diff --git a/src/Model/User.php b/src/Model/User.php
index 990df65db..c329ef91a 100644
--- a/src/Model/User.php
+++ b/src/Model/User.php
@@ -99,6 +99,105 @@ class User
 
 	private static $owner;
 
+	/**
+	 * Fetch the system account
+	 *
+	 * @return array system account
+	 */
+	public static function getSystemAccount()
+	{
+		$system = Contact::selectFirst([], ['self' => true, 'uid' => 0]);
+		if (!DBA::isResult($system)) {
+			self::createSystemAccount();
+			$system = Contact::selectFirst([], ['self' => true, 'uid' => 0]);
+			if (!DBA::isResult($system)) {
+				return [];
+			}
+		}
+
+		$system['spubkey'] = $system['uprvkey'] = $system['prvkey'];
+		$system['username'] = $system['name'];
+		$system['nickname'] = $system['nick'];
+		return $system;
+	}
+
+	/**
+	 * Create the system account
+	 *
+	 * @return void
+	 */
+	private static function createSystemAccount()
+	{
+		$system_actor_name = self::getActorName();
+		if (empty($system_actor_name)) {
+			return;
+		}
+
+		$keys = Crypto::newKeypair(4096);
+		if ($keys === false) {
+			throw new Exception(DI::l10n()->t('SERIOUS ERROR: Generation of security keys failed.'));
+		}
+
+		$system = [];
+		$system['uid'] = 0;
+		$system['created'] = DateTimeFormat::utcNow();
+		$system['self'] = true;
+		$system['network'] = Protocol::ACTIVITYPUB;
+		$system['name'] = 'System Account';
+		$system['addr'] = $system_actor_name . '@' . DI::baseUrl()->getHostname();
+		$system['nick'] = $system_actor_name;
+		$system['avatar'] = DI::baseUrl() . Contact::DEFAULT_AVATAR_PHOTO;
+		$system['photo'] = DI::baseUrl() . Contact::DEFAULT_AVATAR_PHOTO;
+		$system['thumb'] = DI::baseUrl() . Contact::DEFAULT_AVATAR_THUMB;
+		$system['micro'] = DI::baseUrl() . Contact::DEFAULT_AVATAR_MICRO;
+		$system['url'] = DI::baseUrl() . '/friendica';
+		$system['nurl'] = Strings::normaliseLink($system['url']);
+		$system['pubkey'] = $keys['pubkey'];
+		$system['prvkey'] = $keys['prvkey'];
+		$system['blocked'] = 0;
+		$system['pending'] = 0;
+		$system['contact-type'] = Contact::TYPE_RELAY; // In AP this is translated to 'Application'
+		$system['name-date'] = DateTimeFormat::utcNow();
+		$system['uri-date'] = DateTimeFormat::utcNow();
+		$system['avatar-date'] = DateTimeFormat::utcNow();
+		$system['closeness'] = 0;
+		$system['baseurl'] = DI::baseUrl();
+		$system['gsid'] = GServer::getID($system['baseurl']);
+		DBA::insert('contact', $system);
+	}
+
+	/**
+	 * Detect a usable actor name
+	 *
+	 * @return string actor account name
+	 */
+	public static function getActorName()
+	{
+		$system_actor_name = DI::config()->get('system', 'actor_name');
+		if (!empty($system_actor_name)) {
+			$self = Contact::selectFirst(['nick'], ['uid' => 0, 'self' => true]);
+			if (!empty($self['nick'])) {
+				if ($self['nick'] != $system_actor_name) {
+					// Reset the actor name to the already used name
+					DI::config()->set('system', 'actor_name', $self['nick']);
+					$system_actor_name = $self['nick'];
+				}
+			}
+			return $system_actor_name;
+		}
+
+		// List of possible actor names
+		$possible_accounts = ['friendica', 'actor', 'system', 'internal'];
+		foreach ($possible_accounts as $name) {
+			if (!DBA::exists('user', ['nickname' => $name, 'account_removed' => false, 'expire']) &&
+				!DBA::exists('userd', ['username' => $name])) {
+				DI::config()->set('system', 'actor_name', $name);
+				return $name;
+			}
+		}
+		return '';
+	}
+
 	/**
 	 * Returns true if a user record exists with the provided id
 	 *
@@ -588,15 +687,24 @@ class User
 	public static function isNicknameBlocked($nickname)
 	{
 		$forbidden_nicknames = DI::config()->get('system', 'forbidden_nicknames', '');
+		if (!empty($forbidden_nicknames)) {
+			$forbidden = explode(',', $forbidden_nicknames);
+			$forbidden = array_map('trim', $forbidden);
+		} else {
+			$forbidden = [];
+		}
 
-		// if the config variable is empty return false
-		if (empty($forbidden_nicknames)) {
+		// Add the name of the internal actor to the "forbidden" list
+		$actor_name = self::getActorName();
+		if (!empty($actor_name)) {
+			$forbidden[] = $actor_name;
+		}
+
+		if (empty($forbidden)) {
 			return false;
 		}
 
 		// check if the nickname is in the list of blocked nicknames
-		$forbidden = explode(',', $forbidden_nicknames);
-		$forbidden = array_map('trim', $forbidden);
 		if (in_array(strtolower($nickname), $forbidden)) {
 			return true;
 		}
diff --git a/src/Module/Admin/Site.php b/src/Module/Admin/Site.php
index 7cc17fa03..de1ba5f8b 100644
--- a/src/Module/Admin/Site.php
+++ b/src/Module/Admin/Site.php
@@ -29,6 +29,7 @@ use Friendica\Core\Worker;
 use Friendica\Database\DBA;
 use Friendica\DI;
 use Friendica\Model\Contact;
+use Friendica\Model\User;
 use Friendica\Module\BaseAdmin;
 use Friendica\Module\Register;
 use Friendica\Util\BasePath;
@@ -148,6 +149,7 @@ class Site extends BaseAdmin
 		$allowed_sites          = (!empty($_POST['allowed_sites'])           ? Strings::escapeTags(trim($_POST['allowed_sites']))  : '');
 		$allowed_email          = (!empty($_POST['allowed_email'])           ? Strings::escapeTags(trim($_POST['allowed_email']))  : '');
 		$forbidden_nicknames    = (!empty($_POST['forbidden_nicknames'])     ? strtolower(Strings::escapeTags(trim($_POST['forbidden_nicknames']))) : '');
+		$system_actor_name      = (!empty($_POST['system_actor_name'])       ? Strings::escapeTags(trim($_POST['system_actor_name'])) : '');
 		$no_oembed_rich_content = !empty($_POST['no_oembed_rich_content']);
 		$allowed_oembed         = (!empty($_POST['allowed_oembed'])          ? Strings::escapeTags(trim($_POST['allowed_oembed'])) : '');
 		$block_public           = !empty($_POST['block_public']);
@@ -355,6 +357,7 @@ class Site extends BaseAdmin
 		DI::config()->set('system', 'allowed_sites'          , $allowed_sites);
 		DI::config()->set('system', 'allowed_email'          , $allowed_email);
 		DI::config()->set('system', 'forbidden_nicknames'    , $forbidden_nicknames);
+		DI::config()->set('system', 'system_actor_name'      , $system_actor_name);
 		DI::config()->set('system', 'no_oembed_rich_content' , $no_oembed_rich_content);
 		DI::config()->set('system', 'allowed_oembed'         , $allowed_oembed);
 		DI::config()->set('system', 'block_public'           , $block_public);
@@ -600,6 +603,7 @@ class Site extends BaseAdmin
 			// name, label, value, help string, extra data...
 			'$sitename'         => ['sitename', DI::l10n()->t('Site name'), DI::config()->get('config', 'sitename'), ''],
 			'$sender_email'     => ['sender_email', DI::l10n()->t('Sender Email'), DI::config()->get('config', 'sender_email'), DI::l10n()->t('The email address your server shall use to send notification emails from.'), '', '', 'email'],
+			'$system_actor_name' => ['system_actor_name', DI::l10n()->t('Name of the system actor'), User::getActorName(), DI::l10n()->t("Name of the internal system account that is used to perform ActivityPub requests. This must be an unused username. If set, this can't be changed again.")],
 			'$banner'           => ['banner', DI::l10n()->t('Banner/Logo'), $banner, ''],
 			'$email_banner'     => ['email_banner', DI::l10n()->t('Email Banner/Logo'), $email_banner, ''],
 			'$shortcut_icon'    => ['shortcut_icon', DI::l10n()->t('Shortcut icon'), DI::config()->get('system', 'shortcut_icon'), DI::l10n()->t('Link to an icon that will be used for browsers.')],
diff --git a/src/Module/Friendica.php b/src/Module/Friendica.php
index ea693ce27..2d76f80d0 100644
--- a/src/Module/Friendica.php
+++ b/src/Module/Friendica.php
@@ -25,8 +25,10 @@ use Friendica\BaseModule;
 use Friendica\Core\Addon;
 use Friendica\Core\Hook;
 use Friendica\Core\Renderer;
+use Friendica\Core\System;
 use Friendica\DI;
 use Friendica\Model\User;
+use Friendica\Protocol\ActivityPub;
 
 /**
  * Prints information about the current node
@@ -108,6 +110,15 @@ class Friendica extends BaseModule
 
 	public static function rawContent(array $parameters = [])
 	{
+		if (ActivityPub::isRequest()) {
+			$data = ActivityPub\Transmitter::getProfile(0);
+			if (!empty($data)) {
+				header('Access-Control-Allow-Origin: *');
+				header('Cache-Control: max-age=23200, stale-while-revalidate=23200');
+				System::jsonExit($data, 'application/activity+json');
+			}
+		}
+
 		$app = DI::app();
 
 		// @TODO: Replace with parameter from router
diff --git a/src/Module/Xrd.php b/src/Module/Xrd.php
index 249c143ff..be6a3bf9c 100644
--- a/src/Module/Xrd.php
+++ b/src/Module/Xrd.php
@@ -24,6 +24,7 @@ namespace Friendica\Module;
 use Friendica\BaseModule;
 use Friendica\Core\Hook;
 use Friendica\Core\Renderer;
+use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
 use Friendica\Model\Photo;
@@ -77,24 +78,30 @@ class Xrd extends BaseModule
 			$name = substr($local, 0, strpos($local, '@'));
 		}
 
-		$user = User::getByNickname($name);
+		if ($name == User::getActorName()) {
+			$owner = User::getSystemAccount();
+			if (empty($owner)) {
+				throw new \Friendica\Network\HTTPException\NotFoundException();
+			}
+			self::printSystemJSON($owner);
+		} else {
+			$user = User::getByNickname($name);
+			if (empty($user)) {
+				throw new \Friendica\Network\HTTPException\NotFoundException();
+			}
 
-		if (empty($user)) {
-			throw new \Friendica\Network\HTTPException\NotFoundException();
+			$owner = User::getOwnerDataById($user['uid']);
+			if (empty($owner)) {
+				DI::logger()->warning('No owner data for user id', ['uri' => $uri, 'name' => $name, 'user' => $user]);
+				throw new \Friendica\Network\HTTPException\NotFoundException();
+			}
+
+			$alias = str_replace('/profile/', '/~', $owner['url']);
+
+			$avatar = Photo::selectFirst(['type'], ['uid' => $owner['uid'], 'profile' => true]);
 		}
 
-		$owner = User::getOwnerDataById($user['uid']);
-
-		if (empty($owner)) {
-			DI::logger()->warning('No owner data for user id', ['uri' => $uri, 'name' => $name, 'user' => $user]);
-			throw new \Friendica\Network\HTTPException\NotFoundException();
-		}
-
-		$alias = str_replace('/profile/', '/~', $owner['url']);
-
-		$avatar = Photo::selectFirst(['type'], ['uid' => $owner['uid'], 'profile' => true]);
-
-		if (!DBA::isResult($avatar)) {
+		if (empty($avatar)) {
 			$avatar = ['type' => 'image/jpeg'];
 		}
 
@@ -105,6 +112,32 @@ class Xrd extends BaseModule
 		}
 	}
 
+	private static function printSystemJSON(array $owner)
+	{
+		$json = [
+			'subject' => 'acct:' . $owner['addr'],
+			'aliases' => [$owner['url']],
+			'links'   => [
+				[
+					'rel'  => 'http://webfinger.net/rel/profile-page',
+					'type' => 'text/html',
+					'href' => $owner['url'],
+				],
+				[
+					'rel'  => 'self',
+					'type' => 'application/activity+json',
+					'href' => $owner['url'],
+				],
+				[
+					'rel'      => 'http://ostatus.org/schema/1.0/subscribe',
+					'template' => DI::baseUrl()->get() . '/follow?url={uri}',
+				],
+			]
+		];
+		header('Access-Control-Allow-Origin: *');
+		System::jsonExit($json, 'application/jrd+json; charset=utf-8');
+	}
+
 	private static function printJSON($alias, $baseURL, $owner, $avatar)
 	{
 		$salmon_key = Salmon::salmonKey($owner['spubkey']);
diff --git a/src/Network/Probe.php b/src/Network/Probe.php
index 99e62fb46..943d53ff6 100644
--- a/src/Network/Probe.php
+++ b/src/Network/Probe.php
@@ -2200,7 +2200,7 @@ class Probe
 			$profile['gsid'] = GServer::getID($approfile['generator']['url']);
 		}
 
-		$data = ['name' => $profile['name'], 'nick' => $profile['nick'], 'guid' => $approfile['diaspora:guid'],
+		$data = ['name' => $profile['name'], 'nick' => $profile['nick'], 'guid' => $approfile['diaspora:guid'] ?? '',
 			'url' => $profile['url'], 'addr' => $profile['addr'], 'alias' => $profile['alias'],
 			'photo' => $profile['photo'], 'account-type' => $profile['contact-type'],
 			'community' => ($profile['contact-type'] == User::ACCOUNT_TYPE_COMMUNITY),
diff --git a/src/Protocol/ActivityPub.php b/src/Protocol/ActivityPub.php
index c04b9e592..359d361b0 100644
--- a/src/Protocol/ActivityPub.php
+++ b/src/Protocol/ActivityPub.php
@@ -90,20 +90,6 @@ class ActivityPub
 	 */
 	public static function fetchContent(string $url, int $uid = 0)
 	{
-		if (empty($uid)) {
-			$user = User::getFirstAdmin(['uid']);
-		
-			if (empty($user['uid'])) {
-				// When the system setup is missing an admin we just take the first user
-				$condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false];
-				$user = DBA::selectFirst('user', ['uid'], $condition);
-			}
-
-			if (!empty($user['uid'])) {
-				$uid = $user['uid'];
-			}
-		}
-
 		return HTTPSignature::fetch($url, $uid);
 	}
 
diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index b4dba53cc..0937859fb 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -774,6 +774,9 @@ class Processor
 		}
 
 		$owner = User::getOwnerDataById($uid);
+		if (empty($owner)) {
+			return;
+		}
 
 		$cid = Contact::getIdForURL($activity['actor'], $uid);
 		if (!empty($cid)) {
@@ -956,6 +959,9 @@ class Processor
 		}
 
 		$owner = User::getOwnerDataById($uid);
+		if (empty($owner)) {
+			return;
+		}
 
 		$cid = Contact::getIdForURL($activity['actor'], $uid);
 		if (empty($cid)) {
diff --git a/src/Protocol/ActivityPub/Transmitter.php b/src/Protocol/ActivityPub/Transmitter.php
index f1b2d3acc..259c8c225 100644
--- a/src/Protocol/ActivityPub/Transmitter.php
+++ b/src/Protocol/ActivityPub/Transmitter.php
@@ -214,39 +214,63 @@ class Transmitter
 	 */
 	public static function getProfile($uid)
 	{
-		$condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
-			'account_removed' => false, 'verified' => true];
-		$fields = ['guid', 'nickname', 'pubkey', 'account-type', 'page-flags'];
-		$user = DBA::selectFirst('user', $fields, $condition);
-		if (!DBA::isResult($user)) {
-			return [];
-		}
+		if ($uid != 0) {
+			$condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
+				'account_removed' => false, 'verified' => true];
+			$fields = ['guid', 'nickname', 'pubkey', 'account-type', 'page-flags'];
+			$user = DBA::selectFirst('user', $fields, $condition);
+			if (!DBA::isResult($user)) {
+				return [];
+			}
 
-		$fields = ['locality', 'region', 'country-name'];
-		$profile = DBA::selectFirst('profile', $fields, ['uid' => $uid]);
-		if (!DBA::isResult($profile)) {
-			return [];
-		}
+			$fields = ['locality', 'region', 'country-name'];
+			$profile = DBA::selectFirst('profile', $fields, ['uid' => $uid]);
+			if (!DBA::isResult($profile)) {
+				return [];
+			}
 
-		$fields = ['name', 'url', 'location', 'about', 'avatar', 'photo'];
-		$contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
-		if (!DBA::isResult($contact)) {
-			return [];
+			$fields = ['name', 'url', 'location', 'about', 'avatar', 'photo'];
+			$contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
+			if (!DBA::isResult($contact)) {
+				return [];
+			}
+		} else {
+			$contact = User::getSystemAccount();
+			$user = ['guid' => '', 'nickname' => $contact['nick'], 'pubkey' => $contact['pubkey'],
+				'account-type' => $contact['contact-type'], 'page-flags' => User::PAGE_FLAGS_NORMAL];
+			$profile = ['locality' => '', 'region' => '', 'country-name' => ''];
 		}
 
 		$data = ['@context' => ActivityPub::CONTEXT];
 		$data['id'] = $contact['url'];
-		$data['diaspora:guid'] = $user['guid'];
+
+		if (!empty($user['guid'])) {
+			$data['diaspora:guid'] = $user['guid'];
+		}
+
 		$data['type'] = ActivityPub::ACCOUNT_TYPES[$user['account-type']];
-		$data['following'] = DI::baseUrl() . '/following/' . $user['nickname'];
-		$data['followers'] = DI::baseUrl() . '/followers/' . $user['nickname'];
-		$data['inbox'] = DI::baseUrl() . '/inbox/' . $user['nickname'];
-		$data['outbox'] = DI::baseUrl() . '/outbox/' . $user['nickname'];
+		
+		if ($uid != 0) {
+			$data['following'] = DI::baseUrl() . '/following/' . $user['nickname'];
+			$data['followers'] = DI::baseUrl() . '/followers/' . $user['nickname'];
+			$data['inbox'] = DI::baseUrl() . '/inbox/' . $user['nickname'];
+			$data['outbox'] = DI::baseUrl() . '/outbox/' . $user['nickname'];
+		} else {
+			$data['inbox'] = DI::baseUrl() . '/friendica/inbox';
+		}
+
 		$data['preferredUsername'] = $user['nickname'];
 		$data['name'] = $contact['name'];
-		$data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
-			'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
-		$data['summary'] = BBCode::convert($contact['about'], false);
+
+		if (!empty($profile['country-name'] . $profile['region'] . $profile['locality'])) {
+			$data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
+				'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
+		}
+
+		if (!empty($contact['about'])) {
+			$data['summary'] = BBCode::convert($contact['about'], false);
+		}
+
 		$data['url'] = $contact['url'];
 		$data['manuallyApprovesFollowers'] = in_array($user['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
 		$data['publicKey'] = ['id' => $contact['url'] . '#main-key',
@@ -652,6 +676,10 @@ class Transmitter
 			$item_profile = APContact::getByURL($item['owner-link'], false);
 		}
 
+		if (empty($item_profile)) {
+			return [];
+		}
+
 		$profile_uid = User::getIdForURL($item_profile['url']);
 
 		foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
diff --git a/src/Util/HTTPSignature.php b/src/Util/HTTPSignature.php
index bbd5cd9b1..5165f600f 100644
--- a/src/Util/HTTPSignature.php
+++ b/src/Util/HTTPSignature.php
@@ -420,23 +420,28 @@ class HTTPSignature
 			if (!$owner) {
 				return;
 			}
-
-			if (!empty($owner['uprvkey'])) {
-				// Header data that is about to be signed.
-				$host = parse_url($request, PHP_URL_HOST);
-				$path = parse_url($request, PHP_URL_PATH);
-				$date = DateTimeFormat::utcNow(DateTimeFormat::HTTP);
-
-				$headers = ['Date: ' . $date, 'Host: ' . $host];
-
-				$signed_data = "(request-target): get " . $path . "\ndate: ". $date . "\nhost: " . $host;
-
-				$signature = base64_encode(Crypto::rsaSign($signed_data, $owner['uprvkey'], 'sha256'));
-
-				$headers[] = 'Signature: keyId="' . $owner['url'] . '#main-key' . '",algorithm="rsa-sha256",headers="(request-target) date host",signature="' . $signature . '"';
+		} else {
+			$owner = User::getSystemAccount();
+			if (!$owner) {
+				return;
 			}
 		}
 
+		if (!empty($owner['uprvkey'])) {
+			// Header data that is about to be signed.
+			$host = parse_url($request, PHP_URL_HOST);
+			$path = parse_url($request, PHP_URL_PATH);
+			$date = DateTimeFormat::utcNow(DateTimeFormat::HTTP);
+
+			$headers = ['Date: ' . $date, 'Host: ' . $host];
+
+			$signed_data = "(request-target): get " . $path . "\ndate: ". $date . "\nhost: " . $host;
+
+			$signature = base64_encode(Crypto::rsaSign($signed_data, $owner['uprvkey'], 'sha256'));
+
+			$headers[] = 'Signature: keyId="' . $owner['url'] . '#main-key' . '",algorithm="rsa-sha256",headers="(request-target) date host",signature="' . $signature . '"';
+		}
+
 		if (!empty($opts['accept_content'])) {
 			$headers[] = 'Accept: ' . $opts['accept_content'];
 		}
diff --git a/view/templates/admin/site.tpl b/view/templates/admin/site.tpl
index 5c63970e9..0c0974134 100644
--- a/view/templates/admin/site.tpl
+++ b/view/templates/admin/site.tpl
@@ -14,6 +14,7 @@
 
 		{{include file="field_input.tpl" field=$sitename}}
 		{{include file="field_input.tpl" field=$sender_email}}
+		{{include file="field_input.tpl" field=$system_actor_name}}
 		{{include file="field_textarea.tpl" field=$banner}}
 		{{include file="field_input.tpl" field=$email_banner}}
 		{{include file="field_input.tpl" field=$shortcut_icon}}
diff --git a/view/theme/frio/templates/admin/site.tpl b/view/theme/frio/templates/admin/site.tpl
index 0136b1cd4..a60cb06b6 100644
--- a/view/theme/frio/templates/admin/site.tpl
+++ b/view/theme/frio/templates/admin/site.tpl
@@ -41,6 +41,7 @@
 					<div class="panel-body">
 						{{include file="field_input.tpl" field=$sitename}}
 						{{include file="field_input.tpl" field=$sender_email}}
+						{{include file="field_input.tpl" field=$system_actor_name}}
 						{{include file="field_textarea.tpl" field=$banner}}
 						{{include file="field_input.tpl" field=$shortcut_icon}}
 						{{include file="field_input.tpl" field=$touch_icon}}