diff --git a/src/Runner/Application.php b/src/Runner/Application.php
index e142742..0a19d0f 100644
--- a/src/Runner/Application.php
+++ b/src/Runner/Application.php
@@ -1,23 +1,139 @@
 <?php
 
 namespace Nasqueron\SAAS\PhpBB\Runner;
 
 use Keruald\Commands\Command;
 use Keruald\Commands\ExitCode;
 
 use Dotenv\Dotenv;
 
+use InvalidArgumentException;
+use BadMethodCallException;
+use Exception;
+
 class Application extends Command {
 
+    /**
+     * @var string
+     */
+    private $taskName;
+
+    /**
+     * @var string
+     */
+    private $taskClassName = "";
+
     public function main () : int {
+
         self::loadEnvironment();
 
-        return ExitCode::SUCCESS;
+        if ($this->getArgc() > 1) {
+            $this->taskName = $this->getArgv()[1];
+            return $this->runTask();
+        }
+
+        $this->printUsage();
+        return ExitCode::ILLEGAL_OPTION;
     }
 
     private static function loadEnvironment () : void {
         $dotenv = new Dotenv(__DIR__);
         $dotenv->safeLoad();
     }
 
+    ///
+    /// Runner helper methods
+    ///
+
+    private function runTask () : int {
+        try {
+            $this->resolveTaskName();
+        } catch (InvalidArgumentException $exception) {
+            $this->getDisplay()->error("Unknown command " . $this->taskName);
+            return ExitCode::ILLEGAL_OPTION;
+        }
+
+        try {
+            $this->callTaskRunner();
+        } catch (BadMethodCallException $ex) {
+            $this->printUsageForTask();
+            return ExitCode::ILLEGAL_OPTION;
+        } catch (Exception $ex) {
+            $this->handleTaskException($ex);
+            return ExitCode::FAILURE;
+        }
+
+        return ExitCode::SUCCESS;
+    }
+
+    /**
+     * Finds if a tasks with this name exists, and resolves class name.
+     *
+     * @throws \InvalidArgumentException
+     */
+    private function resolveTaskName () : void {
+        $this->taskClassName = TasksMap::getTaskClassName($this->taskName);
+    }
+
+    /**
+     * @throws \BadMethodCallException
+     * @throws \Exception
+     */
+    private function callTaskRunner () : void {
+        forward_static_call(
+            [$this->taskClassName, "runWithArgs"],
+            $this->getTaskArguments()
+        );
+    }
+
+    private function getTaskArguments () : array {
+        // At this stage, the argv array contains
+        // saas-phpbb <task name> [arguments for the tasks]
+        //                        ~~~~~~~~~~~~~~~~~~~~~~~~~
+        //                        ^ the part we return
+
+        return array_slice($this->getArgv(), 2);
+    }
+
+    ///
+    /// Task errors methods
+    ///
+
+    private function handleTaskException (Exception $ex) : void {
+        $this->printTaskError($ex->getMessage());
+    }
+
+    private function printTaskError (string $message) : void {
+        $this->getDisplay()->error(
+            $this->getTaskPrefix() . ": " . $message
+        );
+    }
+
+    private function getTaskPrefix () : string {
+        return $this->getCommandName() . " " . $this->taskName;
+    }
+
+    ///
+    /// Usage helper methods
+    ///
+
+    private function printUsage () {
+        $name = $this->getCommandName();
+        $this->getDisplay()->error("Usage: $name <task> [arguments]");
+    }
+
+    private function printUsageForTask () {
+        $usage = $this->getUsageForTask();
+        $usage = str_replace('%command%', $this->taskName, $usage);
+        $this->getDisplay()->error($usage);
+    }
+
+    private function getUsageForTask () : string {
+        if ($this->taskClassName === "") {
+            $this->resolveTaskName();
+        }
+
+        return forward_static_call([$this->taskClassName, "getUsage"]);
+    }
+
 }
diff --git a/src/Runner/TasksMap.php b/src/Runner/TasksMap.php
new file mode 100644
index 0000000..27bbae8
--- /dev/null
+++ b/src/Runner/TasksMap.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace Nasqueron\SAAS\PhpBB\Runner;
+
+use InvalidArgumentException;
+
+use Nasqueron\SAAS\PhpBB\Tasks\BootstrapSqliteRepository;
+
+class TasksMap {
+
+    public static function getMap () : array {
+        return [
+            'sites:bootstrap' => BootstrapSqliteRepository::class,
+        ];
+    }
+
+    public static function getTaskClassName (string $command) {
+        foreach (self::getMap() as $taskCommand => $taskClassName) {
+            if ($command === $taskCommand) {
+                return $taskClassName;
+            }
+        }
+
+        throw new InvalidArgumentException;
+    }
+
+}
diff --git a/src/Tasks/BootstrapSqliteRepository.php b/src/Tasks/BootstrapSqliteRepository.php
index f131b4d..9bd6f58 100644
--- a/src/Tasks/BootstrapSqliteRepository.php
+++ b/src/Tasks/BootstrapSqliteRepository.php
@@ -1,26 +1,46 @@
 <?php
 
 namespace Nasqueron\SAAS\PhpBB\Tasks;
 
 use Nasqueron\SAAS\PhpBB\SitesRepository\SqliteRepository;
 
 class BootstrapSqliteRepository extends Task {
 
     /**
      * @var string
      */
     private $filename;
 
     public function __construct (?string $filename = null) {
         $this->filename = $filename ?? $this->getDefaultFilename();
     }
 
+    ///
+    /// Public methods
+    ///
+
     public function run () : void {
         (new SqliteRepository($this->filename))->bootstrap();
     }
 
+    public static function getUsage () : string {
+
+        return <<<DOC
+%command% [path to site database]: creates a database with the required table
+
+If the path is omitted, the path is extracted from the environment.
+
+You can set the default path setting SAAS_SITES_DB environment variable.
+DOC;
+
+    }
+
+    ///
+    /// Helper methods
+    ///
+
     private function getDefaultFilename() : string {
-        return $_ENV["SAAS_SITES_DB"];
+        return getenv("SAAS_SITES_DB");
     }
 
 }
diff --git a/src/Tasks/Task.php b/src/Tasks/Task.php
index 088ccaf..cff9b28 100644
--- a/src/Tasks/Task.php
+++ b/src/Tasks/Task.php
@@ -1,9 +1,36 @@
 <?php
 
 namespace Nasqueron\SAAS\PhpBB\Tasks;
 
+use BadMethodCallException;
+use TypeError;
+
 abstract class Task {
 
+    ///
+    /// Usage methods
+    ///
+
+    abstract public static function getUsage () : string;
+
+    ///
+    /// Runner methods
+    ///
+
     abstract public function run () : void;
 
+    /**
+     * @param string[] $args
+     * @suppress PhanParamTooMany
+     */
+    public static function runWithArgs (array $args) : void {
+        try {
+            $task = new static(...$args);
+        } catch (TypeError $exception) {
+            throw new BadMethodCallException;
+        }
+
+        $task->run();
+    }
+
 }
diff --git a/tests/Tasks/BootstrapSqliteRepositoryTest.php b/tests/Tasks/BootstrapSqliteRepositoryTest.php
index 6e02aa1..ba0cccc 100644
--- a/tests/Tasks/BootstrapSqliteRepositoryTest.php
+++ b/tests/Tasks/BootstrapSqliteRepositoryTest.php
@@ -1,50 +1,51 @@
 <?php
 declare(strict_types=1);
 
 namespace Nasqueron\SAAS\PhpBB\Tests\Tasks;
 
 use Nasqueron\SAAS\PhpBB\Tasks\BootstrapSqliteRepository;
 use Nasqueron\SAAS\PhpBB\Tests\Utilities\WithSqliteAssertions;
 use PHPUnit\Framework\TestCase;
 
 final class BootstrapSqliteRepositoryTest extends TestCase {
 
     use WithSqliteAssertions;
 
     /**
      * @var string
      */
     private $filename;
 
     ///
     /// Fixtures
     ///
 
     public function setUp () {
         $this->filename = tempnam("", "test-db-");
     }
 
     public function tearDown () {
         unlink($this->filename);
     }
 
     ///
     /// Tests
     ///
 
     public function testBootstrap () : void {
         $task = new BootstrapSqliteRepository($this->filename);
         $task->run();
 
         $this->assertDatabaseHasBeenCreated($this->filename);
     }
 
     public function testBootstrapWithDefaultFile () : void {
-        $_ENV["SAAS_SITES_DB"] = $this->filename;
+        putenv("SAAS_SITES_DB=$this->filename"); // default file
+
         $task = new BootstrapSqliteRepository();
         $task->run();
 
         $this->assertDatabaseHasBeenCreated($this->filename);
     }
 
 }