diff --git a/README.md b/README.md
index 04ad4941..077b326b 100644
--- a/README.md
+++ b/README.md
@@ -292,7 +292,7 @@ Also see [here](/lua/CopilotChat/config.lua):
     },
     submit_prompt = {
       normal = '<CR>',
-      insert = '<C-m>'
+      insert = '<C-s>'
     },
     accept_diff = {
       normal = '<C-y>',
diff --git a/lua/CopilotChat/chat.lua b/lua/CopilotChat/chat.lua
index 469fcb04..ccdbcaf8 100644
--- a/lua/CopilotChat/chat.lua
+++ b/lua/CopilotChat/chat.lua
@@ -10,7 +10,7 @@
 ---@field last fun(self: CopilotChat.Chat)
 ---@field clear fun(self: CopilotChat.Chat)
 ---@field open fun(self: CopilotChat.Chat, config: CopilotChat.config)
----@field close fun(self: CopilotChat.Chat)
+---@field close fun(self: CopilotChat.Chat, bufnr: number?)
 ---@field focus fun(self: CopilotChat.Chat)
 ---@field follow fun(self: CopilotChat.Chat)
 ---@field finish fun(self: CopilotChat.Chat, msg: string?)
@@ -40,6 +40,7 @@ local Chat = class(function(self, help, on_buf_create)
   self.winnr = nil
   self.spinner = nil
   self.separator = nil
+  self.layout = nil
 
   self.buf_create = function()
     local bufnr = vim.api.nvim_create_buf(false, true)
@@ -192,6 +193,7 @@ function Chat:open(config)
     vim.api.nvim_win_set_buf(self.winnr, self.bufnr)
   end
 
+  self.layout = layout
   self.separator = config.separator
 
   vim.wo[self.winnr].wrap = true
@@ -209,13 +211,17 @@ function Chat:open(config)
   self:render()
 end
 
-function Chat:close()
+function Chat:close(bufnr)
   if self.spinner then
     self.spinner:finish()
   end
 
   if self:visible() then
-    vim.api.nvim_win_close(self.winnr, true)
+    if self.layout == 'replace' then
+      self:restore(self.winnr, bufnr)
+    else
+      vim.api.nvim_win_close(self.winnr, true)
+    end
     self.winnr = nil
   end
 end
diff --git a/lua/CopilotChat/context.lua b/lua/CopilotChat/context.lua
index 65dff289..8b8a4016 100644
--- a/lua/CopilotChat/context.lua
+++ b/lua/CopilotChat/context.lua
@@ -248,6 +248,10 @@ function M.find_for_query(copilot, opts)
         on_error = on_error,
         on_done = function(query_out)
           local query = query_out[1]
+          if not query then
+            on_done({})
+            return
+          end
           log.debug('Prompt:', query.prompt)
           log.debug('Content:', query.content)
           local data = data_ranked_by_relatedness(query, out, 20)
diff --git a/lua/CopilotChat/copilot.lua b/lua/CopilotChat/copilot.lua
index 2a954fee..01031f98 100644
--- a/lua/CopilotChat/copilot.lua
+++ b/lua/CopilotChat/copilot.lua
@@ -43,6 +43,7 @@ local temp_file = utils.temp_file
 local prompts = require('CopilotChat.prompts')
 local tiktoken = require('CopilotChat.tiktoken')
 local max_tokens = 8192
+local timeout = 30000
 local version_headers = {
   ['editor-version'] = 'Neovim/'
     .. vim.version().major
@@ -309,6 +310,7 @@ function Copilot:with_auth(on_done, on_error)
     end
 
     curl.get(url, {
+      timeout = timeout,
       headers = headers,
       proxy = self.proxy,
       insecure = self.allow_insecure,
@@ -421,6 +423,7 @@ function Copilot:ask(prompt, opts)
     local headers = generate_headers(self.token.token, self.sessionid, self.machineid)
     self.current_job = curl
       .post(url, {
+        timeout = timeout,
         headers = headers,
         body = temp_file(body),
         proxy = self.proxy,
@@ -505,15 +508,15 @@ end
 ---@param callback fun(table):nil
 function Copilot:select_model(callback)
   if self.models_cache ~= nil then
-    vim.schedule(function()
-      callback(self.models_cache)
-    end)
+    callback(self.models_cache)
     return
   end
+
   local url = 'https://api.githubcopilot.com/models'
   self:with_auth(function()
     local headers = generate_headers(self.token.token, self.sessionid, self.machineid)
     curl.get(url, {
+      timeout = timeout,
       headers = headers,
       proxy = self.proxy,
       insecure = self.allow_insecure,
@@ -545,9 +548,7 @@ function Copilot:select_model(callback)
           return false
         end, selections)
         self.models_cache = selections
-        vim.schedule(function()
-          callback(self.models_cache)
-        end)
+        callback(self.models_cache)
       end,
     })
   end)
@@ -584,6 +585,7 @@ function Copilot:embed(inputs, opts)
     table.insert(jobs, function(resolve)
       local headers = generate_headers(self.token.token, self.sessionid, self.machineid)
       curl.post(url, {
+        timeout = timeout,
         headers = headers,
         body = temp_file(body),
         proxy = self.proxy,
diff --git a/lua/CopilotChat/init.lua b/lua/CopilotChat/init.lua
index 0370f4bf..b7df7523 100644
--- a/lua/CopilotChat/init.lua
+++ b/lua/CopilotChat/init.lua
@@ -340,7 +340,7 @@ end
 --- Close the chat window.
 function M.close()
   vim.cmd('stopinsert')
-  state.chat:close()
+  state.chat:close(state.source and state.source.bufnr or nil)
 end
 
 --- Toggle the chat window.
@@ -359,12 +359,15 @@ function M.response()
   return state.response
 end
 
+--- Select a Copilot GPT model.
 function M.select_model()
   state.copilot:select_model(function(models)
-    vim.ui.select(models, {
-      prompt = 'Select a model',
-    }, function(choice)
-      M.config.model = choice
+    vim.schedule(function()
+      vim.ui.select(models, {
+        prompt = 'Select a model',
+      }, function(choice)
+        M.config.model = choice
+      end)
     end)
   end)
 end
@@ -712,7 +715,7 @@ function M.setup(config)
   end
 
   if state.chat then
-    state.chat:close()
+    state.chat:close(state.source and state.source.bufnr or nil)
     state.chat:delete()
   end
   state.chat = Chat(chat_help, function(bufnr)
diff --git a/lua/CopilotChat/overlay.lua b/lua/CopilotChat/overlay.lua
index 804e0709..1c12b442 100644
--- a/lua/CopilotChat/overlay.lua
+++ b/lua/CopilotChat/overlay.lua
@@ -63,7 +63,7 @@ end
 
 function Overlay:restore(winnr, bufnr)
   self.current = nil
-  vim.api.nvim_win_set_buf(winnr, bufnr)
+  vim.api.nvim_win_set_buf(winnr, bufnr or 0)
   vim.api.nvim_win_set_hl_ns(winnr, 0)
 end