diff --git a/dev/bots/pubspec.yaml b/dev/bots/pubspec.yaml
index 321a203297..7ac238d9b3 100644
--- a/dev/bots/pubspec.yaml
+++ b/dev/bots/pubspec.yaml
@@ -22,6 +22,7 @@ dependencies:
   async: 2.7.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   boolean_selector: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   charcode: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  checked_yaml: 2.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   cli_util: 0.3.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   collection: 1.15.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   convert: 3.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -33,6 +34,7 @@ dependencies:
   http_multi_server: 3.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   io: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   js: 0.6.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  json_annotation: 4.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   logging: 1.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   matcher: 0.12.10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   mime: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -41,6 +43,7 @@ dependencies:
   pedantic: 1.11.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   pool: 1.5.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   pub_semver: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pubspec_parse: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   shelf: 1.1.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   shelf_packages_handler: 3.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   shelf_static: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -63,4 +66,4 @@ dependencies:
 dev_dependencies:
   test_api: 0.4.0
 
-# PUBSPEC CHECKSUM: 08fb
+# PUBSPEC CHECKSUM: 9c84
diff --git a/dev/devicelab/bin/tasks/technical_debt__cost.dart b/dev/devicelab/bin/tasks/technical_debt__cost.dart
index 0a182adeec..34bdcd4ccb 100644
--- a/dev/devicelab/bin/tasks/technical_debt__cost.dart
+++ b/dev/devicelab/bin/tasks/technical_debt__cost.dart
@@ -9,6 +9,8 @@ import 'package:flutter_devicelab/framework/framework.dart';
 import 'package:flutter_devicelab/framework/task_result.dart';
 import 'package:flutter_devicelab/framework/utils.dart';
 import 'package:path/path.dart' as path;
+import 'package:pub_semver/pub_semver.dart';
+import 'package:pubspec_parse/pubspec_parse.dart';
 
 // the numbers below are prime, so that the totals don't seem round. :-)
 const double todoCost = 1009.0; // about two average SWE days, in dollars
@@ -19,6 +21,8 @@ const double ignoreForFileCost = 2477.0; // similar thinking as skipCost
 const double asDynamicCost = 2011.0; // a few days to refactor the code.
 const double deprecationCost = 233.0; // a few hours to remove the old code.
 const double legacyDeprecationCost = 9973.0; // a couple of weeks.
+const double packageNullSafetyMigrationCost = 2017.0; // a few days to migrate package.
+const double fileNullSafetyMigrationCost = 257.0; // a few hours to migrate file.
 
 final RegExp todoPattern = RegExp(r'(?://|#) *TODO');
 final RegExp ignorePattern = RegExp(r'// *ignore:');
@@ -27,6 +31,9 @@ final RegExp asDynamicPattern = RegExp(r'\bas dynamic\b');
 final RegExp deprecationPattern = RegExp(r'^ *@[dD]eprecated');
 const Pattern globalsPattern = 'globals.';
 const String legacyDeprecationPattern = '// flutter_ignore: deprecation_syntax, https';
+final RegExp dartVersionPattern = RegExp(r'// *@dart *= *(\d+).(\d+)');
+
+final Version firstNullSafeDartVersion = Version(2, 12, 0);
 
 Future<double> findCostsForFile(File file) async {
   if (path.extension(file.path) == '.py')
@@ -36,6 +43,7 @@ Future<double> findCostsForFile(File file) async {
       path.extension(file.path) != '.sh')
     return 0.0;
   final bool isTest = file.path.endsWith('_test.dart');
+  final bool isDart = file.path.endsWith('.dart');
   double total = 0.0;
   for (final String line in await file.readAsLines()) {
     if (line.contains(todoPattern))
@@ -52,10 +60,34 @@ Future<double> findCostsForFile(File file) async {
       total += legacyDeprecationCost;
     if (isTest && line.contains('skip:'))
       total += skipCost;
+    if (isDart && isOptingOutOfNullSafety(line))
+      total += fileNullSafetyMigrationCost;
   }
+  if (path.basename(file.path) == 'pubspec.yaml' && !packageIsNullSafe(file))
+    total += packageNullSafetyMigrationCost;
   return total;
 }
 
+bool isOptingOutOfNullSafety(String line) {
+  final RegExpMatch match = dartVersionPattern.firstMatch(line);
+  if (match == null) {
+    return false;
+  }
+  assert(match.groupCount == 2);
+  return Version(int.parse(match.group(1)), int.parse(match.group(2)), 0) < firstNullSafeDartVersion;
+}
+
+bool packageIsNullSafe(File file) {
+  assert(path.basename(file.path) == 'pubspec.yaml');
+  final Pubspec pubspec = Pubspec.parse(file.readAsStringSync());
+  final VersionConstraint constraint = pubspec.environment == null ? null : pubspec.environment['sdk'];
+  final bool hasConstraint = constraint != null && !constraint.isAny && !constraint.isEmpty;
+  return hasConstraint &&
+      constraint is VersionRange &&
+      constraint.min != null &&
+      Version(constraint.min.major, constraint.min.minor, 0) >= firstNullSafeDartVersion;
+}
+
 Future<int> findGlobalsForFile(File file) async {
   if (path.extension(file.path) != '.dart')
     return 0;
diff --git a/dev/devicelab/pubspec.yaml b/dev/devicelab/pubspec.yaml
index 0f57ad77db..ac5bad43aa 100644
--- a/dev/devicelab/pubspec.yaml
+++ b/dev/devicelab/pubspec.yaml
@@ -15,20 +15,25 @@ dependencies:
   path: 1.8.0
   platform: 3.0.0
   process: 4.2.1
+  pubspec_parse: 1.0.0
   stack_trace: 1.10.0
 
   logging: 1.0.1
 
   async: 2.7.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   charcode: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  checked_yaml: 2.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   collection: 1.15.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   crypto: 3.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   http_parser: 4.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  json_annotation: 4.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   pedantic: 1.11.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pub_semver: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   source_span: 1.8.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   string_scanner: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.3.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  yaml: 3.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
 dev_dependencies:
   test: 1.17.5
@@ -49,7 +54,6 @@ dev_dependencies:
   node_preamble: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   package_config: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   pool: 1.5.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  pub_semver: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   shelf: 1.1.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   shelf_packages_handler: 3.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   shelf_static: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -63,6 +67,5 @@ dev_dependencies:
   watcher: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   web_socket_channel: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   webkit_inspection_protocol: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  yaml: 3.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
-# PUBSPEC CHECKSUM: 08fb
+# PUBSPEC CHECKSUM: 9c84