What is API Key Security?
Best practices for generating, storing, transmitting, and rotating API keys — the secret tokens that grant access to APIs and third-party services.
In plain English
An API key is like the master code to your office alarm system. If you tape it to the front door or share it with everyone, anyone can walk in. It needs to be shared only with people who need it, changed regularly, and never left in plain sight.
How it works
API keys are unique strings that identify and authenticate an application or user when making API requests. They're typically sent as headers or query parameters. Services use them to track usage, enforce rate limits, and control access. Unlike passwords, API keys are usually long random strings generated by the service provider.
Why it matters for AI-built apps
AI coding tools are notorious for placing API keys directly in source code. When that code is pushed to a public GitHub repo, automated bots can find and exploit those keys within minutes. Exposed keys for services like AWS, Stripe, or OpenAI can lead to thousands of dollars in unauthorized charges or full data breaches.
Common issues
Hardcoding keys in source files, committing .env files to version control, using the same key across all environments (dev, staging, production), not rotating keys after team members leave, exposing server-side keys in client-side code, and lacking monitoring for unusual API key usage patterns.
Best practices
Store API keys in environment variables, never in code. Add .env to your .gitignore immediately. Use different keys for development, staging, and production. Rotate keys regularly, especially after team changes. Set the narrowest permissions possible on each key. Monitor usage dashboards for unexpected spikes. Use a secrets manager for production deployments.
Frequently asked questions
I accidentally pushed my API key to GitHub — what do I do?
Rotate the key immediately in the provider's dashboard — deleting the commit isn't enough since it's still in git history. Then add your .env file to .gitignore, use 'git rm --cached .env' to untrack it, and consider using a tool like git-secrets or GitHub's secret scanning to prevent this in the future.
Can I use my API keys in frontend JavaScript code?
Only publishable/public keys that are designed for client-side use (like Stripe's publishable key). Secret keys must never be exposed in frontend code — anyone can read them via browser dev tools. Make API calls that require secret keys from your backend server instead.
How often should I rotate API keys?
At minimum, rotate keys when any team member with access leaves. Best practice is to rotate production keys every 90 days. Automate this with a secrets manager if possible. Always rotate immediately if you suspect a key has been compromised.
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