diff --git a/src/StaticPHP/Command/DownloadCommand.php b/src/StaticPHP/Command/DownloadCommand.php
index 277585e5..270f5538 100644
--- a/src/StaticPHP/Command/DownloadCommand.php
+++ b/src/StaticPHP/Command/DownloadCommand.php
@@ -6,11 +6,13 @@ namespace StaticPHP\Command;
 
 use StaticPHP\Artifact\ArtifactDownloader;
 use StaticPHP\Artifact\DownloaderOptions;
+use StaticPHP\Registry\ArtifactLoader;
 use StaticPHP\Registry\PackageLoader;
 use StaticPHP\Util\DependencyResolver;
 use StaticPHP\Util\FileSystem;
 use StaticPHP\Util\InteractiveTerm;
 use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Completion\CompletionInput;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputOption;
 
@@ -19,7 +21,17 @@ class DownloadCommand extends BaseCommand
 {
     public function configure(): void
     {
-        $this->addArgument('artifacts', InputArgument::OPTIONAL, 'Specific artifacts to download, comma separated, e.g "php-src,openssl,curl"');
+        $this->addArgument(
+            'artifacts',
+            InputArgument::OPTIONAL,
+            'Specific artifacts to download, comma separated, e.g "php-src,openssl,curl"',
+            suggestedValues: function (CompletionInput $input) {
+                $input_val = $input->getCompletionValue();
+                $all_names = ArtifactLoader::getLoadedArtifactNames();
+                // filter by input value
+                return array_filter($all_names, fn ($name) => str_starts_with($name, $input_val));
+            },
+        );
 
         // 2.x compatible options
         $this->addOption('shallow-clone', null, null, '(deprecated) Clone shallowly repositories when downloading sources');
diff --git a/src/StaticPHP/Command/InstallPackageCommand.php b/src/StaticPHP/Command/InstallPackageCommand.php
index 89814f01..23032261 100644
--- a/src/StaticPHP/Command/InstallPackageCommand.php
+++ b/src/StaticPHP/Command/InstallPackageCommand.php
@@ -6,14 +6,29 @@ namespace StaticPHP\Command;
 
 use StaticPHP\DI\ApplicationContext;
 use StaticPHP\Package\PackageInstaller;
+use StaticPHP\Registry\PackageLoader;
 use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Completion\CompletionInput;
+use Symfony\Component\Console\Input\InputArgument;
 
 #[AsCommand('install-pkg', 'Install additional package', ['i', 'install-package'])]
 class InstallPackageCommand extends BaseCommand
 {
-    public function configure()
+    public function configure(): void
     {
-        $this->addArgument('package', null, 'The package to install (name or path)');
+        $this->addArgument(
+            'package',
+            InputArgument::REQUIRED,
+            'The package to install (name or path)',
+            suggestedValues: function (CompletionInput $input) {
+                $packages = [];
+                foreach (PackageLoader::getPackages(['target', 'virtual-target']) as $name => $_) {
+                    $packages[] = $name;
+                }
+                $val = $input->getCompletionValue();
+                return array_filter($packages, fn ($name) => str_starts_with($name, $val));
+            }
+        );
     }
 
     public function handle(): int
diff --git a/src/StaticPHP/Registry/ArtifactLoader.php b/src/StaticPHP/Registry/ArtifactLoader.php
index 22942452..d53d9be0 100644
--- a/src/StaticPHP/Registry/ArtifactLoader.php
+++ b/src/StaticPHP/Registry/ArtifactLoader.php
@@ -69,6 +69,17 @@ class ArtifactLoader
         }
     }
 
+    /**
+     * Get names of all loaded artifacts.
+     *
+     * @return string[]
+     */
+    public static function getLoadedArtifactNames(): array
+    {
+        self::initArtifactInstances();
+        return array_keys(self::$artifacts ?? []);
+    }
+
     /**
      * Process #[CustomSource] attribute.
      */