diff --git a/src/lib/Chat.svelte b/src/lib/Chat.svelte
index ce69fda..f349ac9 100644
--- a/src/lib/Chat.svelte
+++ b/src/lib/Chat.svelte
@@ -9,7 +9,8 @@
     type Settings,
     supportedModels,
     type ResponseModels,
-    type SettingsSelect
+    type SettingsSelect,
+    type Chat
   } from './Types.svelte'
   import Code from './Code.svelte'
 
@@ -17,7 +18,7 @@
   import { replace } from 'svelte-spa-router'
   import SvelteMarkdown from 'svelte-markdown'
 
-  export let params = { chatId: undefined }
+  export let params = { chatId: '' }
   const chatId: number = parseInt(params.chatId)
   let updating: boolean = false
 
@@ -90,7 +91,7 @@
     }
   ]
 
-  $: chat = $chatsStorage.find((chat) => chat.id === chatId)
+  $: chat = $chatsStorage.find((chat) => chat.id === chatId) as Chat
   const tokenPrice = 0.000002 // $0.002 per 1000 tokens
 
   // Focus the input on mount
diff --git a/src/lib/Code.svelte b/src/lib/Code.svelte
index 3f35780..403eb78 100644
--- a/src/lib/Code.svelte
+++ b/src/lib/Code.svelte
@@ -78,7 +78,7 @@
     const clickedElement = event.target as HTMLButtonElement
 
     // Get the next element
-    const nextElement = clickedElement.nextElementSibling
+    const nextElement = clickedElement.nextElementSibling as HTMLElement
 
     // Modify the appearance of the button
     const originalButtonContent = clickedElement.innerHTML
diff --git a/src/lib/Export.svelte b/src/lib/Export.svelte
index b816c65..7dae814 100644
--- a/src/lib/Export.svelte
+++ b/src/lib/Export.svelte
@@ -1,10 +1,11 @@
 <script context="module" lang="ts">
   import { get } from 'svelte/store'
+  import type { Chat } from './Types.svelte'
   import { chatsStorage } from './Storage.svelte'
 
   export const exportAsMarkdown = (chatId: number) => {
     const chats = get(chatsStorage)
-    const chat = chats.find((chat) => chat.id === chatId)
+    const chat = chats.find((chat) => chat.id === chatId) as Chat
     const messages = chat.messages
     console.log(chat)
     let markdownContent = `# ${chat.name}\n`
diff --git a/src/lib/Home.svelte b/src/lib/Home.svelte
index ab3ec79..ec3d765 100644
--- a/src/lib/Home.svelte
+++ b/src/lib/Home.svelte
@@ -22,7 +22,9 @@
     <form
       class="field has-addons has-addons-right"
       on:submit|preventDefault={(event) => {
+        if (event.target && event.target[0].value) {
         apiKeyStorage.set(event.target[0].value)
+        }
       }}
     >
       <p class="control is-expanded">
diff --git a/src/lib/Sidebar.svelte b/src/lib/Sidebar.svelte
index 5d495e2..572a24e 100644
--- a/src/lib/Sidebar.svelte
+++ b/src/lib/Sidebar.svelte
@@ -61,7 +61,9 @@
           class="panel-block"
           class:is-disabled={!apiKey}
           on:click|preventDefault={() => {
-            exportAsMarkdown(activeChatId)
+            if (activeChatId) {
+              exportAsMarkdown(activeChatId)
+            }
           }}><span class="greyscale mr-2">📥</span> Export chat</a
         >
       </li>
diff --git a/src/lib/Storage.svelte b/src/lib/Storage.svelte
index c5f18fa..e3f8f3d 100644
--- a/src/lib/Storage.svelte
+++ b/src/lib/Storage.svelte
@@ -4,7 +4,7 @@
   import type { Chat, Message } from './Types.svelte'
 
   export const chatsStorage = persisted('chats', [] as Chat[])
-  export const apiKeyStorage = persisted('apiKey', null as string)
+  export const apiKeyStorage = persisted('apiKey', '' as string)
 
   export const addChat = (): number => {
     const chats = get(chatsStorage)
@@ -28,14 +28,14 @@
 
   export const addMessage = (chatId: number, message: Message) => {
     const chats = get(chatsStorage)
-    const chat = chats.find((chat) => chat.id === chatId)
+    const chat = chats.find((chat) => chat.id === chatId) as Chat
     chat.messages.push(message)
     chatsStorage.set(chats)
   }
 
   export const editMessage = (chatId: number, index: number, newMessage: Message) => {
     const chats = get(chatsStorage)
-    const chat = chats.find((chat) => chat.id === chatId)
+    const chat = chats.find((chat) => chat.id === chatId) as Chat
     chat.messages[index] = newMessage
     chat.messages.splice(index + 1) // remove the rest of the messages
     chatsStorage.set(chats)
@@ -43,7 +43,7 @@
 
   export const clearMessages = (chatId: number) => {
     const chats = get(chatsStorage)
-    const chat = chats.find((chat) => chat.id === chatId)
+    const chat = chats.find((chat) => chat.id === chatId) as Chat
     chat.messages = []
     chatsStorage.set(chats)
   }