diff --git a/common.c b/common.c
index 4b7e6bf..10d4293 100644
--- a/common.c
+++ b/common.c
@@ -32,6 +32,7 @@
 
 #include "liberty/liberty.c"
 #include <setjmp.h>
+#include <inttypes.h>
 #include <arpa/inet.h>
 
 // --- Logging -----------------------------------------------------------------
@@ -639,10 +640,95 @@ config_item_get (struct config_item_ *self, const char *path)
 	// TODO
 }
 
-static void
-config_item_write (struct config_item_ *root, struct str *output)
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+struct config_writer
 {
-	// TODO
+	struct str *output;
+	unsigned indent;
+};
+
+static void config_item_write_object_innards
+	(struct config_writer *self, struct config_item_ *object);
+
+static void
+config_item_write_value (struct config_writer *self, struct config_item_ *value)
+{
+	switch (value->type)
+	{
+	case CONFIG_ITEM_NULL:
+		str_append (self->output, "null");
+		break;
+	case CONFIG_ITEM_BOOLEAN:
+		str_append (self->output, value->value.boolean ? "on" : "off");
+		break;
+	case CONFIG_ITEM_INTEGER:
+		str_append_printf (self->output, "%" PRIi64, value->value.integer);
+		break;
+	case CONFIG_ITEM_STRING:
+	case CONFIG_ITEM_STRING_ARRAY:
+		// TODO
+		break;
+	case CONFIG_ITEM_OBJECT:
+	{
+		char indent[self->indent + 1];
+		memset (indent, '\t', self->indent);
+		indent[self->indent] = 0;
+
+		str_append (self->output, "{\n");
+
+		self->indent++;
+		config_item_write_object_innards (self, value);
+		self->indent--;
+
+		str_append_printf (self->output, "%s}", indent);
+		break;
+	}
+	default:
+		hard_assert (!"invalid item type");
+	}
+}
+
+static void
+config_item_write_kv_pair (struct config_writer *self,
+	const char *key, struct config_item_ *value)
+{
+	char indent[self->indent + 1];
+	memset (indent, '\t', self->indent);
+	indent[self->indent] = 0;
+
+	if (value->schema && value->schema->comment)
+		str_append_printf (self->output,
+			"%s# %s\n", indent, value->schema->comment);
+
+	str_append_printf (self->output, "%s%s = ", indent, key);
+	config_item_write_value (self, value);
+	str_append_c (self->output, '\n');
+}
+
+static void
+config_item_write_object_innards
+	(struct config_writer *self, struct config_item_ *object)
+{
+	hard_assert (object->type == CONFIG_ITEM_OBJECT);
+
+	struct str_map_iter iter;
+	str_map_iter_init (&iter, &object->value.object);
+
+	struct config_item_ *value;
+	while ((value = str_map_iter_next (&iter)))
+		config_item_write_kv_pair (self, iter.link->key, value);
+}
+
+static void
+config_item_write (struct config_item_ *value,
+	bool object_innards, struct str *output)
+{
+	struct config_writer writer = { .output = output, .indent = 0 };
+	if (object_innards)
+		config_item_write_object_innards (&writer, value);
+	else
+		config_item_write_value (&writer, value);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -