diff --git a/index.html b/index.html
index 14a374f..f633ea8 100644
--- a/index.html
+++ b/index.html
@@ -200,16 +200,10 @@
       }
 
       .allow_file_access {
-        height: 100%;
-        padding: 10px;
         display: flex;
         flex-direction: column;
-        justify-content: center;
-        align-items: center;
-        text-align: center;
       }
       .allow_file_access .subtitle {
-        padding: 10px;
         font-size: 0.8em;
       }
 
diff --git a/src/cmd.js b/src/cmd.js
index bafde88..57d4284 100644
--- a/src/cmd.js
+++ b/src/cmd.js
@@ -808,7 +808,7 @@ const clear_io_trace = state => {
   return run_code({...state, io_trace: null})
 }
 
-const do_load_dir = (state, dir) => {
+const load_files = (state, dir) => {
   const collect_files = dir => dir.kind == 'file' 
     ? [dir]
     : dir.children.map(collect_files).flat()
@@ -820,7 +820,7 @@ const do_load_dir = (state, dir) => {
   return {
     ...state,
     project_dir: dir,
-    files: {...files, ...state.files},
+    files: {...files, '': state.files['']},
   }
 }
 
@@ -842,24 +842,29 @@ const apply_entrypoint_settings = (state, entrypoint_settings) => {
   }
 }
 
-const load_dir = (state, dir, entrypoint_settings) => {
+const load_dir = (state, dir, has_file_system_access, entrypoint_settings) => {
   // Clear parse cache and rerun code
-  const with_dir = do_load_dir(state, dir)
+  const with_dir = load_files(state, dir)
   return run_code({
     ...(
       entrypoint_settings == null
         ? with_dir
         : apply_entrypoint_settings(with_dir, entrypoint_settings)
     ),
+
+    has_file_system_access,
+
     // remove cache. We have to clear cache because imports of modules that are
     // not available because project_dir is not available have errors and the
     // errors are cached
     parse_result: null,
+
+    external_imports_cache: null,
   })
 }
 
 const create_file = (state, dir, current_module) => {
-  return {...load_dir(state, dir), current_module}
+  return {...load_dir(state, dir, true), current_module}
 }
 
 const open_run_window = (state, globals) => {
@@ -877,7 +882,7 @@ const open_run_window = (state, globals) => {
 const get_initial_state = (state, entrypoint_settings) => {
   const with_files = state.project_dir == null
     ? state
-    : do_load_dir(state, state.project_dir)
+    : load_files(state, state.project_dir)
 
   const with_settings = apply_entrypoint_settings(with_files, entrypoint_settings)
 
diff --git a/src/editor/domutils.js b/src/editor/domutils.js
index 7e53282..9558319 100644
--- a/src/editor/domutils.js
+++ b/src/editor/domutils.js
@@ -21,7 +21,7 @@ export function el(tag, className, ...children){
     const append = child => {
       if(typeof(child) == 'undefined') {
         throw new Error('illegal state')
-      } else if(child !== null) {
+      } else if(child !== null && child !== false) {
         result.appendChild(
           typeof(child) == 'string'
             ? document.createTextNode(child)
diff --git a/src/editor/files.js b/src/editor/files.js
index 6931224..3fe0c79 100644
--- a/src/editor/files.js
+++ b/src/editor/files.js
@@ -1,7 +1,13 @@
 import {el} from './domutils.js'
 import {map_find} from '../utils.js'
-import {load_dir, create_file} from '../filesystem.js'
-import {exec, get_state, open_directory, reload_run_window} from '../index.js'
+import {open_dir, create_file} from '../filesystem.js'
+import {
+  exec, 
+  get_state, 
+  open_directory, 
+  reload_run_window,
+  close_directory,
+} from '../index.js'
 
 const is_html = path => path.endsWith('.htm') || path.endsWith('.html')
 const is_js = path => path == '' || path.endsWith('.js') || path.endsWith('.mjs')
@@ -25,27 +31,56 @@ export class Files {
     reload_run_window(get_state())
   }
 
-  render(state) {
-    if(state.project_dir == null) {
-      this.el.innerHTML = ''
-      this.el.appendChild(
-        el('div', 'allow_file_access',
-          el('a', {
-              href: 'javascript:void(0)',
-              click: open_directory,
-          },
-            `Allow access to local project folder`,
-          ),
-          el('div', 'subtitle', `Your files will never leave your device`)
-        )
-      )
-    } else {
-      this.render_files(state)
-    }
-  }
 
-  render_files(state) {
-    const children = [
+  render(state) {
+    const file_actions = state.has_file_system_access
+      ? el('div', 'file_actions',
+          el('a', {
+            'class': 'file_action',
+            href: 'javascript: void(0)', 
+            click: this.create_file.bind(this, false),
+          }, 
+            'New file'
+          ),
+
+          el('a', {
+            'class': 'file_action',
+            href: 'javascript: void(0)',
+            click: this.create_file.bind(this, true),
+          }, 
+            'New dir'
+          ),
+
+          el('a', {
+            'class': 'file_action',
+            href: 'javascript: void(0)',
+            click: close_directory,
+          }, 
+            'Revoke access'
+          ),
+
+          el('a', {
+            href: 'https://github.com/leporello-js/leporello-js#selecting-entrypoint-module',
+            target: '__blank',
+            "class": 'select_entrypoint_title',
+            title: 'Select entrypoint',
+          }, 
+            'Entry point'
+          ),
+      )
+      : el('div', 'file_actions',
+          el('div', 'file_action allow_file_access',
+            el('a', {
+              href: 'javascript: void(0)',
+              click: open_directory,
+            }, 'Allow access to local project folder'),
+            el('span', 'subtitle', `Your files will never leave your device`)
+          ),
+        )
+
+
+
+    const file_elements = [
       this.render_file({name: '*scratch*', path: ''}, state),
       this.render_file(state.project_dir, state),
     ]
@@ -54,41 +89,19 @@ export class Files {
 
     if(files == null) {
       this.el.innerHTML = ''
+      this.el.appendChild(file_actions)
       this.el.appendChild(
-        el('div', 'file_actions',
-          el('a', {
-            'class': 'file_action',
-            href: 'javascript: void(0)', 
-            click: this.create_file.bind(this, false),
-          }, 
-            'Create file'
-          ),
-          el('a', {
-            'class': 'file_action',
-            href: 'javascript: void(0)',
-            click: this.create_file.bind(this, true),
-          }, 'Create dir'),
-          el('a', {
-            href: 'https://github.com/leporello-js/leporello-js#selecting-entrypoint-module',
-            target: '__blank',
-            "class": 'select_entrypoint_title',
-            title: 'Select entrypoint',
-          }, 'Entry point'),
-        )
-      )
-      this.el.appendChild(
-        el('div', 'files',
-          children
-        )
+        el('div', 'files', file_elements)
       )
     } else {
       // Replace to preserve scroll position
-      files.replaceChildren(...children)
+      this.el.replaceChild(file_actions, this.el.children[0])
+      files.replaceChildren(...file_elements)
     }
   }
 
   render_select_entrypoint(file, state) {
-    if(file.kind == 'directory') {
+    if(!state.has_file_system_access || file.kind == 'directory') {
       return null
     } else if(is_js(file.path)) {
       return el('span', 'select_entrypoint',
@@ -189,9 +202,9 @@ export class Files {
     await create_file(path, is_dir)
 
     // Reload all files for simplicity
-    load_dir(false).then(dir => {
+    open_dir(false).then(dir => {
       if(is_dir) {
-        exec('load_dir', dir)
+        exec('load_dir', dir, true)
       } else {
         exec('create_file', dir, path)
       }
@@ -205,8 +218,15 @@ export class Files {
     this.active_el = e.currentTarget.parentElement
     e.currentTarget.classList.add('active')
     this.active_file = file
+
     if(file.kind != 'directory') {
-      exec('change_current_module', file.path)
+      if(get_state().has_file_system_access) {
+        exec('change_current_module', file.path)
+      } else {
+        // in examples mode, on click file we also change entrypoint for
+        // simplicity
+        exec('change_entrypoint', file.path)
+      }
     }
   }
 }
diff --git a/src/effects.js b/src/effects.js
index 629ce6f..531d9d5 100644
--- a/src/effects.js
+++ b/src/effects.js
@@ -1,4 +1,5 @@
 import {write_file} from './filesystem.js'
+import {write_example} from './examples.js'
 import {color_file} from './color.js'
 import {
   root_calltree_node, 
@@ -293,6 +294,12 @@ export const EFFECTS = {
     localStorage[key] = value
   },
 
-  write: (state, [name, contents], ui) => write_file(name, contents),
+  write: (state, [name, contents], ui) => {
+    if(state.has_file_system_access) {
+      write_file(name, contents)
+    } else {
+      write_example(name, contents)
+    }
+  }
 }
 
diff --git a/src/examples.js b/src/examples.js
new file mode 100644
index 0000000..c2b2a0c
--- /dev/null
+++ b/src/examples.js
@@ -0,0 +1,57 @@
+export const write_example = (name, contents) => {
+  localStorage['examples_' + name] = contents
+}
+
+const read_example = name => {
+  return localStorage['examples_' + name]
+}
+
+const list = [
+  'github_api/index.js',
+  'ethers/block_by_timestamp.js',
+  'ethers/index.js',
+  // TODO for html5 example, open run window or hint that it should be opened
+]
+.map(l => l.split('/'))
+
+
+const get_children = path => {
+  const children = list.filter(l => path.every((elem, i) => elem == l[i] ))
+  const files = children.filter(c => c.length == path.length + 1)
+  const dirs = [...new Set(children
+    .filter(c => c.length != path.length + 1)
+    .map(c => c[path.length])
+  )]
+  return Promise.all(files.map(async f => {
+      const name = f[path.length]
+      const filepath = f.slice(0, path.length + 1).join('/')
+      return {
+        name,
+        path: filepath,
+        kind: 'file',
+        contents: 
+          read_example(filepath) ??
+          await fetch(globalThis.location.origin + '/docs/examples/'+ filepath)
+            .then(r => r.text()),
+      }
+    })
+    .concat(dirs.map(async d => {
+      const p = [...path, d] 
+      return {
+        name: d,
+        path: p.join('/'),
+        kind: 'directory',
+        children: await get_children(p),
+      }
+    })))
+}
+
+export const examples_promise = get_children([]).then(children => {
+  return {
+    kind: 'directory',
+    name: 'examples',
+    path: null,
+    children,
+  }
+})
+
diff --git a/src/filesystem.js b/src/filesystem.js
index a7bc2b0..b865620 100644
--- a/src/filesystem.js
+++ b/src/filesystem.js
@@ -15,11 +15,10 @@ const send_message = (message) => {
   });
 }
 
-globalThis.clear_directory_handle = () => {
+export const close_dir = () => {
   send_message({type: 'SET_DIR_HANDLE', data: null})
   clearInterval(keepalive_interval_id)
   keepalive_interval_id = null
-  window.location.reload()
 }
 
 let dir_handle
@@ -120,7 +119,7 @@ const read_file = async handle => {
   return await file_data.text()
 }
 
-const do_load_dir = async (handle, path) => {
+const do_open_dir = async (handle, path) => {
   if(handle.kind == 'directory') {
     const children = []
     for await (let [name, h] of handle) {
@@ -134,7 +133,7 @@ const do_load_dir = async (handle, path) => {
       kind: 'directory',
       children: (await Promise.all(
           children.map(c => 
-            do_load_dir(c, path == null ? c.name : path + '/' + c.name)
+            do_open_dir(c, path == null ? c.name : path + '/' + c.name)
           )
         )).sort((a, b) => a.name.localeCompare(b.name))
     }
@@ -159,7 +158,7 @@ export const create_file = (path, is_dir) => {
   )
 }
 
-export const load_dir = async (should_request_access) => {
+export const open_dir = async (should_request_access) => {
   let handle
   if(should_request_access) {
     handle = await request_directory_handle()
@@ -171,5 +170,5 @@ export const load_dir = async (should_request_access) => {
   } else {
     keep_service_worker_alive()
   }
-  return do_load_dir(handle, null)
+  return do_open_dir(handle, null)
 }
diff --git a/src/index.js b/src/index.js
index d48c475..89f3b7c 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,12 +1,22 @@
 import {UI} from './editor/ui.js'
 import {EFFECTS, render_initial_state, apply_side_effects} from './effects.js'
-import {load_dir, init_window_service_worker} from './filesystem.js'
+import {
+  open_dir, 
+  close_dir, 
+  init_window_service_worker
+} from './filesystem.js'
+import {examples_promise} from './examples.js'
 
-const EXAMPLE = `const fib = n =>
-  n == 0 || n == 1
-    ? n
-    : fib(n - 1) + fib(n - 2)
-fib(6)`
+const EXAMPLE = `function fib(n) {
+  if(n == 0 || n == 1) {
+    return n
+  } else {
+    return fib(n - 1) + fib(n - 2)
+  }
+}
+
+fib(6)
+`
 
 
 const set_error_handler = (w, with_unhandled_rejection = true) => {
@@ -131,38 +141,56 @@ export const reload_run_window = state => {
   globalThis.run_window.location = get_html_url(state)
 }
 
+
 const read_modules = async () => {
   const default_module = {'': localStorage.code || EXAMPLE}
-  const project_dir = await load_dir(false)
+  const project_dir = await open_dir(false)
   if(project_dir == null) {
-    // Single anonymous module
     return {
+      project_dir: await examples_promise,
       files: default_module,
+      has_file_system_access: false,
     }
   } else {
     return {
       project_dir,
       files: default_module,
+      has_file_system_access: true,
     }
   }
 }
 
-const get_entrypoint_settings = () => ({
-  current_module: localStorage.current_module ?? '',
-  entrypoint: localStorage.entrypoint ?? '',
-  html_file: localStorage.html_file ?? '',
-})
+const get_entrypoint_settings = () => {
+
+  const params = new URLSearchParams(window.location.search)
+
+  const entrypoint = null 
+    ?? params.get('entrypoint')
+    ?? localStorage.entrypoint
+    ?? ''
+
+  return {
+    current_module: params.get('entrypoint') ?? localStorage.current_module ?? '',
+    entrypoint,
+    html_file: localStorage.html_file ?? '',
+  }
+}
 
 
 export const open_directory = () => {
   if(globalThis.showDirectoryPicker == null) {
     throw new Error('Your browser is not supporting File System Access API')
   }
-  load_dir(true).then(dir => {
-    exec('load_dir', dir, get_entrypoint_settings())
+  open_dir(true).then(dir => {
+    exec('load_dir', dir, true, get_entrypoint_settings())
   })
 }
 
+export const close_directory = async () => {
+  close_dir()
+  exec('load_dir', await examples_promise, false, get_entrypoint_settings())
+}
+
 
 let COMMANDS
 let ui