diff --git a/resources/sql/autopatches/20180410.almanac.01.iface.xaction.sql b/resources/sql/autopatches/20180410.almanac.01.iface.xaction.sql
new file mode 100644
--- /dev/null
+++ b/resources/sql/autopatches/20180410.almanac.01.iface.xaction.sql
@@ -0,0 +1,19 @@
+CREATE TABLE {$NAMESPACE}_almanac.almanac_interfacetransaction (
+  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  phid VARBINARY(64) NOT NULL,
+  authorPHID VARBINARY(64) NOT NULL,
+  objectPHID VARBINARY(64) NOT NULL,
+  viewPolicy VARBINARY(64) NOT NULL,
+  editPolicy VARBINARY(64) NOT NULL,
+  commentPHID VARBINARY(64) DEFAULT NULL,
+  commentVersion INT UNSIGNED NOT NULL,
+  transactionType VARCHAR(32) COLLATE {$COLLATE_TEXT} NOT NULL,
+  oldValue LONGTEXT COLLATE {$COLLATE_TEXT} NOT NULL,
+  newValue LONGTEXT COLLATE {$COLLATE_TEXT} NOT NULL,
+  contentSource LONGTEXT COLLATE {$COLLATE_TEXT} NOT NULL,
+  metadata LONGTEXT COLLATE {$COLLATE_TEXT} NOT NULL,
+  dateCreated INT UNSIGNED NOT NULL,
+  dateModified INT UNSIGNED NOT NULL,
+  UNIQUE KEY `key_phid` (`phid`),
+  KEY `key_object` (`objectPHID`)
+) ENGINE=InnoDB, COLLATE {$COLLATE_TEXT};
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
@@ -57,12 +57,19 @@
     'AlmanacDrydockPoolServiceType' => 'applications/almanac/servicetype/AlmanacDrydockPoolServiceType.php',
     'AlmanacEditor' => 'applications/almanac/editor/AlmanacEditor.php',
     'AlmanacInterface' => 'applications/almanac/storage/AlmanacInterface.php',
+    'AlmanacInterfaceAddressTransaction' => 'applications/almanac/xaction/AlmanacInterfaceAddressTransaction.php',
     'AlmanacInterfaceDatasource' => 'applications/almanac/typeahead/AlmanacInterfaceDatasource.php',
     'AlmanacInterfaceDeleteController' => 'applications/almanac/controller/AlmanacInterfaceDeleteController.php',
+    'AlmanacInterfaceDeviceTransaction' => 'applications/almanac/xaction/AlmanacInterfaceDeviceTransaction.php',
     'AlmanacInterfaceEditController' => 'applications/almanac/controller/AlmanacInterfaceEditController.php',
+    'AlmanacInterfaceEditor' => 'applications/almanac/editor/AlmanacInterfaceEditor.php',
+    'AlmanacInterfaceNetworkTransaction' => 'applications/almanac/xaction/AlmanacInterfaceNetworkTransaction.php',
     'AlmanacInterfacePHIDType' => 'applications/almanac/phid/AlmanacInterfacePHIDType.php',
+    'AlmanacInterfacePortTransaction' => 'applications/almanac/xaction/AlmanacInterfacePortTransaction.php',
     'AlmanacInterfaceQuery' => 'applications/almanac/query/AlmanacInterfaceQuery.php',
     'AlmanacInterfaceTableView' => 'applications/almanac/view/AlmanacInterfaceTableView.php',
+    'AlmanacInterfaceTransaction' => 'applications/almanac/storage/AlmanacInterfaceTransaction.php',
+    'AlmanacInterfaceTransactionType' => 'applications/almanac/xaction/AlmanacInterfaceTransactionType.php',
     'AlmanacKeys' => 'applications/almanac/util/AlmanacKeys.php',
     'AlmanacManageClusterServicesCapability' => 'applications/almanac/capability/AlmanacManageClusterServicesCapability.php',
     'AlmanacManagementRegisterWorkflow' => 'applications/almanac/management/AlmanacManagementRegisterWorkflow.php',
@@ -5243,13 +5250,21 @@
       'PhabricatorPolicyInterface',
       'PhabricatorDestructibleInterface',
       'PhabricatorExtendedPolicyInterface',
+      'PhabricatorApplicationTransactionInterface',
     ),
+    'AlmanacInterfaceAddressTransaction' => 'AlmanacNetworkTransactionType',
     'AlmanacInterfaceDatasource' => 'PhabricatorTypeaheadDatasource',
     'AlmanacInterfaceDeleteController' => 'AlmanacDeviceController',
+    'AlmanacInterfaceDeviceTransaction' => 'AlmanacNetworkTransactionType',
     'AlmanacInterfaceEditController' => 'AlmanacDeviceController',
+    'AlmanacInterfaceEditor' => 'PhabricatorApplicationTransactionEditor',
+    'AlmanacInterfaceNetworkTransaction' => 'AlmanacNetworkTransactionType',
     'AlmanacInterfacePHIDType' => 'PhabricatorPHIDType',
+    'AlmanacInterfacePortTransaction' => 'AlmanacNetworkTransactionType',
     'AlmanacInterfaceQuery' => 'AlmanacQuery',
     'AlmanacInterfaceTableView' => 'AphrontView',
+    'AlmanacInterfaceTransaction' => 'PhabricatorModularTransaction',
+    'AlmanacInterfaceTransactionType' => 'AlmanacTransactionType',
     'AlmanacKeys' => 'Phobject',
     'AlmanacManageClusterServicesCapability' => 'PhabricatorPolicyCapability',
     'AlmanacManagementRegisterWorkflow' => 'AlmanacManagementWorkflow',
diff --git a/src/applications/almanac/editor/AlmanacInterfaceEditor.php b/src/applications/almanac/editor/AlmanacInterfaceEditor.php
new file mode 100644
--- /dev/null
+++ b/src/applications/almanac/editor/AlmanacInterfaceEditor.php
@@ -0,0 +1,22 @@
+<?php
+
+final class AlmanacInterfaceEditor
+  extends PhabricatorApplicationTransactionEditor {
+
+  public function getEditorApplicationClass() {
+    return 'PhabricatorAlmanacApplication';
+  }
+
+  public function getEditorObjectsDescription() {
+    return pht('Almanac Interface');
+  }
+
+  public function getCreateObjectTitle($author, $object) {
+    return pht('%s created this interface.', $author);
+  }
+
+  public function getCreateObjectTitleForFeed($author, $object) {
+    return pht('%s created %s.', $author, $object);
+  }
+
+}
diff --git a/src/applications/almanac/storage/AlmanacInterface.php b/src/applications/almanac/storage/AlmanacInterface.php
--- a/src/applications/almanac/storage/AlmanacInterface.php
+++ b/src/applications/almanac/storage/AlmanacInterface.php
@@ -5,7 +5,8 @@
   implements
     PhabricatorPolicyInterface,
     PhabricatorDestructibleInterface,
-    PhabricatorExtendedPolicyInterface {
+    PhabricatorExtendedPolicyInterface,
+    PhabricatorApplicationTransactionInterface {
 
   protected $devicePHID;
   protected $networkPHID;
@@ -154,4 +155,26 @@
     $this->delete();
   }
 
+
+/* -(  PhabricatorApplicationTransactionInterface  )------------------------- */
+
+
+  public function getApplicationTransactionEditor() {
+    return new AlmanacInterfaceEditor();
+  }
+
+  public function getApplicationTransactionObject() {
+    return $this;
+  }
+
+  public function getApplicationTransactionTemplate() {
+    return new AlmanacInterfaceTransaction();
+  }
+
+  public function willRenderTimeline(
+    PhabricatorApplicationTransactionView $timeline,
+    AphrontRequest $request) {
+    return $timeline;
+  }
+
 }
diff --git a/src/applications/almanac/storage/AlmanacInterfaceTransaction.php b/src/applications/almanac/storage/AlmanacInterfaceTransaction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/almanac/storage/AlmanacInterfaceTransaction.php
@@ -0,0 +1,22 @@
+<?php
+
+final class AlmanacInterfaceTransaction
+  extends PhabricatorModularTransaction {
+
+  public function getApplicationName() {
+    return 'almanac';
+  }
+
+  public function getApplicationTransactionType() {
+    return AlmanacInterfacePHIDType::TYPECONST;
+  }
+
+  public function getApplicationTransactionCommentObject() {
+    return null;
+  }
+
+  public function getBaseTransactionClass() {
+    return 'AlmanacInterfaceTransactionType';
+  }
+
+}
diff --git a/src/applications/almanac/xaction/AlmanacInterfaceAddressTransaction.php b/src/applications/almanac/xaction/AlmanacInterfaceAddressTransaction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/almanac/xaction/AlmanacInterfaceAddressTransaction.php
@@ -0,0 +1,44 @@
+<?php
+
+final class AlmanacInterfaceAddressTransaction
+  extends AlmanacNetworkTransactionType {
+
+  const TRANSACTIONTYPE = 'almanac:interface:address';
+
+  public function generateOldValue($object) {
+    return $object->getAddress();
+  }
+
+  public function applyInternalEffects($object, $value) {
+    $object->setAddress($value);
+  }
+
+  public function getTitle() {
+    return pht(
+      '%s changed the address for this interface from %s to %s.',
+      $this->renderAuthor(),
+      $this->renderOldValue(),
+      $this->renderNewValue());
+  }
+
+  public function validateTransactions($object, array $xactions) {
+    $errors = array();
+
+    if ($this->isEmptyTextTransaction($object->getAddress(), $xactions)) {
+      $errors[] = $this->newRequiredError(
+        pht('Interfaces must have an address.'));
+    }
+
+    foreach ($xactions as $xaction) {
+
+      // NOTE: For now, we don't validate addresses. We generally expect users
+      // to provide IPv4 addresses, but it's reasonable for them to provide
+      // IPv6 addresses, and some installs currently use DNS names. This is
+      // off-label but works today.
+
+    }
+
+    return $errors;
+  }
+
+}
diff --git a/src/applications/almanac/xaction/AlmanacInterfaceDeviceTransaction.php b/src/applications/almanac/xaction/AlmanacInterfaceDeviceTransaction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/almanac/xaction/AlmanacInterfaceDeviceTransaction.php
@@ -0,0 +1,60 @@
+<?php
+
+final class AlmanacInterfaceDeviceTransaction
+  extends AlmanacNetworkTransactionType {
+
+  const TRANSACTIONTYPE = 'almanac:interface:device';
+
+  public function generateOldValue($object) {
+    return $object->getDevicePHID();
+  }
+
+  public function applyInternalEffects($object, $value) {
+    $object->setDevicePHID($value);
+  }
+
+  public function getTitle() {
+    return pht(
+      '%s changed the device for this interface from %s to %s.',
+      $this->renderAuthor(),
+      $this->renderOldHandle(),
+      $this->renderNewHandle());
+  }
+
+  public function validateTransactions($object, array $xactions) {
+    $errors = array();
+
+    if ($this->isEmptyTextTransaction($object->getAddress(), $xactions)) {
+      $errors[] = $this->newRequiredError(
+        pht('Interfaces must have a device.'));
+    }
+
+    foreach ($xactions as $xaction) {
+      if (!$this->isNewObject()) {
+        $errors[] = $this->newInvalidError(
+          pht(
+            'The device for an interface can not be changed once it has '.
+            'been created.'),
+          $xaction);
+        continue;
+      }
+
+      $device_phid = $xaction->getNewValue();
+      $devices = id(new AlmanacDeviceQuery())
+        ->setViewer($this->getActor())
+        ->withPHIDs(array($device_phid))
+        ->execute();
+      if (!$devices) {
+        $errors[] = $this->newInvalidError(
+          pht(
+            'You can not attach an interface to a nonexistent or restricted '.
+            'device.'),
+          $xaction);
+        continue;
+      }
+    }
+
+    return $errors;
+  }
+
+}
diff --git a/src/applications/almanac/xaction/AlmanacInterfaceNetworkTransaction.php b/src/applications/almanac/xaction/AlmanacInterfaceNetworkTransaction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/almanac/xaction/AlmanacInterfaceNetworkTransaction.php
@@ -0,0 +1,53 @@
+<?php
+
+final class AlmanacInterfaceNetworkTransaction
+  extends AlmanacNetworkTransactionType {
+
+  const TRANSACTIONTYPE = 'almanac:interface:network';
+
+  public function generateOldValue($object) {
+    return $object->getNetworkPHID();
+  }
+
+  public function applyInternalEffects($object, $value) {
+    $object->setNetworkPHID($value);
+  }
+
+  public function getTitle() {
+    return pht(
+      '%s changed the network for this interface from %s to %s.',
+      $this->renderAuthor(),
+      $this->renderOldHandle(),
+      $this->renderNewHandle());
+  }
+
+  public function validateTransactions($object, array $xactions) {
+    $errors = array();
+
+    $network_phid = $object->getNetworkPHID();
+    if ($this->isEmptyTextTransaction($network_phid, $xactions)) {
+      $errors[] = $this->newRequiredError(
+        pht('Interfaces must have a network.'));
+    }
+
+    foreach ($xactions as $xaction) {
+      $network_phid = $xaction->getNewValue();
+
+      $networks = id(new AlmanacNetworkQuery())
+        ->setViewer($this->getActor())
+        ->withPHIDs(array($network_phid))
+        ->execute();
+      if (!$networks) {
+        $errors[] = $this->newInvalidError(
+          pht(
+            'You can not put an interface on a nonexistent or restricted '.
+            'network.'),
+          $xaction);
+        continue;
+      }
+    }
+
+    return $errors;
+  }
+
+}
diff --git a/src/applications/almanac/xaction/AlmanacInterfacePortTransaction.php b/src/applications/almanac/xaction/AlmanacInterfacePortTransaction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/almanac/xaction/AlmanacInterfacePortTransaction.php
@@ -0,0 +1,53 @@
+<?php
+
+final class AlmanacInterfacePortTransaction
+  extends AlmanacNetworkTransactionType {
+
+  const TRANSACTIONTYPE = 'almanac:interface:port';
+
+  public function generateOldValue($object) {
+    $port = $object->getPort();
+
+    if ($port !== null) {
+      $port = (int)$port;
+    }
+
+    return $port;
+  }
+
+  public function applyInternalEffects($object, $value) {
+    $object->setPort((int)$value);
+  }
+
+  public function getTitle() {
+    return pht(
+      '%s changed the port for this interface from %s to %s.',
+      $this->renderAuthor(),
+      $this->renderOldValue(),
+      $this->renderNewValue());
+  }
+
+  public function validateTransactions($object, array $xactions) {
+    $errors = array();
+
+    if ($this->isEmptyTextTransaction($object->getName(), $xactions)) {
+      $errors[] = $this->newRequiredError(
+        pht('Interfaces must have a port number.'));
+    }
+
+    foreach ($xactions as $xaction) {
+      $port = $xaction->getNewValue();
+
+      $port = (int)$port;
+      if ($port < 1 || $port > 65535) {
+        $errors[] = $this->newInvalidError(
+          pht('Port numbers must be between 1 and 65535, inclusive.'),
+          $xaction);
+        continue;
+      }
+    }
+
+    return $errors;
+  }
+
+}
diff --git a/src/applications/almanac/xaction/AlmanacInterfaceTransactionType.php b/src/applications/almanac/xaction/AlmanacInterfaceTransactionType.php
new file mode 100644
--- /dev/null
+++ b/src/applications/almanac/xaction/AlmanacInterfaceTransactionType.php
@@ -0,0 +1,4 @@
+<?php
+
+abstract class AlmanacInterfaceTransactionType
+  extends AlmanacTransactionType {}