diff --git a/resources/sql/autopatches/20140211.dx.2.migcommenttext.php b/resources/sql/autopatches/20140211.dx.2.migcommenttext.php
--- a/resources/sql/autopatches/20140211.dx.2.migcommenttext.php
+++ b/resources/sql/autopatches/20140211.dx.2.migcommenttext.php
@@ -4,8 +4,7 @@
 $rows = new LiskRawMigrationIterator($conn_w, 'differential_comment');
 
 $content_source = PhabricatorContentSource::newForSource(
-  PhabricatorContentSource::SOURCE_LEGACY,
-  array())->serialize();
+  PhabricatorOldWorldContentSource::SOURCECONST)->serialize();
 
 echo pht('Migrating Differential comment text to modern storage...')."\n";
 foreach ($rows as $row) {
diff --git a/resources/sql/autopatches/20140212.dx.1.armageddon.php b/resources/sql/autopatches/20140212.dx.1.armageddon.php
--- a/resources/sql/autopatches/20140212.dx.1.armageddon.php
+++ b/resources/sql/autopatches/20140212.dx.1.armageddon.php
@@ -4,8 +4,7 @@
 $rows = new LiskRawMigrationIterator($conn_w, 'differential_comment');
 
 $content_source = PhabricatorContentSource::newForSource(
-  PhabricatorContentSource::SOURCE_LEGACY,
-  array())->serialize();
+  PhabricatorOldWorldContentSource::SOURCECONST)->serialize();
 
 echo pht('Migrating Differential comments to modern storage...')."\n";
 foreach ($rows as $row) {
diff --git a/resources/sql/autopatches/20140722.audit.3.miginlines.php b/resources/sql/autopatches/20140722.audit.3.miginlines.php
--- a/resources/sql/autopatches/20140722.audit.3.miginlines.php
+++ b/resources/sql/autopatches/20140722.audit.3.miginlines.php
@@ -10,8 +10,7 @@
 echo pht('Migrating Audit inline comments to new format...')."\n";
 
 $content_source = PhabricatorContentSource::newForSource(
-  PhabricatorContentSource::SOURCE_LEGACY,
-  array())->serialize();
+  PhabricatorOldWorldContentSource::SOURCECONST)->serialize();
 
 $rows = new LiskRawMigrationIterator($conn_w, $src_table);
 foreach ($rows as $row) {
diff --git a/resources/sql/autopatches/20140722.audit.4.migtext.php b/resources/sql/autopatches/20140722.audit.4.migtext.php
--- a/resources/sql/autopatches/20140722.audit.4.migtext.php
+++ b/resources/sql/autopatches/20140722.audit.4.migtext.php
@@ -4,8 +4,7 @@
 $rows = new LiskRawMigrationIterator($conn_w, 'audit_comment');
 
 $content_source = PhabricatorContentSource::newForSource(
-  PhabricatorContentSource::SOURCE_LEGACY,
-  array())->serialize();
+  PhabricatorOldWorldContentSource::SOURCECONST)->serialize();
 
 echo pht('Migrating Audit comment text to modern storage...')."\n";
 foreach ($rows as $row) {
diff --git a/resources/sql/autopatches/20140725.audit.1.migxactions.php b/resources/sql/autopatches/20140725.audit.1.migxactions.php
--- a/resources/sql/autopatches/20140725.audit.1.migxactions.php
+++ b/resources/sql/autopatches/20140725.audit.1.migxactions.php
@@ -4,8 +4,7 @@
 $rows = new LiskRawMigrationIterator($conn_w, 'audit_comment');
 
 $content_source = PhabricatorContentSource::newForSource(
-  PhabricatorContentSource::SOURCE_LEGACY,
-  array())->serialize();
+  PhabricatorOldWorldContentSource::SOURCECONST)->serialize();
 
 echo pht('Migrating Audit comments to modern storage...')."\n";
 foreach ($rows as $row) {
diff --git a/resources/sql/patches/20130715.votecomments.php b/resources/sql/patches/20130715.votecomments.php
--- a/resources/sql/patches/20130715.votecomments.php
+++ b/resources/sql/patches/20130715.votecomments.php
@@ -46,9 +46,8 @@
     PhabricatorApplicationTransactionTransactionPHIDType::TYPECONST,
     PhabricatorSlowvotePollPHIDType::TYPECONST);
 
-  $source = PhabricatorContentSource::newForSource(
-    PhabricatorContentSource::SOURCE_LEGACY,
-    array())->serialize();
+  $content_source = PhabricatorContentSource::newForSource(
+    PhabricatorOldWorldContentSource::SOURCECONST)->serialize();
 
   queryfx(
     $conn_w,
diff --git a/resources/sql/patches/20130728.ponderxcomment.php b/resources/sql/patches/20130728.ponderxcomment.php
--- a/resources/sql/patches/20130728.ponderxcomment.php
+++ b/resources/sql/patches/20130728.ponderxcomment.php
@@ -49,8 +49,7 @@
     1,
     $row['content'],
     PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_LEGACY,
-      array())->serialize(),
+      PhabricatorOldWorldContentSource::SOURCECONST)->serialize(),
     0,
     $row['dateCreated'],
     $row['dateModified']);
@@ -73,8 +72,7 @@
     'null',
     'null',
     PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_LEGACY,
-      array())->serialize(),
+      PhabricatorOldWorldContentSource::SOURCECONST)->serialize(),
     '[]',
     $row['dateCreated'],
     $row['dateModified']);
diff --git a/resources/sql/patches/20130801.pastexactions.php b/resources/sql/patches/20130801.pastexactions.php
--- a/resources/sql/patches/20130801.pastexactions.php
+++ b/resources/sql/patches/20130801.pastexactions.php
@@ -34,8 +34,7 @@
     'null',
     $row['filePHID'],
     PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_LEGACY,
-      array())->serialize(),
+      PhabricatorOldWorldContentSource::SOURCECONST)->serialize(),
     '[]',
     $row['dateCreated'],
     $row['dateCreated'],
diff --git a/resources/sql/patches/20130926.dinline.php b/resources/sql/patches/20130926.dinline.php
--- a/resources/sql/patches/20130926.dinline.php
+++ b/resources/sql/patches/20130926.dinline.php
@@ -10,8 +10,7 @@
 echo pht('Migrating Differential inline comments to new format...')."\n";
 
 $content_source = PhabricatorContentSource::newForSource(
-  PhabricatorContentSource::SOURCE_LEGACY,
-  array())->serialize();
+  PhabricatorOldWorldContentSource::SOURCECONST)->serialize();
 
 $rows = new LiskRawMigrationIterator($conn_w, $src_table);
 foreach ($rows as $row) {
diff --git a/resources/sql/patches/20131020.pxactionmig.php b/resources/sql/patches/20131020.pxactionmig.php
--- a/resources/sql/patches/20131020.pxactionmig.php
+++ b/resources/sql/patches/20131020.pxactionmig.php
@@ -10,8 +10,7 @@
 echo pht('Migrating Project transactions to new format...')."\n";
 
 $content_source = PhabricatorContentSource::newForSource(
-  PhabricatorContentSource::SOURCE_LEGACY,
-  array())->serialize();
+  PhabricatorOldWorldContentSource::SOURCECONST)->serialize();
 
 $rows = new LiskRawMigrationIterator($conn_w, $src_table);
 foreach ($rows as $row) {
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -1919,6 +1919,7 @@
     'PhabricatorBotWhatsNewHandler' => 'infrastructure/daemon/bot/handler/PhabricatorBotWhatsNewHandler.php',
     'PhabricatorBritishEnglishTranslation' => 'infrastructure/internationalization/translation/PhabricatorBritishEnglishTranslation.php',
     'PhabricatorBuiltinPatchList' => 'infrastructure/storage/patch/PhabricatorBuiltinPatchList.php',
+    'PhabricatorBulkContentSource' => 'infrastructure/daemon/contentsource/PhabricatorBulkContentSource.php',
     'PhabricatorBusyUIExample' => 'applications/uiexample/examples/PhabricatorBusyUIExample.php',
     'PhabricatorCacheDAO' => 'applications/cache/storage/PhabricatorCacheDAO.php',
     'PhabricatorCacheGeneralGarbageCollector' => 'applications/cache/garbagecollector/PhabricatorCacheGeneralGarbageCollector.php',
@@ -1993,6 +1994,7 @@
     'PhabricatorConduitCertificateToken' => 'applications/conduit/storage/PhabricatorConduitCertificateToken.php',
     'PhabricatorConduitConnectionLog' => 'applications/conduit/storage/PhabricatorConduitConnectionLog.php',
     'PhabricatorConduitConsoleController' => 'applications/conduit/controller/PhabricatorConduitConsoleController.php',
+    'PhabricatorConduitContentSource' => 'infrastructure/contentsource/PhabricatorConduitContentSource.php',
     'PhabricatorConduitController' => 'applications/conduit/controller/PhabricatorConduitController.php',
     'PhabricatorConduitDAO' => 'applications/conduit/storage/PhabricatorConduitDAO.php',
     'PhabricatorConduitEditField' => 'applications/transactions/editfield/PhabricatorConduitEditField.php',
@@ -2080,8 +2082,10 @@
     'PhabricatorConpherencePreferencesSettingsPanel' => 'applications/settings/panel/PhabricatorConpherencePreferencesSettingsPanel.php',
     'PhabricatorConpherenceThreadPHIDType' => 'applications/conpherence/phid/PhabricatorConpherenceThreadPHIDType.php',
     'PhabricatorConsoleApplication' => 'applications/console/application/PhabricatorConsoleApplication.php',
-    'PhabricatorContentSource' => 'applications/metamta/contentsource/PhabricatorContentSource.php',
-    'PhabricatorContentSourceView' => 'applications/metamta/contentsource/PhabricatorContentSourceView.php',
+    'PhabricatorConsoleContentSource' => 'infrastructure/contentsource/PhabricatorConsoleContentSource.php',
+    'PhabricatorContentSource' => 'infrastructure/contentsource/PhabricatorContentSource.php',
+    'PhabricatorContentSourceModule' => 'infrastructure/contentsource/PhabricatorContentSourceModule.php',
+    'PhabricatorContentSourceView' => 'infrastructure/contentsource/PhabricatorContentSourceView.php',
     'PhabricatorContributedToObjectEdgeType' => 'applications/transactions/edges/PhabricatorContributedToObjectEdgeType.php',
     'PhabricatorController' => 'applications/base/controller/PhabricatorController.php',
     'PhabricatorCookies' => 'applications/auth/constants/PhabricatorCookies.php',
@@ -2138,6 +2142,7 @@
     'PhabricatorDaemonBulkJobMonitorController' => 'applications/daemon/controller/PhabricatorDaemonBulkJobMonitorController.php',
     'PhabricatorDaemonBulkJobViewController' => 'applications/daemon/controller/PhabricatorDaemonBulkJobViewController.php',
     'PhabricatorDaemonConsoleController' => 'applications/daemon/controller/PhabricatorDaemonConsoleController.php',
+    'PhabricatorDaemonContentSource' => 'infrastructure/daemon/contentsource/PhabricatorDaemonContentSource.php',
     'PhabricatorDaemonController' => 'applications/daemon/controller/PhabricatorDaemonController.php',
     'PhabricatorDaemonDAO' => 'applications/daemon/storage/PhabricatorDaemonDAO.php',
     'PhabricatorDaemonEventListener' => 'applications/daemon/event/PhabricatorDaemonEventListener.php',
@@ -2302,6 +2307,7 @@
     'PhabricatorElasticFulltextStorageEngine' => 'applications/search/fulltextstorage/PhabricatorElasticFulltextStorageEngine.php',
     'PhabricatorElasticSearchSetupCheck' => 'applications/config/check/PhabricatorElasticSearchSetupCheck.php',
     'PhabricatorEmailAddressesSettingsPanel' => 'applications/settings/panel/PhabricatorEmailAddressesSettingsPanel.php',
+    'PhabricatorEmailContentSource' => 'applications/metamta/contentsource/PhabricatorEmailContentSource.php',
     'PhabricatorEmailFormatSettingsPanel' => 'applications/settings/panel/PhabricatorEmailFormatSettingsPanel.php',
     'PhabricatorEmailLoginController' => 'applications/auth/controller/PhabricatorEmailLoginController.php',
     'PhabricatorEmailPreferencesSettingsPanel' => 'applications/settings/panel/PhabricatorEmailPreferencesSettingsPanel.php',
@@ -2347,6 +2353,7 @@
     'PhabricatorFactSimpleSpec' => 'applications/fact/spec/PhabricatorFactSimpleSpec.php',
     'PhabricatorFactSpec' => 'applications/fact/spec/PhabricatorFactSpec.php',
     'PhabricatorFactUpdateIterator' => 'applications/fact/extract/PhabricatorFactUpdateIterator.php',
+    'PhabricatorFaxContentSource' => 'infrastructure/contentsource/PhabricatorFaxContentSource.php',
     'PhabricatorFeedApplication' => 'applications/feed/application/PhabricatorFeedApplication.php',
     'PhabricatorFeedBuilder' => 'applications/feed/builder/PhabricatorFeedBuilder.php',
     'PhabricatorFeedConfigOptions' => 'applications/feed/config/PhabricatorFeedConfigOptions.php',
@@ -2476,6 +2483,7 @@
     'PhabricatorHelpKeyboardShortcutController' => 'applications/help/controller/PhabricatorHelpKeyboardShortcutController.php',
     'PhabricatorHelpMainMenuBarExtension' => 'applications/help/extension/PhabricatorHelpMainMenuBarExtension.php',
     'PhabricatorHeraldApplication' => 'applications/herald/application/PhabricatorHeraldApplication.php',
+    'PhabricatorHeraldContentSource' => 'applications/herald/contentsource/PhabricatorHeraldContentSource.php',
     'PhabricatorHighSecurityRequestExceptionHandler' => 'aphront/handler/PhabricatorHighSecurityRequestExceptionHandler.php',
     'PhabricatorHomeApplication' => 'applications/home/application/PhabricatorHomeApplication.php',
     'PhabricatorHomeController' => 'applications/home/controller/PhabricatorHomeController.php',
@@ -2524,6 +2532,7 @@
     'PhabricatorLibraryTestCase' => '__tests__/PhabricatorLibraryTestCase.php',
     'PhabricatorLinkProfilePanel' => 'applications/search/profilepanel/PhabricatorLinkProfilePanel.php',
     'PhabricatorLipsumArtist' => 'applications/lipsum/image/PhabricatorLipsumArtist.php',
+    'PhabricatorLipsumContentSource' => 'infrastructure/contentsource/PhabricatorLipsumContentSource.php',
     'PhabricatorLipsumGenerateWorkflow' => 'applications/lipsum/management/PhabricatorLipsumGenerateWorkflow.php',
     'PhabricatorLipsumManagementWorkflow' => 'applications/lipsum/management/PhabricatorLipsumManagementWorkflow.php',
     'PhabricatorLipsumMondrianArtist' => 'applications/lipsum/image/PhabricatorLipsumMondrianArtist.php',
@@ -2737,6 +2746,7 @@
     'PhabricatorObjectSelectorDialog' => 'view/control/PhabricatorObjectSelectorDialog.php',
     'PhabricatorObjectUsesCredentialsEdgeType' => 'applications/transactions/edges/PhabricatorObjectUsesCredentialsEdgeType.php',
     'PhabricatorOffsetPagedQuery' => 'infrastructure/query/PhabricatorOffsetPagedQuery.php',
+    'PhabricatorOldWorldContentSource' => 'infrastructure/contentsource/PhabricatorOldWorldContentSource.php',
     'PhabricatorOneTimeTriggerClock' => 'infrastructure/daemon/workers/clock/PhabricatorOneTimeTriggerClock.php',
     'PhabricatorOpcodeCacheSpec' => 'applications/cache/spec/PhabricatorOpcodeCacheSpec.php',
     'PhabricatorOwnerPathQuery' => 'applications/owners/query/PhabricatorOwnerPathQuery.php',
@@ -2871,6 +2881,7 @@
     'PhabricatorPholioConfigOptions' => 'applications/pholio/config/PhabricatorPholioConfigOptions.php',
     'PhabricatorPholioMockTestDataGenerator' => 'applications/pholio/lipsum/PhabricatorPholioMockTestDataGenerator.php',
     'PhabricatorPhortuneApplication' => 'applications/phortune/application/PhabricatorPhortuneApplication.php',
+    'PhabricatorPhortuneContentSource' => 'applications/phortune/contentsource/PhabricatorPhortuneContentSource.php',
     'PhabricatorPhortuneManagementInvoiceWorkflow' => 'applications/phortune/management/PhabricatorPhortuneManagementInvoiceWorkflow.php',
     'PhabricatorPhortuneManagementWorkflow' => 'applications/phortune/management/PhabricatorPhortuneManagementWorkflow.php',
     'PhabricatorPhragmentApplication' => 'applications/phragment/application/PhabricatorPhragmentApplication.php',
@@ -3471,7 +3482,9 @@
     'PhabricatorUIExampleRenderController' => 'applications/uiexample/controller/PhabricatorUIExampleRenderController.php',
     'PhabricatorUIExamplesApplication' => 'applications/uiexample/application/PhabricatorUIExamplesApplication.php',
     'PhabricatorUSEnglishTranslation' => 'infrastructure/internationalization/translation/PhabricatorUSEnglishTranslation.php',
+    'PhabricatorUnitTestContentSource' => 'infrastructure/contentsource/PhabricatorUnitTestContentSource.php',
     'PhabricatorUnitsTestCase' => 'view/__tests__/PhabricatorUnitsTestCase.php',
+    'PhabricatorUnknownContentSource' => 'infrastructure/contentsource/PhabricatorUnknownContentSource.php',
     'PhabricatorUnsubscribedFromObjectEdgeType' => 'applications/transactions/edges/PhabricatorUnsubscribedFromObjectEdgeType.php',
     'PhabricatorUser' => 'applications/people/storage/PhabricatorUser.php',
     'PhabricatorUserBlurbField' => 'applications/people/customfield/PhabricatorUserBlurbField.php',
@@ -3511,6 +3524,7 @@
     'PhabricatorVeryWowEnglishTranslation' => 'infrastructure/internationalization/translation/PhabricatorVeryWowEnglishTranslation.php',
     'PhabricatorViewerDatasource' => 'applications/people/typeahead/PhabricatorViewerDatasource.php',
     'PhabricatorWatcherHasObjectEdgeType' => 'applications/transactions/edges/PhabricatorWatcherHasObjectEdgeType.php',
+    'PhabricatorWebContentSource' => 'infrastructure/contentsource/PhabricatorWebContentSource.php',
     'PhabricatorWordPressAuthProvider' => 'applications/auth/provider/PhabricatorWordPressAuthProvider.php',
     'PhabricatorWorker' => 'infrastructure/daemon/workers/PhabricatorWorker.php',
     'PhabricatorWorkerActiveTask' => 'infrastructure/daemon/workers/storage/PhabricatorWorkerActiveTask.php',
@@ -6274,6 +6288,7 @@
     'PhabricatorBotWhatsNewHandler' => 'PhabricatorBotHandler',
     'PhabricatorBritishEnglishTranslation' => 'PhutilTranslation',
     'PhabricatorBuiltinPatchList' => 'PhabricatorSQLPatchList',
+    'PhabricatorBulkContentSource' => 'PhabricatorContentSource',
     'PhabricatorBusyUIExample' => 'PhabricatorUIExample',
     'PhabricatorCacheDAO' => 'PhabricatorLiskDAO',
     'PhabricatorCacheGeneralGarbageCollector' => 'PhabricatorGarbageCollector',
@@ -6369,6 +6384,7 @@
     'PhabricatorConduitCertificateToken' => 'PhabricatorConduitDAO',
     'PhabricatorConduitConnectionLog' => 'PhabricatorConduitDAO',
     'PhabricatorConduitConsoleController' => 'PhabricatorConduitController',
+    'PhabricatorConduitContentSource' => 'PhabricatorContentSource',
     'PhabricatorConduitController' => 'PhabricatorController',
     'PhabricatorConduitDAO' => 'PhabricatorLiskDAO',
     'PhabricatorConduitEditField' => 'PhabricatorEditField',
@@ -6469,7 +6485,9 @@
     'PhabricatorConpherencePreferencesSettingsPanel' => 'PhabricatorSettingsPanel',
     'PhabricatorConpherenceThreadPHIDType' => 'PhabricatorPHIDType',
     'PhabricatorConsoleApplication' => 'PhabricatorApplication',
+    'PhabricatorConsoleContentSource' => 'PhabricatorContentSource',
     'PhabricatorContentSource' => 'Phobject',
+    'PhabricatorContentSourceModule' => 'PhabricatorConfigModule',
     'PhabricatorContentSourceView' => 'AphrontView',
     'PhabricatorContributedToObjectEdgeType' => 'PhabricatorEdgeType',
     'PhabricatorController' => 'AphrontController',
@@ -6535,6 +6553,7 @@
     'PhabricatorDaemonBulkJobMonitorController' => 'PhabricatorDaemonController',
     'PhabricatorDaemonBulkJobViewController' => 'PhabricatorDaemonController',
     'PhabricatorDaemonConsoleController' => 'PhabricatorDaemonController',
+    'PhabricatorDaemonContentSource' => 'PhabricatorContentSource',
     'PhabricatorDaemonController' => 'PhabricatorController',
     'PhabricatorDaemonDAO' => 'PhabricatorLiskDAO',
     'PhabricatorDaemonEventListener' => 'PhabricatorEventListener',
@@ -6726,6 +6745,7 @@
     'PhabricatorElasticFulltextStorageEngine' => 'PhabricatorFulltextStorageEngine',
     'PhabricatorElasticSearchSetupCheck' => 'PhabricatorSetupCheck',
     'PhabricatorEmailAddressesSettingsPanel' => 'PhabricatorSettingsPanel',
+    'PhabricatorEmailContentSource' => 'PhabricatorContentSource',
     'PhabricatorEmailFormatSettingsPanel' => 'PhabricatorSettingsPanel',
     'PhabricatorEmailLoginController' => 'PhabricatorAuthController',
     'PhabricatorEmailPreferencesSettingsPanel' => 'PhabricatorSettingsPanel',
@@ -6773,6 +6793,7 @@
     'PhabricatorFactSimpleSpec' => 'PhabricatorFactSpec',
     'PhabricatorFactSpec' => 'Phobject',
     'PhabricatorFactUpdateIterator' => 'PhutilBufferedIterator',
+    'PhabricatorFaxContentSource' => 'PhabricatorContentSource',
     'PhabricatorFeedApplication' => 'PhabricatorApplication',
     'PhabricatorFeedBuilder' => 'Phobject',
     'PhabricatorFeedConfigOptions' => 'PhabricatorApplicationConfigOptions',
@@ -6935,6 +6956,7 @@
     'PhabricatorHelpKeyboardShortcutController' => 'PhabricatorHelpController',
     'PhabricatorHelpMainMenuBarExtension' => 'PhabricatorMainMenuBarExtension',
     'PhabricatorHeraldApplication' => 'PhabricatorApplication',
+    'PhabricatorHeraldContentSource' => 'PhabricatorContentSource',
     'PhabricatorHighSecurityRequestExceptionHandler' => 'PhabricatorRequestExceptionHandler',
     'PhabricatorHomeApplication' => 'PhabricatorApplication',
     'PhabricatorHomeController' => 'PhabricatorController',
@@ -6983,6 +7005,7 @@
     'PhabricatorLibraryTestCase' => 'PhutilLibraryTestCase',
     'PhabricatorLinkProfilePanel' => 'PhabricatorProfilePanel',
     'PhabricatorLipsumArtist' => 'Phobject',
+    'PhabricatorLipsumContentSource' => 'PhabricatorContentSource',
     'PhabricatorLipsumGenerateWorkflow' => 'PhabricatorLipsumManagementWorkflow',
     'PhabricatorLipsumManagementWorkflow' => 'PhabricatorManagementWorkflow',
     'PhabricatorLipsumMondrianArtist' => 'PhabricatorLipsumArtist',
@@ -7218,6 +7241,7 @@
     'PhabricatorObjectSelectorDialog' => 'Phobject',
     'PhabricatorObjectUsesCredentialsEdgeType' => 'PhabricatorEdgeType',
     'PhabricatorOffsetPagedQuery' => 'PhabricatorQuery',
+    'PhabricatorOldWorldContentSource' => 'PhabricatorContentSource',
     'PhabricatorOneTimeTriggerClock' => 'PhabricatorTriggerClock',
     'PhabricatorOpcodeCacheSpec' => 'PhabricatorCacheSpec',
     'PhabricatorOwnerPathQuery' => 'Phobject',
@@ -7375,6 +7399,7 @@
     'PhabricatorPholioConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorPholioMockTestDataGenerator' => 'PhabricatorTestDataGenerator',
     'PhabricatorPhortuneApplication' => 'PhabricatorApplication',
+    'PhabricatorPhortuneContentSource' => 'PhabricatorContentSource',
     'PhabricatorPhortuneManagementInvoiceWorkflow' => 'PhabricatorPhortuneManagementWorkflow',
     'PhabricatorPhortuneManagementWorkflow' => 'PhabricatorManagementWorkflow',
     'PhabricatorPhragmentApplication' => 'PhabricatorApplication',
@@ -8094,7 +8119,9 @@
     'PhabricatorUIExampleRenderController' => 'PhabricatorController',
     'PhabricatorUIExamplesApplication' => 'PhabricatorApplication',
     'PhabricatorUSEnglishTranslation' => 'PhutilTranslation',
+    'PhabricatorUnitTestContentSource' => 'PhabricatorContentSource',
     'PhabricatorUnitsTestCase' => 'PhabricatorTestCase',
+    'PhabricatorUnknownContentSource' => 'PhabricatorContentSource',
     'PhabricatorUnsubscribedFromObjectEdgeType' => 'PhabricatorEdgeType',
     'PhabricatorUser' => array(
       'PhabricatorUserDAO',
@@ -8150,6 +8177,7 @@
     'PhabricatorVeryWowEnglishTranslation' => 'PhutilTranslation',
     'PhabricatorViewerDatasource' => 'PhabricatorTypeaheadDatasource',
     'PhabricatorWatcherHasObjectEdgeType' => 'PhabricatorEdgeType',
+    'PhabricatorWebContentSource' => 'PhabricatorContentSource',
     'PhabricatorWordPressAuthProvider' => 'PhabricatorOAuth2AuthProvider',
     'PhabricatorWorker' => 'Phobject',
     'PhabricatorWorkerActiveTask' => 'PhabricatorWorkerTask',
diff --git a/src/applications/almanac/management/AlmanacManagementWorkflow.php b/src/applications/almanac/management/AlmanacManagementWorkflow.php
--- a/src/applications/almanac/management/AlmanacManagementWorkflow.php
+++ b/src/applications/almanac/management/AlmanacManagementWorkflow.php
@@ -3,7 +3,6 @@
 abstract class AlmanacManagementWorkflow
   extends PhabricatorManagementWorkflow {
 
-
   protected function loadServices(array $names) {
     if (!$names) {
       return array();
@@ -37,7 +36,7 @@
     $editor = id(new AlmanacServiceEditor())
       ->setActor($this->getViewer())
       ->setActingAsPHID($almanac_phid)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource())
+      ->setContentSource($this->newContentSource())
       ->setContinueOnMissingFields(true);
 
     $editor->applyTransactions($service, array($xaction));
diff --git a/src/applications/audit/storage/PhabricatorAuditInlineComment.php b/src/applications/audit/storage/PhabricatorAuditInlineComment.php
--- a/src/applications/audit/storage/PhabricatorAuditInlineComment.php
+++ b/src/applications/audit/storage/PhabricatorAuditInlineComment.php
@@ -34,8 +34,7 @@
 
   public function getTransactionCommentForSave() {
     $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_LEGACY,
-      array());
+      PhabricatorOldWorldContentSource::SOURCECONST);
 
     $this->proxy
       ->setViewPolicy('public')
diff --git a/src/applications/conduit/protocol/ConduitAPIRequest.php b/src/applications/conduit/protocol/ConduitAPIRequest.php
--- a/src/applications/conduit/protocol/ConduitAPIRequest.php
+++ b/src/applications/conduit/protocol/ConduitAPIRequest.php
@@ -57,4 +57,9 @@
     return $this->isClusterRequest;
   }
 
+  public function newContentSource() {
+    return PhabricatorContentSource::newForSource(
+      PhabricatorConduitContentSource::SOURCECONST);
+  }
+
 }
diff --git a/src/applications/conpherence/__tests__/ConpherenceRoomTestCase.php b/src/applications/conpherence/__tests__/ConpherenceRoomTestCase.php
--- a/src/applications/conpherence/__tests__/ConpherenceRoomTestCase.php
+++ b/src/applications/conpherence/__tests__/ConpherenceRoomTestCase.php
@@ -147,7 +147,7 @@
 
     id(new ConpherenceEditor())
       ->setActor($creator)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource())
+      ->setContentSource($this->newContentSource())
       ->setContinueOnNoEffect(true)
       ->applyTransactions($conpherence, $xactions);
 
@@ -166,7 +166,7 @@
 
     id(new ConpherenceEditor())
       ->setActor($actor)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource())
+      ->setContentSource($this->newContentSource())
       ->setContinueOnNoEffect(true)
       ->applyTransactions($room, $xactions);
   }
diff --git a/src/applications/conpherence/__tests__/ConpherenceTestCase.php b/src/applications/conpherence/__tests__/ConpherenceTestCase.php
--- a/src/applications/conpherence/__tests__/ConpherenceTestCase.php
+++ b/src/applications/conpherence/__tests__/ConpherenceTestCase.php
@@ -14,7 +14,7 @@
     );
     $editor = id(new ConpherenceEditor())
       ->setActor($actor)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource())
+      ->setContentSource($this->newContentSource())
       ->applyTransactions($conpherence, $xactions);
 
   }
@@ -31,7 +31,7 @@
     );
     $editor = id(new ConpherenceEditor())
       ->setActor($actor)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource())
+      ->setContentSource($this->newContentSource())
       ->applyTransactions($conpherence, $xactions);
   }
 
@@ -45,7 +45,7 @@
 
     $editor = id(new ConpherenceEditor())
       ->setActor($actor)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource());
+      ->setContentSource($this->newContentSource());
 
     $xactions = $editor->generateTransactionsFromText(
       $actor,
diff --git a/src/applications/conpherence/conduit/ConpherenceCreateThreadConduitAPIMethod.php b/src/applications/conpherence/conduit/ConpherenceCreateThreadConduitAPIMethod.php
--- a/src/applications/conpherence/conduit/ConpherenceCreateThreadConduitAPIMethod.php
+++ b/src/applications/conpherence/conduit/ConpherenceCreateThreadConduitAPIMethod.php
@@ -42,7 +42,7 @@
       $participant_phids,
       $title,
       $message,
-      PhabricatorContentSource::newFromConduitRequest($request));
+      $request->newContentSource());
 
     if ($errors) {
       foreach ($errors as $error_code) {
diff --git a/src/applications/conpherence/conduit/ConpherenceUpdateThreadConduitAPIMethod.php b/src/applications/conpherence/conduit/ConpherenceUpdateThreadConduitAPIMethod.php
--- a/src/applications/conpherence/conduit/ConpherenceUpdateThreadConduitAPIMethod.php
+++ b/src/applications/conpherence/conduit/ConpherenceUpdateThreadConduitAPIMethod.php
@@ -58,7 +58,7 @@
       throw new ConduitException('ERR_USAGE_ROOM_NOT_FOUND');
     }
 
-    $source = PhabricatorContentSource::newFromConduitRequest($request);
+    $source = $request->newContentSource();
     $editor = id(new ConpherenceEditor())
       ->setContentSource($source)
       ->setActor($user);
diff --git a/src/applications/conpherence/mail/ConpherenceReplyHandler.php b/src/applications/conpherence/mail/ConpherenceReplyHandler.php
--- a/src/applications/conpherence/mail/ConpherenceReplyHandler.php
+++ b/src/applications/conpherence/mail/ConpherenceReplyHandler.php
@@ -48,11 +48,7 @@
       $conpherence->attachParticipants($participants);
     }
 
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_EMAIL,
-      array(
-        'id' => $mail->getID(),
-      ));
+    $content_source = $mail->newContentSource();
 
     $editor = id(new ConpherenceEditor())
       ->setActor($user)
diff --git a/src/applications/differential/conduit/DifferentialCloseConduitAPIMethod.php b/src/applications/differential/conduit/DifferentialCloseConduitAPIMethod.php
--- a/src/applications/differential/conduit/DifferentialCloseConduitAPIMethod.php
+++ b/src/applications/differential/conduit/DifferentialCloseConduitAPIMethod.php
@@ -45,13 +45,11 @@
       ->setTransactionType(DifferentialTransaction::TYPE_ACTION)
       ->setNewValue(DifferentialAction::ACTION_CLOSE);
 
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_CONDUIT,
-      array());
+    $content_source = $request->newContentSource();
 
     $editor = id(new DifferentialTransactionEditor())
       ->setActor($viewer)
-      ->setContentSourceFromConduitRequest($request)
+      ->setContentSource($request->newContentSource())
       ->setContinueOnMissingFields(true)
       ->setContinueOnNoEffect(true);
 
diff --git a/src/applications/differential/conduit/DifferentialConduitAPIMethod.php b/src/applications/differential/conduit/DifferentialConduitAPIMethod.php
--- a/src/applications/differential/conduit/DifferentialConduitAPIMethod.php
+++ b/src/applications/differential/conduit/DifferentialConduitAPIMethod.php
@@ -138,7 +138,7 @@
 
     $editor = id(new DifferentialTransactionEditor())
       ->setActor($viewer)
-      ->setContentSourceFromConduitRequest($request)
+      ->setContentSource($request->newContentSource())
       ->setContinueOnNoEffect(true)
       ->setContinueOnMissingFields(true);
 
diff --git a/src/applications/differential/conduit/DifferentialCreateCommentConduitAPIMethod.php b/src/applications/differential/conduit/DifferentialCreateCommentConduitAPIMethod.php
--- a/src/applications/differential/conduit/DifferentialCreateCommentConduitAPIMethod.php
+++ b/src/applications/differential/conduit/DifferentialCreateCommentConduitAPIMethod.php
@@ -77,7 +77,7 @@
     $editor = id(new DifferentialTransactionEditor())
       ->setActor($viewer)
       ->setDisableEmail($request->getValue('silent'))
-      ->setContentSourceFromConduitRequest($request)
+      ->setContentSource($request->newContentSource())
       ->setContinueOnNoEffect(true)
       ->setContinueOnMissingFields(true);
 
diff --git a/src/applications/differential/conduit/DifferentialCreateDiffConduitAPIMethod.php b/src/applications/differential/conduit/DifferentialCreateDiffConduitAPIMethod.php
--- a/src/applications/differential/conduit/DifferentialCreateDiffConduitAPIMethod.php
+++ b/src/applications/differential/conduit/DifferentialCreateDiffConduitAPIMethod.php
@@ -144,7 +144,7 @@
 
     id(new DifferentialDiffEditor())
       ->setActor($viewer)
-      ->setContentSourceFromConduitRequest($request)
+      ->setContentSource($request->newContentSource())
       ->setContinueOnNoEffect(true)
       ->applyTransactions($diff, $xactions);
 
diff --git a/src/applications/differential/conduit/DifferentialCreateRawDiffConduitAPIMethod.php b/src/applications/differential/conduit/DifferentialCreateRawDiffConduitAPIMethod.php
--- a/src/applications/differential/conduit/DifferentialCreateRawDiffConduitAPIMethod.php
+++ b/src/applications/differential/conduit/DifferentialCreateRawDiffConduitAPIMethod.php
@@ -85,7 +85,7 @@
 
     id(new DifferentialDiffEditor())
       ->setActor($viewer)
-      ->setContentSourceFromConduitRequest($request)
+      ->setContentSource($request->newContentSource())
       ->setContinueOnNoEffect(true)
       ->setLookupRepository(false) // respect user choice
       ->applyTransactions($diff, $xactions);
diff --git a/src/applications/differential/management/PhabricatorDifferentialAttachCommitWorkflow.php b/src/applications/differential/management/PhabricatorDifferentialAttachCommitWorkflow.php
--- a/src/applications/differential/management/PhabricatorDifferentialAttachCommitWorkflow.php
+++ b/src/applications/differential/management/PhabricatorDifferentialAttachCommitWorkflow.php
@@ -68,9 +68,7 @@
       ->setViewer($viewer)
       ->setAuthorPHID($differential_phid);
 
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_CONSOLE,
-      array());
+    $content_source = $this->newContentSource();
 
     $extraction_engine->updateRevisionWithCommit(
       $revision,
diff --git a/src/applications/differential/storage/DifferentialInlineComment.php b/src/applications/differential/storage/DifferentialInlineComment.php
--- a/src/applications/differential/storage/DifferentialInlineComment.php
+++ b/src/applications/differential/storage/DifferentialInlineComment.php
@@ -18,8 +18,7 @@
 
   public function getTransactionCommentForSave() {
     $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_LEGACY,
-      array());
+      PhabricatorOldWorldContentSource::SOURCECONST);
 
     $this->proxy
       ->setViewPolicy('public')
diff --git a/src/applications/diffusion/conduit/DiffusionCreateCommentConduitAPIMethod.php b/src/applications/diffusion/conduit/DiffusionCreateCommentConduitAPIMethod.php
--- a/src/applications/diffusion/conduit/DiffusionCreateCommentConduitAPIMethod.php
+++ b/src/applications/diffusion/conduit/DiffusionCreateCommentConduitAPIMethod.php
@@ -95,7 +95,7 @@
 
     id(new PhabricatorAuditEditor())
       ->setActor($request->getUser())
-      ->setContentSourceFromConduitRequest($request)
+      ->setContentSource($request->newContentSource())
       ->setDisableEmail($request->getValue('silent'))
       ->setContinueOnMissingFields(true)
       ->applyTransactions($commit, $xactions);
diff --git a/src/applications/harbormaster/engine/HarbormasterBuildEngine.php b/src/applications/harbormaster/engine/HarbormasterBuildEngine.php
--- a/src/applications/harbormaster/engine/HarbormasterBuildEngine.php
+++ b/src/applications/harbormaster/engine/HarbormasterBuildEngine.php
@@ -458,8 +458,7 @@
       ->getPHID();
 
     $daemon_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_DAEMON,
-      array());
+      PhabricatorDaemonContentSource::SOURCECONST);
 
     $editor = $object->getApplicationTransactionEditor()
       ->setActor($viewer)
diff --git a/src/applications/herald/contentsource/PhabricatorHeraldContentSource.php b/src/applications/herald/contentsource/PhabricatorHeraldContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/applications/herald/contentsource/PhabricatorHeraldContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorHeraldContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'herald';
+
+  public function getSourceName() {
+    return pht('Herald');
+  }
+
+  public function getSourceDescription() {
+    return pht('Changes triggered by Herald rules.');
+  }
+
+}
diff --git a/src/applications/herald/field/HeraldContentSourceField.php b/src/applications/herald/field/HeraldContentSourceField.php
--- a/src/applications/herald/field/HeraldContentSourceField.php
+++ b/src/applications/herald/field/HeraldContentSourceField.php
@@ -24,12 +24,13 @@
   }
 
   public function getHeraldFieldValueType($condition) {
-    $map = PhabricatorContentSource::getSourceNameMap();
+    $map = PhabricatorContentSource::getAllContentSources();
+    $map = mpull($map, 'getSourceName');
     asort($map);
 
     return id(new HeraldSelectFieldValue())
       ->setKey(self::FIELDCONST)
-      ->setDefault(PhabricatorContentSource::SOURCE_WEB)
+      ->setDefault(PhabricatorWebContentSource::SOURCECONST)
       ->setOptions($map);
   }
 
diff --git a/src/applications/lipsum/generator/PhabricatorTestDataGenerator.php b/src/applications/lipsum/generator/PhabricatorTestDataGenerator.php
--- a/src/applications/lipsum/generator/PhabricatorTestDataGenerator.php
+++ b/src/applications/lipsum/generator/PhabricatorTestDataGenerator.php
@@ -56,8 +56,7 @@
 
   protected function getLipsumContentSource() {
     return PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_LIPSUM,
-      array());
+      PhabricatorLipsumContentSource::SOURCECONST);
   }
 
   /**
diff --git a/src/applications/maniphest/__tests__/ManiphestTaskTestCase.php b/src/applications/maniphest/__tests__/ManiphestTaskTestCase.php
--- a/src/applications/maniphest/__tests__/ManiphestTaskTestCase.php
+++ b/src/applications/maniphest/__tests__/ManiphestTaskTestCase.php
@@ -207,7 +207,7 @@
     ManiphestTask $task,
     array $xactions) {
 
-    $content_source = PhabricatorContentSource::newConsoleSource();
+    $content_source = $this->newContentSource();
 
     $editor = id(new ManiphestTransactionEditor())
       ->setActor($viewer)
diff --git a/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php b/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php
--- a/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php
+++ b/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php
@@ -192,9 +192,7 @@
       return;
     }
 
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_CONDUIT,
-      array());
+    $content_source = $request->newContentSource();
 
     $editor = id(new ManiphestTransactionEditor())
       ->setActor($request->getUser())
diff --git a/src/applications/maniphest/lipsum/PhabricatorManiphestTaskTestDataGenerator.php b/src/applications/maniphest/lipsum/PhabricatorManiphestTaskTestDataGenerator.php
--- a/src/applications/maniphest/lipsum/PhabricatorManiphestTaskTestDataGenerator.php
+++ b/src/applications/maniphest/lipsum/PhabricatorManiphestTaskTestDataGenerator.php
@@ -15,9 +15,7 @@
       ->setSubPriority($this->generateTaskSubPriority())
       ->setTitle($this->generateTitle());
 
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_UNKNOWN,
-      array());
+    $content_source = $this->getLipsumContentSource();
 
     $template = new ManiphestTransaction();
     // Accumulate Transactions
diff --git a/src/applications/metamta/contentsource/PhabricatorContentSource.php b/src/applications/metamta/contentsource/PhabricatorContentSource.php
deleted file mode 100644
--- a/src/applications/metamta/contentsource/PhabricatorContentSource.php
+++ /dev/null
@@ -1,104 +0,0 @@
-<?php
-
-final class PhabricatorContentSource extends Phobject {
-
-  const SOURCE_UNKNOWN  = 'unknown';
-  const SOURCE_WEB      = 'web';
-  const SOURCE_EMAIL    = 'email';
-  const SOURCE_CONDUIT  = 'conduit';
-  const SOURCE_MOBILE   = 'mobile';
-  const SOURCE_TABLET   = 'tablet';
-  const SOURCE_FAX      = 'fax';
-  const SOURCE_CONSOLE  = 'console';
-  const SOURCE_HERALD   = 'herald';
-  const SOURCE_LEGACY   = 'legacy';
-  const SOURCE_DAEMON   = 'daemon';
-  const SOURCE_LIPSUM   = 'lipsum';
-  const SOURCE_PHORTUNE = 'phortune';
-  const SOURCE_BULK = 'bulk';
-
-  private $source;
-  private $params = array();
-
-  private function __construct() {
-    // <empty>
-  }
-
-  public static function newForSource($source, array $params) {
-    $obj = new PhabricatorContentSource();
-    $obj->source = $source;
-    $obj->params = $params;
-
-    return $obj;
-  }
-
-  public static function newFromSerialized($serialized) {
-    $dict = json_decode($serialized, true);
-    if (!is_array($dict)) {
-      $dict = array();
-    }
-
-    $obj = new PhabricatorContentSource();
-    $obj->source = idx($dict, 'source', self::SOURCE_UNKNOWN);
-    $obj->params = idx($dict, 'params', array());
-
-    return $obj;
-  }
-
-  public static function newConsoleSource() {
-    return self::newForSource(
-      self::SOURCE_CONSOLE,
-      array());
-  }
-
-  public static function newFromRequest(AphrontRequest $request) {
-    return self::newForSource(
-      self::SOURCE_WEB,
-      array());
-  }
-
-  public static function newFromConduitRequest(ConduitAPIRequest $request) {
-    return self::newForSource(
-      self::SOURCE_CONDUIT,
-      array());
-  }
-
-  public static function getSourceNameMap() {
-    return array(
-      self::SOURCE_WEB      => pht('Web'),
-      self::SOURCE_EMAIL    => pht('Email'),
-      self::SOURCE_CONDUIT  => pht('Conduit'),
-      self::SOURCE_MOBILE   => pht('Mobile'),
-      self::SOURCE_TABLET   => pht('Tablet'),
-      self::SOURCE_FAX      => pht('Fax'),
-      self::SOURCE_CONSOLE  => pht('Console'),
-      self::SOURCE_LEGACY   => pht('Legacy'),
-      self::SOURCE_HERALD   => pht('Herald'),
-      self::SOURCE_DAEMON   => pht('Daemons'),
-      self::SOURCE_LIPSUM   => pht('Lipsum'),
-      self::SOURCE_UNKNOWN  => pht('Old World'),
-      self::SOURCE_PHORTUNE => pht('Phortune'),
-      self::SOURCE_BULK => pht('Bulk Edit'),
-    );
-  }
-
-  public function serialize() {
-    return json_encode(array(
-      'source' => $this->getSource(),
-      'params' => $this->getParams(),
-    ));
-  }
-
-  public function getSource() {
-    return $this->source;
-  }
-
-  public function getParams() {
-    return $this->params;
-  }
-
-  public function getParam($key, $default = null) {
-    return idx($this->params, $key, $default);
-  }
-
-}
diff --git a/src/applications/metamta/contentsource/PhabricatorEmailContentSource.php b/src/applications/metamta/contentsource/PhabricatorEmailContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/applications/metamta/contentsource/PhabricatorEmailContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorEmailContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'email';
+
+  public function getSourceName() {
+    return pht('Email');
+  }
+
+  public function getSourceDescription() {
+    return pht('Content sent by electronic mail, also known as e-mail.');
+  }
+
+}
diff --git a/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php b/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
--- a/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
+++ b/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
@@ -371,4 +371,12 @@
       ->saveAndSend();
   }
 
+  public function newContentSource() {
+    return PhabricatorContentSource::newForSource(
+      PhabricatorEmailContentSource::SOURCECONST,
+      array(
+        'id' => $this->getID(),
+      ));
+  }
+
 }
diff --git a/src/applications/nuance/item/NuanceGitHubEventItemType.php b/src/applications/nuance/item/NuanceGitHubEventItemType.php
--- a/src/applications/nuance/item/NuanceGitHubEventItemType.php
+++ b/src/applications/nuance/item/NuanceGitHubEventItemType.php
@@ -323,10 +323,9 @@
 
     // TODO: Preserve the item's original source.
     $source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_DAEMON,
-      array());
+      PhabricatorDaemonContentSource::SOURCECONST);
 
-    // TOOD: This should really be the external source.
+    // TODO: This should really be the external source.
     $acting_phid = $nuance_phid;
 
     $editor = id(new ManiphestTransactionEditor())
diff --git a/src/applications/nuance/item/NuanceItemType.php b/src/applications/nuance/item/NuanceItemType.php
--- a/src/applications/nuance/item/NuanceItemType.php
+++ b/src/applications/nuance/item/NuanceItemType.php
@@ -119,8 +119,7 @@
 
     // TODO: Maybe preserve the actor's original content source?
     $source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_DAEMON,
-      array());
+      PhabricatorDaemonContentSource::SOURCECONST);
 
     $editor = id(new NuanceItemEditor())
       ->setActor($viewer)
diff --git a/src/applications/paste/conduit/PasteCreateConduitAPIMethod.php b/src/applications/paste/conduit/PasteCreateConduitAPIMethod.php
--- a/src/applications/paste/conduit/PasteCreateConduitAPIMethod.php
+++ b/src/applications/paste/conduit/PasteCreateConduitAPIMethod.php
@@ -61,7 +61,7 @@
     $editor = id(new PhabricatorPasteEditor())
       ->setActor($viewer)
       ->setContinueOnNoEffect(true)
-      ->setContentSourceFromConduitRequest($request);
+      ->setContentSource($request->newContentSource());
 
     $xactions = $editor->applyTransactions($paste, $xactions);
 
diff --git a/src/applications/paste/mail/PasteCreateMailReceiver.php b/src/applications/paste/mail/PasteCreateMailReceiver.php
--- a/src/applications/paste/mail/PasteCreateMailReceiver.php
+++ b/src/applications/paste/mail/PasteCreateMailReceiver.php
@@ -37,11 +37,7 @@
 
     $paste = PhabricatorPaste::initializeNewPaste($sender);
 
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_EMAIL,
-      array(
-        'id' => $mail->getID(),
-      ));
+    $content_source = $mail->newContentSource();
 
     $editor = id(new PhabricatorPasteEditor())
       ->setActor($sender)
@@ -69,4 +65,5 @@
       ->saveAndSend();
   }
 
+
 }
diff --git a/src/applications/pholio/lipsum/PhabricatorPholioMockTestDataGenerator.php b/src/applications/pholio/lipsum/PhabricatorPholioMockTestDataGenerator.php
--- a/src/applications/pholio/lipsum/PhabricatorPholioMockTestDataGenerator.php
+++ b/src/applications/pholio/lipsum/PhabricatorPholioMockTestDataGenerator.php
@@ -13,9 +13,8 @@
           ->loadOneWhere('phid = %s', $author_phid);
     $mock = PholioMock::initializeNewMock($author);
 
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_UNKNOWN,
-      array());
+    $content_source = $this->getLipsumContentSource();
+
     $template = id(new PholioTransaction())
       ->setContentSource($content_source);
 
diff --git a/src/applications/phortune/contentsource/PhabricatorPhortuneContentSource.php b/src/applications/phortune/contentsource/PhabricatorPhortuneContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/applications/phortune/contentsource/PhabricatorPhortuneContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorPhortuneContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'phortune';
+
+  public function getSourceName() {
+    return pht('Phortune');
+  }
+
+  public function getSourceDescription() {
+    return pht('Updates from subscriptions and payment processors.');
+  }
+
+}
diff --git a/src/applications/phortune/product/PhortuneProductImplementation.php b/src/applications/phortune/product/PhortuneProductImplementation.php
--- a/src/applications/phortune/product/PhortuneProductImplementation.php
+++ b/src/applications/phortune/product/PhortuneProductImplementation.php
@@ -12,8 +12,7 @@
 
   protected function getContentSource() {
     return PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_PHORTUNE,
-      array());
+      PhabricatorPhortuneContentSource::SOURCECONST);
   }
 
   public function getPurchaseName(
diff --git a/src/applications/phortune/storage/PhortuneCart.php b/src/applications/phortune/storage/PhortuneCart.php
--- a/src/applications/phortune/storage/PhortuneCart.php
+++ b/src/applications/phortune/storage/PhortuneCart.php
@@ -431,8 +431,7 @@
       ->setNewValue(true);
 
     $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_PHORTUNE,
-      array());
+      PhabricatorPhortuneContentSource::SOURCECONST);
 
     $editor = id(new PhortuneCartEditor())
       ->setActor($omnipotent_user)
diff --git a/src/applications/phortune/worker/PhortuneSubscriptionWorker.php b/src/applications/phortune/worker/PhortuneSubscriptionWorker.php
--- a/src/applications/phortune/worker/PhortuneSubscriptionWorker.php
+++ b/src/applications/phortune/worker/PhortuneSubscriptionWorker.php
@@ -96,8 +96,7 @@
       ->setNewValue(true);
 
     $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_PHORTUNE,
-      array());
+      PhabricatorPhortuneContentSource::SOURCECONST);
 
     $acting_phid = id(new PhabricatorPhortuneApplication())->getPHID();
     $editor = id(new PhortuneCartEditor())
diff --git a/src/applications/phriction/conduit/PhrictionCreateConduitAPIMethod.php b/src/applications/phriction/conduit/PhrictionCreateConduitAPIMethod.php
--- a/src/applications/phriction/conduit/PhrictionCreateConduitAPIMethod.php
+++ b/src/applications/phriction/conduit/PhrictionCreateConduitAPIMethod.php
@@ -55,7 +55,7 @@
 
     $editor = id(new PhrictionTransactionEditor())
       ->setActor($request->getUser())
-      ->setContentSourceFromConduitRequest($request)
+      ->setContentSource($request->newContentSource())
       ->setContinueOnNoEffect(true)
       ->setDescription($request->getValue('description'));
 
diff --git a/src/applications/phriction/conduit/PhrictionEditConduitAPIMethod.php b/src/applications/phriction/conduit/PhrictionEditConduitAPIMethod.php
--- a/src/applications/phriction/conduit/PhrictionEditConduitAPIMethod.php
+++ b/src/applications/phriction/conduit/PhrictionEditConduitAPIMethod.php
@@ -50,7 +50,7 @@
 
     $editor = id(new PhrictionTransactionEditor())
       ->setActor($request->getUser())
-      ->setContentSourceFromConduitRequest($request)
+      ->setContentSource($request->newContentSource())
       ->setContinueOnNoEffect(true)
       ->setDescription($request->getValue('description'));
 
diff --git a/src/applications/project/__tests__/PhabricatorProjectCoreTestCase.php b/src/applications/project/__tests__/PhabricatorProjectCoreTestCase.php
--- a/src/applications/project/__tests__/PhabricatorProjectCoreTestCase.php
+++ b/src/applications/project/__tests__/PhabricatorProjectCoreTestCase.php
@@ -1087,7 +1087,7 @@
 
     $editor = id(new ManiphestTransactionEditor())
       ->setActor($viewer)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource())
+      ->setContentSource($this->newContentSource())
       ->setContinueOnNoEffect(true)
       ->applyTransactions($task, $xactions);
   }
@@ -1203,7 +1203,7 @@
 
     $editor = id(new ManiphestTransactionEditor())
       ->setActor($viewer)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource())
+      ->setContentSource($this->newContentSource())
       ->setContinueOnNoEffect(true)
       ->applyTransactions($task, $xactions);
   }
@@ -1239,7 +1239,7 @@
 
     $editor = id(new ManiphestTransactionEditor())
       ->setActor($viewer)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource())
+      ->setContentSource($this->newContentSource())
       ->setContinueOnNoEffect(true)
       ->applyTransactions($task, $xactions);
 
@@ -1464,7 +1464,7 @@
 
     $editor = id(new PhabricatorProjectTransactionEditor())
       ->setActor($user)
-      ->setContentSource(PhabricatorContentSource::newConsoleSource())
+      ->setContentSource($this->newContentSource())
       ->setContinueOnNoEffect(true)
       ->applyTransactions($project, $xactions);
   }
diff --git a/src/applications/project/conduit/ProjectCreateConduitAPIMethod.php b/src/applications/project/conduit/ProjectCreateConduitAPIMethod.php
--- a/src/applications/project/conduit/ProjectCreateConduitAPIMethod.php
+++ b/src/applications/project/conduit/ProjectCreateConduitAPIMethod.php
@@ -71,7 +71,7 @@
     $editor = id(new PhabricatorProjectTransactionEditor())
       ->setActor($user)
       ->setContinueOnNoEffect(true)
-      ->setContentSourceFromConduitRequest($request);
+      ->setContentSource($request->newContentSource());
 
     $editor->applyTransactions($project, $xactions);
 
diff --git a/src/applications/releeph/conduit/ReleephRequestConduitAPIMethod.php b/src/applications/releeph/conduit/ReleephRequestConduitAPIMethod.php
--- a/src/applications/releeph/conduit/ReleephRequestConduitAPIMethod.php
+++ b/src/applications/releeph/conduit/ReleephRequestConduitAPIMethod.php
@@ -144,10 +144,7 @@
         $editor = id(new ReleephRequestTransactionalEditor())
           ->setActor($user)
           ->setContinueOnNoEffect(true)
-          ->setContentSource(
-            PhabricatorContentSource::newForSource(
-              PhabricatorContentSource::SOURCE_CONDUIT,
-              array()));
+          ->setContentSource($request->newContentSource());
 
         $editor->applyTransactions($releeph_request, $xactions);
       }
diff --git a/src/applications/releeph/conduit/work/ReleephWorkRecordConduitAPIMethod.php b/src/applications/releeph/conduit/work/ReleephWorkRecordConduitAPIMethod.php
--- a/src/applications/releeph/conduit/work/ReleephWorkRecordConduitAPIMethod.php
+++ b/src/applications/releeph/conduit/work/ReleephWorkRecordConduitAPIMethod.php
@@ -65,10 +65,7 @@
     $editor = id(new ReleephRequestTransactionalEditor())
       ->setActor($request->getUser())
       ->setContinueOnNoEffect(true)
-      ->setContentSource(
-        PhabricatorContentSource::newForSource(
-          PhabricatorContentSource::SOURCE_CONDUIT,
-          array()));
+      ->setContentSource($request->newContentSource());
 
     $editor->applyTransactions($releeph_request, $xactions);
   }
diff --git a/src/applications/releeph/conduit/work/ReleephWorkRecordPickStatusConduitAPIMethod.php b/src/applications/releeph/conduit/work/ReleephWorkRecordPickStatusConduitAPIMethod.php
--- a/src/applications/releeph/conduit/work/ReleephWorkRecordPickStatusConduitAPIMethod.php
+++ b/src/applications/releeph/conduit/work/ReleephWorkRecordPickStatusConduitAPIMethod.php
@@ -64,10 +64,7 @@
     $editor = id(new ReleephRequestTransactionalEditor())
       ->setActor($request->getUser())
       ->setContinueOnNoEffect(true)
-      ->setContentSource(
-        PhabricatorContentSource::newForSource(
-          PhabricatorContentSource::SOURCE_CONDUIT,
-          array()));
+      ->setContentSource($request->newContentSource());
 
     $xactions = array();
 
diff --git a/src/applications/releeph/differential/DifferentialReleephRequestFieldSpecification.php b/src/applications/releeph/differential/DifferentialReleephRequestFieldSpecification.php
--- a/src/applications/releeph/differential/DifferentialReleephRequestFieldSpecification.php
+++ b/src/applications/releeph/differential/DifferentialReleephRequestFieldSpecification.php
@@ -301,8 +301,7 @@
         ->setContinueOnNoEffect(true)
         ->setContentSource(
           PhabricatorContentSource::newForSource(
-            PhabricatorContentSource::SOURCE_UNKNOWN,
-            array()));
+            PhabricatorUnknownContentSource::SOURCECONST));
 
       $editor->applyTransactions($releeph_request, $xactions);
     }
diff --git a/src/applications/repository/management/PhabricatorRepositoryManagementEditWorkflow.php b/src/applications/repository/management/PhabricatorRepositoryManagementEditWorkflow.php
--- a/src/applications/repository/management/PhabricatorRepositoryManagementEditWorkflow.php
+++ b/src/applications/repository/management/PhabricatorRepositoryManagementEditWorkflow.php
@@ -117,7 +117,7 @@
           pht('Specify one or more fields to edit!'));
       }
 
-      $content_source = PhabricatorContentSource::newConsoleSource();
+      $content_source = $this->newContentSource();
 
       $editor = id(new PhabricatorRepositoryEditor())
         ->setActor($actor)
diff --git a/src/applications/repository/worker/PhabricatorRepositoryCommitHeraldWorker.php b/src/applications/repository/worker/PhabricatorRepositoryCommitHeraldWorker.php
--- a/src/applications/repository/worker/PhabricatorRepositoryCommitHeraldWorker.php
+++ b/src/applications/repository/worker/PhabricatorRepositoryCommitHeraldWorker.php
@@ -30,9 +30,7 @@
 
     $commit->attachRepository($repository);
 
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_DAEMON,
-      array());
+    $content_source = $this->newContentSource();
 
     $committer_phid = $data->getCommitDetail('committerPHID');
     $author_phid = $data->getCommitDetail('authorPHID');
diff --git a/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php b/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php
--- a/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php
+++ b/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php
@@ -221,9 +221,7 @@
             ->setViewer($actor)
             ->setAuthorPHID($acting_as_phid);
 
-          $content_source = PhabricatorContentSource::newForSource(
-            PhabricatorContentSource::SOURCE_DAEMON,
-            array());
+          $content_source = $this->newContentSource();
 
           $update_data = $extraction_engine->updateRevisionWithCommit(
             $revision,
@@ -337,9 +335,7 @@
 
       $xactions[] = $edge_xaction;
 
-      $content_source = PhabricatorContentSource::newForSource(
-        PhabricatorContentSource::SOURCE_DAEMON,
-        array());
+      $content_source = $this->newContentSource();
 
       $editor = id(new ManiphestTransactionEditor())
         ->setActor($actor)
diff --git a/src/applications/spaces/__tests__/PhabricatorSpacesTestCase.php b/src/applications/spaces/__tests__/PhabricatorSpacesTestCase.php
--- a/src/applications/spaces/__tests__/PhabricatorSpacesTestCase.php
+++ b/src/applications/spaces/__tests__/PhabricatorSpacesTestCase.php
@@ -215,7 +215,7 @@
         ->setNewValue($is_default);
     }
 
-    $content_source = PhabricatorContentSource::newConsoleSource();
+    $content_source = $this->newContentSource();
 
     $editor = id(new PhabricatorSpacesNamespaceEditor())
       ->setActor($actor)
diff --git a/src/applications/tokens/conduit/TokenGiveConduitAPIMethod.php b/src/applications/tokens/conduit/TokenGiveConduitAPIMethod.php
--- a/src/applications/tokens/conduit/TokenGiveConduitAPIMethod.php
+++ b/src/applications/tokens/conduit/TokenGiveConduitAPIMethod.php
@@ -22,7 +22,7 @@
   }
 
   protected function execute(ConduitAPIRequest $request) {
-    $content_source = PhabricatorContentSource::newFromConduitRequest($request);
+    $content_source = $request->newContentSource();
 
     $editor = id(new PhabricatorTokenGivenEditor())
       ->setActor($request->getUser())
diff --git a/src/applications/transactions/controller/PhabricatorApplicationTransactionCommentRawController.php b/src/applications/transactions/controller/PhabricatorApplicationTransactionCommentRawController.php
--- a/src/applications/transactions/controller/PhabricatorApplicationTransactionCommentRawController.php
+++ b/src/applications/transactions/controller/PhabricatorApplicationTransactionCommentRawController.php
@@ -37,9 +37,9 @@
     $addendum = null;
     if ($request->getExists('email')) {
       $content_source = $xaction->getContentSource();
-      $source_email = PhabricatorContentSource::SOURCE_EMAIL;
+      $source_email = PhabricatorEmailContentSource::SOURCECONST;
       if ($content_source->getSource() == $source_email) {
-        $source_id = $content_source->getParam('id');
+        $source_id = $content_source->getContentSourceParameter('id');
         if ($source_id) {
           $message = id(new PhabricatorMetaMTAReceivedMail())->loadOneWhere(
             'id = %d',
diff --git a/src/applications/transactions/editengine/PhabricatorEditEngine.php b/src/applications/transactions/editengine/PhabricatorEditEngine.php
--- a/src/applications/transactions/editengine/PhabricatorEditEngine.php
+++ b/src/applications/transactions/editengine/PhabricatorEditEngine.php
@@ -1684,7 +1684,7 @@
 
     $editor = $object->getApplicationTransactionEditor()
       ->setActor($viewer)
-      ->setContentSourceFromConduitRequest($request)
+      ->setContentSource($request->newContentSource())
       ->setContinueOnNoEffect(true);
 
     if (!$this->getIsCreate()) {
diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
--- a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -733,16 +733,6 @@
       PhabricatorContentSource::newFromRequest($request));
   }
 
-  public function setContentSourceFromConduitRequest(
-    ConduitAPIRequest $request) {
-
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_CONDUIT,
-      array());
-
-    return $this->setContentSource($content_source);
-  }
-
   public function getContentSource() {
     return $this->contentSource;
   }
@@ -979,8 +969,7 @@
         // out from transcripts, but it would be cleaner if you didn't have to.
 
         $herald_source = PhabricatorContentSource::newForSource(
-          PhabricatorContentSource::SOURCE_HERALD,
-          array());
+          PhabricatorHeraldContentSource::SOURCECONST);
 
         $herald_editor = newv(get_class($this), array())
           ->setContinueOnNoEffect(true)
diff --git a/src/applications/transactions/replyhandler/PhabricatorApplicationTransactionReplyHandler.php b/src/applications/transactions/replyhandler/PhabricatorApplicationTransactionReplyHandler.php
--- a/src/applications/transactions/replyhandler/PhabricatorApplicationTransactionReplyHandler.php
+++ b/src/applications/transactions/replyhandler/PhabricatorApplicationTransactionReplyHandler.php
@@ -18,11 +18,7 @@
   }
 
   private function newEditor(PhabricatorMetaMTAReceivedMail $mail) {
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_EMAIL,
-      array(
-        'id' => $mail->getID(),
-      ));
+    $content_source = $mail->newContentSource();
 
     $editor = $this->getMailReceiver()
       ->getApplicationTransactionEditor()
diff --git a/src/applications/transactions/worker/PhabricatorApplicationTransactionPublishWorker.php b/src/applications/transactions/worker/PhabricatorApplicationTransactionPublishWorker.php
--- a/src/applications/transactions/worker/PhabricatorApplicationTransactionPublishWorker.php
+++ b/src/applications/transactions/worker/PhabricatorApplicationTransactionPublishWorker.php
@@ -62,9 +62,7 @@
     PhabricatorApplicationTransactionInterface $object) {
     $data = $this->getTaskData();
 
-    $daemon_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_DAEMON,
-      array());
+    $daemon_source = $this->newContentSource();
 
     $viewer = PhabricatorUser::getOmnipotentUser();
     $editor = $object->getApplicationTransactionEditor()
diff --git a/src/infrastructure/contentsource/PhabricatorConduitContentSource.php b/src/infrastructure/contentsource/PhabricatorConduitContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorConduitContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorConduitContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'conduit';
+
+  public function getSourceName() {
+    return pht('Conduit');
+  }
+
+  public function getSourceDescription() {
+    return pht('Content from the Conduit API.');
+  }
+
+}
diff --git a/src/infrastructure/contentsource/PhabricatorConsoleContentSource.php b/src/infrastructure/contentsource/PhabricatorConsoleContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorConsoleContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorConsoleContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'console';
+
+  public function getSourceName() {
+    return pht('Console');
+  }
+
+  public function getSourceDescription() {
+    return pht('Content generated by CLI administrative tools.');
+  }
+
+}
diff --git a/src/infrastructure/contentsource/PhabricatorContentSource.php b/src/infrastructure/contentsource/PhabricatorContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorContentSource.php
@@ -0,0 +1,92 @@
+<?php
+
+abstract class PhabricatorContentSource extends Phobject {
+
+  private $source;
+  private $params = array();
+
+  abstract public function getSourceName();
+  abstract public function getSourceDescription();
+
+  final public function getSourceTypeConstant() {
+    return $this->getPhobjectClassConstant('SOURCECONST', 32);
+  }
+
+  final public static function getAllContentSources() {
+    return id(new PhutilClassMapQuery())
+      ->setAncestorClass(__CLASS__)
+      ->setUniqueMethod('getSourceTypeConstant')
+      ->execute();
+  }
+
+  /**
+   * Construct a new content source object.
+   *
+   * @param const The source type constant to build a source for.
+   * @param array Source parameters.
+   * @param bool True to suppress errors and force construction of a source
+   *   even if the source type is not valid.
+   * @return PhabricatorContentSource New source object.
+   */
+  final public static function newForSource(
+    $source,
+    array $params = array(),
+    $force = false) {
+
+    $map = self::getAllContentSources();
+    if (isset($map[$source])) {
+      $obj = clone $map[$source];
+    } else {
+      if ($force) {
+        $obj = new PhabricatorUnknownContentSource();
+      } else {
+        throw new Exception(
+          pht(
+            'Content source type "%s" is not known to Phabricator!',
+            $source));
+      }
+    }
+
+    $obj->source = $source;
+    $obj->params = $params;
+
+    return $obj;
+  }
+
+  public static function newFromSerialized($serialized) {
+    $dict = json_decode($serialized, true);
+    if (!is_array($dict)) {
+      $dict = array();
+    }
+
+    $source = idx($dict, 'source');
+    $params = idx($dict, 'params');
+    if (!is_array($params)) {
+      $params = array();
+    }
+
+    return self::newForSource($source, $params, true);
+  }
+
+  public static function newFromRequest(AphrontRequest $request) {
+    return self::newForSource(
+      PhabricatorWebContentSource::SOURCECONST);
+  }
+
+  final public function serialize() {
+    return phutil_json_encode(
+      array(
+        'source' => $this->getSource(),
+        'params' => $this->params,
+      ));
+  }
+
+  final public function getSource() {
+    return $this->source;
+  }
+
+  final public function getContentSourceParameter($key, $default = null) {
+    return idx($this->params, $key, $default);
+  }
+
+}
diff --git a/src/infrastructure/contentsource/PhabricatorContentSourceModule.php b/src/infrastructure/contentsource/PhabricatorContentSourceModule.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorContentSourceModule.php
@@ -0,0 +1,51 @@
+<?php
+
+final class PhabricatorContentSourceModule
+  extends PhabricatorConfigModule {
+
+  public function getModuleKey() {
+    return 'contentsource';
+  }
+
+  public function getModuleName() {
+    return pht('Content Sources');
+  }
+
+  public function renderModuleStatus(AphrontRequest $request) {
+    $viewer = $request->getViewer();
+
+    $sources = PhabricatorContentSource::getAllContentSources();
+    ksort($sources);
+
+    $rows = array();
+    foreach ($sources as $source) {
+      $rows[] = array(
+        $source->getSourceTypeConstant(),
+        get_class($source),
+        $source->getSourceName(),
+        $source->getSourceDescription(),
+      );
+    }
+
+    $table = id(new AphrontTableView($rows))
+      ->setHeaders(
+        array(
+          pht('Key'),
+          pht('Class'),
+          pht('Source'),
+          pht('Description'),
+        ))
+      ->setColumnClasses(
+        array(
+          null,
+          null,
+          'pri',
+          'wide',
+        ));
+
+    return id(new PHUIObjectBoxView())
+      ->setHeaderText(pht('Content Sources'))
+      ->setTable($table);
+  }
+
+}
diff --git a/src/applications/metamta/contentsource/PhabricatorContentSourceView.php b/src/infrastructure/contentsource/PhabricatorContentSourceView.php
rename from src/applications/metamta/contentsource/PhabricatorContentSourceView.php
rename to src/infrastructure/contentsource/PhabricatorContentSourceView.php
--- a/src/applications/metamta/contentsource/PhabricatorContentSourceView.php
+++ b/src/infrastructure/contentsource/PhabricatorContentSourceView.php
@@ -10,21 +10,14 @@
   }
 
   public function getSourceName() {
-    $map = PhabricatorContentSource::getSourceNameMap();
-    $source = $this->contentSource->getSource();
-    return idx($map, $source, null);
-
+    return $this->contentSource->getSourceName();
   }
 
   public function render() {
     require_celerity_resource('phabricator-content-source-view-css');
 
-    $map = PhabricatorContentSource::getSourceNameMap();
-
-    $source = $this->contentSource->getSource();
-    $type = idx($map, $source, null);
-
-    if (!$type) {
+    $name = $this->getSourceName();
+    if ($name === null) {
       return null;
     }
 
@@ -33,7 +26,7 @@
       array(
         'class' => 'phabricator-content-source-view',
       ),
-      pht('Via %s', $type));
+      pht('Via %s', $name));
   }
 
 }
diff --git a/src/infrastructure/contentsource/PhabricatorFaxContentSource.php b/src/infrastructure/contentsource/PhabricatorFaxContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorFaxContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorFaxContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'fax';
+
+  public function getSourceName() {
+    return pht('Fax');
+  }
+
+  public function getSourceDescription() {
+    return pht('Content received via fax (telefacsimile).');
+  }
+
+}
diff --git a/src/infrastructure/contentsource/PhabricatorLipsumContentSource.php b/src/infrastructure/contentsource/PhabricatorLipsumContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorLipsumContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorLipsumContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'lipsum';
+
+  public function getSourceName() {
+    return pht('Lipsum');
+  }
+
+  public function getSourceDescription() {
+    return pht('Test data created with bin/lipsum.');
+  }
+
+}
diff --git a/src/infrastructure/contentsource/PhabricatorOldWorldContentSource.php b/src/infrastructure/contentsource/PhabricatorOldWorldContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorOldWorldContentSource.php
@@ -0,0 +1,17 @@
+<?php
+
+final class PhabricatorOldWorldContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'legacy';
+
+  public function getSourceName() {
+    return pht('Old World');
+  }
+
+  public function getSourceDescription() {
+    return pht(
+      'Content from the distant past, before content sources existed.');
+  }
+
+}
diff --git a/src/infrastructure/contentsource/PhabricatorUnitTestContentSource.php b/src/infrastructure/contentsource/PhabricatorUnitTestContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorUnitTestContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorUnitTestContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'unittest';
+
+  public function getSourceName() {
+    return pht('Unit Test');
+  }
+
+  public function getSourceDescription() {
+    return pht('Content created by unit tests.');
+  }
+
+}
diff --git a/src/infrastructure/contentsource/PhabricatorUnknownContentSource.php b/src/infrastructure/contentsource/PhabricatorUnknownContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorUnknownContentSource.php
@@ -0,0 +1,21 @@
+<?php
+
+final class PhabricatorUnknownContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'unknown';
+
+  public function getSourceName() {
+    $source = $this->getSource();
+    if (strlen($source)) {
+      return pht('Unknown ("%s")', $source);
+    } else {
+      return pht('Unknown');
+    }
+  }
+
+  public function getSourceDescription() {
+    return pht('Content with no known source.');
+  }
+
+}
diff --git a/src/infrastructure/contentsource/PhabricatorWebContentSource.php b/src/infrastructure/contentsource/PhabricatorWebContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/contentsource/PhabricatorWebContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorWebContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'web';
+
+  public function getSourceName() {
+    return pht('Web');
+  }
+
+  public function getSourceDescription() {
+    return pht('Content created from the web UI.');
+  }
+
+}
diff --git a/src/infrastructure/daemon/contentsource/PhabricatorBulkContentSource.php b/src/infrastructure/daemon/contentsource/PhabricatorBulkContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/daemon/contentsource/PhabricatorBulkContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorBulkContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'bulk';
+
+  public function getSourceName() {
+    return pht('Bulk Update');
+  }
+
+  public function getSourceDescription() {
+    return pht('Changes made by bulk update.');
+  }
+
+}
diff --git a/src/infrastructure/daemon/contentsource/PhabricatorDaemonContentSource.php b/src/infrastructure/daemon/contentsource/PhabricatorDaemonContentSource.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/daemon/contentsource/PhabricatorDaemonContentSource.php
@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorDaemonContentSource
+  extends PhabricatorContentSource {
+
+  const SOURCECONST = 'daemon';
+
+  public function getSourceName() {
+    return pht('Daemon');
+  }
+
+  public function getSourceDescription() {
+    return pht('Updates from background processing in daemons.');
+  }
+
+}
diff --git a/src/infrastructure/daemon/workers/PhabricatorWorker.php b/src/infrastructure/daemon/workers/PhabricatorWorker.php
--- a/src/infrastructure/daemon/workers/PhabricatorWorker.php
+++ b/src/infrastructure/daemon/workers/PhabricatorWorker.php
@@ -305,4 +305,9 @@
       $epoch_ago);
   }
 
+  protected function newContentSource() {
+    return PhabricatorContentSource::newForSource(
+      PhabricatorDaemonContentSource::SOURCECONST);
+  }
+
 }
diff --git a/src/infrastructure/daemon/workers/bulk/PhabricatorWorkerBulkJobWorker.php b/src/infrastructure/daemon/workers/bulk/PhabricatorWorkerBulkJobWorker.php
--- a/src/infrastructure/daemon/workers/bulk/PhabricatorWorkerBulkJobWorker.php
+++ b/src/infrastructure/daemon/workers/bulk/PhabricatorWorkerBulkJobWorker.php
@@ -121,9 +121,7 @@
       ->setTransactionType($type_status)
       ->setNewValue($status);
 
-    $daemon_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_DAEMON,
-      array());
+    $daemon_source = $this->newContentSource();
 
     $app_phid = id(new PhabricatorDaemonsApplication())->getPHID();
 
diff --git a/src/infrastructure/daemon/workers/storage/PhabricatorWorkerBulkJob.php b/src/infrastructure/daemon/workers/storage/PhabricatorWorkerBulkJob.php
--- a/src/infrastructure/daemon/workers/storage/PhabricatorWorkerBulkJob.php
+++ b/src/infrastructure/daemon/workers/storage/PhabricatorWorkerBulkJob.php
@@ -102,7 +102,7 @@
 
   public function newContentSource() {
     return PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_BULK,
+      PhabricatorBulkContentSource::SOURCECONST,
       array(
         'jobID' => $this->getID(),
       ));
diff --git a/src/infrastructure/management/PhabricatorManagementWorkflow.php b/src/infrastructure/management/PhabricatorManagementWorkflow.php
--- a/src/infrastructure/management/PhabricatorManagementWorkflow.php
+++ b/src/infrastructure/management/PhabricatorManagementWorkflow.php
@@ -26,4 +26,9 @@
     return $epoch;
   }
 
+  protected function newContentSource() {
+    return PhabricatorContentSource::newForSource(
+      PhabricatorConsoleContentSource::SOURCECONST);
+  }
+
 }
diff --git a/src/infrastructure/testing/PhabricatorTestCase.php b/src/infrastructure/testing/PhabricatorTestCase.php
--- a/src/infrastructure/testing/PhabricatorTestCase.php
+++ b/src/infrastructure/testing/PhabricatorTestCase.php
@@ -229,5 +229,9 @@
     }
   }
 
+  protected function newContentSource() {
+    return PhabricatorContentSource::newForSource(
+      PhabricatorUnitTestContentSource::SOURCECONST);
+  }
 
 }
diff --git a/src/view/phui/PHUITimelineEventView.php b/src/view/phui/PHUITimelineEventView.php
--- a/src/view/phui/PHUITimelineEventView.php
+++ b/src/view/phui/PHUITimelineEventView.php
@@ -622,9 +622,9 @@
           ));
 
       $content_source = $this->getContentSource();
-      $source_email = PhabricatorContentSource::SOURCE_EMAIL;
+      $source_email = PhabricatorEmailContentSource::SOURCECONST;
       if ($content_source->getSource() == $source_email) {
-        $source_id = $content_source->getParam('id');
+        $source_id = $content_source->getContentSourceParameter('id');
         if ($source_id) {
           $items[] = id(new PhabricatorActionView())
             ->setIcon('fa-envelope-o')