diff --git a/src/classes/cli/commands/errors/argument-missing.class.php b/src/classes/cli/commands/errors/argument-missing.class.php
new file mode 100644
index 0000000..2270c0f
--- /dev/null
+++ b/src/classes/cli/commands/errors/argument-missing.class.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace Obadiah\Cli\Commands\Errors;
+
+use Obadiah\App;
+use Obadiah\Cli\Command;
+
+App::check();
+
+class Argument_Missing extends Command
+{
+    /**
+     * Executed when a Command requires an argument that is missing.
+     *
+     * @param string $command_name              Command name.
+     * @param string $arg_long                  Long form of the missing argument.
+     * @param string|null $arg_short            Optional short form of the missing argument.
+     * @return void
+     */
+    public function __construct(
+        public readonly string $command_name,
+        public readonly string $arg_long,
+        public readonly ?string $arg_short
+    ) {}
+
+    /**
+     * Output error message and exit.
+     *
+     * @return never
+     */
+    public function execute(): void
+    {
+        App::die("Command %s requires parameter %s%s.", $this->command_name, $this->arg_long, $this->arg_short == null ? "" : " | $this->arg_short");
+    }
+}
diff --git a/src/classes/cli/commands/errors/invalid.class.php b/src/classes/cli/commands/errors/invalid.class.php
new file mode 100644
index 0000000..7add37b
--- /dev/null
+++ b/src/classes/cli/commands/errors/invalid.class.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Obadiah\Cli\Commands\Errors;
+
+use Obadiah\App;
+use Obadiah\Cli\Command;
+
+App::check();
+
+class Invalid extends Command
+{
+    /**
+     * Executed when something goes wrong creating an instance of a command.
+     *
+     * @param string $command_class         Command class name.
+     * @return void
+     */
+    public function __construct(
+        public readonly string $command_class
+    ) {}
+
+    /**
+     * Output error message and exit.
+     *
+     * @return never
+     */
+    public function execute(): void
+    {
+        App::die("Error creating %s.", $this->command_class);
+    }
+}
diff --git a/src/classes/cli/commands/errors/unknown.class.php b/src/classes/cli/commands/errors/unknown.class.php
new file mode 100644
index 0000000..85de863
--- /dev/null
+++ b/src/classes/cli/commands/errors/unknown.class.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Obadiah\Cli\Commands\Errors;
+
+use Obadiah\App;
+use Obadiah\Cli\Command;
+
+App::check();
+
+class Unknown extends Command
+{
+    /**
+     * Executed when a command has been called and is not mapped to an implementation class.
+     *
+     * @param string $command_name          Command name.
+     * @return void
+     */
+    public function __construct(
+        public readonly string $command_name
+    ) {}
+
+    /**
+     * Output error message and exit.
+     *
+     * @return never
+     */
+    public function execute(): void
+    {
+        App::die("Unknown command: %s.", $this->command_name);
+    }
+}
diff --git a/src/classes/cli/commands/hello-world.class.php b/src/classes/cli/commands/hello-world.class.php
new file mode 100644
index 0000000..406b4e4
--- /dev/null
+++ b/src/classes/cli/commands/hello-world.class.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace Obadiah\Cli\Commands;
+
+use Obadiah\App;
+use Obadiah\Cli\Argument;
+use Obadiah\Cli\Command;
+
+App::check();
+
+class Hello_World extends Command
+{
+    /**
+     * Create command.
+     *
+     * @param string $person                The person to say hello to.
+     * @return void
+     */
+    public function __construct(
+        #[Argument("The name of the person to say hello to.", long: "to", required: true)]
+        public readonly string $person
+    ) {}
+
+    /**
+     * Say hello!
+     *
+     * @return void
+     */
+    public function execute(): void
+    {
+        App::die("Hello, $this->person!");
+    }
+}
diff --git a/src/classes/cli/commands/password-hash.class.php b/src/classes/cli/commands/password-hash.class.php
new file mode 100644
index 0000000..6bc4c41
--- /dev/null
+++ b/src/classes/cli/commands/password-hash.class.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace Obadiah\Cli\Commands;
+
+use Obadiah\App;
+use Obadiah\Cli\Argument;
+use Obadiah\Cli\Command;
+use Obadiah\Crypto\Crypto;
+use SensitiveParameter;
+
+App::check();
+
+class Password_Hash extends Command
+{
+    /**
+     * Create command.
+     *
+     * @param string $password              The password to hash.
+     * @return void
+     */
+    public function __construct(
+        #[Argument("The password to hash.", short: "p", required: true)]
+        #[SensitiveParameter] public readonly string $password
+    ) {}
+
+    /**
+     * Output the hashed password.
+     *
+     * @return never
+     */
+    public function execute(): void
+    {
+        App::die(Crypto::hash_password($this->password));
+    }
+}
diff --git a/src/api/safeguarding/safeguarding.class.php b/src/pages/safeguarding/safeguarding.class.php
similarity index 100%
rename from src/api/safeguarding/safeguarding.class.php
rename to src/pages/safeguarding/safeguarding.class.php