diff --git a/resources/celerity/map.php b/resources/celerity/map.php
index 9716b00f16..fed195555c 100644
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -7,7 +7,7 @@
  */
 return array(
   'names' => array(
-    'core.pkg.css' => 'e2460e8f',
+    'core.pkg.css' => 'd7ecac6d',
     'core.pkg.js' => '3bbe23c6',
     'darkconsole.pkg.js' => 'e7393ebb',
     'differential.pkg.css' => '02273347',
@@ -136,7 +136,7 @@ return array(
     'rsrc/css/phui/phui-fontkit.css' => 'dd8ddf27',
     'rsrc/css/phui/phui-form-view.css' => '808329f2',
     'rsrc/css/phui/phui-form.css' => '25876baf',
-    'rsrc/css/phui/phui-header-view.css' => '75aaf372',
+    'rsrc/css/phui/phui-header-view.css' => '2dd74fe0',
     'rsrc/css/phui/phui-icon.css' => 'bc766998',
     'rsrc/css/phui/phui-image-mask.css' => '5a8b09c8',
     'rsrc/css/phui/phui-info-panel.css' => '27ea50a1',
@@ -779,7 +779,7 @@ return array(
     'phui-fontkit-css' => 'dd8ddf27',
     'phui-form-css' => '25876baf',
     'phui-form-view-css' => '808329f2',
-    'phui-header-view-css' => '75aaf372',
+    'phui-header-view-css' => '2dd74fe0',
     'phui-icon-view-css' => 'bc766998',
     'phui-image-mask-css' => '5a8b09c8',
     'phui-info-panel-css' => '27ea50a1',
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index 682bf8a835..4b078a54b3 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -2560,6 +2560,7 @@ phutil_register_library_map(array(
     'PhabricatorSpacesCapabilityCreateSpaces' => 'applications/spaces/capability/PhabricatorSpacesCapabilityCreateSpaces.php',
     'PhabricatorSpacesCapabilityDefaultEdit' => 'applications/spaces/capability/PhabricatorSpacesCapabilityDefaultEdit.php',
     'PhabricatorSpacesCapabilityDefaultView' => 'applications/spaces/capability/PhabricatorSpacesCapabilityDefaultView.php',
+    'PhabricatorSpacesControl' => 'applications/spaces/view/PhabricatorSpacesControl.php',
     'PhabricatorSpacesController' => 'applications/spaces/controller/PhabricatorSpacesController.php',
     'PhabricatorSpacesDAO' => 'applications/spaces/storage/PhabricatorSpacesDAO.php',
     'PhabricatorSpacesEditController' => 'applications/spaces/controller/PhabricatorSpacesEditController.php',
@@ -6041,6 +6042,7 @@ phutil_register_library_map(array(
     'PhabricatorSpacesCapabilityCreateSpaces' => 'PhabricatorPolicyCapability',
     'PhabricatorSpacesCapabilityDefaultEdit' => 'PhabricatorPolicyCapability',
     'PhabricatorSpacesCapabilityDefaultView' => 'PhabricatorPolicyCapability',
+    'PhabricatorSpacesControl' => 'AphrontFormControl',
     'PhabricatorSpacesController' => 'PhabricatorController',
     'PhabricatorSpacesDAO' => 'PhabricatorLiskDAO',
     'PhabricatorSpacesEditController' => 'PhabricatorSpacesController',
diff --git a/src/applications/paste/controller/PhabricatorPasteEditController.php b/src/applications/paste/controller/PhabricatorPasteEditController.php
index 32cc465737..7aa28673da 100644
--- a/src/applications/paste/controller/PhabricatorPasteEditController.php
+++ b/src/applications/paste/controller/PhabricatorPasteEditController.php
@@ -57,13 +57,12 @@ final class PhabricatorPasteEditController extends PhabricatorPasteController {
       }
     }
 
-    $text = null;
-    $e_text = true;
-    $errors = array();
+    $v_space = $paste->getSpacePHID();
     if ($is_create && $parent) {
       $v_title = pht('Fork of %s', $parent->getFullName());
       $v_language = $parent->getLanguage();
       $v_text = $parent->getRawContent();
+      $v_space = $parent->getSpacePHID();
     } else {
       $v_title = $paste->getTitle();
       $v_language = $paste->getLanguage();
@@ -81,68 +80,64 @@ final class PhabricatorPasteEditController extends PhabricatorPasteController {
       $v_projects = array_reverse($v_projects);
     }
 
+    $validation_exception = null;
     if ($request->isFormPost()) {
       $xactions = array();
 
       $v_text = $request->getStr('text');
-      if (!strlen($v_text)) {
-        $e_text = pht('Required');
-        $errors[] = pht('The paste may not be blank.');
-      } else {
-        $e_text = null;
-      }
-
       $v_title = $request->getStr('title');
       $v_language = $request->getStr('language');
       $v_view_policy = $request->getStr('can_view');
       $v_edit_policy = $request->getStr('can_edit');
       $v_projects = $request->getArr('projects');
+      $v_space = $request->getStr('spacePHID');
 
       // NOTE: The author is the only editor and can always view the paste,
       // so it's impossible for them to choose an invalid policy.
 
-      if (!$errors) {
-        if ($is_create || ($v_text !== $paste->getRawContent())) {
-          $file = PhabricatorPasteEditor::initializeFileForPaste(
-            $user,
-            $v_title,
-            $v_text);
-
-          $xactions[] = id(new PhabricatorPasteTransaction())
-            ->setTransactionType(PhabricatorPasteTransaction::TYPE_CONTENT)
-            ->setNewValue($file->getPHID());
-        }
+      if ($is_create || ($v_text !== $paste->getRawContent())) {
+        $file = PhabricatorPasteEditor::initializeFileForPaste(
+          $user,
+          $v_title,
+          $v_text);
 
         $xactions[] = id(new PhabricatorPasteTransaction())
-          ->setTransactionType(PhabricatorPasteTransaction::TYPE_TITLE)
-          ->setNewValue($v_title);
-        $xactions[] = id(new PhabricatorPasteTransaction())
-          ->setTransactionType(PhabricatorPasteTransaction::TYPE_LANGUAGE)
-          ->setNewValue($v_language);
-        $xactions[] = id(new PhabricatorPasteTransaction())
-          ->setTransactionType(PhabricatorTransactions::TYPE_VIEW_POLICY)
-          ->setNewValue($v_view_policy);
-        $xactions[] = id(new PhabricatorPasteTransaction())
-          ->setTransactionType(PhabricatorTransactions::TYPE_EDIT_POLICY)
-          ->setNewValue($v_edit_policy);
+          ->setTransactionType(PhabricatorPasteTransaction::TYPE_CONTENT)
+          ->setNewValue($file->getPHID());
+      }
 
-        $proj_edge_type = PhabricatorProjectObjectHasProjectEdgeType::EDGECONST;
-        $xactions[] = id(new PhabricatorPasteTransaction())
-          ->setTransactionType(PhabricatorTransactions::TYPE_EDGE)
-          ->setMetadataValue('edge:type', $proj_edge_type)
-          ->setNewValue(array('=' => array_fuse($v_projects)));
+      $xactions[] = id(new PhabricatorPasteTransaction())
+        ->setTransactionType(PhabricatorPasteTransaction::TYPE_TITLE)
+        ->setNewValue($v_title);
+      $xactions[] = id(new PhabricatorPasteTransaction())
+        ->setTransactionType(PhabricatorPasteTransaction::TYPE_LANGUAGE)
+        ->setNewValue($v_language);
+      $xactions[] = id(new PhabricatorPasteTransaction())
+        ->setTransactionType(PhabricatorTransactions::TYPE_VIEW_POLICY)
+        ->setNewValue($v_view_policy);
+      $xactions[] = id(new PhabricatorPasteTransaction())
+        ->setTransactionType(PhabricatorTransactions::TYPE_EDIT_POLICY)
+        ->setNewValue($v_edit_policy);
+      $xactions[] = id(new PhabricatorPasteTransaction())
+        ->setTransactionType(PhabricatorTransactions::TYPE_SPACE)
+        ->setNewValue($v_space);
 
-        $editor = id(new PhabricatorPasteEditor())
-          ->setActor($user)
-          ->setContentSourceFromRequest($request)
-          ->setContinueOnNoEffect(true);
+      $proj_edge_type = PhabricatorProjectObjectHasProjectEdgeType::EDGECONST;
+      $xactions[] = id(new PhabricatorPasteTransaction())
+        ->setTransactionType(PhabricatorTransactions::TYPE_EDGE)
+        ->setMetadataValue('edge:type', $proj_edge_type)
+        ->setNewValue(array('=' => array_fuse($v_projects)));
+
+      $editor = id(new PhabricatorPasteEditor())
+        ->setActor($user)
+        ->setContentSourceFromRequest($request)
+        ->setContinueOnNoEffect(true);
+
+      try {
         $xactions = $editor->applyTransactions($paste, $xactions);
         return id(new AphrontRedirectResponse())->setURI($paste->getURI());
-      } else {
-        // make sure we update policy so its correctly populated to what
-        // the user chose
-        $paste->setViewPolicy($v_view_policy);
-        $paste->setEditPolicy($v_edit_policy);
+      } catch (PhabricatorApplicationTransactionValidationException $ex) {
+        $validation_exception = $ex;
       }
     }
 
@@ -172,12 +167,19 @@ final class PhabricatorPasteEditController extends PhabricatorPasteController {
       ->setObject($paste)
       ->execute();
 
+    $form->appendControl(
+      id(new PhabricatorSpacesControl())
+        ->setObject($paste)
+        ->setValue($v_space)
+        ->setName('spacePHID'));
+
     $form->appendChild(
       id(new AphrontFormPolicyControl())
         ->setUser($user)
         ->setCapability(PhabricatorPolicyCapability::CAN_VIEW)
         ->setPolicyObject($paste)
         ->setPolicies($policies)
+        ->setValue($v_view_policy)
         ->setName('can_view'));
 
     $form->appendChild(
@@ -186,6 +188,7 @@ final class PhabricatorPasteEditController extends PhabricatorPasteController {
         ->setCapability(PhabricatorPolicyCapability::CAN_EDIT)
         ->setPolicyObject($paste)
         ->setPolicies($policies)
+        ->setValue($v_edit_policy)
         ->setName('can_edit'));
 
     $form->appendControl(
@@ -199,7 +202,6 @@ final class PhabricatorPasteEditController extends PhabricatorPasteController {
       ->appendChild(
         id(new AphrontFormTextAreaControl())
           ->setLabel(pht('Text'))
-          ->setError($e_text)
           ->setValue($v_text)
           ->setHeight(AphrontFormTextAreaControl::HEIGHT_VERY_TALL)
           ->setCustomClass('PhabricatorMonospaced')
@@ -222,9 +224,12 @@ final class PhabricatorPasteEditController extends PhabricatorPasteController {
 
     $form_box = id(new PHUIObjectBoxView())
       ->setHeaderText($title)
-      ->setFormErrors($errors)
       ->setForm($form);
 
+    if ($validation_exception) {
+      $form_box->setValidationException($validation_exception);
+    }
+
     $crumbs = $this->buildApplicationCrumbs($this->buildSideNavView());
     if (!$is_create) {
       $crumbs->addTextCrumb('P'.$paste->getID(), '/P'.$paste->getID());
diff --git a/src/applications/paste/storage/PhabricatorPaste.php b/src/applications/paste/storage/PhabricatorPaste.php
index c0eeda8c92..da129b8cf4 100644
--- a/src/applications/paste/storage/PhabricatorPaste.php
+++ b/src/applications/paste/storage/PhabricatorPaste.php
@@ -42,7 +42,11 @@ final class PhabricatorPaste extends PhabricatorPasteDAO
   }
 
   public function getURI() {
-    return '/P'.$this->getID();
+    return '/'.$this->getMonogram();
+  }
+
+  public function getMonogram() {
+    return 'P'.$this->getID();
   }
 
   protected function getConfiguration() {
diff --git a/src/applications/people/storage/PhabricatorUser.php b/src/applications/people/storage/PhabricatorUser.php
index e60f50650c..87fdb84447 100644
--- a/src/applications/people/storage/PhabricatorUser.php
+++ b/src/applications/people/storage/PhabricatorUser.php
@@ -751,6 +751,20 @@ final class PhabricatorUser
       $email->getUserPHID());
   }
 
+  public function getDefaultSpacePHID() {
+    // TODO: We might let the user switch which space they're "in" later on;
+    // for now just use the global space if one exists.
+
+    $spaces = PhabricatorSpacesNamespaceQuery::getViewerSpaces($this);
+    foreach ($spaces as $space) {
+      if ($space->getIsDefaultNamespace()) {
+        return $space->getPHID();
+      }
+    }
+
+    return null;
+  }
+
 
   /**
    * Grant a user a source of authority, to let them bypass policy checks they
diff --git a/src/applications/spaces/application/PhabricatorSpacesApplication.php b/src/applications/spaces/application/PhabricatorSpacesApplication.php
index f6f1d2b097..3733dc87ae 100644
--- a/src/applications/spaces/application/PhabricatorSpacesApplication.php
+++ b/src/applications/spaces/application/PhabricatorSpacesApplication.php
@@ -15,7 +15,7 @@ final class PhabricatorSpacesApplication extends PhabricatorApplication {
   }
 
   public function getFontIcon() {
-    return 'fa-compass';
+    return 'fa-th-large';
   }
 
   public function getTitleGlyph() {
diff --git a/src/applications/spaces/phid/PhabricatorSpacesNamespacePHIDType.php b/src/applications/spaces/phid/PhabricatorSpacesNamespacePHIDType.php
index 8c0aae956f..ad7fd05130 100644
--- a/src/applications/spaces/phid/PhabricatorSpacesNamespacePHIDType.php
+++ b/src/applications/spaces/phid/PhabricatorSpacesNamespacePHIDType.php
@@ -28,7 +28,10 @@ final class PhabricatorSpacesNamespacePHIDType
 
     foreach ($handles as $phid => $handle) {
       $namespace = $objects[$phid];
+      $monogram = $namespace->getMonogram();
+
       $handle->setName($namespace->getNamespaceName());
+      $handle->setURI('/'.$monogram);
     }
   }
 
diff --git a/src/applications/spaces/view/PhabricatorSpacesControl.php b/src/applications/spaces/view/PhabricatorSpacesControl.php
new file mode 100644
index 0000000000..659de58b1a
--- /dev/null
+++ b/src/applications/spaces/view/PhabricatorSpacesControl.php
@@ -0,0 +1,49 @@
+<?php
+
+final class PhabricatorSpacesControl extends AphrontFormControl {
+
+  private $object;
+
+  protected function shouldRender() {
+    // Render this control only if some Spaces exist.
+    return PhabricatorSpacesNamespaceQuery::getAllSpaces();
+  }
+
+  public function setObject(PhabricatorSpacesInterface $object) {
+    $this->object = $object;
+    return $this;
+  }
+
+  protected function getCustomControlClass() {
+    return '';
+  }
+
+  protected function getOptions() {
+    $viewer = $this->getUser();
+    $viewer_spaces = PhabricatorSpacesNamespaceQuery::getViewerSpaces($viewer);
+
+    $map = mpull($viewer_spaces, 'getNamespaceName', 'getPHID');
+    asort($map);
+
+    return $map;
+  }
+
+  public function renderInput() {
+    $viewer = $this->getUser();
+
+    $this->setLabel(pht('Space'));
+
+    $value = $this->getValue();
+    if ($value === null) {
+      $value = $viewer->getDefaultSpacePHID();
+    }
+
+    return AphrontFormSelectControl::renderSelectTag(
+      $value,
+      $this->getOptions(),
+      array(
+        'name' => $this->getName(),
+      ));
+  }
+
+}
diff --git a/src/applications/transactions/constants/PhabricatorTransactions.php b/src/applications/transactions/constants/PhabricatorTransactions.php
index 5abc9fa486..6bdbd2f2db 100644
--- a/src/applications/transactions/constants/PhabricatorTransactions.php
+++ b/src/applications/transactions/constants/PhabricatorTransactions.php
@@ -12,6 +12,7 @@ final class PhabricatorTransactions {
   const TYPE_BUILDABLE    = 'harbormaster:buildable';
   const TYPE_TOKEN        = 'token:give';
   const TYPE_INLINESTATE  = 'core:inlinestate';
+  const TYPE_SPACE = 'core:space';
 
   const COLOR_RED         = 'red';
   const COLOR_ORANGE      = 'orange';
diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
index 1769544045..bb8348d8b7 100644
--- a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -264,6 +264,10 @@ abstract class PhabricatorApplicationTransactionEditor
       $types[] = PhabricatorTransactions::TYPE_EDGE;
     }
 
+    if ($this->object instanceof PhabricatorSpacesInterface) {
+      $types[] = PhabricatorTransactions::TYPE_SPACE;
+    }
+
     return $types;
   }
 
@@ -292,6 +296,21 @@ abstract class PhabricatorApplicationTransactionEditor
         return $object->getEditPolicy();
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         return $object->getJoinPolicy();
+      case PhabricatorTransactions::TYPE_SPACE:
+        $space_phid = $object->getSpacePHID();
+        if ($space_phid === null) {
+          if ($this->getIsNewObject()) {
+            // In this case, just return `null` so we know this is the initial
+            // transaction and it should be hidden.
+            return null;
+          }
+
+          $default_space = PhabricatorSpacesNamespaceQuery::getDefaultSpace();
+          if ($default_space) {
+            $space_phid = $default_space->getPHID();
+          }
+        }
+        return $space_phid;
       case PhabricatorTransactions::TYPE_EDGE:
         $edge_type = $xaction->getMetadataValue('edge:type');
         if (!$edge_type) {
@@ -337,7 +356,16 @@ abstract class PhabricatorApplicationTransactionEditor
       case PhabricatorTransactions::TYPE_BUILDABLE:
       case PhabricatorTransactions::TYPE_TOKEN:
       case PhabricatorTransactions::TYPE_INLINESTATE:
-        return $xaction->getNewValue();
+      case PhabricatorTransactions::TYPE_SPACE:
+        $space_phid = $xaction->getNewValue();
+        if (!strlen($space_phid)) {
+          // If an install has no Spaces, we might end up with the empty string
+          // here instead of a strict `null`. Just make this work like callers
+          // might reasonably expect.
+          return null;
+        } else {
+          return $space_phid;
+        }
       case PhabricatorTransactions::TYPE_EDGE:
         return $this->getEdgeTransactionNewValue($xaction);
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
@@ -437,6 +465,7 @@ abstract class PhabricatorApplicationTransactionEditor
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
       case PhabricatorTransactions::TYPE_INLINESTATE:
       case PhabricatorTransactions::TYPE_EDGE:
+      case PhabricatorTransactions::TYPE_SPACE:
       case PhabricatorTransactions::TYPE_COMMENT:
         return $this->applyBuiltinInternalTransaction($object, $xaction);
     }
@@ -485,6 +514,7 @@ abstract class PhabricatorApplicationTransactionEditor
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
       case PhabricatorTransactions::TYPE_INLINESTATE:
+      case PhabricatorTransactions::TYPE_SPACE:
       case PhabricatorTransactions::TYPE_COMMENT:
         return $this->applyBuiltinExternalTransaction($object, $xaction);
     }
@@ -537,6 +567,9 @@ abstract class PhabricatorApplicationTransactionEditor
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         $object->setJoinPolicy($xaction->getNewValue());
         break;
+      case PhabricatorTransactions::TYPE_SPACE:
+        $object->setSpacePHID($xaction->getNewValue());
+        break;
     }
   }
 
@@ -1190,18 +1223,9 @@ abstract class PhabricatorApplicationTransactionEditor
           PhabricatorPolicyCapability::CAN_VIEW);
         break;
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
-        PhabricatorPolicyFilter::requireCapability(
-          $actor,
-          $object,
-          PhabricatorPolicyCapability::CAN_EDIT);
-        break;
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
-        PhabricatorPolicyFilter::requireCapability(
-          $actor,
-          $object,
-          PhabricatorPolicyCapability::CAN_EDIT);
-        break;
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
+      case PhabricatorTransactions::TYPE_SPACE:
         PhabricatorPolicyFilter::requireCapability(
           $actor,
           $object,
@@ -1882,6 +1906,12 @@ abstract class PhabricatorApplicationTransactionEditor
           $type,
           PhabricatorPolicyCapability::CAN_EDIT);
         break;
+      case PhabricatorTransactions::TYPE_SPACE:
+        $errors[] = $this->validateSpaceTransactions(
+          $object,
+          $xactions,
+          $type);
+        break;
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $groups = array();
         foreach ($xactions as $xaction) {
@@ -1968,6 +1998,52 @@ abstract class PhabricatorApplicationTransactionEditor
     return $errors;
   }
 
+
+  private function validateSpaceTransactions(
+    PhabricatorLiskDAO $object,
+    array $xactions,
+    $transaction_type) {
+    $errors = array();
+
+    $all_spaces = PhabricatorSpacesNamespaceQuery::getAllSpaces();
+    $viewer_spaces = PhabricatorSpacesNamespaceQuery::getViewerSpaces(
+      $this->getActor());
+    foreach ($xactions as $xaction) {
+      $space_phid = $xaction->getNewValue();
+
+      if ($space_phid === null) {
+        if (!$all_spaces) {
+          // The install doesn't have any spaces, so this is fine.
+          continue;
+        }
+
+        // The install has some spaces, so every object needs to be put
+        // in a valid space.
+        $errors[] = new PhabricatorApplicationTransactionValidationError(
+          $transaction_type,
+          pht('Invalid'),
+          pht('You must choose a space for this object.'),
+          $xaction);
+        continue;
+      }
+
+      // If the PHID isn't `null`, it needs to be a valid space that the
+      // viewer can see.
+      if (empty($viewer_spaces[$space_phid])) {
+        $errors[] = new PhabricatorApplicationTransactionValidationError(
+          $transaction_type,
+          pht('Invalid'),
+          pht(
+            'You can not shift this object in the selected space, because '.
+            'the space does not exist or you do not have access to it.'),
+          $xaction);
+      }
+    }
+
+    return $errors;
+  }
+
+
   protected function adjustObjectForPolicyChecks(
     PhabricatorLiskDAO $object,
     array $xactions) {
diff --git a/src/applications/transactions/storage/PhabricatorApplicationTransaction.php b/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
index a6c1715115..7439c8728e 100644
--- a/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
+++ b/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
@@ -250,6 +250,14 @@ abstract class PhabricatorApplicationTransaction
           $phids[] = array($new);
         }
         break;
+      case PhabricatorTransactions::TYPE_SPACE:
+        if ($old) {
+          $phids[] = array($old);
+        }
+        if ($new) {
+          $phids[] = array($new);
+        }
+        break;
       case PhabricatorTransactions::TYPE_TOKEN:
         break;
       case PhabricatorTransactions::TYPE_BUILDABLE:
@@ -369,6 +377,8 @@ abstract class PhabricatorApplicationTransaction
         return 'fa-wrench';
       case PhabricatorTransactions::TYPE_TOKEN:
         return 'fa-trophy';
+      case PhabricatorTransactions::TYPE_SPACE:
+        return 'fa-th-large';
     }
 
     return 'fa-pencil';
@@ -438,6 +448,7 @@ abstract class PhabricatorApplicationTransaction
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
+      case PhabricatorTransactions::TYPE_SPACE:
         if ($this->getOldValue() === null) {
           return true;
         } else {
@@ -597,6 +608,8 @@ abstract class PhabricatorApplicationTransaction
         return pht(
           'All users are already subscribed to this %s.',
           $this->getApplicationObjectTypeName());
+      case PhabricatorTransactions::TYPE_SPACE:
+        return pht('This object is already in that space.');
       case PhabricatorTransactions::TYPE_EDGE:
         return pht('Edges already exist; transaction has no effect.');
     }
@@ -636,6 +649,12 @@ abstract class PhabricatorApplicationTransaction
           $this->getApplicationObjectTypeName(),
           $this->renderPolicyName($old, 'old'),
           $this->renderPolicyName($new, 'new'));
+      case PhabricatorTransactions::TYPE_SPACE:
+        return pht(
+          '%s shifted this object from the %s space to the %s space.',
+          $this->renderHandleLink($author_phid),
+          $this->renderHandleLink($old),
+          $this->renderHandleLink($new));
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         $add = array_diff($new, $old);
         $rem = array_diff($old, $new);
@@ -821,6 +840,13 @@ abstract class PhabricatorApplicationTransaction
           '%s updated subscribers of %s.',
           $this->renderHandleLink($author_phid),
           $this->renderHandleLink($object_phid));
+      case PhabricatorTransactions::TYPE_SPACE:
+        return pht(
+          '%s shifted %s from the %s space to the %s space.',
+          $this->renderHandleLink($author_phid),
+          $this->renderHandleLink($object_phid),
+          $this->renderHandleLink($old),
+          $this->renderHandleLink($new));
       case PhabricatorTransactions::TYPE_EDGE:
         $new = ipull($new, 'dst');
         $old = ipull($old, 'dst');
diff --git a/src/view/phui/PHUIHeaderView.php b/src/view/phui/PHUIHeaderView.php
index c87f1c4868..62842001a7 100644
--- a/src/view/phui/PHUIHeaderView.php
+++ b/src/view/phui/PHUIHeaderView.php
@@ -174,6 +174,20 @@ final class PHUIHeaderView extends AphrontTagView {
 
     $header = array();
 
+    $header[] = $this->renderObjectSpaceInformation();
+
+    if ($this->objectName) {
+      $header[] = array(
+        phutil_tag(
+          'a',
+          array(
+            'href' => '/'.$this->objectName,
+          ),
+          $this->objectName),
+        ' ',
+      );
+    }
+
     if ($this->actionLinks) {
       $actions = array();
       foreach ($this->actionLinks as $button) {
@@ -200,18 +214,6 @@ final class PHUIHeaderView extends AphrontTagView {
     }
     $header[] = $this->header;
 
-    if ($this->objectName) {
-      array_unshift(
-        $header,
-        phutil_tag(
-          'a',
-          array(
-            'href' => '/'.$this->objectName,
-          ),
-          $this->objectName),
-        ' ');
-    }
-
     if ($this->tags) {
       $header[] = ' ';
       $header[] = phutil_tag(
@@ -268,9 +270,9 @@ final class PHUIHeaderView extends AphrontTagView {
   }
 
   private function renderPolicyProperty(PhabricatorPolicyInterface $object) {
-    $policies = PhabricatorPolicyQuery::loadPolicies(
-      $this->getUser(),
-      $object);
+    $viewer = $this->getUser();
+
+    $policies = PhabricatorPolicyQuery::loadPolicies($viewer, $object);
 
     $view_capability = PhabricatorPolicyCapability::CAN_VIEW;
     $policy = idx($policies, $view_capability);
@@ -294,4 +296,41 @@ final class PHUIHeaderView extends AphrontTagView {
 
     return array($icon, $link);
   }
+
+  private function renderObjectSpaceInformation() {
+    $viewer = $this->getUser();
+
+    $object = $this->policyObject;
+    if (!$object) {
+      return;
+    }
+
+    if (!($object instanceof PhabricatorSpacesInterface)) {
+      return;
+    }
+
+    $space_phid = $object->getSpacePHID();
+    if ($space_phid === null) {
+      $default_space = PhabricatorSpacesNamespaceQuery::getDefaultSpace();
+      if ($default_space) {
+        $space_phid = $default_space->getPHID();
+      }
+    }
+
+    if ($space_phid === null) {
+      return;
+    }
+
+    return phutil_tag(
+      'span',
+      array(
+        'class' => 'spaces-name',
+      ),
+      array(
+        $viewer->renderHandle($space_phid),
+        ' | ',
+      ));
+  }
+
+
 }
diff --git a/webroot/rsrc/css/phui/phui-header-view.css b/webroot/rsrc/css/phui/phui-header-view.css
index 6790ed09e8..842441dae0 100644
--- a/webroot/rsrc/css/phui/phui-header-view.css
+++ b/webroot/rsrc/css/phui/phui-header-view.css
@@ -140,3 +140,11 @@ body.device-phone .phui-header-view {
 .device .phui-header-action-links .phui-mobile-menu {
   display: inline-block;
 }
+
+.spaces-name {
+  color: {$lightbluetext};
+}
+
+.spaces-name .phui-handle {
+  color: #000;
+}