diff --git a/src/components/Settings/SettingsField.tsx b/src/components/Settings/SettingsField.tsx
index c1b0d9d..5245a4a 100644
--- a/src/components/Settings/SettingsField.tsx
+++ b/src/components/Settings/SettingsField.tsx
@@ -1,6 +1,7 @@
 import {
   SelectUIConfigField,
   StringUIConfigField,
+  TextareaUIConfigField,
   UIConfigField,
 } from '@/lib/config/types';
 import { useState } from 'react';
@@ -156,6 +157,82 @@ const SettingsInput = ({
   );
 };
 
+const SettingsTextarea = ({
+  field,
+  value,
+  setValue,
+  dataAdd,
+}: {
+  field: TextareaUIConfigField;
+  value?: any;
+  setValue: (value: any) => void;
+  dataAdd: string;
+}) => {
+  const [loading, setLoading] = useState(false);
+
+  const handleSave = async (newValue: any) => {
+    setLoading(true);
+    setValue(newValue);
+    try {
+      if (field.scope === 'client') {
+        localStorage.setItem(field.key, newValue);
+      } else {
+        const res = await fetch('/api/config', {
+          method: 'POST',
+          headers: {
+            'Content-Type': 'application/json',
+          },
+          body: JSON.stringify({
+            key: `${dataAdd}.${field.key}`,
+            value: newValue,
+          }),
+        });
+
+        if (!res.ok) {
+          console.error('Failed to save config:', await res.text());
+          throw new Error('Failed to save configuration');
+        }
+      }
+    } catch (error) {
+      console.error('Error saving config:', error);
+      toast.error('Failed to save configuration.');
+    } finally {
+      setTimeout(() => setLoading(false), 150);
+    }
+  };
+
+  return (
+    <section className="rounded-xl border border-light-200 bg-light-primary/80 p-4 lg:p-6 transition-colors dark:border-dark-200 dark:bg-dark-primary/80">
+      <div className="space-y-3 lg:space-y-5">
+        <div>
+          <h4 className="text-sm lg:text-base text-black dark:text-white">
+            {field.name}
+          </h4>
+          <p className="text-[11px] lg:text-xs text-black/50 dark:text-white/50">
+            {field.description}
+          </p>
+        </div>
+        <div className="relative">
+          <textarea
+            value={value ?? field.default ?? ''}
+            onChange={(event) => setValue(event.target.value)}
+            onBlur={(event) => handleSave(event.target.value)}
+            className="w-full rounded-lg border border-light-200 dark:border-dark-200 bg-light-primary dark:bg-dark-primary px-3 py-2 lg:px-4 lg:py-3 pr-10 !text-xs lg:!text-sm text-black/80 dark:text-white/80 placeholder:text-black/40 dark:placeholder:text-white/40 focus-visible:outline-none focus-visible:border-light-300 dark:focus-visible:border-dark-300 transition-colors disabled:cursor-not-allowed disabled:opacity-60"
+            placeholder={field.placeholder}
+            rows={4}
+            disabled={loading}
+          />
+          {loading && (
+            <span className="pointer-events-none absolute right-3 translate-y-3 text-black/40 dark:text-white/40">
+              <Loader2 className="h-4 w-4 animate-spin" />
+            </span>
+          )}
+        </div>
+      </div>
+    </section>
+  );
+};
+
 const SettingsField = ({
   field,
   value,
@@ -186,6 +263,15 @@ const SettingsField = ({
           dataAdd={dataAdd}
         />
       );
+    case 'textarea':
+      return (
+        <SettingsTextarea
+          field={field}
+          value={val}
+          setValue={setVal}
+          dataAdd={dataAdd}
+        />
+      );
     default:
       return <div>Unsupported field type: {field.type}</div>;
   }
diff --git a/src/lib/config/index.ts b/src/lib/config/index.ts
index 409ae3a..ce1a81e 100644
--- a/src/lib/config/index.ts
+++ b/src/lib/config/index.ts
@@ -40,6 +40,16 @@ class ConfigManager {
         default: 'dark',
         scope: 'client',
       },
+      {
+        name: 'System Instructions',
+        key: 'systemInstructions',
+        type: 'textarea',
+        required: false,
+        description: 'Add custom behavior or tone for the model.',
+        placeholder:
+          'e.g., "Respond in a friendly and concise tone" or "Use British English and format answers as bullet points."',
+        scope: 'client',
+      },
     ],
     modelProviders: [],
     search: [
diff --git a/src/lib/config/types.ts b/src/lib/config/types.ts
index 3d69bbc..8497cb5 100644
--- a/src/lib/config/types.ts
+++ b/src/lib/config/types.ts
@@ -32,10 +32,17 @@ type PasswordUIConfigField = BaseUIConfigField & {
   default?: string;
 };
 
+type TextareaUIConfigField = BaseUIConfigField & {
+  type: 'textarea';
+  placeholder?: string;
+  default?: string;
+};
+
 type UIConfigField =
   | StringUIConfigField
   | SelectUIConfigField
-  | PasswordUIConfigField;
+  | PasswordUIConfigField
+  | TextareaUIConfigField;
 
 type ConfigModelProvider = {
   id: string;
@@ -87,4 +94,5 @@ export type {
   StringUIConfigField,
   ModelProviderUISection,
   ConfigModelProvider,
+  TextareaUIConfigField,
 };