Make react/http an optional dependency

README.md

@@ -30,7 +30,7 @@ This package supports the **2025-03-26** version of the Model Context Protocol w
 
 - **PHP** >= 8.1
 - **Composer**
-- **For HTTP Transport**: An event-driven PHP environment (CLI recommended)
+- **For HTTP Transport**: An event-driven PHP environment (CLI recommended) and the optional `react/http` package (see Installation)
 - **Extensions**: `json`, `mbstring`, `pcre` (typically enabled by default)
 
 ## 📦 Installation
@@ -39,6 +39,14 @@ This package supports the **2025-03-26** version of the Model Context Protocol w
 composer require php-mcp/server
 ```
 
+The HTTP transports need `react/http`, which is an optional dependency so that
+projects using only the stdio transport or their own framework integration are
+not tied to its dependency tree:
+
+```bash
+composer require react/http
+```
+
 > **💡 Laravel Users**: Consider using [`php-mcp/laravel`](https://github.com/php-mcp/laravel) for enhanced framework integration, configuration management, and Artisan commands.
 
 ## ⚡ Quick Start: Stdio Server with Discovery

composer.json

@@ -29,10 +29,10 @@
         "phpdocumentor/reflection-docblock": "^5.6",
         "psr/clock": "^1.0",
         "psr/container": "^1.0 || ^2.0",
+        "psr/http-message": "^1.0 || ^2.0",
         "psr/log": "^1.0 || ^2.0 || ^3.0",
         "psr/simple-cache": "^1.0 || ^2.0 || ^3.0",
         "react/event-loop": "^1.5",
-        "react/http": "^1.11",
         "react/promise": "^3.0",
         "react/stream": "^1.4",
         "symfony/finder": "^6.4 || ^7.2"
@@ -43,10 +43,12 @@
         "pestphp/pest": "^2.36.0|^3.5.0",
         "react/async": "^4.0",
         "react/child-process": "^0.6.6",
+        "react/http": "^1.11",
         "symfony/var-dumper": "^6.4.11|^7.1.5"
     },
     "suggest": {
-        "ext-pcntl": "For signal handling support when using StdioServerTransport with StreamSelectLoop"
+        "ext-pcntl": "For signal handling support when using StdioServerTransport with StreamSelectLoop",
+        "react/http": "Required for HttpServerTransport and StreamableHttpServerTransport (^1.11)"
     },
     "autoload": {
         "psr-4": {

src/Transports/HttpServerTransport.php

@@ -71,6 +71,12 @@ public function __construct(
         private readonly ?array $sslContext = null,
         private array $middlewares = []
     ) {
+        if (! class_exists(HttpServer::class)) {
+            throw new TransportException(
+                'react/http is not installed. It is an optional dependency, required only by the HTTP transports. Install it with "composer require react/http".'
+            );
+        }
+
         $this->logger = new NullLogger();
         $this->loop = Loop::get();
         $this->ssePath = '/' . trim($mcpPathPrefix, '/') . '/sse';

src/Transports/StreamableHttpServerTransport.php

@@ -82,6 +82,12 @@ public function __construct(
         ?EventStoreInterface $eventStore = null,
         private array $middlewares = []
     ) {
+        if (! class_exists(HttpServer::class)) {
+            throw new TransportException(
+                'react/http is not installed. It is an optional dependency, required only by the HTTP transports. Install it with "composer require react/http".'
+            );
+        }
+
         $this->logger = new NullLogger();
         $this->loop = Loop::get();
         $this->mcpPath = '/' . trim($mcpPath, '/');