diff --git a/controllers/API.php b/controllers/API.php
index e116abc..be65c20 100644
--- a/controllers/API.php
+++ b/controllers/API.php
@@ -44,19 +44,28 @@ class API {
       ]);
     }
 
-    # Require source and target parameters
-    if((!$source=$request->get('source')) || (!$target=$request->get('target'))) {
+    # Require source and target or target_domain parameters
+    $target = $target_domain = null;
+    if((!$source=$request->get('source')) || ((!$target=$request->get('target')) && (!$target_domain=$request->get('target_domain')))) {
       return $this->respond($response, 400, [
         'error' => 'missing_parameters',
-        'error_description' => 'The source or target parameters were missing'
+        'error_description' => 'The source or target or target_domain parameters were missing'
+      ]);
+    }
+    if($target && $target_domain) {
+      return $this->respond($response, 400, [
+        'error' => 'invalid_parameter',
+        'error_description' => 'Can\'t provide both target and target_domain together'
       ]);
     }
 
     $urlregex = '/^https?:\/\/[^ ]+\.[^ ]+$/';
+    $domainregex = '/^[^ ]+$/';
 
     # Verify source, target, and callback are URLs
     $callback = $request->get('callback');
-    if(!preg_match($urlregex, $source) || !preg_match($urlregex, $target) ||
+    if(!preg_match($urlregex, $source) ||
+       (!preg_match($urlregex, $target) && !preg_match($domainregex, $target_domain)) ||
        ($callback && !preg_match($urlregex, $callback))) {
       return $this->respond($response, 400, [
         'error' => 'invalid_parameter',
@@ -90,44 +99,59 @@ class API {
 
     $xpath = new DOMXPath($doc);
 
-    $found = false;
+    $found = [];
     foreach($xpath->query('//a[@href]') as $href) {
-      if($href->getAttribute('href') == $target) {
-        $found = true;
-        continue;
+      $url = $href->getAttribute('href');
+      $domain = parse_url($url, PHP_URL_HOST);
+      if($url == $target || $domain == $target_domain ||
+         # subdomain check
+         ($target_domain and substr_compare($domain, '.' . $target_domain, -(strlen($target_domain) + 1)) == 0)) {
+        $found[$url] = null;
       }
     }
 
     if(!$found) {
       return $this->respond($response, 400, [
         'error' => 'no_link_found',
-        'error_description' => 'The source document does not have a link to the target URL'
+        'error_description' => 'The source document does not have a link to the target URL or domain'
       ]);
     }
 
     # Everything checked out, so write the webmention to the log and queue a job to start sending
+    # TODO: database transaction?
+
+    $statusURLs = [];
+    foreach($found as $url=>$_) {
+      $w = ORM::for_table('webmentions')->create();
+      $w->site_id = $role->site_id;
+      $w->created_by = $role->user_id;
+      $w->created_at = date('Y-m-d H:i:s');
+      $w->token = self::generateStatusToken();
+      $w->source = $source;
+      $w->target = $url;
+      $w->vouch = $request->get('vouch');
+      $w->callback = $callback;
+      $w->save();
+
+      q()->queue('Telegraph\Webmention', 'send', [$w->id]);
+
+      $statusURLs[] = Config::$base . 'webmention/' . $w->token;
+    }
 
-    $w = ORM::for_table('webmentions')->create();
-    $w->site_id = $role->site_id;
-    $w->created_by = $role->user_id;
-    $w->created_at = date('Y-m-d H:i:s');
-    $w->token = self::generateStatusToken();
-    $w->source = $source;
-    $w->target = $target;
-    $w->vouch = $request->get('vouch');
-    $w->callback = $callback;
-    $w->save();
-
-    q()->queue('Telegraph\Webmention', 'send', [$w->id]);
-
-    $statusURL = Config::$base . 'webmention/' . $w->token;
-
-    return $this->respond($response, 201, [
-      'status' => 'queued',
-      'location' => $statusURL
-    ], [
-      'Location' => $statusURL
-    ]);
+    if ($target) {
+      $body = [
+        'status' => 'queued',
+        'location' => $statusURLs[0]
+      ];
+      $headers = ['Location' => $statusURLs[0]];
+    } else {
+      $body = [
+        'status' => 'queued',
+        'location' => $statusURLs
+      ];
+      $headers = [];
+    }
+    return $this->respond($response, 201, $body, $headers);
   }
 
   public function webmention_status(Request $request, Response $response, $args) {
diff --git a/tests/APITest.php b/tests/APITest.php
index 9012386..a447f0b 100644
--- a/tests/APITest.php
+++ b/tests/APITest.php
@@ -46,6 +46,22 @@ class APITest extends PHPUnit_Framework_TestCase {
     $role->save();
   }
 
+  private function _assertQueued($source, $target, $status_url) {
+    preg_match('/\/webmention\/(.+)/', $status_url, $match);
+    $this->assertNotNull($match);
+
+    # Verify it queued the mention in the database
+    $d = ORM::for_table('webmentions')->where(['source' => $source, 'target' => $target])->find_one();
+    $this->assertNotNull($d);
+    $this->assertEquals($match[1], $d->token);
+
+    # Check the status endpoint to make sure it says it's still queued
+    $response = $this->status($d->token);
+    $this->assertEquals(200, $response->getStatusCode());
+    $data = json_decode($response->getContent());
+    $this->assertEquals('queued', $data->status);
+  }
+
   public function testAuthentication() {
     $response = $this->webmention([]);
     $this->assertEquals(401, $response->getStatusCode());
@@ -82,6 +98,20 @@ class APITest extends PHPUnit_Framework_TestCase {
     $this->assertEquals(400, $response->getStatusCode());
     $data = json_decode($response->getContent());
     $this->assertEquals('missing_parameters', $data->error);
+
+    $response = $this->webmention(['token'=>'a','target_domain'=>'foo']);
+    $this->assertEquals(400, $response->getStatusCode());
+    $data = json_decode($response->getContent());
+    $this->assertEquals('missing_parameters', $data->error);
+  }
+
+  public function testTargetAndTargetDomain() {
+    $this->_createExampleAccount();
+
+    $response = $this->webmention(['token'=>'a','source'=>'foo','target'=>'foo','target_domain'=>'foo']);
+    $this->assertEquals(400, $response->getStatusCode());
+    $data = json_decode($response->getContent());
+    $this->assertEquals('invalid_parameter', $data->error);
   }
 
   public function testInvalidURLs() {
@@ -122,7 +152,7 @@ class APITest extends PHPUnit_Framework_TestCase {
     $this->assertEquals(false, property_exists($data, 'error'));
   }
 
-  public function testQueuesWebmention() {
+  public function testTargetQueuesWebmention() {
     $this->_createExampleAccount();
 
     $response = $this->webmention(['token'=>'a','source'=>'http://source.example.com/basictest','target'=>'http://target.example.com']);
@@ -130,21 +160,35 @@ class APITest extends PHPUnit_Framework_TestCase {
     $data = json_decode($response->getContent());
     $this->assertEquals(false, property_exists($data, 'error'));
     $this->assertEquals('queued', $data->status);
-    $this->assertEquals(true, property_exists($data, 'location'));
+    $this->_assertQueued('http://source.example.com/basictest', 'http://target.example.com', $data->location);
+  }
 
-    preg_match('/\/webmention\/(.+)/', $data->location, $match);
-    $this->assertNotNull($match);
+  public function testTargetDomainQueuesOneWebmention() {
+    $this->_createExampleAccount();
 
-    # Verify it queued the mention in the database
-    $d = ORM::for_table('webmentions')->where(['source' => 'http://source.example.com/basictest', 'target' => 'http://target.example.com'])->find_one();
-    $this->assertNotNull($d);
-    $this->assertEquals($match[1], $d->token);
+    $response = $this->webmention(['token'=>'a','source'=>'http://source.example.com/basictest','target_domain'=>'target.example.com']);
+    $body = $response->getContent();
+    $this->assertEquals(201, $response->getStatusCode(), $body);
+    $data = json_decode($body);
+    $this->assertEquals(false, property_exists($data, 'error'), $body);
+    $this->assertEquals('queued', $data->status, $body);
+    $this->assertEquals(true, property_exists($data, 'location'), $body);
+    $this->assertEquals(1, count($data->location), $body);
+    $this->_assertQueued('http://source.example.com/basictest', 'http://target.example.com', $data->location[0]);
+  }
 
-    # Check the status endpoint to make sure it says it's still queued
-    $response = $this->status($d->token);
-    $this->assertEquals(200, $response->getStatusCode());
-    $data = json_decode($response->getContent());
-    $this->assertEquals('queued', $data->status);
+  public function testTargetDomainQueuesMultipleWebmentions() {
+    $this->_createExampleAccount();
+
+    $response = $this->webmention(['token'=>'a','source'=>'http://source.example.com/basictest','target_domain'=>'example.com']);
+    $body = $response->getContent();
+    $this->assertEquals(201, $response->getStatusCode(), $body);
+    $data = json_decode($body);
+    $this->assertEquals(false, property_exists($data, 'error'), $body);
+    $this->assertEquals('queued', $data->status, $body);
+    $this->assertEquals(2, count($data->location), $body);
+    $this->_assertQueued('http://source.example.com/basictest', 'http://target.example.com', $data->location[0]);
+    $this->_assertQueued('http://source.example.com/basictest', 'http://target2.example.com', $data->location[1]);
   }
 
   public function testStatusNotFound() {
diff --git a/tests/data/source.example.com/basictest b/tests/data/source.example.com/basictest
index 0841787..b22f10b 100644
--- a/tests/data/source.example.com/basictest
+++ b/tests/data/source.example.com/basictest
@@ -9,6 +9,6 @@ Connection: keep-alive
     <title>Test</title>
   </head>
   <body class="h-entry">
-    <p class="e-content">This page has a link to <a href="http://target.example.com">target.example.com</a>.</p>
+    <p class="e-content">This page has links to <a href="http://target.example.com">target.example.com</a> and <a href="http://target2.example.com">target2.example.com</a>.</p>
   </body>
 </html>