diff --git a/package-lock.json b/package-lock.json
index ee8e9b6..e2a640f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1868,22 +1868,6 @@
         "normalize-path": "^2.1.1"
       }
     },
-    "apollo-boost": {
-      "version": "0.4.4",
-      "resolved": "https://registry.npmjs.org/apollo-boost/-/apollo-boost-0.4.4.tgz",
-      "integrity": "sha512-ASngBvazmp9xNxXfJ2InAzfDwz65o4lswlEPrWoN35scXmCz8Nz4k3CboUXbrcN/G0IExkRf/W7o9Rg0cjEBqg==",
-      "requires": {
-        "apollo-cache": "^1.3.2",
-        "apollo-cache-inmemory": "^1.6.3",
-        "apollo-client": "^2.6.4",
-        "apollo-link": "^1.0.6",
-        "apollo-link-error": "^1.0.3",
-        "apollo-link-http": "^1.3.1",
-        "graphql-tag": "^2.4.2",
-        "ts-invariant": "^0.4.0",
-        "tslib": "^1.9.3"
-      }
-    },
     "apollo-cache": {
       "version": "1.3.2",
       "resolved": "https://registry.npmjs.org/apollo-cache/-/apollo-cache-1.3.2.tgz",
diff --git a/package.json b/package.json
index 5641314..461eb2f 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,6 @@
   "dependencies": {
     "@apollo/react-components": "^3.1.1",
     "@apollo/react-hooks": "^3.1.0",
-    "apollo-boost": "^0.4.4",
     "apollo-cache-inmemory": "^1.6.3",
     "apollo-client": "^2.6.4",
     "apollo-link": "^1.2.13",
diff --git a/src/Components/Singin.jsx b/src/Components/Singin.jsx
index 9e7ade3..1808778 100644
--- a/src/Components/Singin.jsx
+++ b/src/Components/Singin.jsx
@@ -1,19 +1,32 @@
 import React, { useState, useContext } from 'react';
 import { Redirect, Link } from 'react-router-dom';
+import { useApolloClient } from '@apollo/react-hooks';
 import { Button, Form, Container } from 'react-bootstrap';
 
 import UserContext from '../Context/UserContext';
+import queries from '../query';
 
 const Signin = () => {
   const [email, setEmail] = useState('');
   const [password, setPassword] = useState('');
-  const [isLoading] = useState(false);
-  const { user } = useContext(UserContext);
+  const [isLoading, setIsLoading] = useState(false);
+  const { user, setUser } = useContext(UserContext);
+  const apolloClient = useApolloClient();
 
-  // TODO: TASK 2. handleSingin
   const handleSingin = (event) => {
     event.preventDefault();
-    console.log('handleSingin');
+    if (email && password && !isLoading) {
+      setIsLoading(true);
+      apolloClient.query({
+        query: queries.user.SIGNIN_QUERY,
+        variables: { email, password },
+      }).then(({ data: { signin } }) => {
+        setUser(signin);
+      }).catch(() => {
+        alert('Wrong email/password');
+        setIsLoading(false);
+      });
+    }
   };
 
   if (user) return <Redirect to="/" />;
diff --git a/src/apollo.js b/src/apollo.js
index fded694..580620f 100644
--- a/src/apollo.js
+++ b/src/apollo.js
@@ -1,8 +1,35 @@
-import ApolloClient from 'apollo-boost';
+import { ApolloClient } from 'apollo-client';
+import { InMemoryCache } from 'apollo-cache-inmemory';
+import { HttpLink } from 'apollo-link-http';
+import { onError } from 'apollo-link-error';
+import { ApolloLink } from 'apollo-link';
 
-// TODO: TASK 1. migrate from apollo-boost
+const globalLoader = new ApolloLink((operation, forward) => {
+  // Use Mobx or Redux (or other) for a global state manager
+  console.log('increment loading count');
+  return forward(operation).map((response) => {
+    console.log('decrement loading count');
+    return response;
+  });
+});
 
 export default new ApolloClient({
-  uri: 'http://localhost:8000/graphql',
-  credentials: 'same-origin',
+  link: ApolloLink.from([
+    onError(({ graphQLErrors, networkError }) => {
+      if (graphQLErrors) {
+        graphQLErrors.forEach(({ message, locations, path }) => (
+          console.log(`[GraphQL error]: Message: ${message}, Location: ${JSON.stringify(locations)}, Path: ${path}`)
+        ));
+      }
+      if (networkError) {
+        console.log(`[Network error]: ${networkError}`);
+      }
+    }),
+    globalLoader,
+    new HttpLink({
+      uri: 'http://localhost:8000/graphql',
+      credentials: 'same-origin',
+    }),
+  ]),
+  cache: new InMemoryCache(),
 });
diff --git a/src/query/fragments.js b/src/query/fragments.js
index 4d29d12..b1a93d9 100644
--- a/src/query/fragments.js
+++ b/src/query/fragments.js
@@ -1,6 +1,13 @@
 import gql from 'graphql-tag';
 
-// TODO: TASK 2. EXTRA User Fragment
+const user = gql`
+  fragment User on User {
+    id
+    name
+    username
+    email
+  }
+`;
 
 const comment = gql`
   fragment Comment on Comment {
@@ -8,12 +15,10 @@ const comment = gql`
     content
     timestamp
     author {
-      id
-      name
-      username
-      email
+      ...User
     }
   }
+  ${user}
 `;
 
 const post = gql`
@@ -24,10 +29,7 @@ const post = gql`
     content
     timestamp
     author {
-      id
-      name
-      username
-      email
+      ...User
     }
     comments {
       pageInfo {
@@ -42,10 +44,12 @@ const post = gql`
       }
     }
   }
+  ${user}
   ${comment}
 `;
 
 export default {
+  user,
   post,
   comment,
 };
diff --git a/src/query/user.js b/src/query/user.js
index 7a9bcd0..11e2321 100644
--- a/src/query/user.js
+++ b/src/query/user.js
@@ -1,5 +1,5 @@
 import gql from 'graphql-tag';
-// TODO: TASK 2. EXTRA User Fragment for every query/mutation
+import fragments from './fragments';
 
 const GET_USERS_QUERY = gql`
   query getUsers(
@@ -21,18 +21,28 @@ const GET_USERS_QUERY = gql`
       }
       edges {
         node {
-          id
-          name
-          username
-          email
+          ...User
         }
       }
     }
   }
+  ${fragments.user}
 `;
 
-// TODO: TASK 2. SIGNIN_QUERY
-const SIGNIN_QUERY = '';
+const SIGNIN_QUERY = gql`
+  query signin(
+    $email: String!
+    $password: String!
+  ) {
+    signin (
+      email: $email
+      password: $password
+    ) {
+      ...User
+    }
+  }
+  ${fragments.user}
+`;
 
 const CREATE_USER_MUTATION = gql`
   mutation createUser(
@@ -48,13 +58,11 @@ const CREATE_USER_MUTATION = gql`
         email: $email
         password: $password
       }) {
-        id
-        name
-        username
-        email
+        ...User
       }
     }
   }
+  ${fragments.user}
 `;
 
 export default {