diff --git a/src/interfaces.ts b/src/interfaces.ts
index 7b42d7c..1ee60d3 100644
--- a/src/interfaces.ts
+++ b/src/interfaces.ts
@@ -1,4 +1,4 @@
-import type { SessionStorage, SessionIdStorageStrategy, data } from 'react-router';
+import type { SessionStorage, SessionIdStorageStrategy, data, SessionData } from 'react-router';
 import type { OauthTokens, User } from '@workos-inc/node';
 
 export type DataWithResponseInit<T> = ReturnType<typeof data<T>>;
@@ -16,6 +16,19 @@ export interface AuthLoaderSuccessData {
   user: User;
 }
 
+export interface RefreshErrorOptions {
+  error: unknown;
+  request: Request;
+  sessionData: SessionData;
+}
+
+export interface RefreshSuccessOptions {
+  accessToken: string;
+  user: User;
+  impersonator: Impersonator | null;
+  organizationId: string | null;
+}
+
 export interface Impersonator {
   email: string;
   reason: string | null;
@@ -67,6 +80,8 @@ export interface GetAuthURLOptions {
 export type AuthKitLoaderOptions = {
   ensureSignedIn?: boolean;
   debug?: boolean;
+  onSessionRefreshError?: (options: RefreshErrorOptions) => void | Response | Promise<void | Response>;
+  onSessionRefreshSuccess?: (options: RefreshSuccessOptions) => void | Promise<void>;
 } & (
   | {
       storage?: never;
diff --git a/src/session.spec.ts b/src/session.spec.ts
index 3074236..54794d0 100644
--- a/src/session.spec.ts
+++ b/src/session.spec.ts
@@ -559,6 +559,43 @@ describe('session', () => {
           expect(response.headers.get('Set-Cookie')).toBe('destroyed-session-cookie');
         }
       });
+
+      it('calls onSessionRefreshSuccess when provided', async () => {
+        const onSessionRefreshSuccess = jest.fn();
+        await authkitLoader(createLoaderArgs(createMockRequest()), {
+          onSessionRefreshSuccess,
+        });
+
+        expect(onSessionRefreshSuccess).toHaveBeenCalled();
+      });
+
+      it('calls onSessionRefreshError when provided and refresh fails', async () => {
+        authenticateWithRefreshToken.mockRejectedValue(new Error('Refresh token invalid'));
+        const onSessionRefreshError = jest.fn().mockReturnValue(redirect('/error'));
+
+        await authkitLoader(createLoaderArgs(createMockRequest()), {
+          onSessionRefreshError,
+        });
+
+        expect(onSessionRefreshError).toHaveBeenCalled();
+      });
+
+      it('allows redirect from onSessionRefreshError callback', async () => {
+        authenticateWithRefreshToken.mockRejectedValue(new Error('Refresh token invalid'));
+
+        try {
+          await authkitLoader(createLoaderArgs(createMockRequest()), {
+            onSessionRefreshError: () => {
+              throw redirect('/');
+            },
+          });
+          fail('Expected redirect response to be thrown');
+        } catch (response: unknown) {
+          assertIsResponse(response);
+          expect(response.status).toBe(302);
+          expect(response.headers.get('Location')).toBe('/');
+        }
+      });
     });
   });
 
diff --git a/src/session.ts b/src/session.ts
index 87d569d..6e93197 100644
--- a/src/session.ts
+++ b/src/session.ts
@@ -22,6 +22,13 @@ export type TypedResponse<T> = Response & {
   json(): Promise<T>;
 };
 
+export class SessionRefreshError extends Error {
+  constructor(cause: unknown) {
+    super('Session refresh error', { cause });
+    this.name = 'SessionRefreshError';
+  }
+}
+
 /**
  * This function is used to refresh the session by using the refresh token.
  * It will authenticate the user with the refresh token and return a new session object.
@@ -89,7 +96,7 @@ export async function refreshSession(request: Request, { organizationId }: { org
 
 async function updateSession(request: Request, debug: boolean) {
   const session = await getSessionFromCookie(request.headers.get('Cookie') as string);
-  const { commitSession, getSession, destroySession } = await getSessionStorage();
+  const { commitSession, getSession } = await getSessionStorage();
 
   // If no session, just continue
   if (!session) {
@@ -138,13 +145,7 @@ async function updateSession(request: Request, debug: boolean) {
     // istanbul ignore next
     if (debug) console.log('Failed to refresh. Deleting cookie and redirecting.', e);
 
-    const cookieSession = await getSession(request.headers.get('Cookie'));
-
-    throw redirect('/', {
-      headers: {
-        'Set-Cookie': await destroySession(cookieSession),
-      },
-    });
+    throw new SessionRefreshError(e);
   }
 }
 
@@ -287,6 +288,8 @@ export async function authkitLoader<Data = unknown>(
   const {
     ensureSignedIn = false,
     debug = false,
+    onSessionRefreshSuccess,
+    onSessionRefreshError,
     storage,
     cookie,
   } = typeof loaderOrOptions === 'object' ? loaderOrOptions : options;
@@ -295,62 +298,107 @@ export async function authkitLoader<Data = unknown>(
   const { getSession, destroySession } = await configureSessionStorage({ storage, cookieName });
 
   const { request } = loaderArgs;
-  const session = await updateSession(request, debug);
 
-  if (!session) {
-    if (ensureSignedIn) {
-      const returnPathname = getReturnPathname(request.url);
+  try {
+    // Try to get session, this might throw SessionRefreshError
+    const session = await updateSession(request, debug);
+
+    if (!session) {
+      // No session found case (not authenticated)
+      if (ensureSignedIn) {
+        const returnPathname = getReturnPathname(request.url);
+        const cookieSession = await getSession(request.headers.get('Cookie'));
+
+        throw redirect(await getAuthorizationUrl({ returnPathname }), {
+          headers: {
+            'Set-Cookie': await destroySession(cookieSession),
+          },
+        });
+      }
+
+      const auth: UnauthorizedData = {
+        user: null,
+        accessToken: null,
+        impersonator: null,
+        organizationId: null,
+        permissions: null,
+        entitlements: null,
+        role: null,
+        sessionId: null,
+        sealedSession: null,
+      };
+
+      return await handleAuthLoader(loader, loaderArgs, auth);
+    }
+
+    // Session found and valid (or refreshed successfully)
+    const {
+      sessionId,
+      organizationId = null,
+      role = null,
+      permissions = [],
+      entitlements = [],
+    } = getClaimsFromAccessToken(session.accessToken);
+
+    const cookieSession = await getSession(request.headers.get('Cookie'));
+    const { impersonator = null } = session;
+
+    // checking for 'headers' in session determines if the session was refreshed or not
+    if (onSessionRefreshSuccess && 'headers' in session) {
+      await onSessionRefreshSuccess({
+        accessToken: session.accessToken,
+        user: session.user,
+        impersonator,
+        organizationId,
+      });
+    }
+
+    const auth: AuthorizedData = {
+      user: session.user,
+      sessionId,
+      accessToken: session.accessToken,
+      organizationId,
+      role,
+      permissions,
+      entitlements,
+      impersonator,
+      sealedSession: cookieSession.get('jwt'),
+    };
+
+    return await handleAuthLoader(loader, loaderArgs, auth, session);
+  } catch (error) {
+    if (error instanceof SessionRefreshError) {
       const cookieSession = await getSession(request.headers.get('Cookie'));
 
-      throw redirect(await getAuthorizationUrl({ returnPathname }), {
+      if (onSessionRefreshError) {
+        try {
+          const result = await onSessionRefreshError({
+            error: error.cause,
+            request,
+            sessionData: cookieSession,
+          });
+
+          if (result instanceof Response) {
+            return result;
+          }
+        } catch (callbackError) {
+          // If callback throws a Response (like redirect), propagate it
+          if (callbackError instanceof Response) {
+            throw callbackError;
+          }
+        }
+      }
+
+      throw redirect('/', {
         headers: {
           'Set-Cookie': await destroySession(cookieSession),
         },
       });
     }
 
-    const auth: UnauthorizedData = {
-      user: null,
-      accessToken: null,
-      impersonator: null,
-      organizationId: null,
-      permissions: null,
-      entitlements: null,
-      role: null,
-      sessionId: null,
-      sealedSession: null,
-    };
-
-    return await handleAuthLoader(loader, loaderArgs, auth);
+    // Propagate other errors
+    throw error;
   }
-
-  // istanbul ignore next
-  const {
-    sessionId,
-    organizationId = null,
-    role = null,
-    permissions = [],
-    entitlements = [],
-  } = getClaimsFromAccessToken(session.accessToken);
-
-  const cookieSession = await getSession(request.headers.get('Cookie'));
-
-  // istanbul ignore next
-  const { impersonator = null } = session;
-
-  const auth: AuthorizedData = {
-    user: session.user,
-    sessionId,
-    accessToken: session.accessToken,
-    organizationId,
-    role,
-    permissions,
-    entitlements,
-    impersonator,
-    sealedSession: cookieSession.get('jwt'),
-  };
-
-  return await handleAuthLoader(loader, loaderArgs, auth, session);
 }
 
 async function handleAuthLoader(