diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index d5adf9e..e18fb6d 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -12,8 +12,8 @@
         <testsuite name="unit">
             <directory>tests/Unit</directory>
         </testsuite>
-        <testsuite name="inspector">
-            <directory>tests/Inspector</directory>
+        <testsuite name="application">
+            <directory>tests/Application</directory>
         </testsuite>
     </testsuites>
 
diff --git a/tests/Application/ApplicationTestCase.php b/tests/Application/ApplicationTestCase.php
new file mode 100644
index 0000000..5f2da9f
--- /dev/null
+++ b/tests/Application/ApplicationTestCase.php
@@ -0,0 +1,172 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the official PHP MCP SDK.
+ *
+ * A collaboration between Symfony and the PHP Foundation.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Mcp\Tests\Application;
+
+use Mcp\Schema\JsonRpc\MessageInterface;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Process\Process;
+
+abstract class ApplicationTestCase extends TestCase
+{
+    /**
+     * @param list<string>         $messages
+     * @param array<string,string> $env
+     *
+     * @return array<string, array<string, array<string,mixed>>>
+     */
+    protected function runServer(array $messages, float $timeout = 5.0, array $env = []): array
+    {
+        if (0 === \count($messages)) {
+            return [];
+        }
+
+        $process = new Process([
+            'php',
+            $this->getServerScript(),
+        ], \dirname(__DIR__, 2), [] === $env ? null : $env, null, $timeout);
+
+        $process->setInput($this->formatInput($messages));
+        $process->mustRun();
+
+        return $this->decodeJsonLines($process->getOutput());
+    }
+
+    abstract protected function getServerScript(): string;
+
+    /**
+     * @param mixed[] $params
+     *
+     * @throws \JsonException
+     */
+    protected function jsonRequest(string $method, ?array $params = null, ?string $id = null): string
+    {
+        $payload = [
+            'jsonrpc' => MessageInterface::JSONRPC_VERSION,
+            'id' => $id,
+            'method' => $method,
+        ];
+
+        if (null !== $params) {
+            $payload['params'] = $params;
+        }
+
+        return (string) json_encode($payload, \JSON_THROW_ON_ERROR);
+    }
+
+    /**
+     * @param list<string> $messages
+     */
+    private function formatInput(array $messages): string
+    {
+        return implode("\n", $messages)."\n";
+    }
+
+    /**
+     * @return array<string, array<string, array<string,mixed>>>
+     */
+    private function decodeJsonLines(string $output): array
+    {
+        $output = trim($output);
+        $responses = [];
+
+        if ('' === $output) {
+            return $responses;
+        }
+
+        foreach (preg_split('/\R+/', $output) as $line) {
+            if ('' === $line) {
+                continue;
+            }
+
+            try {
+                $decoded = json_decode($line, true, 512, \JSON_THROW_ON_ERROR);
+            } catch (\JsonException) {
+                continue;
+            }
+
+            if (!\is_array($decoded)) {
+                continue;
+            }
+
+            $id = $decoded['id'] ?? null;
+
+            if (\is_string($id) || \is_int($id)) {
+                $responses[(string) $id] = $decoded;
+            }
+        }
+
+        return $responses;
+    }
+
+    protected function getSnapshotFilePath(string $method): string
+    {
+        $className = substr(static::class, strrpos(static::class, '\\') + 1);
+
+        return __DIR__.'/snapshots/'.$className.'-'.str_replace('/', '_', $method).'.json';
+    }
+
+    /**
+     * @return array<string,mixed>
+     *
+     * @throws \JsonException
+     */
+    protected function loadSnapshot(string $method): array
+    {
+        $path = $this->getSnapshotFilePath($method);
+
+        $contents = file_get_contents($path);
+        $this->assertNotFalse($contents, 'Failed to read snapshot: '.$path);
+
+        return json_decode($contents, true, 512, \JSON_THROW_ON_ERROR);
+    }
+
+    /**
+     * @param array<string, array<string, mixed>> $response
+     *
+     * @throws \JsonException
+     */
+    protected function assertResponseMatchesSnapshot(array $response, string $method): void
+    {
+        $this->assertArrayHasKey('result', $response);
+        $actual = $response['result'];
+
+        $expected = $this->loadSnapshot($method);
+
+        $this->assertEquals($expected, $actual, 'Response payload does not match snapshot '.$this->getSnapshotFilePath($method));
+    }
+
+    /**
+     * @param array<string, array<string, mixed>> $capabilities
+     * @param string[]                            $clientInfo
+     *
+     * @throws \JsonException
+     */
+    protected function initializeMessage(
+        ?string $id = null,
+        string $protocolVersion = MessageInterface::PROTOCOL_VERSION,
+        array $capabilities = [],
+        array $clientInfo = [
+            'name' => 'test-suite',
+            'version' => '1.0.0',
+        ],
+    ): string {
+        $id ??= uniqid();
+
+        return $this->jsonRequest('initialize', [
+            'protocolVersion' => $protocolVersion,
+            'capabilities' => $capabilities,
+            'clientInfo' => $clientInfo,
+        ], $id);
+    }
+}
diff --git a/tests/Application/ManualStdioExampleTest.php b/tests/Application/ManualStdioExampleTest.php
new file mode 100644
index 0000000..72c6408
--- /dev/null
+++ b/tests/Application/ManualStdioExampleTest.php
@@ -0,0 +1,107 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the official PHP MCP SDK.
+ *
+ * A collaboration between Symfony and the PHP Foundation.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Mcp\Tests\Application;
+
+final class ManualStdioExampleTest extends ApplicationTestCase
+{
+    /**
+     * @throws \JsonException
+     */
+    public function testInitializeResponseMatchesSnapshot(): void
+    {
+        $initializeId = uniqid('i_');
+
+        $responses = $this->runServer([
+            $this->initializeMessage($initializeId),
+        ]);
+
+        $this->assertArrayHasKey($initializeId, $responses);
+
+        $initialize = $responses[$initializeId];
+        $this->assertResponseMatchesSnapshot($initialize, 'initialize');
+    }
+
+    /**
+     * @throws \JsonException
+     */
+    public function testToolsListMatchesSnapshot(): void
+    {
+        $toolsListId = uniqid('t_');
+
+        $responses = $this->runServer([
+            $this->initializeMessage(),
+            $this->jsonRequest('tools/list', id: $toolsListId),
+        ]);
+
+        $this->assertArrayHasKey($toolsListId, $responses);
+        $toolsList = $responses[$toolsListId];
+        $this->assertResponseMatchesSnapshot($toolsList, 'tools/list');
+    }
+
+    /**
+     * @throws \JsonException
+     */
+    public function testPromptsListMatchesSnapshot(): void
+    {
+        $promptsListId = uniqid('t_');
+
+        $responses = $this->runServer([
+            $this->initializeMessage(),
+            $this->jsonRequest('prompts/list', id: $promptsListId),
+        ]);
+
+        $this->assertArrayHasKey($promptsListId, $responses);
+        $promptsList = $responses[$promptsListId];
+        $this->assertResponseMatchesSnapshot($promptsList, 'prompts/list');
+    }
+
+    /**
+     * @throws \JsonException
+     */
+    public function testResourcesListMatchesSnapshot(): void
+    {
+        $resourcesListId = uniqid('t_');
+
+        $responses = $this->runServer([
+            $this->initializeMessage(),
+            $this->jsonRequest('resources/list', id: $resourcesListId),
+        ]);
+
+        $this->assertArrayHasKey($resourcesListId, $responses);
+        $resourcesList = $responses[$resourcesListId];
+        $this->assertResponseMatchesSnapshot($resourcesList, 'resources/list');
+    }
+
+    /**
+     * @throws \JsonException
+     */
+    public function testResourceTemplatesListMatchesSnapshot(): void
+    {
+        $templatesListId = uniqid('t_');
+
+        $responses = $this->runServer([
+            $this->initializeMessage(),
+            $this->jsonRequest('resources/templates/list', id: $templatesListId),
+        ]);
+
+        $this->assertArrayHasKey($templatesListId, $responses);
+        $templatesList = $responses[$templatesListId];
+        $this->assertResponseMatchesSnapshot($templatesList, 'resources/templates/list');
+    }
+
+    protected function getServerScript(): string
+    {
+        return \dirname(__DIR__, 2).'/examples/stdio-explicit-registration/server.php';
+    }
+}
diff --git a/tests/Application/StdioCalculatorExampleTest.php b/tests/Application/StdioCalculatorExampleTest.php
new file mode 100644
index 0000000..36973b0
--- /dev/null
+++ b/tests/Application/StdioCalculatorExampleTest.php
@@ -0,0 +1,92 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the official PHP MCP SDK.
+ *
+ * A collaboration between Symfony and the PHP Foundation.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Application;
+
+use Mcp\Tests\Application\ApplicationTestCase;
+
+final class StdioCalculatorExampleTest extends ApplicationTestCase
+{
+    /**
+     * @throws \JsonException
+     */
+    public function testToolsListMatchesSnapshot(): void
+    {
+        $toolsListId = uniqid('t_');
+
+        $responses = $this->runServer([
+            $this->initializeMessage(),
+            $this->jsonRequest('tools/list', id: $toolsListId),
+        ]);
+
+        $this->assertArrayHasKey($toolsListId, $responses);
+        $toolsList = $responses[$toolsListId];
+        $this->assertResponseMatchesSnapshot($toolsList, 'tools/list');
+    }
+
+    /**
+     * @throws \JsonException
+     */
+    public function testPromptsListMatchesSnapshot(): void
+    {
+        $promptsListId = uniqid('t_');
+
+        $responses = $this->runServer([
+            $this->initializeMessage(),
+            $this->jsonRequest('prompts/list', id: $promptsListId),
+        ]);
+
+        $this->assertArrayHasKey($promptsListId, $responses);
+        $promptsList = $responses[$promptsListId];
+        $this->assertResponseMatchesSnapshot($promptsList, 'prompts/list');
+    }
+
+    /**
+     * @throws \JsonException
+     */
+    public function testResourcesListMatchesSnapshot(): void
+    {
+        $resourcesListId = uniqid('t_');
+
+        $responses = $this->runServer([
+            $this->initializeMessage(),
+            $this->jsonRequest('resources/list', id: $resourcesListId),
+        ]);
+
+        $this->assertArrayHasKey($resourcesListId, $responses);
+        $resourcesList = $responses[$resourcesListId];
+        $this->assertResponseMatchesSnapshot($resourcesList, 'resources/list');
+    }
+
+    /**
+     * @throws \JsonException
+     */
+    public function testResourceTemplatesListMatchesSnapshot(): void
+    {
+        $templatesListId = uniqid('t_');
+
+        $responses = $this->runServer([
+            $this->initializeMessage(),
+            $this->jsonRequest('resources/templates/list', id: $templatesListId),
+        ]);
+
+        $this->assertArrayHasKey($templatesListId, $responses);
+        $templatesList = $responses[$templatesListId];
+        $this->assertResponseMatchesSnapshot($templatesList, 'resources/templates/list');
+    }
+
+    protected function getServerScript(): string
+    {
+        return \dirname(__DIR__, 2).'/examples/stdio-discovery-calculator/server.php';
+    }
+}
diff --git a/tests/Application/snapshots/ManualStdioExampleTest-initialize.json b/tests/Application/snapshots/ManualStdioExampleTest-initialize.json
new file mode 100644
index 0000000..30da842
--- /dev/null
+++ b/tests/Application/snapshots/ManualStdioExampleTest-initialize.json
@@ -0,0 +1,13 @@
+{
+  "capabilities": {
+    "prompts": {},
+    "resources": {},
+    "tools": {},
+    "completions": {}
+  },
+  "serverInfo": {
+    "name": "Manual Reg Server",
+    "version": "1.0.0"
+  },
+  "protocolVersion": "2025-06-18"
+}
diff --git a/tests/Inspector/snapshots/ManualStdioExampleTest-prompts_list.json b/tests/Application/snapshots/ManualStdioExampleTest-prompts_list.json
similarity index 100%
rename from tests/Inspector/snapshots/ManualStdioExampleTest-prompts_list.json
rename to tests/Application/snapshots/ManualStdioExampleTest-prompts_list.json
diff --git a/tests/Inspector/snapshots/ManualStdioExampleTest-resources_list.json b/tests/Application/snapshots/ManualStdioExampleTest-resources_list.json
similarity index 100%
rename from tests/Inspector/snapshots/ManualStdioExampleTest-resources_list.json
rename to tests/Application/snapshots/ManualStdioExampleTest-resources_list.json
diff --git a/tests/Inspector/snapshots/ManualStdioExampleTest-resources_templates_list.json b/tests/Application/snapshots/ManualStdioExampleTest-resources_templates_list.json
similarity index 100%
rename from tests/Inspector/snapshots/ManualStdioExampleTest-resources_templates_list.json
rename to tests/Application/snapshots/ManualStdioExampleTest-resources_templates_list.json
diff --git a/tests/Inspector/snapshots/ManualStdioExampleTest-tools_list.json b/tests/Application/snapshots/ManualStdioExampleTest-tools_list.json
similarity index 100%
rename from tests/Inspector/snapshots/ManualStdioExampleTest-tools_list.json
rename to tests/Application/snapshots/ManualStdioExampleTest-tools_list.json
diff --git a/tests/Inspector/snapshots/StdioCalculatorExampleTest-prompts_list.json b/tests/Application/snapshots/StdioCalculatorExampleTest-prompts_list.json
similarity index 100%
rename from tests/Inspector/snapshots/StdioCalculatorExampleTest-prompts_list.json
rename to tests/Application/snapshots/StdioCalculatorExampleTest-prompts_list.json
diff --git a/tests/Inspector/snapshots/StdioCalculatorExampleTest-resources_list.json b/tests/Application/snapshots/StdioCalculatorExampleTest-resources_list.json
similarity index 100%
rename from tests/Inspector/snapshots/StdioCalculatorExampleTest-resources_list.json
rename to tests/Application/snapshots/StdioCalculatorExampleTest-resources_list.json
diff --git a/tests/Inspector/snapshots/StdioCalculatorExampleTest-resources_templates_list.json b/tests/Application/snapshots/StdioCalculatorExampleTest-resources_templates_list.json
similarity index 100%
rename from tests/Inspector/snapshots/StdioCalculatorExampleTest-resources_templates_list.json
rename to tests/Application/snapshots/StdioCalculatorExampleTest-resources_templates_list.json
diff --git a/tests/Inspector/snapshots/StdioCalculatorExampleTest-tools_list.json b/tests/Application/snapshots/StdioCalculatorExampleTest-tools_list.json
similarity index 100%
rename from tests/Inspector/snapshots/StdioCalculatorExampleTest-tools_list.json
rename to tests/Application/snapshots/StdioCalculatorExampleTest-tools_list.json
diff --git a/tests/Inspector/InspectorSnapshotTestCase.php b/tests/Inspector/InspectorSnapshotTestCase.php
deleted file mode 100644
index e576795..0000000
--- a/tests/Inspector/InspectorSnapshotTestCase.php
+++ /dev/null
@@ -1,68 +0,0 @@
-<?php
-
-/*
- * This file is part of the official PHP MCP SDK.
- *
- * A collaboration between Symfony and the PHP Foundation.
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Mcp\Tests\Inspector;
-
-use PHPUnit\Framework\Attributes\DataProvider;
-use PHPUnit\Framework\TestCase;
-use Symfony\Component\Process\Process;
-
-abstract class InspectorSnapshotTestCase extends TestCase
-{
-    #[DataProvider('provideMethods')]
-    public function testResourcesListOutputMatchesSnapshot(string $method): void
-    {
-        $process = Process::fromShellCommandline(
-            \sprintf('npx @modelcontextprotocol/inspector --cli php %s --method %s', $this->getServerScript(), $method)
-        )->mustRun();
-
-        $output = $process->getOutput();
-        $snapshotFile = $this->getSnapshotFilePath($method);
-
-        if (!file_exists($snapshotFile)) {
-            file_put_contents($snapshotFile, $output.\PHP_EOL);
-            $this->markTestIncomplete("Snapshot created at $snapshotFile, please re-run tests.");
-        }
-
-        $expected = file_get_contents($snapshotFile);
-
-        $this->assertJsonStringEqualsJsonString($expected, $output);
-    }
-
-    /**
-     * List of methods to test.
-     *
-     * @return array<string, array{method: string}>
-     */
-    abstract public static function provideMethods(): array;
-
-    abstract protected function getServerScript(): string;
-
-    /**
-     * @return array<string, array{method: string}>
-     */
-    protected static function provideListMethods(): array
-    {
-        return [
-            'Prompt Listing' => ['method' => 'prompts/list'],
-            'Resource Listing' => ['method' => 'resources/list'],
-            'Resource Template Listing' => ['method' => 'resources/templates/list'],
-            'Tool Listing' => ['method' => 'tools/list'],
-        ];
-    }
-
-    private function getSnapshotFilePath(string $method): string
-    {
-        $className = substr(static::class, strrpos(static::class, '\\') + 1);
-
-        return __DIR__.'/snapshots/'.$className.'-'.str_replace('/', '_', $method).'.json';
-    }
-}
diff --git a/tests/Inspector/ManualStdioExampleTest.php b/tests/Inspector/ManualStdioExampleTest.php
deleted file mode 100644
index 582de0d..0000000
--- a/tests/Inspector/ManualStdioExampleTest.php
+++ /dev/null
@@ -1,29 +0,0 @@
-<?php
-
-/*
- * This file is part of the official PHP MCP SDK.
- *
- * A collaboration between Symfony and the PHP Foundation.
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Inspector;
-
-use Mcp\Tests\Inspector\InspectorSnapshotTestCase;
-
-final class ManualStdioExampleTest extends InspectorSnapshotTestCase
-{
-    public static function provideMethods(): array
-    {
-        return [
-            ...parent::provideListMethods(),
-        ];
-    }
-
-    protected function getServerScript(): string
-    {
-        return \dirname(__DIR__, 2).'/examples/stdio-explicit-registration/server.php';
-    }
-}
diff --git a/tests/Inspector/StdioCalculatorExampleTest.php b/tests/Inspector/StdioCalculatorExampleTest.php
deleted file mode 100644
index b1b1bc5..0000000
--- a/tests/Inspector/StdioCalculatorExampleTest.php
+++ /dev/null
@@ -1,27 +0,0 @@
-<?php
-
-/*
- * This file is part of the official PHP MCP SDK.
- *
- * A collaboration between Symfony and the PHP Foundation.
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Mcp\Tests\Inspector;
-
-final class StdioCalculatorExampleTest extends InspectorSnapshotTestCase
-{
-    public static function provideMethods(): array
-    {
-        return [
-            ...parent::provideListMethods(),
-        ];
-    }
-
-    protected function getServerScript(): string
-    {
-        return \dirname(__DIR__, 2).'/examples/stdio-discovery-calculator/server.php';
-    }
-}