diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index 8539271141..e6eaec9be0 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -2349,6 +2349,8 @@ phutil_register_library_map(array(
     'PhabricatorHovercardView' => 'view/widget/hovercard/PhabricatorHovercardView.php',
     'PhabricatorHunksManagementMigrateWorkflow' => 'applications/differential/management/PhabricatorHunksManagementMigrateWorkflow.php',
     'PhabricatorHunksManagementWorkflow' => 'applications/differential/management/PhabricatorHunksManagementWorkflow.php',
+    'PhabricatorIDsSearchEngineExtension' => 'applications/search/engineextension/PhabricatorIDsSearchEngineExtension.php',
+    'PhabricatorIDsSearchField' => 'applications/search/field/PhabricatorIDsSearchField.php',
     'PhabricatorIRCProtocolAdapter' => 'infrastructure/daemon/bot/adapter/PhabricatorIRCProtocolAdapter.php',
     'PhabricatorIconRemarkupRule' => 'applications/macro/markup/PhabricatorIconRemarkupRule.php',
     'PhabricatorImageMacroRemarkupRule' => 'applications/macro/markup/PhabricatorImageMacroRemarkupRule.php',
@@ -2625,6 +2627,7 @@ phutil_register_library_map(array(
     'PhabricatorPHIDResolver' => 'applications/phid/resolver/PhabricatorPHIDResolver.php',
     'PhabricatorPHIDType' => 'applications/phid/type/PhabricatorPHIDType.php',
     'PhabricatorPHIDTypeTestCase' => 'applications/phid/type/__tests__/PhabricatorPHIDTypeTestCase.php',
+    'PhabricatorPHIDsSearchField' => 'applications/search/field/PhabricatorPHIDsSearchField.php',
     'PhabricatorPHPASTApplication' => 'applications/phpast/application/PhabricatorPHPASTApplication.php',
     'PhabricatorPHPConfigSetupCheck' => 'applications/config/check/PhabricatorPHPConfigSetupCheck.php',
     'PhabricatorPHPMailerConfigOptions' => 'applications/config/option/PhabricatorPHPMailerConfigOptions.php',
@@ -6539,6 +6542,8 @@ phutil_register_library_map(array(
     'PhabricatorHovercardView' => 'AphrontView',
     'PhabricatorHunksManagementMigrateWorkflow' => 'PhabricatorHunksManagementWorkflow',
     'PhabricatorHunksManagementWorkflow' => 'PhabricatorManagementWorkflow',
+    'PhabricatorIDsSearchEngineExtension' => 'PhabricatorSearchEngineExtension',
+    'PhabricatorIDsSearchField' => 'PhabricatorSearchField',
     'PhabricatorIRCProtocolAdapter' => 'PhabricatorProtocolAdapter',
     'PhabricatorIconRemarkupRule' => 'PhutilRemarkupRule',
     'PhabricatorImageMacroRemarkupRule' => 'PhutilRemarkupRule',
@@ -6847,6 +6852,7 @@ phutil_register_library_map(array(
     'PhabricatorPHIDResolver' => 'Phobject',
     'PhabricatorPHIDType' => 'Phobject',
     'PhabricatorPHIDTypeTestCase' => 'PhutilTestCase',
+    'PhabricatorPHIDsSearchField' => 'PhabricatorSearchField',
     'PhabricatorPHPASTApplication' => 'PhabricatorApplication',
     'PhabricatorPHPConfigSetupCheck' => 'PhabricatorSetupCheck',
     'PhabricatorPHPMailerConfigOptions' => 'PhabricatorApplicationConfigOptions',
diff --git a/src/applications/conduit/parametertype/ConduitIntListParameterType.php b/src/applications/conduit/parametertype/ConduitIntListParameterType.php
index a2f4c95534..07c87dcd8a 100644
--- a/src/applications/conduit/parametertype/ConduitIntListParameterType.php
+++ b/src/applications/conduit/parametertype/ConduitIntListParameterType.php
@@ -18,7 +18,7 @@ final class ConduitIntListParameterType
       }
     }
 
-    return $this->validateIntList($request, $key, $list);
+    return $list;
   }
 
   protected function getParameterTypeName() {
diff --git a/src/applications/conduit/parametertype/ConduitParameterType.php b/src/applications/conduit/parametertype/ConduitParameterType.php
index 2c67886f3e..8f02057c0f 100644
--- a/src/applications/conduit/parametertype/ConduitParameterType.php
+++ b/src/applications/conduit/parametertype/ConduitParameterType.php
@@ -26,7 +26,7 @@ abstract class ConduitParameterType extends Phobject {
 
 
   final public function getExists(array $request, $key) {
-    return $this->getValueExists($request, $key);
+    return $this->getParameterExists($request, $key);
   }
 
 
diff --git a/src/applications/conduit/query/ConduitResultSearchEngineExtension.php b/src/applications/conduit/query/ConduitResultSearchEngineExtension.php
index 70aa1891c7..f3ba5d1694 100644
--- a/src/applications/conduit/query/ConduitResultSearchEngineExtension.php
+++ b/src/applications/conduit/query/ConduitResultSearchEngineExtension.php
@@ -10,7 +10,7 @@ final class ConduitResultSearchEngineExtension
   }
 
   public function getExtensionOrder() {
-    return 1000;
+    return 1500;
   }
 
   public function getExtensionName() {
diff --git a/src/applications/maniphest/query/ManiphestTaskSearchEngine.php b/src/applications/maniphest/query/ManiphestTaskSearchEngine.php
index 2165111e3d..8355e8947e 100644
--- a/src/applications/maniphest/query/ManiphestTaskSearchEngine.php
+++ b/src/applications/maniphest/query/ManiphestTaskSearchEngine.php
@@ -94,9 +94,6 @@ final class ManiphestTaskSearchEngine
         ->setLabel(pht('Group By'))
         ->setKey('group')
         ->setOptions($this->getGroupOptions()),
-      id(new PhabricatorSearchStringListField())
-        ->setLabel(pht('Task IDs'))
-        ->setKey('ids'),
       id(new PhabricatorSearchDateField())
         ->setLabel(pht('Created After'))
         ->setKey('createdStart'),
diff --git a/src/applications/search/engine/PhabricatorApplicationSearchEngine.php b/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
index e8d115d9a2..67caaa1035 100644
--- a/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
+++ b/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
@@ -1070,27 +1070,9 @@ abstract class PhabricatorApplicationSearchEngine extends Phobject {
 
     // These are handled separately for Conduit, so don't show them as
     // supported.
-    unset($fields['ids']);
-    unset($fields['phids']);
     unset($fields['order']);
     unset($fields['limit']);
 
-    // TODO: Clean these up, shortly.
-    $fields = array(
-      'ids' => id(new PhabricatorSearchDatasourceField())
-        ->setKey('ids')
-        ->setLabel(pht('IDs'))
-        ->setDescription(
-          pht('Search for objects with specific IDs.'))
-        ->setConduitParameterType(new ConduitIntListParameterType()),
-      'phids' => id(new PhabricatorSearchDatasourceField())
-        ->setKey('phids')
-        ->setLabel(pht('PHIDs'))
-        ->setDescription(
-          pht('Search for objects with specific PHIDs.'))
-        ->setConduitParameterType(new ConduitPHIDListParameterType()),
-    ) + $fields;
-
     $viewer = $this->requireViewer();
     foreach ($fields as $key => $field) {
       $field->setViewer($viewer);
@@ -1145,7 +1127,6 @@ abstract class PhabricatorApplicationSearchEngine extends Phobject {
     $query = $this->buildQueryFromSavedQuery($saved_query);
     $pager = $this->newPagerForSavedQuery($saved_query);
 
-    $this->setAutomaticConstraintsForConduit($query, $request, $constraints);
     $this->setQueryOrderForConduit($query, $request);
     $this->setPagerLimitForConduit($pager, $request);
     $this->setPagerOffsetsForConduit($pager, $request);
@@ -1222,22 +1203,6 @@ abstract class PhabricatorApplicationSearchEngine extends Phobject {
     return $extensions;
   }
 
-  private function setAutomaticConstraintsForConduit(
-    $query,
-    ConduitAPIRequest $request,
-    array $constraints) {
-
-    $with_ids = idx($constraints, 'ids');
-    if ($with_ids) {
-      $query->withIDs($with_ids);
-    }
-
-    $with_phids = idx($constraints, 'phids');
-    if ($with_phids) {
-      $query->withPHIDs($with_phids);
-    }
-  }
-
   private function setQueryOrderForConduit($query, ConduitAPIRequest $request) {
     $order = $request->getValue('order');
     if ($order === null) {
diff --git a/src/applications/search/engine/PhabricatorSearchEngineAPIMethod.php b/src/applications/search/engine/PhabricatorSearchEngineAPIMethod.php
index df46325079..051061d34c 100644
--- a/src/applications/search/engine/PhabricatorSearchEngineAPIMethod.php
+++ b/src/applications/search/engine/PhabricatorSearchEngineAPIMethod.php
@@ -163,6 +163,13 @@ EOTEXT
 
     $fields = $engine->getSearchFieldsForConduit();
 
+    // As a convenience, put these fields at the very top, even if the engine
+    // specifies and alternate display order for the web UI. These fields are
+    // very important in the API and nearly useless in the web UI.
+    $fields = array_select_keys(
+      $fields,
+      array('ids', 'phids')) + $fields;
+
     $rows = array();
     foreach ($fields as $field) {
       $key = $field->getConduitKey();
diff --git a/src/applications/search/engineextension/PhabricatorIDsSearchEngineExtension.php b/src/applications/search/engineextension/PhabricatorIDsSearchEngineExtension.php
new file mode 100644
index 0000000000..6247ba2825
--- /dev/null
+++ b/src/applications/search/engineextension/PhabricatorIDsSearchEngineExtension.php
@@ -0,0 +1,55 @@
+<?php
+
+final class PhabricatorIDsSearchEngineExtension
+  extends PhabricatorSearchEngineExtension {
+
+  const EXTENSIONKEY = 'ids';
+
+  public function isExtensionEnabled() {
+    return true;
+  }
+
+  public function getExtensionName() {
+    return pht('Supports ID/PHID Queries');
+  }
+
+  public function getExtensionOrder() {
+    return 1000;
+  }
+
+  public function supportsObject($object) {
+    return true;
+  }
+
+  public function getSearchFields($object) {
+    return array(
+      id(new PhabricatorIDsSearchField())
+        ->setKey('ids')
+        ->setLabel(pht('IDs'))
+        ->setDescription(
+          pht('Search for objects with specific IDs.')),
+      id(new PhabricatorPHIDsSearchField())
+        ->setKey('phids')
+        ->setLabel(pht('PHIDs'))
+        ->setDescription(
+          pht('Search for objects with specific PHIDs.')),
+    );
+  }
+
+  public function applyConstraintsToQuery(
+    $object,
+    $query,
+    PhabricatorSavedQuery $saved,
+    array $map) {
+
+    if ($map['ids']) {
+      $query->withIDs($map['ids']);
+    }
+
+    if ($map['phids']) {
+      $query->withPHIDs($map['phids']);
+    }
+
+  }
+
+}
diff --git a/src/applications/search/field/PhabricatorIDsSearchField.php b/src/applications/search/field/PhabricatorIDsSearchField.php
new file mode 100644
index 0000000000..909cce9c4a
--- /dev/null
+++ b/src/applications/search/field/PhabricatorIDsSearchField.php
@@ -0,0 +1,30 @@
+<?php
+
+final class PhabricatorIDsSearchField
+  extends PhabricatorSearchField {
+
+  protected function getDefaultValue() {
+    return array();
+  }
+
+  protected function getValueFromRequest(AphrontRequest $request, $key) {
+    return $request->getStrList($key);
+  }
+
+  protected function newControl() {
+    if (strlen($this->getValueForControl())) {
+      return new AphrontFormTextControl();
+    } else {
+      return null;
+    }
+  }
+
+  protected function getValueForControl() {
+    return implode(', ', parent::getValueForControl());
+  }
+
+  protected function newConduitParameterType() {
+    return new ConduitIntListParameterType();
+  }
+
+}
diff --git a/src/applications/search/field/PhabricatorPHIDsSearchField.php b/src/applications/search/field/PhabricatorPHIDsSearchField.php
new file mode 100644
index 0000000000..459233c472
--- /dev/null
+++ b/src/applications/search/field/PhabricatorPHIDsSearchField.php
@@ -0,0 +1,30 @@
+<?php
+
+final class PhabricatorPHIDsSearchField
+  extends PhabricatorSearchField {
+
+  protected function getDefaultValue() {
+    return array();
+  }
+
+  protected function getValueFromRequest(AphrontRequest $request, $key) {
+    return $request->getStrList($key);
+  }
+
+  protected function newControl() {
+    if (strlen($this->getValueForControl())) {
+      return new AphrontFormTextControl();
+    } else {
+      return null;
+    }
+  }
+
+  protected function getValueForControl() {
+    return implode(', ', parent::getValueForControl());
+  }
+
+  protected function newConduitParameterType() {
+    return new ConduitPHIDListParameterType();
+  }
+
+}
diff --git a/src/applications/search/field/PhabricatorSearchField.php b/src/applications/search/field/PhabricatorSearchField.php
index 380b574f17..9624fe22f9 100644
--- a/src/applications/search/field/PhabricatorSearchField.php
+++ b/src/applications/search/field/PhabricatorSearchField.php
@@ -273,17 +273,26 @@ abstract class PhabricatorSearchField extends Phobject {
 
 
   protected function renderControl() {
+    $control = $this->newControl();
+
+    if (!$control) {
+      return null;
+    }
+
     // TODO: We should `setError($this->getShortError())` here, but it looks
     // terrible in the form layout.
 
-    return $this->newControl()
+    return $control
       ->setValue($this->getValueForControl())
       ->setName($this->getKey())
       ->setLabel($this->getLabel());
   }
 
   public function appendToForm(AphrontFormView $form) {
-    $form->appendControl($this->renderControl());
+    $control = $this->renderControl();
+    if ($control !== null) {
+      $form->appendControl($this->renderControl());
+    }
     return $this;
   }