diff --git a/src/App.tsx b/src/App.tsx
index 81e011f432..332aa14ba6 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -1,26 +1,305 @@
-/* eslint-disable max-len */
-/* eslint-disable jsx-a11y/control-has-associated-label */
-import React from 'react';
+import React, { useEffect, useMemo, useRef, useState } from 'react';
+import { ErrorNotification } from './components/ErrorNotification';
+import { Footer } from './components/Footer';
+import { Header } from './components/Header';
+import { TodoList } from './components/TodoList';
 import { UserWarning } from './UserWarning';
+import {
+  USER_ID,
+  createTodo,
+  deleteTodo,
+  getTodos,
+  updateTodo,
+} from './api/todos';
+import { Filter } from './types/Filter';
+import { TempTodo } from './types/TempTodo';
+import { Todo } from './types/Todo';
 
-const USER_ID = 0;
+const TEMP_TODO_ID = 0;
+
+const getFilterFromHash = (): Filter => {
+  switch (window.location.hash) {
+    case '#/active':
+      return 'active';
+
+    case '#/completed':
+      return 'completed';
+
+    default:
+      return 'all';
+  }
+};
 
 export const App: React.FC = () => {
+  const [todos, setTodos] = useState<Todo[]>([]);
+  const [filter, setFilter] = useState<Filter>(getFilterFromHash);
+  const [newTodoTitle, setNewTodoTitle] = useState('');
+  const [tempTodo, setTempTodo] = useState<TempTodo | null>(null);
+  const [loadingTodoIds, setLoadingTodoIds] = useState<number[]>([]);
+  const [errorMessage, setErrorMessage] = useState('');
+  const [editingTodoId, setEditingTodoId] = useState<number | null>(null);
+  const [editingTitle, setEditingTitle] = useState('');
+
+  const newTodoField = useRef<HTMLInputElement>(null);
+  const errorTimerId = useRef<number | null>(null);
+  const editingCanceled = useRef(false);
+
+  const hideError = React.useCallback(() => {
+    setErrorMessage('');
+
+    if (errorTimerId.current) {
+      window.clearTimeout(errorTimerId.current);
+      errorTimerId.current = null;
+    }
+  }, []);
+
+  const showError = React.useCallback(
+    (message: string) => {
+      hideError();
+      setErrorMessage(message);
+
+      errorTimerId.current = window.setTimeout(() => {
+        setErrorMessage('');
+        errorTimerId.current = null;
+      }, 3000);
+    },
+    [hideError],
+  );
+
+  const markTodoAsLoading = (todoId: number) => {
+    setLoadingTodoIds(currentIds => [...currentIds, todoId]);
+  };
+
+  const unmarkTodoAsLoading = (todoId: number) => {
+    setLoadingTodoIds(currentIds => currentIds.filter(id => id !== todoId));
+  };
+
+  useEffect(() => {
+    const handleHashChange = () => setFilter(getFilterFromHash());
+
+    window.addEventListener('hashchange', handleHashChange);
+
+    return () => {
+      window.removeEventListener('hashchange', handleHashChange);
+    };
+  }, []);
+
+  useEffect(() => {
+    hideError();
+
+    getTodos()
+      .then(setTodos)
+      .catch(() => showError('Unable to load todos'));
+
+    return () => {
+      if (errorTimerId.current) {
+        window.clearTimeout(errorTimerId.current);
+      }
+    };
+  }, [hideError, showError]);
+
+  useEffect(() => {
+    newTodoField.current?.focus();
+  }, [todos.length, tempTodo, errorMessage]);
+
+  const visibleTodos = useMemo(() => {
+    return todos.filter(todo => {
+      switch (filter) {
+        case 'active':
+          return !todo.completed;
+
+        case 'completed':
+          return todo.completed;
+
+        default:
+          return true;
+      }
+    });
+  }, [todos, filter]);
+
+  const activeTodosCount = todos.filter(todo => !todo.completed).length;
+  const completedTodosCount = todos.length - activeTodosCount;
+  const allTodosCompleted = todos.length > 0 && activeTodosCount === 0;
+  const isAdding = Boolean(tempTodo);
+
+  const handleAddTodo = (event: React.FormEvent) => {
+    event.preventDefault();
+
+    const trimmedTitle = newTodoTitle.trim();
+
+    if (!trimmedTitle) {
+      showError('Title should not be empty');
+
+      return;
+    }
+
+    hideError();
+    setTempTodo({
+      id: TEMP_TODO_ID,
+      userId: USER_ID,
+      title: trimmedTitle,
+      completed: false,
+    });
+
+    createTodo(trimmedTitle)
+      .then(todo => {
+        setTodos(currentTodos => [...currentTodos, todo]);
+        setNewTodoTitle('');
+      })
+      .catch(() => showError('Unable to add a todo'))
+      .finally(() => setTempTodo(null));
+  };
+
+  const handleDeleteTodo = (todoId: number) => {
+    hideError();
+    markTodoAsLoading(todoId);
+
+    return deleteTodo(todoId)
+      .then(() => {
+        setTodos(currentTodos =>
+          currentTodos.filter(todo => todo.id !== todoId),
+        );
+      })
+      .catch(error => {
+        showError('Unable to delete a todo');
+        throw error;
+      })
+      .finally(() => unmarkTodoAsLoading(todoId));
+  };
+
+  const handleUpdateTodo = (todoId: number, data: Partial<Todo>) => {
+    hideError();
+    markTodoAsLoading(todoId);
+
+    return updateTodo(todoId, data)
+      .then(updatedTodo => {
+        setTodos(currentTodos =>
+          currentTodos.map(todo => (todo.id === todoId ? updatedTodo : todo)),
+        );
+      })
+      .catch(error => {
+        showError('Unable to update a todo');
+        throw error;
+      })
+      .finally(() => unmarkTodoAsLoading(todoId));
+  };
+
+  const handleToggleTodo = (todo: Todo) => {
+    handleUpdateTodo(todo.id, { completed: !todo.completed }).catch(() => {});
+  };
+
+  const handleToggleAll = () => {
+    const newCompletedStatus = !allTodosCompleted;
+
+    todos
+      .filter(todo => todo.completed !== newCompletedStatus)
+      .forEach(todo => {
+        handleUpdateTodo(todo.id, { completed: newCompletedStatus }).catch(
+          () => {},
+        );
+      });
+  };
+
+  const startEditing = (todo: Todo | TempTodo) => {
+    if (todo.id === TEMP_TODO_ID) {
+      return;
+    }
+
+    editingCanceled.current = false;
+    setEditingTodoId(todo.id);
+    setEditingTitle(todo.title);
+  };
+
+  const cancelEditing = () => {
+    editingCanceled.current = true;
+    setEditingTodoId(null);
+    setEditingTitle('');
+  };
+
+  const submitTodoTitle = (todo: Todo) => {
+    if (editingCanceled.current) {
+      editingCanceled.current = false;
+
+      return;
+    }
+
+    const trimmedTitle = editingTitle.trim();
+
+    if (trimmedTitle === todo.title) {
+      cancelEditing();
+
+      return;
+    }
+
+    if (!trimmedTitle) {
+      handleDeleteTodo(todo.id)
+        .then(cancelEditing)
+        .catch(() => {});
+
+      return;
+    }
+
+    handleUpdateTodo(todo.id, { title: trimmedTitle })
+      .then(cancelEditing)
+      .catch(() => {});
+  };
+
+  const handleClearCompleted = () => {
+    todos
+      .filter(todo => todo.completed)
+      .forEach(todo => {
+        handleDeleteTodo(todo.id).catch(() => {});
+      });
+  };
+
   if (!USER_ID) {
     return <UserWarning />;
   }
 
   return (
-    <section className="section container">
-      <p className="title is-4">
-        Copy all you need from the prev task:
-        <br />
-        <a href="https://github.com/mate-academy/react_todo-app-add-and-delete#react-todo-app-add-and-delete">
-          React Todo App - Add and Delete
-        </a>
-      </p>
-
-      <p className="subtitle">Styles are already copied</p>
-    </section>
+    <div className="todoapp">
+      <h1 className="todoapp__title">todos</h1>
+
+      <div className="todoapp__content">
+        <Header
+          todosCount={todos.length}
+          allTodosCompleted={allTodosCompleted}
+          newTodoTitle={newTodoTitle}
+          isAdding={isAdding}
+          newTodoField={newTodoField}
+          onAddTodo={handleAddTodo}
+          onNewTodoTitleChange={setNewTodoTitle}
+          onToggleAll={handleToggleAll}
+        />
+
+        {(todos.length > 0 || tempTodo) && (
+          <TodoList
+            todos={visibleTodos}
+            tempTodo={tempTodo}
+            tempTodoId={TEMP_TODO_ID}
+            loadingTodoIds={loadingTodoIds}
+            editingTodoId={editingTodoId}
+            editingTitle={editingTitle}
+            onToggleTodo={handleToggleTodo}
+            onDeleteTodo={todoId => handleDeleteTodo(todoId).catch(() => {})}
+            onStartEditing={startEditing}
+            onEditingTitleChange={setEditingTitle}
+            onCancelEditing={cancelEditing}
+            onSubmitTodoTitle={submitTodoTitle}
+          />
+        )}
+
+        {todos.length > 0 && (
+          <Footer
+            activeTodosCount={activeTodosCount}
+            completedTodosCount={completedTodosCount}
+            filter={filter}
+            onClearCompleted={handleClearCompleted}
+          />
+        )}
+      </div>
+
+      <ErrorNotification errorMessage={errorMessage} onHideError={hideError} />
+    </div>
   );
 };
diff --git a/src/api/todos.ts b/src/api/todos.ts
new file mode 100644
index 0000000000..cffb2c5a21
--- /dev/null
+++ b/src/api/todos.ts
@@ -0,0 +1,24 @@
+import { Todo } from '../types/Todo';
+import { client } from '../utils/fetchClient';
+
+export const USER_ID = 4351;
+
+export const getTodos = () => {
+  return client.get<Todo[]>(`/todos?userId=${USER_ID}`);
+};
+
+export const createTodo = (title: string) => {
+  return client.post<Todo>('/todos', {
+    userId: USER_ID,
+    title,
+    completed: false,
+  });
+};
+
+export const deleteTodo = (todoId: number) => {
+  return client.delete(`/todos/${todoId}`);
+};
+
+export const updateTodo = (todoId: number, data: Partial<Todo>) => {
+  return client.patch<Todo>(`/todos/${todoId}`, data);
+};
diff --git a/src/components/ErrorNotification.tsx b/src/components/ErrorNotification.tsx
new file mode 100644
index 0000000000..31bff110c0
--- /dev/null
+++ b/src/components/ErrorNotification.tsx
@@ -0,0 +1,27 @@
+/* eslint-disable jsx-a11y/control-has-associated-label */
+import React from 'react';
+
+type Props = {
+  errorMessage: string;
+  onHideError: () => void;
+};
+
+export const ErrorNotification: React.FC<Props> = ({
+  errorMessage,
+  onHideError,
+}) => (
+  <div
+    data-cy="ErrorNotification"
+    className={`notification is-danger is-light has-text-weight-normal ${
+      errorMessage ? '' : 'hidden'
+    }`}
+  >
+    <button
+      data-cy="HideErrorButton"
+      type="button"
+      className="delete"
+      onClick={onHideError}
+    />
+    {errorMessage}
+  </div>
+);
diff --git a/src/components/Footer.tsx b/src/components/Footer.tsx
new file mode 100644
index 0000000000..27d9ea4369
--- /dev/null
+++ b/src/components/Footer.tsx
@@ -0,0 +1,58 @@
+import React from 'react';
+import { Filter } from '../types/Filter';
+
+type Props = {
+  activeTodosCount: number;
+  completedTodosCount: number;
+  filter: Filter;
+  onClearCompleted: () => void;
+};
+
+export const Footer: React.FC<Props> = ({
+  activeTodosCount,
+  completedTodosCount,
+  filter,
+  onClearCompleted,
+}) => (
+  <footer className="todoapp__footer" data-cy="Footer">
+    <span className="todo-count" data-cy="TodosCounter">
+      {`${activeTodosCount} ${activeTodosCount === 1 ? 'item' : 'items'} left`}
+    </span>
+
+    <nav className="filter" data-cy="Filter">
+      <a
+        href="#/"
+        className={`filter__link ${filter === 'all' ? 'selected' : ''}`}
+        data-cy="FilterLinkAll"
+      >
+        All
+      </a>
+
+      <a
+        href="#/active"
+        className={`filter__link ${filter === 'active' ? 'selected' : ''}`}
+        data-cy="FilterLinkActive"
+      >
+        Active
+      </a>
+
+      <a
+        href="#/completed"
+        className={`filter__link ${filter === 'completed' ? 'selected' : ''}`}
+        data-cy="FilterLinkCompleted"
+      >
+        Completed
+      </a>
+    </nav>
+
+    <button
+      type="button"
+      className="todoapp__clear-completed"
+      data-cy="ClearCompletedButton"
+      disabled={completedTodosCount === 0}
+      onClick={onClearCompleted}
+    >
+      Clear completed
+    </button>
+  </footer>
+);
diff --git a/src/components/Header.tsx b/src/components/Header.tsx
new file mode 100644
index 0000000000..83e7535593
--- /dev/null
+++ b/src/components/Header.tsx
@@ -0,0 +1,48 @@
+/* eslint-disable jsx-a11y/control-has-associated-label */
+import React from 'react';
+
+type Props = {
+  todosCount: number;
+  allTodosCompleted: boolean;
+  newTodoTitle: string;
+  isAdding: boolean;
+  newTodoField: React.RefObject<HTMLInputElement>;
+  onAddTodo: (event: React.FormEvent) => void;
+  onNewTodoTitleChange: (title: string) => void;
+  onToggleAll: () => void;
+};
+
+export const Header: React.FC<Props> = ({
+  todosCount,
+  allTodosCompleted,
+  newTodoTitle,
+  isAdding,
+  newTodoField,
+  onAddTodo,
+  onNewTodoTitleChange,
+  onToggleAll,
+}) => (
+  <header className="todoapp__header">
+    {todosCount > 0 && (
+      <button
+        type="button"
+        className={`todoapp__toggle-all ${allTodosCompleted ? 'active' : ''}`}
+        data-cy="ToggleAllButton"
+        onClick={onToggleAll}
+      />
+    )}
+
+    <form onSubmit={onAddTodo}>
+      <input
+        ref={newTodoField}
+        data-cy="NewTodoField"
+        type="text"
+        className="todoapp__new-todo"
+        placeholder="What needs to be done?"
+        value={newTodoTitle}
+        disabled={isAdding}
+        onChange={event => onNewTodoTitleChange(event.target.value)}
+      />
+    </form>
+  </header>
+);
diff --git a/src/components/TodoItem.tsx b/src/components/TodoItem.tsx
new file mode 100644
index 0000000000..0da5374dcc
--- /dev/null
+++ b/src/components/TodoItem.tsx
@@ -0,0 +1,101 @@
+/* eslint-disable jsx-a11y/label-has-associated-control */
+/* eslint-disable jsx-a11y/control-has-associated-label */
+import React from 'react';
+import { Todo } from '../types/Todo';
+import { TempTodo } from '../types/TempTodo';
+
+type Props = {
+  todo: Todo | TempTodo;
+  isTemp: boolean;
+  isLoading: boolean;
+  isEditing: boolean;
+  editingTitle: string;
+  onToggle: (todo: Todo) => void;
+  onDelete: (todoId: number) => void;
+  onStartEditing: (todo: Todo | TempTodo) => void;
+  onEditingTitleChange: (title: string) => void;
+  onCancelEditing: () => void;
+  onSubmitTitle: (todo: Todo) => void;
+};
+
+export const TodoItem: React.FC<Props> = ({
+  todo,
+  isTemp,
+  isLoading,
+  isEditing,
+  editingTitle,
+  onToggle,
+  onDelete,
+  onStartEditing,
+  onEditingTitleChange,
+  onCancelEditing,
+  onSubmitTitle,
+}) => (
+  <div
+    data-cy="Todo"
+    className={`todo ${todo.completed ? 'completed' : ''}`}
+  >
+    <label className="todo__status-label">
+      <input
+        data-cy="TodoStatus"
+        type="checkbox"
+        className="todo__status"
+        checked={todo.completed}
+        disabled={isLoading || isTemp}
+        onChange={() => !isTemp && onToggle(todo as Todo)}
+      />
+    </label>
+
+    {isEditing && !isTemp ? (
+      <form
+        onSubmit={event => {
+          event.preventDefault();
+          onSubmitTitle(todo as Todo);
+        }}
+      >
+        <input
+          data-cy="TodoTitleField"
+          type="text"
+          className="todo__title-field"
+          value={editingTitle}
+          autoFocus
+          onChange={event => onEditingTitleChange(event.target.value)}
+          onBlur={() => onSubmitTitle(todo as Todo)}
+          onKeyUp={event => {
+            if (event.key === 'Escape') {
+              onCancelEditing();
+            }
+          }}
+        />
+      </form>
+    ) : (
+      <>
+        <span
+          data-cy="TodoTitle"
+          className="todo__title"
+          onDoubleClick={() => onStartEditing(todo)}
+        >
+          {todo.title}
+        </span>
+
+        <button
+          type="button"
+          className="todo__remove"
+          data-cy="TodoDelete"
+          disabled={isLoading || isTemp}
+          onClick={() => !isTemp && onDelete(todo.id)}
+        >
+          ×
+        </button>
+      </>
+    )}
+
+    <div
+      data-cy="TodoLoader"
+      className={`modal overlay ${isLoading ? 'is-active' : ''}`}
+    >
+      <div className="modal-background has-background-white-ter" />
+      <div className="loader" />
+    </div>
+  </div>
+);
diff --git a/src/components/TodoList.tsx b/src/components/TodoList.tsx
new file mode 100644
index 0000000000..3b8c55b53c
--- /dev/null
+++ b/src/components/TodoList.tsx
@@ -0,0 +1,62 @@
+import React from 'react';
+import { Todo } from '../types/Todo';
+import { TempTodo } from '../types/TempTodo';
+import { TodoItem } from './TodoItem';
+
+type Props = {
+  todos: Todo[];
+  tempTodo: TempTodo | null;
+  tempTodoId: number;
+  loadingTodoIds: number[];
+  editingTodoId: number | null;
+  editingTitle: string;
+  onToggleTodo: (todo: Todo) => void;
+  onDeleteTodo: (todoId: number) => void;
+  onStartEditing: (todo: Todo | TempTodo) => void;
+  onEditingTitleChange: (title: string) => void;
+  onCancelEditing: () => void;
+  onSubmitTodoTitle: (todo: Todo) => void;
+};
+
+export const TodoList: React.FC<Props> = ({
+  todos,
+  tempTodo,
+  tempTodoId,
+  loadingTodoIds,
+  editingTodoId,
+  editingTitle,
+  onToggleTodo,
+  onDeleteTodo,
+  onStartEditing,
+  onEditingTitleChange,
+  onCancelEditing,
+  onSubmitTodoTitle,
+}) => {
+  const todosToRender = tempTodo ? [...todos, tempTodo] : todos;
+
+  return (
+    <section className="todoapp__main" data-cy="TodoList">
+      {todosToRender.map(todo => {
+        const isTemp = todo.id === tempTodoId;
+        const isLoading = isTemp || loadingTodoIds.includes(todo.id);
+
+        return (
+          <TodoItem
+            key={todo.id || 'temp-todo'}
+            todo={todo}
+            isTemp={isTemp}
+            isLoading={isLoading}
+            isEditing={editingTodoId === todo.id}
+            editingTitle={editingTitle}
+            onToggle={onToggleTodo}
+            onDelete={onDeleteTodo}
+            onStartEditing={onStartEditing}
+            onEditingTitleChange={onEditingTitleChange}
+            onCancelEditing={onCancelEditing}
+            onSubmitTitle={onSubmitTodoTitle}
+          />
+        );
+      })}
+    </section>
+  );
+};
diff --git a/src/types/Filter.ts b/src/types/Filter.ts
new file mode 100644
index 0000000000..5d90d45a1b
--- /dev/null
+++ b/src/types/Filter.ts
@@ -0,0 +1 @@
+export type Filter = 'all' | 'active' | 'completed';
diff --git a/src/types/TempTodo.ts b/src/types/TempTodo.ts
new file mode 100644
index 0000000000..7c8bc556a9
--- /dev/null
+++ b/src/types/TempTodo.ts
@@ -0,0 +1,3 @@
+import { Todo } from './Todo';
+
+export type TempTodo = Omit<Todo, 'id'> & { id: number };
diff --git a/src/types/Todo.ts b/src/types/Todo.ts
new file mode 100644
index 0000000000..3f52a5fdde
--- /dev/null
+++ b/src/types/Todo.ts
@@ -0,0 +1,6 @@
+export interface Todo {
+  id: number;
+  userId: number;
+  title: string;
+  completed: boolean;
+}
diff --git a/src/utils/fetchClient.ts b/src/utils/fetchClient.ts
new file mode 100644
index 0000000000..708ac4c17b
--- /dev/null
+++ b/src/utils/fetchClient.ts
@@ -0,0 +1,46 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+const BASE_URL = 'https://mate.academy/students-api';
+
+// returns a promise resolved after a given delay
+function wait(delay: number) {
+  return new Promise(resolve => {
+    setTimeout(resolve, delay);
+  });
+}
+
+// To have autocompletion and avoid mistypes
+type RequestMethod = 'GET' | 'POST' | 'PATCH' | 'DELETE';
+
+function request<T>(
+  url: string,
+  method: RequestMethod = 'GET',
+  data: any = null, // we can send any data to the server
+): Promise<T> {
+  const options: RequestInit = { method };
+
+  if (data) {
+    // We add body and Content-Type only for the requests with data
+    options.body = JSON.stringify(data);
+    options.headers = {
+      'Content-Type': 'application/json; charset=UTF-8',
+    };
+  }
+
+  // DON'T change the delay it is required for tests
+  return wait(100)
+    .then(() => fetch(BASE_URL + url, options))
+    .then(response => {
+      if (!response.ok) {
+        throw new Error();
+      }
+
+      return response.json();
+    });
+}
+
+export const client = {
+  get: <T>(url: string) => request<T>(url),
+  post: <T>(url: string, data: any) => request<T>(url, 'POST', data),
+  patch: <T>(url: string, data: any) => request<T>(url, 'PATCH', data),
+  delete: (url: string) => request(url, 'DELETE'),
+};