diff --git a/PropelAuth.Tests/UserTests.cs b/PropelAuth.Tests/UserTests.cs
index d575421..50872f6 100644
--- a/PropelAuth.Tests/UserTests.cs
+++ b/PropelAuth.Tests/UserTests.cs
@@ -91,6 +91,12 @@ private OrgMemberInfo CreateTestOrgMemberInfo(
                 user_permissions: permissions
             );
         }
+        
+        private ClaimsPrincipal CreateEmptyClaimsPrincipal()
+        {
+            var identity = new ClaimsIdentity(new List<Claim>(), "TestAuth");
+            return new ClaimsPrincipal(identity);
+        }
 
         [Fact]
         public void Constructor_ShouldInitializeBasicProperties()
@@ -413,5 +419,14 @@ public void GetUserProperty_ShouldReturnNull_WhenPropertiesNull()
             // Act & Assert
             Assert.Null(user.GetUserProperty("anyProperty"));
         }
+        
+        [Fact]
+        public void GetUser_EmptyClaimsPrincipal_ShouldReturnNull()
+        {
+            // Arrange
+            var principal = CreateEmptyClaimsPrincipal();
+
+            Assert.Null(principal.GetUser());
+        }
     }
 }
\ No newline at end of file
diff --git a/PropelAuth/PropelAuthExtensions.cs b/PropelAuth/PropelAuthExtensions.cs
index cf5a6c1..2b9df80 100644
--- a/PropelAuth/PropelAuthExtensions.cs
+++ b/PropelAuth/PropelAuthExtensions.cs
@@ -1,5 +1,9 @@
+using System.IdentityModel.Tokens.Jwt;
 using System.Security.Cryptography;
+using Microsoft.AspNetCore.Authentication.Cookies;
 using Microsoft.AspNetCore.Authentication.JwtBearer;
+using Microsoft.AspNetCore.Authentication.OAuth;
+using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.IdentityModel.Tokens;
 using Newtonsoft.Json.Linq;
@@ -71,17 +75,70 @@ private static RSA ConfigureRsaWithPublicKey(string publicKey)
         /// <param name="rsa">The RSA instance configured with the public key.</param>
         private static void ConfigureAuthentication(IServiceCollection services, PropelAuthOptions options, RSA rsa)
         {
-            services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
-                .AddJwtBearer(jwtOptions =>
+            var authBuilder = services.AddAuthentication(authOptions =>
+            {
+                if (options.OAuthOptions != null)
+                {
+                    authOptions.DefaultAuthenticateScheme = CookieAuthenticationDefaults.AuthenticationScheme;
+                    authOptions.DefaultSignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
+                    authOptions.DefaultChallengeScheme = "PropelAuth";
+                }
+                else
+                {
+                    authOptions.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
+                    authOptions.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
+                }
+            });
+
+            if (options.OAuthOptions == null || options.OAuthOptions.AllowBearerTokenAuth == true)
+            {
+                authBuilder.AddJwtBearer(jwtOptions =>
                 {
                     jwtOptions.TokenValidationParameters = new TokenValidationParameters
                     {
                         ValidateAudience = false,
                         ValidAlgorithms = new List<string>() {"RS256"},
                         ValidIssuer = options.AuthUrl,
-                        IssuerSigningKey = new RsaSecurityKey(rsa)
+                        IssuerSigningKey = new RsaSecurityKey(rsa),
+                        ValidateLifetime = true,
                     };
                 });
+            }
+            else
+            {
+                authBuilder
+                    .AddCookie(cookieOptions =>
+                    {
+                        cookieOptions.Cookie.SameSite = SameSiteMode.Lax;
+                        cookieOptions.Cookie.HttpOnly = true;
+                        cookieOptions.Cookie.SecurePolicy = CookieSecurePolicy.Always;
+                        cookieOptions.SlidingExpiration = true;
+                    })
+                    .AddOAuth("PropelAuth", configOptions =>
+                    {
+                        configOptions.AuthorizationEndpoint = $"{options.AuthUrl}/propelauth/oauth/authorize";
+                        configOptions.TokenEndpoint = $"{options.AuthUrl}/propelauth/oauth/token";
+                        configOptions.UserInformationEndpoint = $"{options.AuthUrl}/propelauth/oauth/userinfo";
+                        configOptions.ClientId = options.OAuthOptions.ClientId;
+                        configOptions.ClientSecret = options.OAuthOptions.ClientSecret;
+                        configOptions.CallbackPath = options.OAuthOptions.CallbackPath;
+                        configOptions.SaveTokens = true;
+                        configOptions.Events = new OAuthEvents
+                        {
+                            OnCreatingTicket = context =>
+                            {
+                                var token = context.AccessToken;
+                                var handler = new JwtSecurityTokenHandler();
+                                var jwt = handler.ReadJwtToken(token);
+                                foreach (var claim in jwt.Claims)
+                                {
+                                    context.Identity?.AddClaim(claim);
+                                }
+                                return Task.CompletedTask;
+                            }
+                        };
+                    });
+            }
 
             services.AddAuthorization();
         }
diff --git a/PropelAuth/PropelAuthOptions.cs b/PropelAuth/PropelAuthOptions.cs
index 16e1076..9edc63b 100644
--- a/PropelAuth/PropelAuthOptions.cs
+++ b/PropelAuth/PropelAuthOptions.cs
@@ -25,6 +25,11 @@ public class PropelAuthOptions
         /// </summary>
         public string ApiKey { get; }
 
+        /// <summary>
+        /// If you are using PropelAuth's OAuth feature, you can specify the OAuth options here.
+        /// </summary>
+        public OAuthOptions? OAuthOptions { get; }
+
         #endregion
 
         #region Constructors
@@ -35,13 +40,63 @@ public class PropelAuthOptions
         /// <param name="authUrl">The base URL for the PropelAuth authentication service.</param>
         /// <param name="apiKey">The API key used for authenticating requests to PropelAuth.</param>
         /// <param name="publicKey">Optional. The public key used for token verification.</param>
-        public PropelAuthOptions(string authUrl, string apiKey, string? publicKey = null)
+        /// <param name="oAuthOptions">Optional. The OAuth options if you are using PropelAuth's OAuth feature.</param>
+        public PropelAuthOptions(string authUrl, string apiKey, string? publicKey = null,
+            OAuthOptions? oAuthOptions = null)
         {
             AuthUrl = authUrl;
             ApiKey = apiKey;
             PublicKey = publicKey;
+            OAuthOptions = oAuthOptions;
+        }
+
+        #endregion
+    }
+
+    public class OAuthOptions
+    {
+        #region Properties
+        
+        /// <summary>
+        /// The client ID for the OAuth application.
+        /// </summary>
+        public string ClientId { get; }
+
+        /// <summary>
+        /// The client secret for the OAuth application.
+        /// </summary>
+        public string ClientSecret { get; }
+
+        /// <summary>
+        /// The callback path for the OAuth application. Defaults to "/callback"
+        /// </summary>
+        public string? CallbackPath { get; }
+        
+        /// <summary>
+        /// Whether to allow requests via an authorization header `Bearer {TOKEN}`. Default false.
+        /// </summary>
+        public bool? AllowBearerTokenAuth { get; }
+        
+        #endregion
+
+        #region Constructor
+        
+        /// <summary>
+        /// Initializes a new instance of the <see cref="OAuthOptions"/> class.
+        /// </summary>
+        /// <param name="clientId">The client ID for the OAuth application.</param>
+        /// <param name="clientSecret">The client secret for the OAuth application.</param>
+        /// <param name="callbackPath">Optional. The callback path for the OAuth application. Defaults to "/callback"</param>
+        /// <param name="allowBearerTokenAuth">Optional. Whether to allow requests via an authorization header `Bearer {TOKEN}`. Default false.</param>
+        public OAuthOptions(string clientId, string clientSecret, string? callbackPath = "/callback", bool? allowBearerTokenAuth = false)
+        {
+            ClientId = clientId;
+            ClientSecret = clientSecret;
+            CallbackPath = callbackPath;
+            AllowBearerTokenAuth = allowBearerTokenAuth;
         }
 
         #endregion
+        
     }
 }
\ No newline at end of file
diff --git a/PropelAuth/User.cs b/PropelAuth/User.cs
index 09d5842..6c6291e 100644
--- a/PropelAuth/User.cs
+++ b/PropelAuth/User.cs
@@ -175,12 +175,13 @@ private string ExtractEmail(ClaimsPrincipal claimsPrincipal)
             string? email = claimsPrincipal.FindFirstValue(ClaimTypes.Email);
             if (string.IsNullOrEmpty(email))
             {
-                throw new ArgumentException($"Required claim '{ClaimTypes.Email}' is missing or empty", nameof(claimsPrincipal));
+                throw new ArgumentException($"Required claim '{ClaimTypes.Email}' is missing or empty",
+                    nameof(claimsPrincipal));
             }
 
             return email;
         }
-        
+
         /// <summary>
         /// Processes organization information from claims.
         /// </summary>
@@ -193,7 +194,8 @@ private void ProcessOrgInformation(ClaimsPrincipal claimsPrincipal)
 
             if (orgsClaim.Type == "org_id_to_org_member_info")
             {
-                OrgIdToOrgMemberInfo = JsonConvert.DeserializeObject<Dictionary<string, OrgMemberInfo>>(orgsClaim.Value);
+                OrgIdToOrgMemberInfo =
+                    JsonConvert.DeserializeObject<Dictionary<string, OrgMemberInfo>>(orgsClaim.Value);
             }
             else
             {
@@ -215,7 +217,9 @@ private void ProcessOrgInformation(ClaimsPrincipal claimsPrincipal)
         private Dictionary<string, object>? ParseUserProperties(ClaimsPrincipal claimsPrincipal)
         {
             var propertiesClaim = claimsPrincipal.FindFirst("properties");
-            return propertiesClaim != null ? JsonConvert.DeserializeObject<Dictionary<string, object>>(propertiesClaim.Value) : null;
+            return propertiesClaim != null
+                ? JsonConvert.DeserializeObject<Dictionary<string, object>>(propertiesClaim.Value)
+                : null;
         }
 
         /// <summary>
@@ -276,8 +280,8 @@ private static LoginMethod CreateSamlSsoLoginMethod(Dictionary<string, string> l
             var samlProvider = loginMethodData.TryGetValue("provider", out var samlProviderValue)
                 ? samlProviderValue
                 : "unknown";
-            var orgId = loginMethodData.TryGetValue("org_id", out var orgIdValue) 
-                ? orgIdValue 
+            var orgId = loginMethodData.TryGetValue("org_id", out var orgIdValue)
+                ? orgIdValue
                 : "unknown";
             return LoginMethod.SamlSso(samlProvider, orgId);
         }
@@ -293,6 +297,14 @@ public static class ClaimsPrincipalExtensions
         /// <summary>
         /// Gets a PropelAuth User from a ClaimsPrincipal.
         /// </summary>
-        public static User GetUser(this ClaimsPrincipal claimsPrincipal) => new(claimsPrincipal);
+        public static User? GetUser(this ClaimsPrincipal claimsPrincipal)
+        {
+            if (claimsPrincipal.FindFirstValue("user_id") == null)
+            {
+                return null;
+            }
+
+            return new User(claimsPrincipal);
+        }
     }
 }
\ No newline at end of file