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
@@ -199,6 +199,7 @@
     'ConduitConnectConduitAPIMethod' => 'applications/conduit/method/ConduitConnectConduitAPIMethod.php',
     'ConduitConnectionGarbageCollector' => 'applications/conduit/garbagecollector/ConduitConnectionGarbageCollector.php',
     'ConduitException' => 'applications/conduit/protocol/exception/ConduitException.php',
+    'ConduitGetCapabilitiesConduitAPIMethod' => 'applications/conduit/method/ConduitGetCapabilitiesConduitAPIMethod.php',
     'ConduitGetCertificateConduitAPIMethod' => 'applications/conduit/method/ConduitGetCertificateConduitAPIMethod.php',
     'ConduitLogGarbageCollector' => 'applications/conduit/garbagecollector/ConduitLogGarbageCollector.php',
     'ConduitMethodDoesNotExistException' => 'applications/conduit/protocol/exception/ConduitMethodDoesNotExistException.php',
@@ -1434,6 +1435,7 @@
     'PhabricatorConduitToken' => 'applications/conduit/storage/PhabricatorConduitToken.php',
     'PhabricatorConduitTokenController' => 'applications/conduit/controller/PhabricatorConduitTokenController.php',
     'PhabricatorConduitTokenEditController' => 'applications/conduit/controller/PhabricatorConduitTokenEditController.php',
+    'PhabricatorConduitTokenHandshakeController' => 'applications/conduit/controller/PhabricatorConduitTokenHandshakeController.php',
     'PhabricatorConduitTokenQuery' => 'applications/conduit/query/PhabricatorConduitTokenQuery.php',
     'PhabricatorConduitTokenTerminateController' => 'applications/conduit/controller/PhabricatorConduitTokenTerminateController.php',
     'PhabricatorConfigAllController' => 'applications/config/controller/PhabricatorConfigAllController.php',
@@ -3212,6 +3214,7 @@
     'ConduitConnectConduitAPIMethod' => 'ConduitAPIMethod',
     'ConduitConnectionGarbageCollector' => 'PhabricatorGarbageCollector',
     'ConduitException' => 'Exception',
+    'ConduitGetCapabilitiesConduitAPIMethod' => 'ConduitAPIMethod',
     'ConduitGetCertificateConduitAPIMethod' => 'ConduitAPIMethod',
     'ConduitLogGarbageCollector' => 'PhabricatorGarbageCollector',
     'ConduitMethodDoesNotExistException' => 'ConduitMethodNotFoundException',
@@ -4557,6 +4560,7 @@
     ),
     'PhabricatorConduitTokenController' => 'PhabricatorConduitController',
     'PhabricatorConduitTokenEditController' => 'PhabricatorConduitController',
+    'PhabricatorConduitTokenHandshakeController' => 'PhabricatorConduitController',
     'PhabricatorConduitTokenQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
     'PhabricatorConduitTokenTerminateController' => 'PhabricatorConduitController',
     'PhabricatorConfigAllController' => 'PhabricatorConfigController',
diff --git a/src/applications/conduit/application/PhabricatorConduitApplication.php b/src/applications/conduit/application/PhabricatorConduitApplication.php
--- a/src/applications/conduit/application/PhabricatorConduitApplication.php
+++ b/src/applications/conduit/application/PhabricatorConduitApplication.php
@@ -50,6 +50,7 @@
           'PhabricatorConduitTokenEditController',
         'token/terminate/(?:(?P<id>\d+)/)?' =>
           'PhabricatorConduitTokenTerminateController',
+        'login/' => 'PhabricatorConduitTokenHandshakeController',
       ),
       '/api/(?P<method>[^/]+)' => 'PhabricatorConduitAPIController',
     );
diff --git a/src/applications/conduit/controller/PhabricatorConduitAPIController.php b/src/applications/conduit/controller/PhabricatorConduitAPIController.php
--- a/src/applications/conduit/controller/PhabricatorConduitAPIController.php
+++ b/src/applications/conduit/controller/PhabricatorConduitAPIController.php
@@ -301,22 +301,22 @@
           'ERR-INVALID-AUTH',
           pht(
             'API token "%s" has the wrong length. API tokens should be '.
-            '32 characters long.'),
+            '32 characters long.',
+            $token_string),
         );
       }
 
       $type = head(explode('-', $token_string));
-      switch ($type) {
-        case 'api':
-        case 'tmp':
-          break;
-        default:
-          return array(
-            'ERR-INVALID-AUTH',
-            pht(
-              'API token "%s" has the wrong format. API tokens should begin '.
-              'with "api-" or "tmp-" and be 32 characters long.',
-              $token_string),
+      $valid_types = PhabricatorConduitToken::getAllTokenTypes();
+      $valid_types = array_fuse($valid_types);
+      if (empty($valid_types[$type])) {
+        return array(
+          'ERR-INVALID-AUTH',
+          pht(
+            'API token "%s" has the wrong format. API tokens should be '.
+            '32 characters long and begin with one of these prefixes: %s.',
+            $token_string,
+            implode(', ', $valid_types)),
           );
       }
 
@@ -348,6 +348,19 @@
         }
       }
 
+      // If this is a "cli-" token, it expires shortly after it is generated
+      // by default. Once it is actually used, we extend its lifetime and make
+      // it permanent. This allows stray tokens to get cleaned up automatically
+      // if they aren't being used.
+      if ($token->getTokenType() == PhabricatorConduitToken::TYPE_COMMANDLINE) {
+        if ($token->getExpires()) {
+          $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+            $token->setExpires(null);
+            $token->save();
+          unset($unguarded);
+        }
+      }
+
       $user = $token->getObject();
       if (!($user instanceof PhabricatorUser)) {
         return array(
diff --git a/src/applications/conduit/controller/PhabricatorConduitTokenHandshakeController.php b/src/applications/conduit/controller/PhabricatorConduitTokenHandshakeController.php
new file mode 100644
--- /dev/null
+++ b/src/applications/conduit/controller/PhabricatorConduitTokenHandshakeController.php
@@ -0,0 +1,46 @@
+<?php
+
+final class PhabricatorConduitTokenHandshakeController
+  extends PhabricatorConduitController {
+
+  public function handleRequest(AphrontRequest $request) {
+    $viewer = $request->getViewer();
+
+    id(new PhabricatorAuthSessionEngine())->requireHighSecuritySession(
+      $viewer,
+      $request,
+      '/');
+
+    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+      $token = PhabricatorConduitToken::initializeNewToken(
+        $viewer->getPHID(),
+        PhabricatorConduitToken::TYPE_COMMANDLINE);
+      $token->save();
+    unset($unguarded);
+
+    $form = id(new AphrontFormView())
+      ->setUser($viewer)
+      ->appendRemarkupInstructions(
+        pht(
+          'Copy-paste the API Token below to grant access to your account.'))
+      ->appendChild(
+        id(new AphrontFormTextControl())
+          ->setLabel(pht('API Token'))
+          ->setValue($token->getToken()))
+      ->appendRemarkupInstructions(
+        pht(
+          'This will authorize the requesting script to act on your behalf '.
+          'permanently, like giving the script your account password.'))
+      ->appendRemarkupInstructions(
+        pht(
+          'If you change your mind, you can revoke this token later in '.
+          '{nav icon=wrench,name=Settings > Conduit API Tokens}.'));
+
+    return $this->newDialog()
+      ->setTitle(pht('Grant Account Access'))
+      ->setWidth(AphrontDialogView::WIDTH_FULL)
+      ->appendForm($form)
+      ->addCancelButton('/');
+  }
+
+}
diff --git a/src/applications/conduit/method/ConduitGetCapabilitiesConduitAPIMethod.php b/src/applications/conduit/method/ConduitGetCapabilitiesConduitAPIMethod.php
new file mode 100644
--- /dev/null
+++ b/src/applications/conduit/method/ConduitGetCapabilitiesConduitAPIMethod.php
@@ -0,0 +1,60 @@
+<?php
+
+final class ConduitGetCapabilitiesConduitAPIMethod extends ConduitAPIMethod {
+
+  public function getAPIMethodName() {
+    return 'conduit.getcapabilities';
+  }
+
+  public function shouldRequireAuthentication() {
+    return false;
+  }
+
+  public function getMethodDescription() {
+    return pht(
+      'List capabilities, wire formats, and authentication protocols '.
+      'available on this server.');
+  }
+
+  public function defineParamTypes() {
+    return array();
+  }
+
+  public function defineReturnType() {
+    return 'dict<string, any>';
+  }
+
+  public function defineErrorTypes() {
+    return array();
+  }
+
+  protected function execute(ConduitAPIRequest $request) {
+    $authentication = array(
+      'token',
+      'asymmetric',
+      'session',
+      'sessionless',
+    );
+
+    $oauth_app = 'PhabricatorOAuthServerApplication';
+    if (PhabricatorApplication::isClassInstalled($oauth_app)) {
+      $authentication[] = 'oauth';
+    }
+
+    return array(
+      'authentication' => $authentication,
+      'signatures' => array(
+        'consign',
+      ),
+      'input' => array(
+        'json',
+        'urlencoded',
+      ),
+      'output' => array(
+        'json',
+        'human',
+      ),
+    );
+  }
+
+}
diff --git a/src/applications/conduit/storage/PhabricatorConduitToken.php b/src/applications/conduit/storage/PhabricatorConduitToken.php
--- a/src/applications/conduit/storage/PhabricatorConduitToken.php
+++ b/src/applications/conduit/storage/PhabricatorConduitToken.php
@@ -13,6 +13,7 @@
 
   const TYPE_STANDARD = 'api';
   const TYPE_TEMPORARY = 'tmp';
+  const TYPE_COMMANDLINE = 'cli';
 
   public function getConfiguration() {
     return array(
@@ -53,17 +54,28 @@
     $map = array(
       self::TYPE_STANDARD => pht('Standard API Token'),
       self::TYPE_TEMPORARY => pht('Temporary API Token'),
+      self::TYPE_COMMANDLINE => pht('Command Line API Token'),
     );
 
     return idx($map, $type, $type);
   }
 
+  public static function getAllTokenTypes() {
+    return array(
+      self::TYPE_STANDARD,
+      self::TYPE_TEMPORARY,
+      self::TYPE_COMMANDLINE,
+    );
+  }
+
   private function getTokenExpires($token_type) {
     switch ($token_type) {
       case self::TYPE_STANDARD:
         return null;
       case self::TYPE_TEMPORARY:
-        return PhabricatorTime::getNow() + phutil_units('24h in seconds');
+        return PhabricatorTime::getNow() + phutil_units('24 hours in seconds');
+      case self::TYPE_COMMANDLINE:
+        return PhabricatorTime::getNow() + phutil_units('1 hour in seconds');
       default:
         throw new Exception(
           pht('Unknown Conduit token type "%s"!', $token_type));