Authentication Best Practices

Best Practices Overview

Best Practices lets you structure authentication work so it stays readable, testable, and easy to scale. Instead of ad-hoc code, you follow a clear pattern that other developers can recognise immediately.

The key is to keep best practices focused and predictable. Start from the minimal example here, then layer in only the complexity your feature actually needs.

import express from 'express';
import jwt from 'jsonwebtoken';

const app = express();
app.use(express.json());

function authenticate(req, res, next) {
  const token = req.headers.authorization?.replace('Bearer ', '');
  try {
    req.user = jwt.verify(token, process.env.JWT_SECRET);
    next();
  } catch {
    res.status(401).json({ error: 'Unauthorized' });
  }
}

Authentication middleware verifies the caller's identity before protected handlers run.

Best Practices Example

// verify the caller on every protected request
function authenticate(req, res, next) {
  const token = req.headers.authorization?.replace('Bearer ', '');
  req.user = verifyToken(token); // throws if invalid
  next();
}

• Start from a minimal Best Practices example and grow it only as needed.
• Keep configuration explicit so Best Practices behaves the same in every environment.
• Name things clearly so teammates understand your Best Practices at a glance.
• Add tests around Best Practices early to lock in expected behaviour.

Authentication Cheatsheet

Quick authentication reference related to best practices.

How Best Practices Works

Best Practices is part of proving who a user is and what they are allowed to do. Authentication verifies identity, while authorization decides access — and best practices plays a specific role in that flow.

Authentication middleware verifies the caller's identity before protected handlers run.

• Never store or log plain-text passwords or secrets.
• Prefer short-lived tokens with refresh over long-lived ones.
• Always send credentials over HTTPS.
• Fail closed: deny access when anything is uncertain.

Security Guidance for Best Practices

Security is the whole point of best practices. Small mistakes — weak hashing, tokens in localStorage, missing rate limits — are exactly what attackers look for, so follow proven defaults.

Common Mistakes

• Skipping error handling and edge cases when wiring up best practices.
• Leaving best practices untested, so regressions slip into production.
• Over-engineering best practices before you actually need the extra flexibility.
• Ignoring documentation, which makes best practices hard for the next developer to change.

Key Takeaways

• Best Practices is a core part of working effectively with authentication.
• Start small and keep best practices focused on a single responsibility.
• Apply consistent patterns so best practices scales across your project.
• Test and document best practices to keep it maintainable over time.