Index: iknow-api/Services/Implementations/UserService.cs
===================================================================
--- iknow-api/Services/Implementations/UserService.cs	(revision cab02ada65fcd8feda776e5afc86a355f29c7f96)
+++ iknow-api/Services/Implementations/UserService.cs	(revision cab02ada65fcd8feda776e5afc86a355f29c7f96)
@@ -0,0 +1,79 @@
+using iknow_api.Repositories;
+using iknow_api.Services;
+using iknow_api.DTOs;
+using Microsoft.AspNetCore.Http.HttpResults;
+using System.IdentityModel.Tokens.Jwt;
+using System.Security.Claims;
+using System.Text;
+using Microsoft.IdentityModel.Tokens;
+using iknow_api.Models;
+
+namespace iknow_api.Services
+{
+    public class UserService : IUserService
+    {
+
+        private readonly IUserRepository _userRepository;
+        private readonly IConfiguration _configuration;
+        public UserService(IUserRepository userRepository, IConfiguration configuration)
+        {
+            _userRepository = userRepository;
+            _configuration = configuration;
+        }
+        public async Task<User> GetUserData(string JWT)
+        {
+            var userId = ExtractUserIdFromJwt(JWT);
+            if (userId == null)
+                return null;
+
+            // Now you can use userId to fetch user data
+            var user = await _userRepository.GetUserByIdAsync(userId.Value);
+            if(user == null)
+                return null;
+            else
+                return user;
+        }
+
+        private int? ExtractUserIdFromJwt(string token)
+        {
+            try
+            {
+                var tokenHandler = new JwtSecurityTokenHandler();
+                var keyString = _configuration["Jwt:Key"];
+                
+                if (string.IsNullOrEmpty(keyString))
+                    return null;
+
+                var key = Encoding.UTF8.GetBytes(keyString);
+
+                var validationParameters = new TokenValidationParameters
+                {
+                    ValidateIssuerSigningKey = true,
+                    IssuerSigningKey = new SymmetricSecurityKey(key),
+                    ValidateIssuer = true,
+                    ValidIssuer = "iknow-api",
+                    ValidateAudience = true,
+                    ValidAudience = "iknow-api",
+                    ValidateLifetime = true,
+                    ClockSkew = TimeSpan.Zero
+                };
+
+                var principal = tokenHandler.ValidateToken(token, validationParameters, out SecurityToken validatedToken);
+                
+                // Extract the "id" claim that was set in AuthService.CreateToken
+                var userIdClaim = principal.FindFirst("id");
+                
+                if (userIdClaim != null && int.TryParse(userIdClaim.Value, out int userId))
+                {
+                    return userId;
+                }
+
+                return null;
+            }
+            catch
+            {
+                return null;
+            }
+        }
+    }
+}