diff --git a/server/middleware/errorHandler.js b/server/middleware/errorHandler.js
new file mode 100644
index 0000000..ca69270
--- /dev/null
+++ b/server/middleware/errorHandler.js
@@ -0,0 +1,33 @@
+import { ValidationError, DatabaseError, UniqueConstraintError, ForeignKeyConstraintError } from 'sequelize';
+
+export const sequelizeErrorHandler = (error, req, res, next) => {
+  if (error instanceof ValidationError) {
+    return res.status(400).json({ 
+      error: error.errors.map(e => e.message)
+    });
+  }
+  
+  if (error instanceof UniqueConstraintError) {
+    return res.status(409).json({ 
+      error: 'Resource already exists'
+    });
+  }
+  
+  if (error instanceof ForeignKeyConstraintError) {
+    return res.status(400).json({ 
+      error: 'Invalid reference to related resource'
+    });
+  }
+  
+  if (error instanceof DatabaseError) {
+    console.error('Database error:', error);
+    return res.status(500).json({ 
+      error: 'A database error occurred'
+    });
+  }
+  
+  console.error('Unexpected error:', error);
+  res.status(500).json({ 
+    error: 'An unexpected error occurred'
+  });
+}; 
\ No newline at end of file
diff --git a/server/models/todo.js b/server/models/todo.js
index 9a86c0c..daf1977 100644
--- a/server/models/todo.js
+++ b/server/models/todo.js
@@ -12,11 +12,28 @@ Todo.init({
   },
   name: {
     type: DataTypes.STRING,
-    allowNull: false
+    allowNull: false,
+    validate: {
+      notNull: {
+        msg: 'name is required'
+      },
+      notEmpty: {
+        msg: 'name cannot be empty'
+      }
+    }
   },
   priority: {
     type: DataTypes.ENUM('low', 'medium', 'high'),
-    allowNull: false
+    allowNull: false,
+    validate: {
+      notNull: {
+        msg: 'priority is required'
+      },
+      isIn: {
+        args: [['low', 'medium', 'high']],
+        msg: 'priority must be low, medium, or high'
+      }
+    }
   },
   due_date: {
     type: DataTypes.DATE,
diff --git a/server/routes/todos.router.js b/server/routes/todos.router.js
index 609f6af..917edb8 100644
--- a/server/routes/todos.router.js
+++ b/server/routes/todos.router.js
@@ -2,6 +2,7 @@ import express from 'express';
 import Todo from '../models/todo.js';
 import validateTodo from '../middleware/todoValidation.js';
 import { rejectUnauthenticated } from '../middleware/auth.js';
+import { sequelizeErrorHandler } from '../middleware/errorHandler.js';
 
 const router = express.Router();
 
@@ -122,4 +123,8 @@ router.delete('/:id', async (req, res) => {
   }
 });
 
+// Add at the end of your router
+router.use(sequelizeErrorHandler);
+
+
 export default router; 
\ No newline at end of file