diff --git a/src/applications/harbormaster/step/HarbormasterBuildkiteBuildStepImplementation.php b/src/applications/harbormaster/step/HarbormasterBuildkiteBuildStepImplementation.php
--- a/src/applications/harbormaster/step/HarbormasterBuildkiteBuildStepImplementation.php
+++ b/src/applications/harbormaster/step/HarbormasterBuildkiteBuildStepImplementation.php
@@ -106,6 +106,12 @@
       ),
       'meta_data' => array(
         'buildTargetPHID' => $build_target->getPHID(),
+
+        // See PHI611. These are undocumented secret magic.
+        'phabricator_buildable_url' =>
+          PhabricatorEnv::getProductionURI($buildable->getURI()),
+        'phabricator_build_url' =>
+          PhabricatorEnv::getProductionURI($build->getURI()),
       ),
     );