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
@@ -753,6 +753,7 @@
     'HarbormasterDAO' => 'applications/harbormaster/storage/HarbormasterDAO.php',
     'HarbormasterHTTPRequestBuildStepImplementation' => 'applications/harbormaster/step/HarbormasterHTTPRequestBuildStepImplementation.php',
     'HarbormasterLeaseHostBuildStepImplementation' => 'applications/harbormaster/step/HarbormasterLeaseHostBuildStepImplementation.php',
+    'HarbormasterLintSaveBuildStepImplementation' => 'applications/harbormaster/step/HarbormasterLintSaveBuildStepImplementation.php',
     'HarbormasterManagementBuildWorkflow' => 'applications/harbormaster/management/HarbormasterManagementBuildWorkflow.php',
     'HarbormasterManagementUpdateWorkflow' => 'applications/harbormaster/management/HarbormasterManagementUpdateWorkflow.php',
     'HarbormasterManagementWorkflow' => 'applications/harbormaster/management/HarbormasterManagementWorkflow.php',
@@ -3446,6 +3447,7 @@
     'HarbormasterDAO' => 'PhabricatorLiskDAO',
     'HarbormasterHTTPRequestBuildStepImplementation' => 'HarbormasterBuildStepImplementation',
     'HarbormasterLeaseHostBuildStepImplementation' => 'HarbormasterBuildStepImplementation',
+    'HarbormasterLintSaveBuildStepImplementation' => 'HarbormasterBuildStepImplementation',
     'HarbormasterManagementBuildWorkflow' => 'HarbormasterManagementWorkflow',
     'HarbormasterManagementUpdateWorkflow' => 'HarbormasterManagementWorkflow',
     'HarbormasterManagementWorkflow' => 'PhabricatorManagementWorkflow',
diff --git a/src/applications/harbormaster/step/HarbormasterLintSaveBuildStepImplementation.php b/src/applications/harbormaster/step/HarbormasterLintSaveBuildStepImplementation.php
new file mode 100644
--- /dev/null
+++ b/src/applications/harbormaster/step/HarbormasterLintSaveBuildStepImplementation.php
@@ -0,0 +1,402 @@
+<?php
+
+final class HarbormasterLintSaveBuildStepImplementation
+  extends HarbormasterBuildStepImplementation {
+
+  public function getName() {
+    return pht('Lint and Save');
+  }
+
+  public function getGenericDescription() {
+    return pht('Run `arc lint` and report the results into Diffusion.');
+  }
+
+  public function getDescription() {
+    return pht(
+      'Run `arc lint` on host %s and report the results into Diffusion.',
+      $this->formatSettingForDescription('hostartifact'));
+  }
+
+  private $inserts = array();
+
+  public function execute(
+    HarbormasterBuild $build,
+    HarbormasterBuildTarget $build_target) {
+
+    $resolve_log = $build->createLog($build_target, "lint", "determine");
+    $resolve_start = $resolve_log->start();
+
+    $settings = $this->getSettings();
+    $artifact = $build->loadArtifact($settings['hostartifact']);
+    $lease = $artifact->loadDrydockLease();
+    $interface = $lease->getInterface('command');
+
+    $buildable_ref = id(new HarbormasterBuildableQuery())
+      ->setViewer(PhabricatorUser::getOmnipotentUser())
+      ->withPHIDs(array($build->getBuildablePHID()))
+      ->needContainerObjects(true)
+      ->executeOne();
+
+    $buildable = $buildable_ref->getBuildableObject();
+
+    // We skip differential revisions here because it doesn't make sense.
+    if (!($buildable instanceof PhabricatorRepositoryCommit)) {
+      $resolve_log->append(pht('The current buildable is not a commit, so lint will be skipped')."\n");
+      $resolve_log->finalize($resolve_start);
+      return;
+    }
+
+    // Alias just to make code a bit more readable.  This is always a
+    // commit when we get to here.
+    $commit = $buildable;
+    $repository = $buildable_ref->getContainerObject();
+
+    $all = null;
+    if ($settings['lintall']) {
+      $all = '--everything';
+    }
+
+    // Work out the branch based on the commit identifier and
+    // the repository.  If we don't match any branch, just exit now
+    // since we can't generate useful data.
+    $branches = id(new ConduitCall(
+      'diffusion.branchquery',
+      array(
+        'callsign' => $repository->getCallsign()
+      )))
+      ->setUser(PhabricatorUser::getOmnipotentUser())
+      ->execute();
+
+    $mapped_branch = null;
+    foreach ($branches as $branch_json) {
+      if ($branch_json["commitIdentifier"] == $commit->getCommitIdentifier()) {
+        $mapped_branch = $branch_json["shortName"];
+      }
+    }
+
+    if ($mapped_branch === null) {
+      // No branch for this commit, which means we can't store lint data.
+      $resolve_log->append(pht('No branch points to commit %s', $commit->getCommitIdentifier())."\n");
+      $resolve_log->append(pht('The following branches are present:')."\n");
+      foreach ($branches as $branch_json) {
+        $resolve_log->append(pht('  - %s: %s', $branch_json["shortName"], $branch_json["commitIdentifier"])."\n");
+      }
+      $resolve_log->finalize($resolve_start);
+      return;
+    }
+
+    $branch = new PhabricatorRepositoryBranch();
+    $conn = $branch->establishConnection('w');
+    $branch = $branch->loadOneWhere(
+      'repositoryID = %d AND name = %s',
+      $repository->getID(),
+      $mapped_branch);
+    if (!$branch) {
+      $branch = id(new PhabricatorRepositoryBranch())
+        ->setRepositoryID($repository->getID())
+        ->setName($mapped_branch)
+        ->save();
+    }
+
+    // TODO: This might be better solved by having a --working-dir
+    // argument to all Arcanist commands, so we can get Arcanist
+    // to change directory early on without this platform specific
+    // nonsense.
+    if ($lease->getAttribute('platform') === 'windows') {
+      if (substr_count($settings['path'], '&') > 0) {
+        $resolve_log->append(pht('Unsafe Windows path detected')."\n");
+        $resolve_log->finalize($resolve_start);
+        return;
+      }
+
+      $change_directory = csprintf('cd %C &', $settings['path']);
+    } else {
+      $change_directory = csprintf('cd %s &&', $settings['path']);
+    }
+
+    // ===== RUN ARCANIST =====
+    $arcrc = null;
+    if ($settings['arcrcpath']) {
+      if (substr_count($settings['arcrcpath'], '&') > 0) {
+        $resolve_log->append(pht('Unsafe Windows arcrc path detected')."\n");
+        $resolve_log->finalize($resolve_start);
+        return;
+      }
+
+      $arcrc = csprintf('--arcrc-file %C', $settings['arcrcpath']);
+    }
+
+    if (substr_count($settings['severity'], '&') > 0) {
+      $resolve_log->append(pht('Unsafe severity level detected')."\n");
+      $resolve_log->finalize($resolve_start);
+      return;
+    }
+
+    // FIXME: --rev should be since the last lint!
+    $future = $interface->getExecFuture(
+      '%C %C lint %C --lintall --severity %C %C --output json',
+      $change_directory,
+      $settings['arcanist'],
+      $arcrc,
+      $settings['severity'],
+      $all);
+
+    $executed_command = csprintf(
+      '%C %C lint %C --lintall --severity %C %C --output json',
+      $change_directory,
+      $settings['arcanist'],
+      $arcrc,
+      $settings['severity'],
+      $all);
+
+    $resolve_log->append(pht('Starting Arcanist with command: %s', $executed_command)."\n");
+    $resolve_log->finalize($resolve_start);
+
+    $log_stdout = $build->createLog($build_target, "arcanist", "stdout");
+    $log_stderr = $build->createLog($build_target, "arcanist", "stderr");
+
+    $start_stdout = $log_stdout->start();
+    $start_stderr = $log_stderr->start();
+
+    $jsons = '';
+
+    // Read the next amount of available output every second.
+    while (!$future->isReady()) {
+      list($stdout, $stderr) = $future->read();
+      $jsons .= $stdout;
+      $log_stdout->append($stdout);
+      $log_stderr->append($stderr);
+      $future->discardBuffers();
+
+      // Wait one second before querying for more data.
+      sleep(1);
+    }
+
+    // Get the return value so we can log that as well.
+    list($err) = $future->resolve();
+
+    // Retrieve the last few bits of information.
+    list($stdout, $stderr) = $future->read();
+    $jsons .= $stdout;
+    $log_stdout->append($stdout);
+    $log_stderr->append($stderr);
+    $future->discardBuffers();
+
+    $log_stdout->finalize($start_stdout);
+    $log_stderr->finalize($start_stderr);
+
+    // ===== ARCANIST COMPLETE =====
+
+    if ($err !== 0) {
+      throw new Exception(pht('Arcanist failed with error %d.', $err));
+    }
+
+    $inserts = array();
+    $deletes = array();
+
+    $lint_log = $build->createLog($build_target, "lint", "parse");
+    $lint_start = $lint_log->start();
+
+    // NOTE: We can't use --trace and capture STDERR as some sort of
+    // progress indicator, because that doesn't work on Windows (SSH
+    // on Windows routes everything to STDOUT).
+    foreach (phutil_split_lines($jsons) as $json) {
+      if (strlen(trim($json)) === 0) {
+        $lint_log->append(pht('Skipping line: %s', $json)."\n");
+        continue;
+      }
+
+      $lint_log->append(pht('Got JSON line: %s', $json)."\n");
+
+      $paths = phutil_json_decode($json);
+      if (!is_array($paths)) {
+        throw new Exception("Invalid JSON returns from Arcanist");
+      }
+
+      foreach ($paths as $path => $messages) {
+        $path = '/'.trim(str_replace("\\", '/', $path), '/');
+
+        $deletes[] = $path;
+
+        $lint_log->append(pht('%s has %s lint messages', $path, count($messages))."\n");
+
+        foreach ($messages as $message) {
+          $line = idx($message, 'line', 0);
+
+          $inserts[] = qsprintf(
+            $conn,
+            '(%d, %s, %d, %s, %s, %s, %s)',
+            $branch->getID(),
+            $path,
+            $line,
+            idx($message, 'code', ''),
+            idx($message, 'severity', ''),
+            idx($message, 'name', ''),
+            idx($message, 'description', ''));
+
+          // if ($line && $this->needsBlame) {
+            // $this->blame[$path][$line] = true;
+          // }
+        }
+
+        if (count($deletes) >= 1024 || count($inserts) >= 256) {
+          $lint_log->append(pht('Saving messages to database')."\n");
+
+          $this->saveLintMessages($conn, $branch, $deletes, $inserts);
+          $deletes = array();
+          $inserts = array();
+        }
+      }
+    }
+
+    $lint_log->append(pht('Saving messages to database')."\n");
+    $this->saveLintMessages($conn, $branch, $deletes, $inserts);
+
+    $lint_log->append(pht('Saving branch information')."\n");
+    $branch->setLintCommit($commit->getCommitIdentifier());
+    $branch->save();
+
+    /* if ($this->blame) {
+      $this->blameAuthors();
+      $this->blame = array();
+    }*/
+
+    $lint_log->append(pht('Complete')."\n");
+    $lint_log->finalize($lint_start);
+  }
+
+  private function saveLintMessages($conn, $branch, $deletes, $inserts) {
+    $conn->openTransaction();
+
+    foreach (array_chunk($deletes, 1024) as $paths) {
+      queryfx(
+        $conn,
+        'DELETE FROM %T WHERE branchID = %d AND path IN (%Ls)',
+        PhabricatorRepository::TABLE_LINTMESSAGE,
+        $branch->getID(),
+        $paths);
+    }
+
+    foreach (array_chunk($inserts, 256) as $values) {
+      queryfx(
+        $conn,
+        'INSERT INTO %T
+          (branchID, path, line, code, severity, name, description)
+          VALUES %Q',
+        PhabricatorRepository::TABLE_LINTMESSAGE,
+        implode(', ', $values));
+    }
+
+    $conn->saveTransaction();
+  }
+
+/*
+  private function blameAuthors() {
+    $repository = id(new PhabricatorRepositoryQuery())
+      ->setViewer(PhabricatorUser::getOmnipotentUser())
+      ->withIDs(array($this->branch->getRepositoryID()))
+      ->executeOne();
+
+    $queries = array();
+    $futures = array();
+    foreach ($this->blame as $path => $lines) {
+      $drequest = DiffusionRequest::newFromDictionary(array(
+        'user' => PhabricatorUser::getOmnipotentUser(),
+        'initFromConduit' => false,
+        'repository' => $repository,
+        'branch' => $this->branch->getName(),
+        'path' => $path,
+        'commit' => $this->lintCommit,
+      ));
+      $query = DiffusionFileContentQuery::newFromDiffusionRequest($drequest)
+        ->setNeedsBlame(true);
+      $queries[$path] = $query;
+      $futures[$path] = $query->getFileContentFuture();
+    }
+
+    $authors = array();
+
+    foreach (Futures($futures)->limit(8) as $path => $future) {
+      $queries[$path]->loadFileContentFromFuture($future);
+      list(, $rev_list, $blame_dict) = $queries[$path]->getBlameData();
+      foreach (array_keys($this->blame[$path]) as $line) {
+        $commit_identifier = $rev_list[$line - 1];
+        $author = idx($blame_dict[$commit_identifier], 'authorPHID');
+        if ($author) {
+          $authors[$author][$path][] = $line;
+        }
+      }
+    }
+
+    if ($authors) {
+      $this->conn->openTransaction();
+
+      foreach ($authors as $author => $paths) {
+        $where = array();
+        foreach ($paths as $path => $lines) {
+          $where[] = qsprintf(
+            $this->conn,
+            '(path = %s AND line IN (%Ld))',
+            $this->svnRoot.'/'.$path,
+            $lines);
+        }
+        queryfx(
+          $this->conn,
+          'UPDATE %T SET authorPHID = %s WHERE %Q',
+          PhabricatorRepository::TABLE_LINTMESSAGE,
+          $author,
+          implode(' OR ', $where));
+      }
+
+      $this->conn->saveTransaction();
+    }
+  }
+*/
+
+  public function getArtifactInputs() {
+    return array(
+      array(
+        'name'  => pht('Run on Host'),
+        'key'   => $this->getSetting('hostartifact'),
+        'type'  => HarbormasterBuildArtifact::TYPE_HOST,
+      ),
+    );
+  }
+
+  public function getFieldSpecifications() {
+    return array(
+      'severity' => array(
+        'name' => pht('Minimum Severity'),
+        'type' => 'text',
+        'required' => true,
+        'default' => 'advice'
+      ),
+      'arcanist' => array(
+        'name' => pht('Arcanist Path'),
+        'type' => 'text',
+        'required' => true,
+        'default' => 'arc'
+      ),
+      'path' => array(
+        'name' => pht('Project Path'),
+        'type' => 'text',
+        'required' => true
+      ),
+      'hostartifact' => array(
+        'name' => pht('Host'),
+        'type' => 'text',
+        'required' => true,
+      ),
+      'arcrcpath' => array(
+        'name' => pht('.arcrc Path'),
+        'caption' => pht('Specify the .arcrc path on Windows'),
+        'type' => 'text'
+      ),
+      'lintall' => array(
+        'name' => pht('Lint Entire Repository'),
+        'type' => 'bool'
+      ),
+    );
+  }
+
+}