepers of your application services. Poorly managed API keys are responsible for numerous security breaches, data leaks, and unauthorized access incidents every year.
What Are API Keys?
API keys are unique strings that identify and authenticate applications or users when making API requests. They control access to services, track usage, and enforce rate limits.
Generating Secure API Keys
API keys should be generated using cryptographically secure random number generators. Never use predictable patterns, timestamps, or sequential numbers. Our secret key generator creates cryptographically random keys suitable for API authentication.
A good API key should be at least 32 characters long, use a mix of alphanumeric characters, and be generated from a cryptographically secure source.
Storage Best Practices
Never Hardcode Keys
Never embed API keys directly in source code, especially code that may be committed to version control. Accidentally committing API keys to public repositories is one of the most common security mistakes.
Use Environment Variables
Store API keys in environment variables that are loaded at runtime. This keeps keys out of your codebase and makes it easy to use different keys for development, staging, and production.
Server-Side Only
Never expose API keys in client-side code, including JavaScript, mobile apps, or any code that runs on user devices. Client-side code can be inspected, and any embedded keys can be extracted.
Key Rotation
Regularly rotate API keys, especially after team members leave or security incidents occur. Design your systems to support key rotation with minimal downtime by allowing a grace period where both old and new keys work.
Monitoring and Alerting
Monitor API key usage for unusual patterns. Set up alerts for spikes in usage, requests from unexpected locations, or access to sensitive endpoints. Early detection of compromised keys can prevent significant damage.
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