diff --git a/mod/forum/externallib.php b/mod/forum/externallib.php
index 98b144cd4f9..a5f94bd3156 100644
--- a/mod/forum/externallib.php
+++ b/mod/forum/externallib.php
@@ -473,6 +473,29 @@ class mod_forum_external extends external_api {
             $user = username_load_fields_from_object($user, $post);
             $posts[$pid]->userfullname = fullname($user, $canviewfullname);
 
+            // Rewrite embedded images URLs.
+            list($post->message, $post->messageformat) =
+                external_format_text($post->message, $post->messageformat, $modcontext->id, 'mod_forum', 'post', $post->id);
+
+            // List attachments.
+            if (!empty($post->attachment)) {
+                $post->attachments = array();
+
+                $fs = get_file_storage();
+                if ($files = $fs->get_area_files($modcontext->id, 'mod_forum', 'attachment', $post->id, "filename", false)) {
+                    foreach ($files as $file) {
+                        $filename = $file->get_filename();
+
+                        $post->attachments[] = array(
+                            'filename' => $filename,
+                            'mimetype' => $file->get_mimetype(),
+                            'fileurl'  => file_encode_url($CFG->wwwroot.'/webservice/pluginfile.php',
+                                            '/'.$modcontext->id.'/mod_forum/attachment/'.$post->id.'/'.$filename)
+                        );
+                    }
+                }
+            }
+
             $posts[$pid] = (array) $post;
         }
 
@@ -503,9 +526,18 @@ class mod_forum_external extends external_api {
                                 'mailed' => new external_value(PARAM_INT, 'Mailed?'),
                                 'subject' => new external_value(PARAM_TEXT, 'The post subject'),
                                 'message' => new external_value(PARAM_RAW, 'The post message'),
-                                'messageformat' => new external_value(PARAM_INT, 'The post message format'),
+                                'messageformat' => new external_format_value('message'),
                                 'messagetrust' => new external_value(PARAM_INT, 'Can we trust?'),
-                                'attachment' => new external_value(PARAM_RAW, 'Attachments'),
+                                'attachment' => new external_value(PARAM_RAW, 'Has attachments?'),
+                                'attachments' => new external_multiple_structure(
+                                    new external_single_structure(
+                                        array (
+                                            'filename' => new external_value(PARAM_FILE, 'file name'),
+                                            'mimetype' => new external_value(PARAM_RAW, 'mime type'),
+                                            'fileurl'  => new external_value(PARAM_URL, 'file download url')
+                                        )
+                                    ), 'attachments', VALUE_OPTIONAL
+                                ),
                                 'totalscore' => new external_value(PARAM_INT, 'The post message total score'),
                                 'mailnow' => new external_value(PARAM_INT, 'Mail now?'),
                                 'children' => new external_multiple_structure(new external_value(PARAM_INT, 'children post id')),
diff --git a/mod/forum/tests/externallib_test.php b/mod/forum/tests/externallib_test.php
index 3f6c02929e9..9ecbc7ecd37 100644
--- a/mod/forum/tests/externallib_test.php
+++ b/mod/forum/tests/externallib_test.php
@@ -468,14 +468,14 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
             'id' => $discussion1reply2->id,
             'discussion' => $discussion1reply2->discussion,
             'parent' => $discussion1reply2->parent,
-            'userid' => $discussion1reply2->userid,
+            'userid' => (int) $discussion1reply2->userid,
             'created' => $discussion1reply2->created,
             'modified' => $discussion1reply2->modified,
             'mailed' => $discussion1reply2->mailed,
             'subject' => $discussion1reply2->subject,
             'message' => file_rewrite_pluginfile_urls($discussion1reply2->message, 'pluginfile.php',
                     $forum1context->id, 'mod_forum', 'post', $discussion1reply2->id),
-            'messageformat' => $discussion1reply2->messageformat,
+            'messageformat' => 1,   // This value is usually changed by external_format_text() function.
             'messagetrust' => $discussion1reply2->messagetrust,
             'attachment' => $discussion1reply2->attachment,
             'totalscore' => $discussion1reply2->totalscore,
@@ -489,14 +489,14 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
             'id' => $discussion1reply1->id,
             'discussion' => $discussion1reply1->discussion,
             'parent' => $discussion1reply1->parent,
-            'userid' => $discussion1reply1->userid,
+            'userid' => (int) $discussion1reply1->userid,
             'created' => $discussion1reply1->created,
             'modified' => $discussion1reply1->modified,
             'mailed' => $discussion1reply1->mailed,
             'subject' => $discussion1reply1->subject,
             'message' => file_rewrite_pluginfile_urls($discussion1reply1->message, 'pluginfile.php',
                     $forum1context->id, 'mod_forum', 'post', $discussion1reply1->id),
-            'messageformat' => $discussion1reply1->messageformat,
+            'messageformat' => 1,   // This value is usually changed by external_format_text() function.
             'messagetrust' => $discussion1reply1->messagetrust,
             'attachment' => $discussion1reply1->attachment,
             'totalscore' => $discussion1reply1->totalscore,