diff --git a/calc-backend/src/controllers/func.controller.ts b/calc-backend/src/controllers/func.controller.ts
index 0e27fce..5c2f29d 100644
--- a/calc-backend/src/controllers/func.controller.ts
+++ b/calc-backend/src/controllers/func.controller.ts
@@ -4,11 +4,16 @@ import { IntegralData } from "../types";
 
 // will need middleware to check if func is valid and unique to specific topic
 export async function createIntegral(req: Request, res: Response)
-{   
+{
     const { equation, lowerBound, upperBound, topic }: IntegralData = req.body;
-    const userId = req.params.id;
+    const userId = req.user.id;
 
     try {
+        const funcCount = await prisma.func.count({ where: { userId } });
+        if (funcCount >= 30) {
+            return res.status(400).json({ message: "You can only save up to 30 functions" });
+        }
+
         const newFunc = await prisma.func.create({
             data: {
                 equation,
@@ -26,11 +31,8 @@ export async function createIntegral(req: Request, res: Response)
 
 export async function getUserFuncs(req: Request, res: Response)
 {
-    const userId = req.params.id;
-    if(!userId) {
-        return res.status(404).json({message: "Function ID is required"})
-    }
-    
+    const userId = req.user.id;
+
     try {
         const funcs = await prisma.func.findMany({
             where: {userId},
@@ -44,14 +46,20 @@ export async function getUserFuncs(req: Request, res: Response)
 export async function deleteUserFunc(req: Request, res: Response)
 {
     const functionId = req.params.id;
+    const userId = req.user.id;
 
     try {
-        const deletedFunc = await prisma.func.delete({
-            where: {
-                id: functionId,
-            },
-        })
-        res.status(200).json({message: "Function deleted!"})
+        const func = await prisma.func.findUnique({ where: { id: functionId } });
+
+        if (!func) {
+            return res.status(404).json({ message: "Function not found" });
+        }
+        if (func.userId !== userId) {
+            return res.status(403).json({ message: "Forbidden" });
+        }
+
+        await prisma.func.delete({ where: { id: functionId } });
+        res.status(200).json({ message: "Function deleted!" })
     } catch (err) {
         res.status(500).json({message: "Failed to delete function", error: err})
     }
diff --git a/calc-backend/src/index.ts b/calc-backend/src/index.ts
index 548d354..a6bae7b 100644
--- a/calc-backend/src/index.ts
+++ b/calc-backend/src/index.ts
@@ -1,7 +1,6 @@
 import express from "express";
 import cors from "cors";
 import routes from "./server.routes";
-import errorMiddleware from "./middlewares/errorHandler.middleware";
 import { toNodeHandler } from "better-auth/node";
 import { auth } from "./lib/auth";
 
@@ -23,8 +22,6 @@ app.use(express.json()) // use this after better auth
 // Prefixes the endpoint with /
 app.use('/',routes);
 
-//app.use(errorMiddleware);
-
 app.listen(PORT, () => {
     console.log(`Server is running at http://localhost:${PORT}`);
 });
\ No newline at end of file
diff --git a/calc-backend/src/middlewares/errorHandler.middleware.ts b/calc-backend/src/middlewares/errorHandler.middleware.ts
deleted file mode 100644
index b1779b8..0000000
--- a/calc-backend/src/middlewares/errorHandler.middleware.ts
+++ /dev/null
@@ -1,25 +0,0 @@
-// Here would go middleware that handles error checking
-
-import { NextFunction, Request, Response } from "express";
-
-// at the end of every function in here should be a function call of next()
-// this lets the middleware pass to the next piece of logic after its done
-
-const errorMiddleware = (err: Error, req: Request, res: Response, next: NextFunction) => {
-    try {
-        let error = {...err};
-
-        error.message = err.message;
-        console.error("middleware error: " + err);
-
-        // check for specific error types
-        // set error message, maybe error code and throw the new error
-
-
-    } catch(error) {
-        next(error);
-    }
-
-};
-
-export default errorMiddleware
\ No newline at end of file
diff --git a/calc-backend/src/middlewares/requireAuth.middleware.ts b/calc-backend/src/middlewares/requireAuth.middleware.ts
new file mode 100644
index 0000000..ad0ea68
--- /dev/null
+++ b/calc-backend/src/middlewares/requireAuth.middleware.ts
@@ -0,0 +1,14 @@
+import { Request, Response, NextFunction } from "express";
+import { auth } from "../lib/auth";
+import { fromNodeHeaders } from "better-auth/node";
+
+export async function requireAuth(req: Request, res: Response, next: NextFunction) {
+    const session = await auth.api.getSession({
+        headers: fromNodeHeaders(req.headers),
+    });
+    if (!session) {
+        return res.status(401).json({ message: "Unauthorized" });
+    }
+    req.user = session.user;
+    next();
+}
diff --git a/calc-backend/src/routes/func.routes.ts b/calc-backend/src/routes/func.routes.ts
index 59edec1..2a85386 100644
--- a/calc-backend/src/routes/func.routes.ts
+++ b/calc-backend/src/routes/func.routes.ts
@@ -1,10 +1,12 @@
 import { Router } from "express";
 import { createIntegral, deleteUserFunc, getUserFuncs } from "../controllers/func.controller";
+import { requireAuth } from "../middlewares/requireAuth.middleware";
 
 const router = Router();
 
-router.post("/create-integral/:id", createIntegral);
-router.get("/all/:id", getUserFuncs);
-router.delete("/delete/:id", deleteUserFunc);
+// These routes can only be accessed by authenticated users
+router.post("/create-integral", requireAuth, createIntegral);
+router.get("/all", requireAuth, getUserFuncs);
+router.delete("/delete/:id", requireAuth, deleteUserFunc);
 
 export default router;
\ No newline at end of file
diff --git a/calc-backend/src/types.ts b/calc-backend/src/types.ts
index 48366ce..9948b51 100644
--- a/calc-backend/src/types.ts
+++ b/calc-backend/src/types.ts
@@ -1,3 +1,16 @@
+declare global {
+    namespace Express {
+        interface Request {
+            user: {
+                id: string;
+                name: string;
+                email: string;
+                [key: string]: any;
+            };
+        }
+    }
+}
+
 export interface IntegralData {
     equation: string;
     lowerBound: number;
diff --git a/calc-frontend/src/components/Custom/LimCustomGraph.tsx b/calc-frontend/src/components/Custom/LimCustomGraph.tsx
deleted file mode 100644
index e69de29..0000000
diff --git a/calc-frontend/src/components/ui/SaveFunctionButton.tsx b/calc-frontend/src/components/ui/SaveFunctionButton.tsx
index a8be2a2..6bbd099 100644
--- a/calc-frontend/src/components/ui/SaveFunctionButton.tsx
+++ b/calc-frontend/src/components/ui/SaveFunctionButton.tsx
@@ -1,10 +1,9 @@
 import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger, TooltipArrow } from "@radix-ui/react-tooltip";
-import { Session } from "../../lib/auth-client";
 import { AuthContext } from "../../App/AuthProvider";
 import { useContext } from "react";
 import { useNavigate } from "react-router";
 
-function SaveFunctionButton({onSave, saving, enableSave}: {onSave: (session: Session) => void, 
+function SaveFunctionButton({onSave, saving, enableSave}: {onSave: () => void,
   saving: boolean, enableSave: boolean})
 {
   const {session} = useContext(AuthContext);
@@ -16,7 +15,7 @@ function SaveFunctionButton({onSave, saving, enableSave}: {onSave: (session: Ses
         navigate("/sign-in");
         return;
     }
-        onSave(session);
+        onSave();
     }
 
     if(saving){
diff --git a/calc-frontend/src/pages/CustomDerivative.tsx b/calc-frontend/src/pages/CustomDerivative.tsx
index 1ed4468..4027ee4 100644
--- a/calc-frontend/src/pages/CustomDerivative.tsx
+++ b/calc-frontend/src/pages/CustomDerivative.tsx
@@ -8,7 +8,6 @@ import SaveFunctionButton from "../components/ui/SaveFunctionButton.tsx";
 import AskAIButtonDerivative from "@/components/ui/AskAIButtonDerivative.tsx";
 
 import { toast } from "sonner";
-import { Session } from "../lib/auth-client";
 
 function CustomDeriv() {
 
@@ -56,7 +55,7 @@ function CustomDeriv() {
   }
 
   // need to check if func is unique first
-  const saveFunction = async (session: Session) => {
+  const saveFunction = async () => {
 
     // check if function has been graphed
     if(func === ''){
@@ -69,13 +68,11 @@ function CustomDeriv() {
     const lowerBound = bounds[0];
     const upperBound = bounds[1];
     const topic = "Derivative";
-    const userId = session?.user.id || "";
-    
     try {
       setSaving(true) // show loading while saving
 
       // create-integral handles any topic
-      await axios.post(serverUrl + `/func/create-integral/${userId}`, {
+      await axios.post(serverUrl + `/func/create-integral`, {
         equation,
         lowerBound,
         upperBound,
@@ -85,9 +82,13 @@ function CustomDeriv() {
     )
 
       toast.success("Function Saved Successfully!");
-    } 
+    }
     catch (error) {
-      toast.error("Function Failed to Save");
+      if (axios.isAxiosError(error) && error.response?.data?.message === "You can only save up to 30 functions") {
+        toast.error("You can only save up to 30 functions");
+      } else {
+        toast.error("Function Failed to Save");
+      }
       console.error("save function error: ",error);
     }
     finally{
diff --git a/calc-frontend/src/pages/CustomIntegral.tsx b/calc-frontend/src/pages/CustomIntegral.tsx
index 1f1638e..9065cc7 100644
--- a/calc-frontend/src/pages/CustomIntegral.tsx
+++ b/calc-frontend/src/pages/CustomIntegral.tsx
@@ -8,7 +8,6 @@ import SaveFunctionButton from "../components/ui/SaveFunctionButton.tsx";
 import AskAIButton from "../components/ui/AskAIButtonIntegral.tsx";
 
 import { toast } from "sonner";
-import { Session } from "../lib/auth-client";
 
 function CustomInt() {
 
@@ -57,7 +56,7 @@ function CustomInt() {
   }
 
   // need to check if func is unique first
-  const saveFunction = async (session: Session) => {
+  const saveFunction = async () => {
 
       // check if function has been graphed
       if(func === ''){
@@ -70,12 +69,10 @@ function CustomInt() {
       const lowerBound = bounds[0];
       const upperBound = bounds[1];
       const topic = "Integral";
-      const userId = session?.user.id || "";
-      
       try {
         setSaving(true) // show loading while saving
 
-        await axios.post(serverUrl + `/func/create-integral/${userId}`, {
+        await axios.post(serverUrl + `/func/create-integral`, {
           equation,
           lowerBound,
           upperBound,
@@ -85,9 +82,13 @@ function CustomInt() {
       )
 
         toast.success("Function Saved Successfully!");
-      } 
+      }
       catch (error) {
-        toast.error("Function Failed to Save");
+        if (axios.isAxiosError(error) && error.response?.data?.message === "You can only save up to 30 functions") {
+          toast.error("You can only save up to 30 functions");
+        } else {
+          toast.error("Function Failed to Save");
+        }
         console.error("save function error: ",error);
       }
       finally{
diff --git a/calc-frontend/src/pages/CustomLimit.tsx b/calc-frontend/src/pages/CustomLimit.tsx
deleted file mode 100644
index e69de29..0000000
diff --git a/calc-frontend/src/pages/Dashboard.tsx b/calc-frontend/src/pages/Dashboard.tsx
index a98250d..037f42a 100644
--- a/calc-frontend/src/pages/Dashboard.tsx
+++ b/calc-frontend/src/pages/Dashboard.tsx
@@ -46,9 +46,8 @@ function Dashboard()
     }
 
     const getFuncs = async () => {
-        const userId = session.user.id;
         try {
-          const response = await axios.get(serverUrl + `/func/all/${userId}`);
+          const response = await axios.get(serverUrl + `/func/all`, { withCredentials: true });
           setUserFunctions(response.data);
         } catch (error) {
           console.error("get function error: ", error);