diff --git a/lua/preview/compiler.lua b/lua/preview/compiler.lua
index c3ffbfa..90f7367 100644
--- a/lua/preview/compiler.lua
+++ b/lua/preview/compiler.lua
@@ -16,7 +16,7 @@ local log = require('preview.log')
 ---@field has_errors? boolean
 ---@field debounce? uv.uv_timer_t
 ---@field bwp_autocmd? integer
----@field cleanup_autocmd? integer
+---@field unload_autocmd? integer
 
 ---@type table<integer, preview.BufState>
 local state = {}
@@ -189,7 +189,7 @@ local function stop_watching(bufnr, s)
   close_viewer(bufnr)
   s.viewer_open = nil
   if s.bwp_autocmd then
-    pcall(vim.api.nvim_del_autocmd, s.bwp_autocmd)
+    vim.api.nvim_del_autocmd(s.bwp_autocmd)
     s.bwp_autocmd = nil
   end
   if s.debounce then
@@ -215,14 +215,8 @@ function M.compile(bufnr, name, provider, ctx, opts)
     return
   end
 
-  local buf_file = vim.api.nvim_buf_get_name(bufnr)
-  if buf_file ~= '' and buf_file == ctx.file then
-    if vim.bo[bufnr].modified then
-      vim.cmd('silent! update')
-    end
-  else
-    local lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)
-    vim.fn.writefile(lines, ctx.file)
+  if vim.bo[bufnr].modified then
+    vim.cmd('silent! update')
   end
 
   local s = get_state(bufnr)
@@ -514,8 +508,8 @@ end
 function M.stop_all()
   for bufnr, s in pairs(state) do
     stop_watching(bufnr, s)
-    if s.cleanup_autocmd then
-      pcall(vim.api.nvim_del_autocmd, s.cleanup_autocmd)
+    if s.unload_autocmd then
+      vim.api.nvim_del_autocmd(s.unload_autocmd)
     end
     state[bufnr] = nil
   end
@@ -547,10 +541,10 @@ function M.toggle(bufnr, name, provider, ctx_builder)
   log.dbg('toggle on for buffer %d', bufnr)
   s.watching = true
 
-  if s.cleanup_autocmd then
-    vim.api.nvim_del_autocmd(s.cleanup_autocmd)
+  if s.unload_autocmd then
+    vim.api.nvim_del_autocmd(s.unload_autocmd)
   end
-  s.cleanup_autocmd = vim.api.nvim_create_autocmd('BufDelete', {
+  s.unload_autocmd = vim.api.nvim_create_autocmd('BufUnload', {
     buffer = bufnr,
     once = true,
     callback = function()
diff --git a/lua/preview/init.lua b/lua/preview/init.lua
index 5383623..489679f 100644
--- a/lua/preview/init.lua
+++ b/lua/preview/init.lua
@@ -139,49 +139,27 @@ function M.resolve_provider(bufnr)
   return ft
 end
 
-local ft_ext = {
-  markdown = 'md',
-  typst = 'typ',
-  tex = 'tex',
-  asciidoc = 'adoc',
-  plantuml = 'puml',
-  mermaid = 'mmd',
-  quarto = 'qmd',
-}
-
 ---@param bufnr? integer
 ---@return preview.Context
 function M.build_context(bufnr)
   bufnr = bufnr or vim.api.nvim_get_current_buf()
   local file = vim.api.nvim_buf_get_name(bufnr)
-  local ft = vim.bo[bufnr].filetype
-  local root
-
-  if file ~= '' and vim.uv.fs_stat(file) then
-    root = vim.fs.root(bufnr, { '.git' }) or vim.fn.fnamemodify(file, ':h')
-  else
-    local basename
-    if file ~= '' then
-      basename = string.format('%d-%s', bufnr, vim.fn.fnamemodify(file, ':t'))
-    else
-      local ext = ft_ext[ft] or ft
-      basename = string.format('preview-%d.%s', bufnr, ext)
-    end
-    file = '/tmp/' .. basename
-    root = '/tmp'
-  end
-
+  local root = vim.fs.root(bufnr, { '.git' }) or vim.fn.fnamemodify(file, ':h')
   return {
     bufnr = bufnr,
     file = file,
     root = root,
-    ft = ft,
+    ft = vim.bo[bufnr].filetype,
   }
 end
 
 ---@param bufnr? integer
 function M.compile(bufnr)
   bufnr = bufnr or vim.api.nvim_get_current_buf()
+  if vim.api.nvim_buf_get_name(bufnr) == '' then
+    vim.notify('[preview.nvim]: buffer has no file name', vim.log.levels.WARN)
+    return
+  end
   local name = M.resolve_provider(bufnr)
   if not name then
     vim.notify('[preview.nvim]: no provider configured for this filetype', vim.log.levels.WARN)
@@ -201,6 +179,10 @@ end
 ---@param bufnr? integer
 function M.clean(bufnr)
   bufnr = bufnr or vim.api.nvim_get_current_buf()
+  if vim.api.nvim_buf_get_name(bufnr) == '' then
+    vim.notify('[preview.nvim]: buffer has no file name', vim.log.levels.WARN)
+    return
+  end
   local name = M.resolve_provider(bufnr)
   if not name then
     vim.notify('[preview.nvim]: no provider configured for this filetype', vim.log.levels.WARN)
@@ -214,6 +196,10 @@ end
 ---@param bufnr? integer
 function M.toggle(bufnr)
   bufnr = bufnr or vim.api.nvim_get_current_buf()
+  if vim.api.nvim_buf_get_name(bufnr) == '' then
+    vim.notify('[preview.nvim]: buffer has no file name', vim.log.levels.WARN)
+    return
+  end
   local name = M.resolve_provider(bufnr)
   if not name then
     vim.notify('[preview.nvim]: no provider configured for this filetype', vim.log.levels.WARN)
@@ -226,6 +212,10 @@ end
 ---@param bufnr? integer
 function M.open(bufnr)
   bufnr = bufnr or vim.api.nvim_get_current_buf()
+  if vim.api.nvim_buf_get_name(bufnr) == '' then
+    vim.notify('[preview.nvim]: buffer has no file name', vim.log.levels.WARN)
+    return
+  end
   local name = M.resolve_provider(bufnr)
   local open_config = name and config.providers[name] and config.providers[name].open
   if not compiler.open(bufnr, open_config) then
diff --git a/spec/init_spec.lua b/spec/init_spec.lua
index 55c2391..f68438c 100644
--- a/spec/init_spec.lua
+++ b/spec/init_spec.lua
@@ -126,43 +126,43 @@ describe('preview', function()
       return msg
     end
 
-    it('compile falls through to provider check on unnamed buffer', function()
-      local bufnr = helpers.create_buffer({}, 'lua')
+    it('compile warns on unnamed buffer', function()
+      local bufnr = helpers.create_buffer({}, 'typst')
       local msg = capture_notify(function()
         preview.compile(bufnr)
       end)
       assert.is_not_nil(msg)
-      assert.is_truthy(msg:find('no provider configured'))
+      assert.is_truthy(msg:find('no file name'))
       helpers.delete_buffer(bufnr)
     end)
 
-    it('toggle falls through to provider check on unnamed buffer', function()
-      local bufnr = helpers.create_buffer({}, 'lua')
+    it('toggle warns on unnamed buffer', function()
+      local bufnr = helpers.create_buffer({}, 'typst')
       local msg = capture_notify(function()
         preview.toggle(bufnr)
       end)
       assert.is_not_nil(msg)
-      assert.is_truthy(msg:find('no provider configured'))
+      assert.is_truthy(msg:find('no file name'))
       helpers.delete_buffer(bufnr)
     end)
 
-    it('clean falls through to provider check on unnamed buffer', function()
-      local bufnr = helpers.create_buffer({}, 'lua')
+    it('clean warns on unnamed buffer', function()
+      local bufnr = helpers.create_buffer({}, 'typst')
       local msg = capture_notify(function()
         preview.clean(bufnr)
       end)
       assert.is_not_nil(msg)
-      assert.is_truthy(msg:find('no provider configured'))
+      assert.is_truthy(msg:find('no file name'))
       helpers.delete_buffer(bufnr)
     end)
 
-    it('open warns no output on unnamed buffer', function()
-      local bufnr = helpers.create_buffer({}, 'lua')
+    it('open warns on unnamed buffer', function()
+      local bufnr = helpers.create_buffer({}, 'typst')
       local msg = capture_notify(function()
         preview.open(bufnr)
       end)
       assert.is_not_nil(msg)
-      assert.is_truthy(msg:find('no output file'))
+      assert.is_truthy(msg:find('no file name'))
       helpers.delete_buffer(bufnr)
     end)
   end)