Implement Simple API Key Authentication

Express.js

Node.js

Technical Specification

Create middleware that checks for an API key in headers (x-api-key) and rejects requests if it's missing or incorrect.

Input/Output Samples

Input:No x-api-key header

Output:401 Unauthorized

Optimal Logic Path

const API_KEY = process.env.API_KEY || "secret123";

function apiKeyAuth(req, res, next) {
  const key = req.header("x-api-key");
  if (!key || key !== API_KEY) {
    return res.status(401).json({ error: "Unauthorized" });
  }
  next();
}

// Protect routes:
app.use("/admin", apiKeyAuth);

Architectural Deep-Dive

API key middleware allows simple token-based protection for specific routes or groups.