Add roadmap to readme (#20)

* Update README.md

Add roadmap
Add a basic example
Fix default NullLogger() in ServerBuilder

* Update README.md

Update intro
Add roadmap
Add a basic example
Fix default NullLogger() in ServerBuilder
Add Credits

* Update src/Server/ServerBuilder.php

Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>

* Fix code review comments

---------

Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>

README.md

@@ -1,15 +1,16 @@
 # MCP PHP SDK
 
+The official PHP SDK for Model Context Protocol (MCP). It provides a framework-agnostic API for implementing MCP servers in PHP.
+
 > [!IMPORTANT]
-> Currently we are still in the process of merging [Symfony's MCP SDK](https://github.com/symfony/mcp-sdk) and
+> Currently, we are still in the process of merging [Symfony's MCP SDK](https://github.com/symfony/mcp-sdk) and
-> [PHP-MCP](https://github.com/php-mcp) components. Not all code paths are fully tested, complete or this package
+> [PHP-MCP](https://github.com/php-mcp) components. Not all code paths are fully tested, complete, or this package
 > may contain duplicate functionality or dead code.
+> 
 > If you want to help us stabilize the SDK, please see the
 > [issue tracker](https://github.com/modelcontextprotocol/php-sdk/issues).
 
-Low-level SDK implementation of the Model Context Protocol (MCP) in PHP.
+This project is a collaboration between [the PHP Foundation](https://thephp.foundation/) and the
-
-This project is a collaboration between the [PHP Foundation](https://thephp.foundation/) and the
 [Symfony project](https://symfony.com/). It adopts development practices and standards from the Symfony project,
 including [Coding Standards](https://symfony.com/doc/current/contributing/code/standards.html) and the
 [Backward Compatibility Promise](https://symfony.com/doc/current/contributing/code/bc.html).
@@ -17,12 +18,107 @@ including [Coding Standards](https://symfony.com/doc/current/contributing/code/s
 Until the first major release, this SDK is considered
 [experimental](https://symfony.com/doc/current/contributing/code/experimental.html).
 
+## 🚧 Roadmap
+
+Features
+- [x] bring back php-mcp examples
+- [ ] Glue handler, registry and reference handlers
+- [ ] Revive `ServerBuilder`
+- [ ] Revive transports 
+  - [ ] Streamable Transport https://github.com/modelcontextprotocol/php-sdk/issues/7
+  - [ ] Http/SSE-based Transport https://github.com/modelcontextprotocol/php-sdk/issues/8
+- [ ] Support pagination
+- [ ] Support Schema validation
+- [ ] Support Multiple Versions of MCP Specification https://github.com/modelcontextprotocol/php-sdk/issues/14
+- [ ] (Re-)Implement missing Notification & Request Handlers https://github.com/modelcontextprotocol/php-sdk/issues/9
+
+---
+
+Examples working
+- [x] 01-discovery-stdio-calculator
+- [ ] 02-discovery-http-userprofile
+- [x] 03-manual-registration-stdio
+- [ ] 04-combined-registration-http
+- [ ] 05-stdio-env-variables
+- [ ] 06-custom-dependencies-stdio
+- [ ] 07-complex-tool-schema-http
+- [ ] 08-schema-showcase-streamable
+- [ ] 09-standalone-cli
+
 ## Installation
 
 ```bash
 composer require mcp/sdk
 ```
 
+## ⚡ Quick Start: Stdio Server with Discovery
+
+This example demonstrates the most common usage pattern - a `stdio` server using attribute discovery.
+
+**1. Define Your MCP Elements**
+
+Create `src/CalculatorElements.php`:
+
+```php
+<?php
+
+namespace App;
+
+use PhpMcp\Server\Attributes\McpTool;
+use PhpMcp\Server\Attributes\Schema;
+
+class CalculatorElements
+{
+    #[McpTool(name: 'add_numbers')]
+    public function add(int $a, int $b): int
+    {
+        return $a + $b;
+    }
+}
+```
+
+**2. Create the Server Script**
+
+Create `mcp-server.php`:
+
+```php
+#!/usr/bin/env php
+<?php
+
+declare(strict_types=1);
+
+require_once __DIR__ . '/vendor/autoload.php';
+
+use Mcp\Server;
+use Mcp\Server\Transport\StdioTransport;
+
+Server::make()
+    ->withServerInfo('Stdio Calculator', '1.1.0', 'Basic Calculator over STDIO transport.')
+    ->withDiscovery(__DIR__, ['.'])
+    ->build()
+    ->connect(new StdioTransport());
+```
+
+**3. Configure Your MCP Client**
+
+Add to your client configuration (e.g., `mcp.json`):
+
+```json
+{
+    "mcpServers": {
+        "php-calculator": {
+            "command": "php",
+            "args": ["/absolute/path/to/your/mcp-server.php"]
+        }
+    }
+}
+```
+
+**4. Test the Server**
+
+Your AI assistant can now call:
+- `add_numbers` - Add two integers
+
 ## Documentation
 
 - [SDK documentation](doc/index.rst)
@@ -30,6 +126,10 @@ composer require mcp/sdk
 - [Model Context Protocol specification](https://spec.modelcontextprotocol.io)
 - [Officially supported servers](https://github.com/modelcontextprotocol/servers)
 
+## Examples of MCP Tools that use this SDK
+
+- https://github.com/pronskiy/mcp
+
 ## Contributing
 
 We are passionate about supporting contributors of all levels of experience and would love to see you get involved in
@@ -37,6 +137,9 @@ the project. See the [contributing guide](CONTRIBUTING.md) to get started before
 [report issues](https://github.com/modelcontextprotocol/php-sdk/issues) and
 [send pull requests](https://github.com/modelcontextprotocol/php-sdk/pulls).
 
+## Credits
+The starting point for this SDK was [PHP-MCP](https://github.com/php-mcp/server) project, initiated by [Kyrian Obikwelu](https://github.com/CodeWithKyrian). We are grateful for the work done by Kyrian and other contributors to that repository, which created a solid foundation for this SDK.
+
 ## License
 
 This project is licensed under the MIT License - see the LICENSE file for details.

src/Server/ServerBuilder.php

@@ -216,19 +216,21 @@ final class ServerBuilder
      */
     public function build(): Server
     {
-        $container = $this->container ?? new Container();
+        $logger = $this->logger ?? new NullLogger();
-        $registry = new Registry(new ReferenceHandler($container), $this->eventDispatcher, $this->logger);
 
-        $this->registerManualElements($registry, $this->logger);
+        $container = $this->container ?? new Container();
+        $registry = new Registry(new ReferenceHandler($container), $this->eventDispatcher, $logger);
+
+        $this->registerManualElements($registry, $logger);
 
         if (null !== $this->discoveryBasePath) {
-            $discovery = new Discoverer($registry, $this->logger);
+            $discovery = new Discoverer($registry, $logger);
             $discovery->discover($this->discoveryBasePath, $this->discoveryScanDirs, $this->discoveryExcludeDirs);
         }
 
         return new Server(
-            Handler::make($registry, $this->serverInfo, $this->logger),
+            Handler::make($registry, $this->serverInfo, $logger),
-            $this->logger,
+            $logger,
         );
     }