diff --git a/src/ExpoPushConnector.php b/src/ExpoPushConnector.php
index 959d208..d2261e7 100644
--- a/src/ExpoPushConnector.php
+++ b/src/ExpoPushConnector.php
@@ -25,6 +25,8 @@ class ExpoPushConnector extends Connector
 
     public const MAX_CONCURRENT_REQUESTS = 6;
 
+    private static ?string $sdkVersion = null;
+
     public function __construct(
         protected ?string $authToken = null,
         ?RateLimitStore   $rateLimitStore = null,
@@ -83,17 +85,29 @@ protected function resolveRateLimitStore(): RateLimitStore
      */
     public function sdkVersion(): string
     {
-        static $version = null;
+        if (self::$sdkVersion === null) {
+            self::$sdkVersion = self::resolveSdkVersion(dirname(__DIR__) . '/composer.json');
+        }
 
-        if (!$version) {
-            $composer = json_decode(
-                file_get_contents(dirname(__DIR__) . '/composer.json'),
-            );
+        return self::$sdkVersion;
+    }
 
-            $version = InstalledVersions::getPrettyVersion($composer->name);
+    /**
+     * Resolve the installed version from composer.json, falling back to 'unknown' if it can't be determined
+     */
+    private static function resolveSdkVersion(string $composerJsonPath): string
+    {
+        if (!is_readable($composerJsonPath)) {
+            return 'unknown';
         }
 
-        return (string) $version;
+        try {
+            $composer = json_decode(file_get_contents($composerJsonPath), flags: JSON_THROW_ON_ERROR);
+
+            return InstalledVersions::getPrettyVersion($composer->name) ?? 'unknown';
+        } catch (Throwable) {
+            return 'unknown';
+        }
     }
 
     // Internals ----
diff --git a/tests/Unit/ExpoPushConnectorTest.php b/tests/Unit/ExpoPushConnectorTest.php
index 354ef7b..77c09d9 100644
--- a/tests/Unit/ExpoPushConnectorTest.php
+++ b/tests/Unit/ExpoPushConnectorTest.php
@@ -4,10 +4,13 @@
 
 namespace Dru1x\ExpoPush\Tests\Unit;
 
+use Composer\InstalledVersions;
 use Dru1x\ExpoPush\Config\RetryConfig;
 use Dru1x\ExpoPush\ExpoPushConnector;
 use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\TestCase;
+use ReflectionMethod;
+use ReflectionProperty;
 use Saloon\Http\Auth\TokenAuthenticator;
 use Saloon\RateLimitPlugin\Exceptions\LimitException;
 use Saloon\RateLimitPlugin\Limit;
@@ -15,6 +18,31 @@
 
 class ExpoPushConnectorTest extends TestCase
 {
+    private ?string $originalSdkVersion = null;
+
+    /** @var list<string> */
+    private array $tempFiles = [];
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->originalSdkVersion = (new ReflectionProperty(ExpoPushConnector::class, 'sdkVersion'))->getValue();
+    }
+
+    protected function tearDown(): void
+    {
+        (new ReflectionProperty(ExpoPushConnector::class, 'sdkVersion'))->setValue(null, $this->originalSdkVersion);
+
+        foreach ($this->tempFiles as $tempFile) {
+            is_file($tempFile) && unlink($tempFile);
+        }
+
+        $this->tempFiles = [];
+
+        parent::tearDown();
+    }
+
     #[Test]
     public function resolves_the_expo_push_api_base_url(): void
     {
@@ -113,8 +141,89 @@ public function custom_retry_configuration_is_used_when_supplied(): void
         $this->assertFalse($connector->throwOnMaxTries);
     }
 
+    // SDK Version ----
+
+    #[Test]
+    public function sdk_version_resolves(): void
+    {
+        $connector = new ExpoPushConnector();
+
+        $this->assertNotSame('unknown', $connector->sdkVersion());
+    }
+
+    #[Test]
+    public function sdk_version_resolves_the_real_installed_version(): void
+    {
+        $composerJsonPath = dirname(__DIR__, 2) . '/composer.json';
+        $composer         = json_decode(file_get_contents($composerJsonPath));
+
+        $this->assertSame(
+            InstalledVersions::getPrettyVersion($composer->name),
+            $this->resolveSdkVersion($composerJsonPath),
+        );
+    }
+
+    #[Test]
+    public function sdk_version_falls_back_to_unknown_when_composer_json_is_missing(): void
+    {
+        $this->assertSame('unknown', $this->resolveSdkVersion('/nonexistent/composer.json'));
+    }
+
+    #[Test]
+    public function sdk_version_falls_back_to_unknown_when_composer_json_is_malformed(): void
+    {
+        $path = $this->writeTempFile('{not valid json');
+
+        $this->assertSame('unknown', $this->resolveSdkVersion($path));
+    }
+
+    #[Test]
+    public function sdk_version_falls_back_to_unknown_when_the_package_is_not_installed(): void
+    {
+        $path = $this->writeTempFile(json_encode(['name' => 'not/a-real-package']));
+
+        $this->assertSame('unknown', $this->resolveSdkVersion($path));
+    }
+
+    #[Test]
+    public function sdk_version_does_not_recompute_once_resolved(): void
+    {
+        (new ReflectionProperty(ExpoPushConnector::class, 'sdkVersion'))->setValue(null, 'cached-test-value');
+
+        $connector = new ExpoPushConnector();
+
+        $this->assertSame('cached-test-value', $connector->sdkVersion());
+    }
+
+    #[Test]
+    public function sdk_version_caches_a_falsy_resolved_value_instead_of_recomputing_it(): void
+    {
+        (new ReflectionProperty(ExpoPushConnector::class, 'sdkVersion'))->setValue(null, '');
+
+        $connector = new ExpoPushConnector();
+
+        $this->assertSame('', $connector->sdkVersion());
+    }
+
     // Internals ----
 
+    private function resolveSdkVersion(string $composerJsonPath): string
+    {
+        return (new ReflectionMethod(ExpoPushConnector::class, 'resolveSdkVersion'))
+            ->invoke(null, $composerJsonPath);
+    }
+
+    private function writeTempFile(string $contents): string
+    {
+        $path = tempnam(sys_get_temp_dir(), 'expo-push-sdk-version-test-');
+
+        file_put_contents($path, $contents);
+
+        $this->tempFiles[] = $path;
+
+        return $path;
+    }
+
     private function findLimit(ExpoPushConnector $connector, string $name): Limit
     {
         try {