diff --git a/packages/better-auth/src/api/routes/session-api.test.ts b/packages/better-auth/src/api/routes/session-api.test.ts
index fa04e940d7..5753446228 100644
--- a/packages/better-auth/src/api/routes/session-api.test.ts
+++ b/packages/better-auth/src/api/routes/session-api.test.ts
@@ -19,7 +19,7 @@ describe("session", async () => {
 					const cookies = parseSetCookieHeader(header || "");
 					expect(cookies.get("better-auth.session_token")).toMatchObject({
 						value: expect.any(String),
-						"max-age": (60 * 60 * 24 * 7).toString(),
+						"max-age": 60 * 60 * 24 * 7,
 						path: "/",
 						httponly: true,
 						samesite: "lax",
@@ -141,7 +141,7 @@ describe("session", async () => {
 					const cookies = parseSetCookieHeader(header || "");
 					expect(cookies.get("better-auth.session_token")).toMatchObject({
 						value: expect.any(String),
-						"max-age": (60 * 60 * 24 * 7).toString(),
+						"max-age": 60 * 60 * 24 * 7,
 						path: "/",
 						httponly: true,
 						samesite: "lax",
diff --git a/packages/better-auth/src/cookies/cookie-utils.ts b/packages/better-auth/src/cookies/cookie-utils.ts
index ed62699153..52114dbaf8 100644
--- a/packages/better-auth/src/cookies/cookie-utils.ts
+++ b/packages/better-auth/src/cookies/cookie-utils.ts
@@ -1,6 +1,6 @@
 interface CookieAttributes {
 	value: string;
-	"max-age"?: string;
+	"max-age"?: number;
 	expires?: Date;
 	domain?: string;
 	path?: string;
@@ -34,12 +34,13 @@ export function parseSetCookieHeader(
 			const [attrName, ...attrValueParts] = attribute.split("=");
 			const attrValue = attrValueParts.join("=");
 
-			// Normalize the attribute name to camelCase
 			const normalizedAttrName = attrName.trim().toLowerCase();
 
 			switch (normalizedAttrName) {
 				case "max-age":
-					attrObj["max-age"] = attrValue;
+					attrObj["max-age"] = attrValue
+						? parseInt(attrValue.trim(), 10)
+						: undefined;
 					break;
 				case "expires":
 					attrObj.expires = attrValue ? new Date(attrValue.trim()) : undefined;
diff --git a/packages/better-auth/src/integrations/next-js.ts b/packages/better-auth/src/integrations/next-js.ts
index f4f7559a49..68ed2f4fe4 100644
--- a/packages/better-auth/src/integrations/next-js.ts
+++ b/packages/better-auth/src/integrations/next-js.ts
@@ -24,24 +24,23 @@ export const nextCookies = () => {
 		hooks: {
 			after: [
 				{
-					matcher() {
+					matcher(ctx) {
 						return true;
 					},
 					handler: async (ctx) => {
-						const returned = ctx.context.endpoint?.headers;
+						const returned = ctx.responseHeader;
 						if (returned instanceof Headers) {
 							const setCookies = returned?.get("set-cookie");
 							if (!setCookies) return;
 							const parsed = parseSetCookieHeader(setCookies);
 							const cookieHelper = await cookies();
 							parsed.forEach((value, key) => {
-								if (!value) return;
 								if (!key) return;
 								const opts = {
-									samesite: value.samesite,
+									sameSite: value.samesite,
 									secure: value.secure,
-									"max-age": value["max-age"],
-									httponly: value.httponly,
+									maxAge: value["max-age"],
+									httpOnly: value.httponly,
 									domain: value.domain,
 									path: value.path,
 								};
diff --git a/packages/better-auth/src/plugins/multi-session/index.ts b/packages/better-auth/src/plugins/multi-session/index.ts
index 1810549222..3e9e9cc62a 100644
--- a/packages/better-auth/src/plugins/multi-session/index.ts
+++ b/packages/better-auth/src/plugins/multi-session/index.ts
@@ -6,11 +6,13 @@ import {
 	sessionMiddleware,
 } from "../../api";
 import {
+	deleteSessionCookie,
 	parseCookies,
 	parseSetCookieHeader,
 	setSessionCookie,
 } from "../../cookies";
 import type { BetterAuthPlugin } from "../../types";
+import { returnHookResponse } from "../../utils/plugin-helper";
 
 interface MultiSessionConfig {
 	/**
@@ -98,12 +100,7 @@ export const multiSession = (options?: MultiSessionConfig) => {
 							message: "Invalid session id",
 						});
 					}
-					await ctx.setSignedCookie(
-						ctx.context.authCookies.sessionToken.name,
-						sessionId,
-						ctx.context.secret,
-						ctx.context.authCookies.sessionToken.options,
-					);
+					await setSessionCookie(ctx, session);
 					return ctx.json(session);
 				},
 			),
@@ -139,7 +136,6 @@ export const multiSession = (options?: MultiSessionConfig) => {
 					if (!isActive) return ctx.json({ success: true });
 
 					const cookieHeader = ctx.headers?.get("cookie");
-					const authCookies = ctx.context.authCookies;
 					if (cookieHeader) {
 						const cookies = Object.fromEntries(parseCookies(cookieHeader));
 
@@ -165,22 +161,13 @@ export const multiSession = (options?: MultiSessionConfig) => {
 								const nextSession = validSessions[0];
 								await setSessionCookie(ctx, nextSession);
 							} else {
-								ctx.setCookie(authCookies.sessionToken.name, "", {
-									...authCookies.sessionToken.options,
-									maxAge: 0,
-								});
+								deleteSessionCookie(ctx);
 							}
 						} else {
-							ctx.setCookie(authCookies.sessionToken.name, "", {
-								...authCookies.sessionToken.options,
-								maxAge: 0,
-							});
+							deleteSessionCookie(ctx);
 						}
 					} else {
-						ctx.setCookie(authCookies.sessionToken.name, "", {
-							...authCookies.sessionToken.options,
-							maxAge: 0,
-						});
+						deleteSessionCookie(ctx);
 					}
 					return ctx.json({
 						success: true,
@@ -244,22 +231,27 @@ export const multiSession = (options?: MultiSessionConfig) => {
 					handler: createAuthMiddleware(async (ctx) => {
 						const cookieHeader = ctx.headers?.get("cookie");
 						if (!cookieHeader) return;
-
 						const cookies = Object.fromEntries(parseCookies(cookieHeader));
-
-						await Promise.all(
-							Object.entries(cookies).map(async ([key, value]) => {
+						const ids = Object.keys(cookies)
+							.map((key) => {
 								if (isMultiSessionCookie(key)) {
 									ctx.setCookie(key, "", { maxAge: 0 });
 									const id = key.split("_multi-")[1];
-									await ctx.context.internalAdapter.deleteSession(id);
+									return id;
 								}
-							}),
-						);
-
-						return {
-							responseHeader: ctx.responseHeader,
-						};
+								return null;
+							})
+							.filter((v): v is string => v !== null);
+						await ctx.context.internalAdapter.deleteSessions(ids);
+						const response = ctx.context.returned;
+						if (response instanceof Response) {
+							console.log("response", ctx.responseHeader.get("set-cookie"));
+							response.headers.append(
+								"Set-Cookie",
+								ctx.responseHeader.get("set-cookie")!,
+							);
+							return { response };
+						}
 					}),
 				},
 			],