diff --git a/scripts/arcanist.php b/scripts/arcanist.php
index 18109e85..d9715153 100755
--- a/scripts/arcanist.php
+++ b/scripts/arcanist.php
@@ -189,13 +189,17 @@ try {
   $need_auth            = $workflow->requiresAuthentication();
   $need_repository_api  = $workflow->requiresRepositoryAPI();
 
+  $want_repository_api = $workflow->desiresRepositoryAPI();
+  $want_working_copy = $workflow->desiresWorkingCopy() ||
+                       $want_repository_api;
+
   $need_conduit       = $need_conduit ||
                         $need_auth;
   $need_working_copy  = $need_working_copy ||
                         $need_repository_api;
 
-  if ($need_working_copy) {
-    if (!$working_copy->getProjectRoot()) {
+  if ($need_working_copy || $want_working_copy) {
+    if ($need_working_copy && !$working_copy->getProjectRoot()) {
       throw new ArcanistUsageException(
         "This command must be run in a Git, Mercurial or Subversion working ".
         "copy.");
@@ -267,7 +271,7 @@ try {
     $workflow->authenticateConduit();
   }
 
-  if ($need_repository_api) {
+  if ($need_repository_api || ($want_repository_api && $working_copy)) {
     $repository_api = ArcanistRepositoryAPI::newAPIFromWorkingCopyIdentity(
       $working_copy);
     $workflow->setRepositoryAPI($repository_api);
diff --git a/src/workflow/ArcanistBaseWorkflow.php b/src/workflow/ArcanistBaseWorkflow.php
index 18392d7d..403ad124 100644
--- a/src/workflow/ArcanistBaseWorkflow.php
+++ b/src/workflow/ArcanistBaseWorkflow.php
@@ -465,11 +465,18 @@ abstract class ArcanistBaseWorkflow {
     return false;
   }
 
+  public function desiresWorkingCopy() {
+    return false;
+  }
 
   public function requiresRepositoryAPI() {
     return false;
   }
 
+  public function desiresRepositoryAPI() {
+    return false;
+  }
+
   public function setCommand($command) {
     $this->command = $command;
     return $this;
@@ -1020,6 +1027,25 @@ abstract class ArcanistBaseWorkflow {
     self::writeUserConfigurationFile($config);
   }
 
+  public function readLocalArcConfig() {
+    $local = array();
+    $file = $this->readScratchFile('config');
+    if ($file) {
+      $local = json_decode($file, true);
+    }
+
+    return $local;
+  }
+
+  public function writeLocalArcConfig(array $config) {
+    $json_encoder = new PhutilJSON();
+    $json = $json_encoder->encodeFormatted($config);
+
+    $this->writeScratchFile('config', $json);
+
+    return $this;
+  }
+
 
   /**
    * Write a message to stderr so that '--json' flags or stdout which is meant
diff --git a/src/workflow/ArcanistGetConfigWorkflow.php b/src/workflow/ArcanistGetConfigWorkflow.php
index 8ba82ea2..3a889232 100644
--- a/src/workflow/ArcanistGetConfigWorkflow.php
+++ b/src/workflow/ArcanistGetConfigWorkflow.php
@@ -25,7 +25,7 @@ final class ArcanistGetConfigWorkflow extends ArcanistBaseWorkflow {
 
   public function getCommandSynopses() {
     return phutil_console_format(<<<EOTEXT
-      **get-config** [__name__ ...]
+      **get-config** -- [__name__ ...]
 EOTEXT
       );
   }
@@ -45,20 +45,32 @@ EOTEXT
     );
   }
 
+  public function desiresRepositoryAPI() {
+    return true;
+  }
+
   public function run() {
     $argv = $this->getArgument('argv');
 
-    $config = self::readGlobalArcConfig();
+    $configs = array(
+      'global' => self::readGlobalArcConfig(),
+      'local' => $this->readLocalArcConfig(),
+    );
     if ($argv) {
       $keys = $argv;
     } else {
-      $keys = array_keys($config);
+      $keys = array_mergev(array_map('array_keys', $configs));
+      $keys = array_unique($keys);
       sort($keys);
     }
 
     foreach ($keys as $key) {
-      $val = self::formatConfigValueForDisplay(idx($config, $key));
-      echo "{$key} = {$val}\n";
+      foreach ($configs as $name => $config) {
+        if ($name == 'global' || isset($config[$key])) {
+          $val = self::formatConfigValueForDisplay(idx($config, $key));
+          echo "({$name}) {$key} = {$val}\n";
+        }
+      }
     }
 
     return 0;
diff --git a/src/workflow/ArcanistSetConfigWorkflow.php b/src/workflow/ArcanistSetConfigWorkflow.php
index 6c415bad..fcc7cee8 100644
--- a/src/workflow/ArcanistSetConfigWorkflow.php
+++ b/src/workflow/ArcanistSetConfigWorkflow.php
@@ -25,7 +25,7 @@ final class ArcanistSetConfigWorkflow extends ArcanistBaseWorkflow {
 
   public function getCommandSynopses() {
     return phutil_console_format(<<<EOTEXT
-      **set-config** __name__ __value__
+      **set-config** [__options__] -- __name__ __value__
 EOTEXT
       );
   }
@@ -35,8 +35,14 @@ EOTEXT
           Supports: cli
           Sets an arc configuration option.
 
-          Values are written to '~/.arcrc' on Linux and Mac OS X, and an
-          undisclosed location on Windows.
+          Options are either global (apply to all arc commands you invoke
+          from the current user) or local (apply only to the current working
+          copy).  By default, global configuration is written.  Use __--local__
+          to write local configuration.
+
+          Global values are written to '~/.arcrc' on Linux and Mac OS X, and an
+          undisclosed location on Windows.  Local values are written to an arc
+          directory under either .git, .hg, or .svn as appropriate.
 
           With __--show__, a description of supported configuration values
           is shown.
@@ -49,10 +55,17 @@ EOTEXT
       'show' => array(
         'help' => 'Show available configuration values.',
       ),
+      'local' => array(
+        'help' => 'Set a local config value instead of a global one',
+      ),
       '*' => 'argv',
     );
   }
 
+  public function requiresRepositoryAPI() {
+    return $this->getArgument('local');
+  }
+
   public function run() {
     if ($this->getArgument('show')) {
       return $this->show();
@@ -64,7 +77,15 @@ EOTEXT
         "Specify a key and a value, or --show.");
     }
 
-    $config = self::readGlobalArcConfig();
+    $is_local = $this->getArgument('local');
+
+    if ($is_local) {
+      $config = $this->readLocalArcConfig();
+      $which = 'local';
+    } else {
+      $config = self::readGlobalArcConfig();
+      $which = 'global';
+    }
 
     $key = $argv[0];
     $val = $argv[1];
@@ -76,26 +97,34 @@ EOTEXT
 
     if (!strlen($val)) {
       unset($config[$key]);
-      self::writeGlobalArcConfig($config);
+      if ($is_local) {
+        $this->writeLocalArcConfig($config);
+      } else {
+        self::writeGlobalArcConfig($config);
+      }
 
       if ($old === null) {
-        echo "Deleted key '{$key}'.\n";
+        echo "Deleted key '{$key}' from {$which} config.\n";
       } else {
-        echo "Deleted key '{$key}' (was '{$old}').\n";
+        echo "Deleted key '{$key}' from {$which} config (was '{$old}').\n";
       }
     } else {
       $val = $this->parse($key, $val);
 
       $config[$key] = $val;
-      self::writeGlobalArcConfig($config);
+      if ($is_local) {
+        $this->writeLocalArcConfig($config);
+      } else {
+        self::writeGlobalArcConfig($config);
+      }
 
       $val = self::formatConfigValueForDisplay($val);
       $old = self::formatConfigValueForDisplay($old);
 
       if ($old === null) {
-        echo "Set key '{$key}' = '{$val}'.\n";
+        echo "Set key '{$key}' = '{$val}' in {$which} config.\n";
       } else {
-        echo "Set key '{$key}' = '{$val}' (was '{$old}').\n";
+        echo "Set key '{$key}' = '{$val}' in {$which} config (was '{$old}').\n";
       }
     }
 
diff --git a/src/workingcopyidentity/ArcanistWorkingCopyIdentity.php b/src/workingcopyidentity/ArcanistWorkingCopyIdentity.php
index 5adae0c6..e862e169 100644
--- a/src/workingcopyidentity/ArcanistWorkingCopyIdentity.php
+++ b/src/workingcopyidentity/ArcanistWorkingCopyIdentity.php
@@ -26,6 +26,7 @@
  */
 final class ArcanistWorkingCopyIdentity {
 
+  protected $localConfig;
   protected $projectConfig;
   protected $projectRoot;
 
@@ -97,6 +98,26 @@ final class ArcanistWorkingCopyIdentity {
   protected function __construct($root, array $config) {
     $this->projectRoot    = $root;
     $this->projectConfig  = $config;
+    $this->localConfig    = array();
+
+    $vc_dirs = array(
+      '.git',
+      '.hg',
+      '.svn',
+    );
+    foreach ($vc_dirs as $dir) {
+      $local_path = Filesystem::resolvePath(
+        $dir.'/arc/config',
+        $this->projectRoot);
+      if (Filesystem::pathExists($local_path)) {
+        $file = Filesystem::readFile($local_path);
+        if ($file) {
+          $this->localConfig = json_decode($file, true);
+          break;
+        }
+      }
+    }
+
   }
 
   public function getProjectID() {
@@ -132,10 +153,25 @@ final class ArcanistWorkingCopyIdentity {
   }
 
 
+  /**
+   * Read a configuration directive from local configuration.  This
+   * reads ONLY the per-working copy configuration,
+   * i.e. .(git|hg|svn)/arc/config, and not other configuration
+   * sources.  See @{method:getConfigFromAnySource} to read from any
+   * config source or @{method:getConfig} to read permanent
+   * project-level config.
+   *
+   * @task config
+   */
+  public function getLocalConfig($key, $default=null) {
+    return idx($this->localConfig, $key, $default);
+  }
+
   /**
    * Read a configuration directive from any available configuration source.
    * In contrast to @{method:getConfig}, this will look for the directive in
-   * user configuration in addition to project configuration.
+   * local and user configuration in addition to project configuration.
+   * The precedence is local > project > user
    *
    * @param key   Key to read.
    * @param wild  Default value if key is not found.
@@ -144,26 +180,33 @@ final class ArcanistWorkingCopyIdentity {
    * @task config
    */
   public function getConfigFromAnySource($key, $default = null) {
-    $pval = $this->getConfig($key);
-    if ($pval !== null) {
-      return $pval;
+
+    // try local config first
+    $pval = $this->getLocalConfig($key);
+
+    // then per-project config
+    if ($pval === null) {
+      $pval = $this->getConfig($key);
     }
 
-    // Test for older names.
-
+    // Test for older names in the per-project config only, since
+    // they've only been used there
     static $deprecated_names = array(
       'lint.engine' => 'lint_engine',
       'unit.engine' => 'unit_engine',
     );
-    if (isset($deprecated_names[$key])) {
+    if ($pval === null && isset($deprecated_names[$key])) {
       $pval = $this->getConfig($deprecated_names[$key]);
-      if ($pval !== null) {
-        return $pval;
-      }
     }
 
-    $global_config = ArcanistBaseWorkflow::readGlobalArcConfig();
-    return idx($global_config, $key, $default);
+    // lastly, try global (i.e. user-level) config
+    if ($pval === null) {
+      $global_config = ArcanistBaseWorkflow::readGlobalArcConfig();
+      $pval = idx($global_config, $key, $default);
+    }
+
+    return $pval;
+
   }
 
 }