diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 11ebbb7..00fe049 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -18,7 +18,7 @@ jobs:
         uses: "shivammathur/setup-php@v2"
         with:
           coverage: "pcov"
-          php-version: "8.0"
+          php-version: "8.1"
           ini-values: memory_limit=-1
 
       - name: "Cache Composer dependencies"
@@ -27,8 +27,8 @@ jobs:
           path: |
             ~/.composer/cache
             vendor
-          key: "php-8.0"
-          restore-keys: "php-8.0"
+          key: "php-8.1"
+          restore-keys: "php-8.1"
 
       - name: "Validate composer"
         run: "composer validate"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a39dbea..a6e0bc9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [1.0.0] - 2022-05-22
+- Upgrade to PHP 8
+- Add php-cs-fixer
+- Add phpstan by @akondas in #1
+- Configure GitHub Actions by @akondas in #3
 
 ## [0.1.0] - 2018-03-15
 ### Added
@@ -13,4 +17,3 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
  - Storing and validate Blockchain
  - Proof of Work with difficulty (missing consensus on the difficulty)
  - Communicating with other nodes & controlling the node (based on ReactPHP)
-  
\ No newline at end of file
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..bdfad10
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,4 @@
+FROM php:8.1-cli-alpine
+RUN apk add --no-cache bash curl git
+RUN docker-php-ext-install pcntl
+COPY --from=composer:2.1.5 /usr/bin/composer /usr/bin/composer
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..cd5a4ac
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,7 @@
+build:
+	docker build -t php-blockchain .
+
+shell: build
+	docker run -it --rm --name php-blockchain-dev -v $(PWD):/var/app -w /var/app php-blockchain:latest /bin/bash
+
+.PHONY: build shell
diff --git a/README.md b/README.md
index b0677c6..0bb9569 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # Blockchain implementation in PHP
 
-[![Minimum PHP Version](https://img.shields.io/badge/php-%3E%3D%207.2-8892BF.svg)](https://php.net/)
-[![Build Status](https://travis-ci.org/akondas/php-blockchain.svg?branch=master)](https://travis-ci.org/akondas/php-blockchain)
+[![Minimum PHP Version](https://img.shields.io/badge/php-%3E%3D%208.1-8892BF.svg)](https://php.net/)
+[![Build](https://github.com/akondas/php-blockchain/actions/workflows/build.yaml/badge.svg)](https://github.com/akondas/php-blockchain/actions/workflows/build.yaml)
 [![License](https://poser.pugx.org/akondas/php-blockchain/license.svg)](https://packagist.org/packages/akondas/php-blockchain)
 
 Clean code approach to blockchain technology. Learn blockchain by reading source code.
diff --git a/composer.json b/composer.json
index 0010287..9bc923e 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,7 @@
         }
     ],
     "require": {
-        "php": "^8.0",
+        "php": "^8.1",
         "react/http": "^0.8.1",
         "friendsofphp/php-cs-fixer": "^3.8"
     },
diff --git a/composer.lock b/composer.lock
index 260b2eb..5e4aedd 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "9a570098c914ecce1eb1637d3a724860",
+    "content-hash": "ff299feeec7d1b167d0e0d8f577ac65e",
     "packages": [
         {
             "name": "composer/pcre",
@@ -4954,7 +4954,7 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": "^8.0"
+        "php": "^8.1"
     },
     "platform-dev": [],
     "plugin-api-version": "2.1.0"
diff --git a/src/Block.php b/src/Block.php
index 99e14e1..8f9de4b 100644
--- a/src/Block.php
+++ b/src/Block.php
@@ -11,57 +11,15 @@ final class Block implements JsonSerializable
 {
     public const HASH_ALGORITHM = 'sha256';
 
-    /**
-     * @var int
-     */
-    private $index;
-
-    /**
-     * @var string
-     */
-    private $hash;
-
-    /**
-     * @var string
-     */
-    private $previousHash;
-
-    /**
-     * @var \DateTimeImmutable
-     */
-    private $createdAt;
-
-    /**
-     * @var string
-     */
-    private $data;
-
-    /**
-     * @var int
-     */
-    private $difficulty;
-
-    /**
-     * @var int
-     */
-    private $nonce;
-
     public function __construct(
-        int $index,
-        string $hash,
-        string $previousHash,
-        DateTimeImmutable $createdAt,
-        string $data,
-        int $difficulty,
-        int $nonce
+        private int $index,
+        private string $hash,
+        private string $previousHash,
+        private DateTimeImmutable $createdAt,
+        private string $data,
+        private int $difficulty,
+        private int $nonce
     ) {
-        $this->index = $index;
-        $this->hash = $hash;
-        $this->previousHash = $previousHash;
-        $this->createdAt = $createdAt;
-        $this->data = $data;
-        $this->difficulty = $difficulty;
-        $this->nonce = $nonce;
     }
 
     public static function genesis(): self
@@ -134,7 +92,7 @@ public static function calculateHash(
     }
 
     /**
-     * @return mixed[]
+     * @return array<string,string|int>
      */
     public function jsonSerialize(): array
     {
diff --git a/src/Blockchain.php b/src/Blockchain.php
index 580afc3..46341e1 100644
--- a/src/Blockchain.php
+++ b/src/Blockchain.php
@@ -54,7 +54,7 @@ public function withLastBlockOnly(): self
     }
 
     /**
-     * @return Block[]
+     * @return non-empty-array<Block>
      */
     public function blocks(): array
     {
diff --git a/src/Miner.php b/src/Miner.php
index e3ab1ad..b542f1b 100644
--- a/src/Miner.php
+++ b/src/Miner.php
@@ -9,20 +9,8 @@
 
 final class Miner
 {
-    /**
-     * @var Blockchain
-     */
-    private $blockchain;
-
-    /**
-     * @var HashDifficulty
-     */
-    private $hashDifficulty;
-
-    public function __construct(Blockchain $blockchain, HashDifficulty $hashDifficulty)
+    public function __construct(private Blockchain $blockchain, private HashDifficulty $hashDifficulty)
     {
-        $this->blockchain = $blockchain;
-        $this->hashDifficulty = $hashDifficulty;
     }
 
     public function mineBlock(string $data): Block
diff --git a/src/Miner/HashDifficulty/ZeroPrefix.php b/src/Miner/HashDifficulty/ZeroPrefix.php
index a70d755..4e7c332 100644
--- a/src/Miner/HashDifficulty/ZeroPrefix.php
+++ b/src/Miner/HashDifficulty/ZeroPrefix.php
@@ -17,7 +17,7 @@ public function hashMatchesDifficulty(string $hash, int $difficulty): bool
         $binary = $this->binaryString($hash, $difficulty);
         $prefix = \str_repeat('0', $difficulty);
 
-        return \strpos($binary, $prefix) === 0;
+        return \str_starts_with($binary, $prefix);
     }
 
     private function binaryString(string $hash, int $difficulty): string
diff --git a/src/Node.php b/src/Node.php
index c6e09bb..4a64bb0 100644
--- a/src/Node.php
+++ b/src/Node.php
@@ -10,20 +10,8 @@
 
 final class Node
 {
-    /**
-     * @var Miner
-     */
-    private $miner;
-
-    /**
-     * @var P2pServer
-     */
-    private $p2pServer;
-
-    public function __construct(Miner $miner, P2pServer $p2pServer)
+    public function __construct(private Miner $miner, private P2pServer $p2pServer)
     {
-        $this->miner = $miner;
-        $this->p2pServer = $p2pServer;
     }
 
     /**
diff --git a/src/Node/Message.php b/src/Node/Message.php
index 5107491..99af371 100644
--- a/src/Node/Message.php
+++ b/src/Node/Message.php
@@ -12,20 +12,10 @@ final class Message
 
     public const BLOCKCHAIN = 'blockchain';
 
-    /**
-     * @var string
-     */
-    private $type;
-
-    /**
-     * @var ?string
-     */
-    private $data;
-
-    public function __construct(string $type, ?string $data = null)
-    {
-        $this->type = $type;
-        $this->data = $data;
+    public function __construct(
+        private string $type,
+        private ?string $data = null
+    ) {
     }
 
     public function type(): string
diff --git a/src/Node/Peer.php b/src/Node/Peer.php
index 0b03e22..1df7fed 100644
--- a/src/Node/Peer.php
+++ b/src/Node/Peer.php
@@ -29,7 +29,7 @@ public function port(): int
     }
 
     /**
-     * @return mixed[]
+     * @return array<string,string|int>
      */
     public function jsonSerialize(): array
     {
diff --git a/src/WebServer.php b/src/WebServer.php
index e0b41c3..a9c3400 100644
--- a/src/WebServer.php
+++ b/src/WebServer.php
@@ -10,14 +10,8 @@
 
 final class WebServer
 {
-    /**
-     * @var Node
-     */
-    private $node;
-
-    public function __construct(Node $node)
+    public function __construct(private Node $node)
     {
-        $this->node = $node;
     }
 
     public function __invoke(ServerRequestInterface $request): Response
diff --git a/src/WebServer/Response/JsonResponse.php b/src/WebServer/Response/JsonResponse.php
index 426e5fc..a376d37 100644
--- a/src/WebServer/Response/JsonResponse.php
+++ b/src/WebServer/Response/JsonResponse.php
@@ -9,10 +9,7 @@
 
 final class JsonResponse extends HttpResponse implements Response
 {
-    /**
-     * @param mixed $data
-     */
-    public function __construct($data)
+    public function __construct(mixed $data)
     {
         parent::__construct(200, ['Content-Type' => 'application/json'], \json_encode($data));
     }