JWT Decoder & Encoder - Token Authentication for AI Agents

const jwt = require('jsonwebtoken');

// Sign a token
const token = jwt.sign({ 
  userId: '12345',
  username: 'john_doe'
}, 'your-secret-key', { expiresIn: '1h' });

// Verify a token
jwt.verify(token, 'your-secret-key', (err, decoded) => {
  if (err) {
    console.error('Invalid token');
    return;
  }
  console.log(decoded);
});

// Decode without verification
const decoded = jwt.decode(token);

import jwt
from datetime import datetime, timedelta

# Sign a token
token = jwt.encode({
    'user_id': '12345',
    'username': 'john_doe',
    'exp': datetime.utcnow() + timedelta(hours=1)
}, 'your-secret-key', algorithm='HS256')

# Verify a token
try:
    decoded = jwt.decode(token, 'your-secret-key', algorithms=['HS256'])
    print(decoded)
except jwt.InvalidTokenError:
    print('Invalid token')

# Decode without verification
decoded = jwt.decode(token, options={"verify_signature": False})

import io.jsonwebtoken.*;
import java.util.Date;

// Sign a token
String token = Jwts.builder()
    .setSubject("12345")
    .claim("username", "john_doe")
    .setExpiration(new Date(System.currentTimeMillis() + 3600000))
    .signWith(SignatureAlgorithm.HS256, "your-secret-key")
    .compact();

// Verify a token
try {
    Claims claims = Jwts.parser()
        .setSigningKey("your-secret-key")
        .parseClaimsJws(token)
        .getBody();
    System.out.println(claims);
} catch (JwtException e) {
    System.err.println("Invalid token");
}

import (
    "github.com/golang-jwt/jwt/v5"
    "time"
)

// Sign a token
token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
    "user_id":  "12345",
    "username": "john_doe",
    "exp":      time.Now().Add(time.Hour).Unix(),
})

signedToken, _ := token.SignedString([]byte("your-secret-key"))

// Verify a token
parsedToken, err := jwt.Parse(signedToken, func(token *jwt.Token) (interface{}, error) {
    return []byte("your-secret-key"), nil
})

if claims, ok := parsedToken.Claims.(jwt.MapClaims); ok && parsedToken.Valid {
    fmt.Println(claims)
}