API Authentication Strategies Explained
Mon Dec 15 2025
API Authentication Using API Keys
API authentication ensures that only authorized users or systems can access your endpoints. One of the most common and straightforward authentication methods is API key–based authentication.
An API key is a unique token issued to a client and sent with each request to identify the caller. The server validates this key before allowing access to the API.
How API Keys Work
When a client makes a request to an API, the API key is typically included in one of the following ways:
1. Request Headers (Recommended)
GET /api/users
Authorization: Api-Key YOUR_API_KEY
2. OR
X-API-KEY: YOUR_API_KEY