Secure API authentication with JWT, OAuth 2.0, API keys. Use for authentication systems, third-party integrations, service-to-service communication, or encountering token management, security headers, auth flow errors.
/plugin marketplace add secondsky/claude-skills/plugin install api-authentication@claude-skillsThis skill inherits all available tools. When active, it can use any tool Claude has access to.
references/python-flask.mdImplement secure authentication mechanisms for APIs using modern standards and best practices.
| Method | Use Case | Security Level |
|---|---|---|
| JWT | Stateless auth, SPAs | High |
| OAuth 2.0 | Third-party integration | High |
| API Keys | Service-to-service | Medium |
| Session | Traditional web apps | High |
const jwt = require('jsonwebtoken');
const generateTokens = (user) => ({
accessToken: jwt.sign(
{ userId: user.id, role: user.role },
process.env.JWT_SECRET,
{ expiresIn: '15m' }
),
refreshToken: jwt.sign(
{ userId: user.id, type: 'refresh' },
process.env.REFRESH_SECRET,
{ expiresIn: '7d' }
)
});
const authMiddleware = (req, res, next) => {
const authHeader = req.headers.authorization;
// Validate authorization header format
if (!authHeader || !authHeader.startsWith('Bearer ')) {
return res.status(401).json({ error: 'Malformed authorization header' });
}
const parts = authHeader.split(' ');
if (parts.length !== 2) {
return res.status(401).json({ error: 'Malformed authorization header' });
}
const token = parts[1];
if (!token) {
return res.status(401).json({ error: 'No token provided' });
}
try {
req.user = jwt.verify(token, process.env.JWT_SECRET);
next();
} catch (err) {
res.status(401).json({ error: 'Invalid token' });
}
};
app.use((req, res, next) => {
res.setHeader('X-Content-Type-Options', 'nosniff');
res.setHeader('X-Frame-Options', 'DENY');
res.setHeader('Strict-Transport-Security', 'max-age=31536000');
next();
});
See references/python-flask.md for:
Build comprehensive attack trees to visualize threat paths. Use when mapping attack scenarios, identifying defense gaps, or communicating security risks to stakeholders.