diff --git a/README.md b/README.md
index 332b108..036fa41 100644
--- a/README.md
+++ b/README.md
@@ -6,9 +6,13 @@ This repository contains the common utility packages required for developing dar
 
 ## Available Packages
 
-* Html Builder
+* Body Parser
 * Code Buffer
 * Combinator
+* Html Builder
 * Merge Map
+* Pub Sub
+* Range Header
 * Symbol Table
+* User Agent
   
\ No newline at end of file
diff --git a/packages/body_parser/.travis.yml b/packages/body_parser/.travis.yml
new file mode 100644
index 0000000..a9e2c10
--- /dev/null
+++ b/packages/body_parser/.travis.yml
@@ -0,0 +1,4 @@
+language: dart
+dart:
+  - dev
+  - stable
\ No newline at end of file
diff --git a/packages/body_parser/AUTHORS.md b/packages/body_parser/AUTHORS.md
new file mode 100644
index 0000000..ac95ab5
--- /dev/null
+++ b/packages/body_parser/AUTHORS.md
@@ -0,0 +1,12 @@
+Primary Authors
+===============
+
+* __[Thomas Hii](dukefirehawk.apps@gmail.com)__
+
+    Thomas is the current maintainer of the code base. He has refactored and migrated the 
+    code base to support NNBD.
+
+* __[Tobe O](thosakwe@gmail.com)__
+
+    Tobe has written much of the original code prior to NNBD migration. He has moved on and
+    is no longer involved with the project.
diff --git a/packages/body_parser/CHANGELOG.md b/packages/body_parser/CHANGELOG.md
new file mode 100644
index 0000000..d83faa8
--- /dev/null
+++ b/packages/body_parser/CHANGELOG.md
@@ -0,0 +1,32 @@
+# Change Log
+
+## 3.0.0
+
+* Upgraded from `pendantic` to `lints` linter
+* Published as `belatuk_body_parser` package
+* Fixed linter warnings
+
+## 2.1.1
+
+* Fixed calling deprecated methods in unit test
+
+## 2.1.0
+
+* Replaced `http_server` with `belatuk_http_server`
+
+## 2.0.1
+
+* Fixed source code formating warning
+* Updated README
+
+## 2.0.0
+
+* Migrated to support Dart SDK 2.12.x NNBD
+
+## 1.1.1
+
+* Dart 2 updates; should fix Angel in Travis.
+
+## 1.1.0
+
+* Add `parseBodyFromStream`
diff --git a/packages/body_parser/LICENSE b/packages/body_parser/LICENSE
new file mode 100644
index 0000000..e37a346
--- /dev/null
+++ b/packages/body_parser/LICENSE
@@ -0,0 +1,29 @@
+BSD 3-Clause License
+
+Copyright (c) 2021, dukefirehawk.com
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
diff --git a/packages/body_parser/README.md b/packages/body_parser/README.md
new file mode 100644
index 0000000..ea47860
--- /dev/null
+++ b/packages/body_parser/README.md
@@ -0,0 +1,75 @@
+# Belatuk Body Parser
+
+[![version](https://img.shields.io/badge/pub-v3.0.0-brightgreen)](https://pub.dev/packages/belatuk_body_parser)
+[![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
+[![License](https://img.shields.io/github/license/dart-backend/belatuk-common-utilities)](https://github.com/dart-backend/belatuk-common-utilities/packages/body_parser/LICENSE)
+
+**Replacement of `package:body_parser` with breaking changes to support NNBD.**
+
+Parse request bodies and query strings in Dart, as well multipart/form-data uploads. No external dependencies required.
+
+This is the request body parser powering the [Angel3 framework](https://pub.dev/packages/angel3_framework). If you are looking for a server-side solution with dependency injection, WebSockets, and more, then I highly recommend it as your first choice. Bam!
+
+## Contents
+
+- [Belatuk Body Parser](#belatuk-body-parser)
+  - [Contents](#contents)
+    - [About](#about)
+    - [Installation](#installation)
+    - [Usage](#usage)
+    - [Custom Body Parsing](#custom-body-parsing)
+
+### About
+
+I needed something like Express.js's `body-parser` module, so I made it here. It fully supports JSON requests. x-www-form-urlencoded fully supported, as well as query strings. You can also include arrays in your query, in the same way you would for a PHP application. Full file upload support will also be present by the production 1.0.0 release.
+
+A benefit of this is that primitive types are automatically deserialized correctly. As in, if you have a `hello=1.5` request, then `body['hello']` will equal `1.5` and not `'1.5'`. A very semantic difference, yes, but it relieves stress in my head.
+
+### Installation
+
+To install Body Parser for your Dart project, simply add body_parser to your pub dependencies.
+
+  dependencies:
+      belatuk_body_parser: ^3.0.0
+
+### Usage
+
+Body Parser exposes a simple class called `BodyParseResult`. You can easily parse the query string and request body for a request by calling `Future<BodyParseResult> parseBody`.
+
+  ```dart
+  import 'dart:convert';
+  import 'package:belatuk_body_parser/belatuk_body_parser.dart';
+
+  main() async {
+    // ...
+    await for (HttpRequest request in server) {
+      request.response.write(JSON.encode(await parseBody(request).body));
+      await request.response.close();
+    }
+  }
+  ```
+
+You can also use `buildMapFromUri(Map, String)` to populate a map from a URL encoded string.
+
+This can easily be used with a library like [Angel3 JSON God](https://pub.dev/packages/angel3_json_god) to build structured JSON/REST APIs. Add validation and you've got an instant backend.
+
+  ```dart
+  MyClass create(HttpRequest request) async {
+      return god.deserialize(await parseBody(request).body, MyClass);
+  }
+  ```
+
+### Custom Body Parsing
+
+In cases where you need to parse unrecognized content types, `body_parser` won't be of any help to you on its own. However, you can use the `originalBuffer` property of a `BodyParseResult` to see the original request buffer. To get this functionality, pass `storeOriginalBuffer` as `true` when calling `parseBody`.
+
+For example, if you wanted to [parse GraphQL queries within your server](https://github.com/dukefirehawk/graphql_dart)...
+
+  ```dart
+  app.get('/graphql', (req, res) async {
+    if (req.headers.contentType.mimeType == 'application/graphql') {
+      var graphQlString = String.fromCharCodes(req.originalBuffer);
+      // ...
+    }
+  });
+  ```
diff --git a/packages/body_parser/analysis_options.yaml b/packages/body_parser/analysis_options.yaml
new file mode 100644
index 0000000..ea2c9e9
--- /dev/null
+++ b/packages/body_parser/analysis_options.yaml
@@ -0,0 +1 @@
+include: package:lints/recommended.yaml
\ No newline at end of file
diff --git a/packages/body_parser/example/main.dart b/packages/body_parser/example/main.dart
new file mode 100644
index 0000000..3d63482
--- /dev/null
+++ b/packages/body_parser/example/main.dart
@@ -0,0 +1,61 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+import 'dart:isolate';
+import 'package:http_parser/http_parser.dart';
+import 'package:belatuk_body_parser/belatuk_body_parser.dart';
+
+void main() async {
+  var address = '127.0.0.1';
+  var port = 3000;
+  var futures = <Future>[];
+
+  for (var i = 1; i < Platform.numberOfProcessors; i++) {
+    futures.add(Isolate.spawn(start, [address, port, i]));
+  }
+
+  await Future.wait(futures).then((_) {
+    print('All instances started.');
+    print(
+        'Test with "wrk -t12 -c400 -d30s -s ./example/post.lua http://localhost:3000" or similar');
+    start([address, port, 0]);
+  });
+}
+
+void start(List args) {
+  var address = InternetAddress(args[0] as String);
+  var port = 8080;
+  if (args[1] is int) {
+    args[1];
+  }
+
+  var id = 0;
+  if (args[2] is int) {
+    args[2];
+  }
+
+  HttpServer.bind(address, port, shared: true).then((server) {
+    server.listen((request) async {
+      // ignore: deprecated_member_use
+      var body = await defaultParseBody(request);
+      request.response
+        ..headers.contentType = ContentType('application', 'json')
+        ..write(json.encode(body.body));
+      await request.response.close();
+    });
+
+    print(
+        'Server #$id listening at http://${server.address.address}:${server.port}');
+  });
+}
+
+Future<BodyParseResult> defaultParseBody(HttpRequest request,
+    {bool storeOriginalBuffer = false}) {
+  return parseBodyFromStream(
+      request,
+      request.headers.contentType != null
+          ? MediaType.parse(request.headers.contentType.toString())
+          : null,
+      request.uri,
+      storeOriginalBuffer: storeOriginalBuffer);
+}
diff --git a/packages/body_parser/example/post.lua b/packages/body_parser/example/post.lua
new file mode 100644
index 0000000..524febc
--- /dev/null
+++ b/packages/body_parser/example/post.lua
@@ -0,0 +1,6 @@
+-- example HTTP POST script which demonstrates setting the
+-- HTTP method, body, and adding a header
+
+wrk.method = "POST"
+wrk.body   = "foo=bar&baz=quux"
+wrk.headers["Content-Type"] = "application/x-www-form-urlencoded"
\ No newline at end of file
diff --git a/packages/body_parser/lib/belatuk_body_parser.dart b/packages/body_parser/lib/belatuk_body_parser.dart
new file mode 100644
index 0000000..05a163e
--- /dev/null
+++ b/packages/body_parser/lib/belatuk_body_parser.dart
@@ -0,0 +1,6 @@
+/// A library for parsing HTTP request bodies and queries.
+library angel3_body_parser;
+
+export 'src/body_parse_result.dart';
+export 'src/file_upload_info.dart';
+export 'src/parse_body.dart';
diff --git a/packages/body_parser/lib/src/body_parse_result.dart b/packages/body_parser/lib/src/body_parse_result.dart
new file mode 100644
index 0000000..e47fc89
--- /dev/null
+++ b/packages/body_parser/lib/src/body_parse_result.dart
@@ -0,0 +1,28 @@
+import 'file_upload_info.dart';
+
+/// A representation of data from an incoming request.
+abstract class BodyParseResult {
+  /// The parsed body.
+  Map<String?, dynamic> get body;
+
+  /// The parsed query string.
+  Map<String?, dynamic> get query;
+
+  /// All files uploaded within this request.
+  List<FileUploadInfo> get files;
+
+  /// The original body bytes sent with this request.
+  ///
+  /// You must set [storeOriginalBuffer] to `true` to see this.
+  List<int>? get originalBuffer;
+
+  /// If an error was encountered while parsing the body, it will appear here.
+  ///
+  /// Otherwise, this is `null`.
+  dynamic get error;
+
+  /// If an error was encountered while parsing the body, the call stack will appear here.
+  ///
+  /// Otherwise, this is `null`.
+  StackTrace? get stack;
+}
diff --git a/packages/body_parser/lib/src/chunk.dart b/packages/body_parser/lib/src/chunk.dart
new file mode 100644
index 0000000..90c078b
--- /dev/null
+++ b/packages/body_parser/lib/src/chunk.dart
@@ -0,0 +1,7 @@
+import 'file_upload_info.dart';
+
+List<FileUploadInfo> getFileDataFromChunk(
+    String chunk, String boundary, String fileUploadName, Map body) {
+  var result = <FileUploadInfo>[];
+  return result;
+}
diff --git a/packages/body_parser/lib/src/file_upload_info.dart b/packages/body_parser/lib/src/file_upload_info.dart
new file mode 100644
index 0000000..285d72d
--- /dev/null
+++ b/packages/body_parser/lib/src/file_upload_info.dart
@@ -0,0 +1,17 @@
+/// Represents a file uploaded to the server.
+class FileUploadInfo {
+  /// The MIME type of the uploaded file.
+  String? mimeType;
+
+  /// The name of the file field from the request.
+  String? name;
+
+  /// The filename of the file.
+  String? filename;
+
+  /// The bytes that make up this file.
+  List<int> data;
+
+  FileUploadInfo(
+      {this.mimeType, this.name, this.filename, this.data = const []});
+}
diff --git a/packages/body_parser/lib/src/get_value.dart b/packages/body_parser/lib/src/get_value.dart
new file mode 100644
index 0000000..8d2106e
--- /dev/null
+++ b/packages/body_parser/lib/src/get_value.dart
@@ -0,0 +1,22 @@
+import 'dart:convert';
+
+dynamic getValue(String value) {
+  try {
+    var numValue = num.parse(value);
+    if (!numValue.isNaN) {
+      return numValue;
+    } else {
+      return value;
+    }
+  } on FormatException {
+    if (value.startsWith('[') && value.endsWith(']')) {
+      return json.decode(value);
+    } else if (value.startsWith('{') && value.endsWith('}')) {
+      return json.decode(value);
+    } else if (value.trim().toLowerCase() == 'null') {
+      return null;
+    } else {
+      return value;
+    }
+  }
+}
diff --git a/packages/body_parser/lib/src/map_from_uri.dart b/packages/body_parser/lib/src/map_from_uri.dart
new file mode 100644
index 0000000..d9ed8e2
--- /dev/null
+++ b/packages/body_parser/lib/src/map_from_uri.dart
@@ -0,0 +1,44 @@
+import 'get_value.dart';
+
+/// Parses a URI-encoded string into real data! **Wow!**
+///
+/// Whichever map you provide will be automatically populated from the urlencoded body string you provide.
+void buildMapFromUri(Map map, String body) {
+  var parseArrayRgx = RegExp(r'^(.+)\[\]$');
+
+  for (var keyValuePair in body.split('&')) {
+    if (keyValuePair.contains('=')) {
+      var equals = keyValuePair.indexOf('=');
+      var key = Uri.decodeQueryComponent(keyValuePair.substring(0, equals));
+      var value = Uri.decodeQueryComponent(keyValuePair.substring(equals + 1));
+
+      if (parseArrayRgx.hasMatch(key)) {
+        Match queryMatch = parseArrayRgx.firstMatch(key)!;
+        key = queryMatch.group(1)!;
+        if (map[key] is! List) {
+          map[key] = [];
+        }
+
+        map[key].add(getValue(value));
+      } else if (key.contains('.')) {
+        // i.e. map.foo.bar => [map, foo, bar]
+        var keys = key.split('.');
+
+        var targetMap = map[keys[0]] != null ? map[keys[0]] as Map? : {};
+        map[keys[0]] = targetMap;
+        for (var i = 1; i < keys.length; i++) {
+          if (i < keys.length - 1) {
+            targetMap![keys[i]] = targetMap[keys[i]] ?? {};
+            targetMap = targetMap[keys[i]] as Map?;
+          } else {
+            targetMap![keys[i]] = getValue(value);
+          }
+        }
+      } else {
+        map[key] = getValue(value);
+      }
+    } else {
+      map[Uri.decodeQueryComponent(keyValuePair)] = true;
+    }
+  }
+}
diff --git a/packages/body_parser/lib/src/parse_body.dart b/packages/body_parser/lib/src/parse_body.dart
new file mode 100644
index 0000000..cb0588b
--- /dev/null
+++ b/packages/body_parser/lib/src/parse_body.dart
@@ -0,0 +1,147 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+import 'dart:typed_data';
+
+import 'package:http_parser/http_parser.dart';
+import 'package:belatuk_http_server/belatuk_http_server.dart';
+import 'package:mime/mime.dart';
+
+import 'body_parse_result.dart';
+import 'file_upload_info.dart';
+import 'map_from_uri.dart';
+
+/// Forwards to [parseBodyFromStream].
+@deprecated
+Future<BodyParseResult> parseBody(HttpRequest request,
+    {bool storeOriginalBuffer = false}) {
+  return parseBodyFromStream(
+      request,
+      request.headers.contentType != null
+          ? MediaType.parse(request.headers.contentType.toString())
+          : null,
+      request.uri,
+      storeOriginalBuffer: storeOriginalBuffer);
+}
+
+/// Grabs data from an incoming request.
+///
+/// Supports URL-encoded and JSON, as well as multipart/* forms.
+/// On a file upload request, only fields with the name **'file'** are processed
+/// as files. Anything else is put in the body. You can change the upload file name
+/// via the *fileUploadName* parameter. :)
+///
+/// Use [storeOriginalBuffer] to add  the original request bytes to the result.
+Future<BodyParseResult> parseBodyFromStream(
+    Stream<Uint8List> data, MediaType? contentType, Uri requestUri,
+    {bool storeOriginalBuffer = false}) async {
+  var result = _BodyParseResultImpl();
+
+  Future<Uint8List> getBytes() {
+    return data
+        .fold<BytesBuilder>(BytesBuilder(copy: false), (a, b) => a..add(b))
+        .then((b) => b.takeBytes());
+  }
+
+  Future<String> getBody() {
+    if (storeOriginalBuffer) {
+      return getBytes().then((bytes) {
+        result.originalBuffer = bytes;
+        return utf8.decode(bytes);
+      });
+    } else {
+      return utf8.decoder.bind(data).join();
+    }
+  }
+
+  try {
+    if (contentType != null) {
+      if (contentType.type == 'multipart' &&
+          contentType.parameters.containsKey('boundary')) {
+        Stream<Uint8List> stream;
+
+        if (storeOriginalBuffer) {
+          var bytes = result.originalBuffer = await getBytes();
+          var ctrl = StreamController<Uint8List>()..add(bytes);
+          await ctrl.close();
+          stream = ctrl.stream;
+        } else {
+          stream = data;
+        }
+
+        var parts =
+            MimeMultipartTransformer(contentType.parameters['boundary']!)
+                .bind(stream)
+                .map((part) =>
+                    HttpMultipartFormData.parse(part, defaultEncoding: utf8));
+
+        await for (HttpMultipartFormData part in parts) {
+          if (part.isBinary ||
+              part.contentDisposition.parameters.containsKey('filename')) {
+            var builder = await part.fold(
+                BytesBuilder(copy: false),
+                (BytesBuilder b, d) =>
+                    b..add(d is! String ? (d as List<int>?)! : d.codeUnits));
+            var upload = FileUploadInfo(
+                mimeType: part.contentType!.mimeType,
+                name: part.contentDisposition.parameters['name'],
+                filename:
+                    part.contentDisposition.parameters['filename'] ?? 'file',
+                data: builder.takeBytes());
+            result.files.add(upload);
+          } else if (part.isText) {
+            var text = await part.join();
+            buildMapFromUri(result.body,
+                '${part.contentDisposition.parameters["name"]}=$text');
+          }
+        }
+      } else if (contentType.mimeType == 'application/json') {
+        result.body.addAll(
+            _foldToStringDynamic(json.decode(await getBody()) as Map?)!);
+      } else if (contentType.mimeType == 'application/x-www-form-urlencoded') {
+        var body = await getBody();
+        buildMapFromUri(result.body, body);
+      } else if (storeOriginalBuffer == true) {
+        result.originalBuffer = await getBytes();
+      }
+    } else {
+      if (requestUri.hasQuery) {
+        buildMapFromUri(result.query, requestUri.query);
+      }
+
+      if (storeOriginalBuffer == true) {
+        result.originalBuffer = await getBytes();
+      }
+    }
+  } catch (e, st) {
+    result.error = e;
+    result.stack = st;
+  }
+
+  return result;
+}
+
+class _BodyParseResultImpl implements BodyParseResult {
+  @override
+  Map<String?, dynamic> body = {};
+
+  @override
+  List<FileUploadInfo> files = [];
+
+  @override
+  List<int>? originalBuffer;
+
+  @override
+  Map<String?, dynamic> query = {};
+
+  @override
+  var error;
+
+  @override
+  StackTrace? stack;
+}
+
+Map<String, dynamic>? _foldToStringDynamic(Map? map) {
+  return map?.keys.fold<Map<String, dynamic>>(
+      <String, dynamic>{}, (out, k) => out..[k.toString()] = map[k]);
+}
diff --git a/packages/body_parser/pubspec.yaml b/packages/body_parser/pubspec.yaml
new file mode 100644
index 0000000..43755b6
--- /dev/null
+++ b/packages/body_parser/pubspec.yaml
@@ -0,0 +1,14 @@
+name: belatuk_body_parser
+version: 3.0.0
+description: Parse request bodies and query strings in Dart. Supports JSON, URL-encoded, and multi-part bodies.
+homepage: https://github.com/dart-backend/belatuk-common-utilities/tree/main/packages/body_parser
+environment:
+  sdk: '>=2.12.0 <3.0.0'
+dependencies:
+  http_parser: ^4.0.0
+  belatuk_http_server: ^2.0.0
+  mime: ^1.0.0
+dev_dependencies:
+  http: ^0.13.0
+  test: ^1.17.8
+  lints: ^1.0.0
\ No newline at end of file
diff --git a/packages/body_parser/test/form_data_test.dart b/packages/body_parser/test/form_data_test.dart
new file mode 100644
index 0000000..87fb4bc
--- /dev/null
+++ b/packages/body_parser/test/form_data_test.dart
@@ -0,0 +1,156 @@
+import 'dart:io';
+import 'dart:convert';
+import 'package:belatuk_body_parser/belatuk_body_parser.dart';
+import 'package:http/http.dart' as http;
+import 'package:http_parser/http_parser.dart';
+import 'package:test/test.dart';
+import 'server_test.dart';
+
+Future<BodyParseResult> _parseBody(HttpRequest request) {
+  return parseBodyFromStream(
+      request,
+      request.headers.contentType != null
+          ? MediaType.parse(request.headers.contentType.toString())
+          : null,
+      request.uri,
+      storeOriginalBuffer: false);
+}
+
+void main() {
+  HttpServer? server;
+  String? url;
+  http.Client? client;
+
+  setUp(() async {
+    server = await HttpServer.bind('127.0.0.1', 0);
+    server!.listen((HttpRequest request) async {
+      //Server will simply return a JSON representation of the parsed body
+      // ignore: deprecated_member_use
+      request.response.write(jsonEncodeBody(await _parseBody(request)));
+      await request.response.close();
+    });
+    url = 'http://localhost:${server!.port}';
+    print('Test server listening on $url');
+    client = http.Client();
+  });
+
+  tearDown(() async {
+    await server!.close(force: true);
+    client!.close();
+    server = null;
+    url = null;
+    client = null;
+  });
+
+  test('No upload', () async {
+    var boundary = 'myBoundary';
+    var headers = <String, String>{
+      'content-type': 'multipart/form-data; boundary=$boundary'
+    };
+    var postData = '''
+--$boundary
+Content-Disposition: form-data; name="hello"
+
+world
+--$boundary--
+'''
+        .replaceAll('\n', '\r\n');
+
+    print(
+        'Form Data: \n${postData.replaceAll("\r", "\\r").replaceAll("\n", "\\n")}');
+    var response =
+        await client!.post(Uri.parse(url!), headers: headers, body: postData);
+    print('Response: ${response.body}');
+    var jsons = json.decode(response.body);
+    var files = jsons['files'].map((map) {
+      return map == null
+          ? null
+          : map.keys.fold<Map<String, dynamic>>(
+              <String, dynamic>{}, (out, k) => out..[k.toString()] = map[k]);
+    });
+    expect(files.length, equals(0));
+    expect(jsons['body']['hello'], equals('world'));
+  });
+
+  test('Single upload', () async {
+    var boundary = 'myBoundary';
+    var headers = <String, String>{
+      'content-type': ContentType('multipart', 'form-data',
+          parameters: {'boundary': boundary}).toString()
+    };
+    var postData = '''
+--$boundary
+Content-Disposition: form-data; name="hello"
+
+world
+--$boundary
+Content-Disposition: form-data; name="file"; filename="app.dart"
+Content-Type: application/dart
+
+Hello world
+--$boundary--
+'''
+        .replaceAll('\n', '\r\n');
+
+    print(
+        'Form Data: \n${postData.replaceAll("\r", "\\r").replaceAll("\n", "\\n")}');
+    var response =
+        await client!.post(Uri.parse(url!), headers: headers, body: postData);
+    print('Response: ${response.body}');
+    var jsons = json.decode(response.body);
+    var files = jsons['files'];
+    expect(files.length, equals(1));
+    expect(files[0]['name'], equals('file'));
+    expect(files[0]['mimeType'], equals('application/dart'));
+    expect(files[0]['data'].length, equals(11));
+    expect(files[0]['filename'], equals('app.dart'));
+    expect(jsons['body']['hello'], equals('world'));
+  });
+
+  test('Multiple upload', () async {
+    var boundary = 'myBoundary';
+    var headers = <String, String>{
+      'content-type': 'multipart/form-data; boundary=$boundary'
+    };
+    var postData = '''
+--$boundary
+Content-Disposition: form-data; name="json"
+
+god
+--$boundary
+Content-Disposition: form-data; name="num"
+
+14.50000
+--$boundary
+Content-Disposition: form-data; name="file"; filename="app.dart"
+Content-Type: text/plain
+
+Hello world
+--$boundary
+Content-Disposition: form-data; name="entry-point"; filename="main.js"
+Content-Type: text/javascript
+
+function main() {
+  console.log("Hello, world!");
+}
+--$boundary--
+'''
+        .replaceAll('\n', '\r\n');
+
+    print(
+        'Form Data: \n${postData.replaceAll("\r", "\\r").replaceAll("\n", "\\n")}');
+    var response =
+        await client!.post(Uri.parse(url!), headers: headers, body: postData);
+    print('Response: ${response.body}');
+    var jsons = json.decode(response.body);
+    var files = jsons['files'];
+    expect(files.length, equals(2));
+    expect(files[0]['name'], equals('file'));
+    expect(files[0]['mimeType'], equals('text/plain'));
+    expect(files[0]['data'].length, equals(11));
+    expect(files[1]['name'], equals('entry-point'));
+    expect(files[1]['mimeType'], equals('text/javascript'));
+    expect(jsons['body']['json'], equals('god'));
+    expect(jsons['body']['num'], equals(14.5));
+  });
+}
diff --git a/packages/body_parser/test/server_test.dart b/packages/body_parser/test/server_test.dart
new file mode 100644
index 0000000..ee0048b
--- /dev/null
+++ b/packages/body_parser/test/server_test.dart
@@ -0,0 +1,174 @@
+import 'dart:convert';
+import 'dart:io' show HttpRequest, HttpServer;
+
+import 'package:belatuk_body_parser/belatuk_body_parser.dart';
+import 'package:http/http.dart' as http;
+import 'package:http_parser/http_parser.dart';
+import 'package:test/test.dart';
+
+const TOKEN =
+    'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiIxMjcuMC4wLjEiLCJleHAiOi0xLCJpYXQiOiIyMDE2LTEyLTIyVDEyOjQ5OjUwLjM2MTQ0NiIsImlzcyI6ImFuZ2VsX2F1dGgiLCJzdWIiOiIxMDY2OTQ4Mzk2MDIwMjg5ODM2NTYifQ==.PYw7yUb-cFWD7N0sSLztP7eeRvO44nu1J2OgDNyT060=';
+
+String jsonEncodeBody(BodyParseResult result) {
+  return json.encode({
+    'query': result.query,
+    'body': result.body,
+    'error': result.error?.toString(),
+    'files': result.files.map((f) {
+      return {
+        'name': f.name,
+        'mimeType': f.mimeType,
+        'filename': f.filename,
+        'data': f.data,
+      };
+    }).toList(),
+    'originalBuffer': result.originalBuffer,
+    'stack': null, //result.stack.toString(),
+  });
+}
+
+Future<BodyParseResult> _parseBody(HttpRequest request) {
+  return parseBodyFromStream(
+      request,
+      request.headers.contentType != null
+          ? MediaType.parse(request.headers.contentType.toString())
+          : null,
+      request.uri,
+      storeOriginalBuffer: true);
+}
+
+void main() {
+  HttpServer? server;
+  String? url;
+  http.Client? client;
+
+  setUp(() async {
+    server = await HttpServer.bind('127.0.0.1', 0);
+    server!.listen((HttpRequest request) async {
+      //Server will simply return a JSON representation of the parsed body
+      request.response.write(
+          // ignore: deprecated_member_use
+          jsonEncodeBody(await _parseBody(request)));
+      await request.response.close();
+    });
+    url = 'http://localhost:${server!.port}';
+    print('Test server listening on $url');
+    client = http.Client();
+  });
+  tearDown(() async {
+    await server!.close(force: true);
+    client!.close();
+    server = null;
+    url = null;
+    client = null;
+  });
+
+  group('query string', () {
+    test('GET Simple', () async {
+      print('GET $url/?hello=world');
+      var response = await client!.get(Uri.parse('$url/?hello=world'));
+      print('Response: ${response.body}');
+      var result = json.decode(response.body);
+      expect(result['body'], equals({}));
+      expect(result['query'], equals({'hello': 'world'}));
+      expect(result['files'], equals([]));
+      //expect(result['originalBuffer'], isNull);
+    });
+
+    test('GET Complex', () async {
+      var postData =
+          'hello=world&nums%5B%5D=1&nums%5B%5D=2.0&nums%5B%5D=${3 - 1}&map.foo.bar=baz';
+      print('Body: $postData');
+      var response = await client!.get(Uri.parse('$url/?$postData'));
+      print('Response: ${response.body}');
+      var query = json.decode(response.body)['query'];
+      expect(query['hello'], equals('world'));
+      expect(query['nums'][2], equals(2));
+      expect(query['map'] is Map, equals(true));
+      expect(query['map']['foo'], equals({'bar': 'baz'}));
+    });
+
+    test('JWT', () async {
+      var postData = 'token=$TOKEN';
+      print('Body: $postData');
+      var response = await client!.get(Uri.parse('$url/?$postData'));
+      print('Response: ${response.body}');
+      var query = json.decode(response.body)['query'];
+      expect(query['token'], equals(TOKEN));
+    });
+  });
+
+  group('urlencoded', () {
+    var headers = <String, String>{
+      'content-type': 'application/x-www-form-urlencoded'
+    };
+    test('POST Simple', () async {
+      print('Body: hello=world');
+      var response = await client!
+          .post(Uri.parse(url!), headers: headers, body: 'hello=world');
+      print('Response: ${response.body}');
+      var result = json.decode(response.body);
+      expect(result['query'], equals({}));
+      expect(result['body'], equals({'hello': 'world'}));
+      expect(result['files'], equals([]));
+      expect(result['originalBuffer'], isList);
+      expect(result['originalBuffer'], isNotEmpty);
+    });
+
+    test('Post Complex', () async {
+      var postData =
+          'hello=world&nums%5B%5D=1&nums%5B%5D=2.0&nums%5B%5D=${3 - 1}&map.foo.bar=baz';
+      var response =
+          await client!.post(Uri.parse(url!), headers: headers, body: postData);
+      print('Response: ${response.body}');
+      var body = json.decode(response.body)['body'];
+      expect(body['hello'], equals('world'));
+      expect(body['nums'][2], equals(2));
+      expect(body['map'] is Map, equals(true));
+      expect(body['map']['foo'], equals({'bar': 'baz'}));
+    });
+
+    test('JWT', () async {
+      var postData = 'token=$TOKEN';
+      var response =
+          await client!.post(Uri.parse(url!), headers: headers, body: postData);
+      var body = json.decode(response.body)['body'];
+      expect(body['token'], equals(TOKEN));
+    });
+  });
+
+  group('json', () {
+    var headers = <String, String>{'content-type': 'application/json'};
+    test('Post Simple', () async {
+      var postData = json.encode({'hello': 'world'});
+      print('Body: $postData');
+      var response =
+          await client!.post(Uri.parse(url!), headers: headers, body: postData);
+      print('Response: ${response.body}');
+      var result = json.decode(response.body);
+      expect(result['body'], equals({'hello': 'world'}));
+      expect(result['query'], equals({}));
+      expect(result['files'], equals([]));
+      expect(result['originalBuffer'], allOf(isList, isNotEmpty));
+    });
+
+    test('Post Complex', () async {
+      var postData = json.encode({
+        'hello': 'world',
+        'nums': [1, 2.0, 3 - 1],
+        'map': {
+          'foo': {'bar': 'baz'}
+        }
+      });
+      print('Body: $postData');
+      var response =
+          await client!.post(Uri.parse(url!), headers: headers, body: postData);
+      print('Response: ${response.body}');
+      var body = json.decode(response.body)['body'];
+      expect(body['hello'], equals('world'));
+      expect(body['nums'][2], equals(2));
+      expect(body['map'] is Map, equals(true));
+      expect(body['map']['foo'], equals({'bar': 'baz'}));
+    });
+  });
+}
diff --git a/packages/code_buffer/README.md b/packages/code_buffer/README.md
index b779eab..06ae31a 100644
--- a/packages/code_buffer/README.md
+++ b/packages/code_buffer/README.md
@@ -1,6 +1,6 @@
 # Belatuk Code Buffer
 
-[![version](https://img.shields.io/badge/pub-v3.0.1-brightgreen)](https://pub.dartlang.org/packages/belatuk_code_buffer)
+[![version](https://img.shields.io/badge/pub-v3.0.1-brightgreen)](https://pub.dev/packages/belatuk_code_buffer)
 [![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
 [![License](https://img.shields.io/github/license/dart-backend/belatuk-common-utilities)](https://github.com/dart-backend/belatuk-common-utilities/packages/code_buffer/LICENSE)
 
diff --git a/packages/combinator/README.md b/packages/combinator/README.md
index f1e543c..05fabd4 100644
--- a/packages/combinator/README.md
+++ b/packages/combinator/README.md
@@ -1,6 +1,6 @@
 # Belatuk Combinator
 
-[![version](https://img.shields.io/badge/pub-v3.0.0-brightgreen)](https://pub.dartlang.org/packages/belatuk_combinator)
+[![version](https://img.shields.io/badge/pub-v3.0.0-brightgreen)](https://pub.dev/packages/belatuk_combinator)
 [![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
 [![License](https://img.shields.io/github/license/dart-backend/belatuk-common-utilities)](https://github.com/dart-backend/belatuk-common-utilities/packages/combinator/LICENSE)
 
diff --git a/packages/html_builder/README.md b/packages/html_builder/README.md
index 9d930a4..9f9a24a 100644
--- a/packages/html_builder/README.md
+++ b/packages/html_builder/README.md
@@ -1,6 +1,6 @@
 # Betaluk Html Builder
 
-[![version](https://img.shields.io/badge/pub-v3.0.1-brightgreen)](https://pub.dartlang.org/packages/belatuk_html_builder)
+[![version](https://img.shields.io/badge/pub-v3.0.1-brightgreen)](https://pub.dev/packages/belatuk_html_builder)
 [![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
 [![License](https://img.shields.io/github/license/dart-backend/belatuk-common-utilities)](https://github.com/dart-backend/belatuk-common-utilities/packages/html_builder/LICENSE)
 
diff --git a/packages/merge_map/README.md b/packages/merge_map/README.md
index cf62b85..a12469b 100644
--- a/packages/merge_map/README.md
+++ b/packages/merge_map/README.md
@@ -1,6 +1,6 @@
 # Belatuk Merge Map
 
-[![version](https://img.shields.io/badge/pub-v3.0.1-brightgreen)](https://pub.dartlang.org/packages/belatuk_merge_map)
+[![version](https://img.shields.io/badge/pub-v3.0.1-brightgreen)](https://pub.dev/packages/belatuk_merge_map)
 [![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
 [![License](https://img.shields.io/github/license/dart-backend/belatuk-common-utilities)](https://github.com/dart-backend/belatuk-common-utilities/packages/merge_map/LICENSE)
 
diff --git a/packages/pub_sub/README.md b/packages/pub_sub/README.md
index 22bb36b..abdd7c8 100644
--- a/packages/pub_sub/README.md
+++ b/packages/pub_sub/README.md
@@ -1,6 +1,6 @@
 # Belatuk Pub Sub
 
-[![version](https://img.shields.io/badge/pub-v4.0.2-brightgreen)](https://pub.dartlang.org/packages/belatuk_pub_sub)
+[![version](https://img.shields.io/badge/pub-v4.0.2-brightgreen)](https://pub.dev/packages/belatuk_pub_sub)
 [![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
 [![License](https://img.shields.io/github/license/dart-backend/belatuk-common-utilities)](https://github.com/dart-backend/belatuk-common-utilities/packages/pub_sub/LICENSE)
 
diff --git a/packages/range_header/AUTHORS.md b/packages/range_header/AUTHORS.md
new file mode 100644
index 0000000..ac95ab5
--- /dev/null
+++ b/packages/range_header/AUTHORS.md
@@ -0,0 +1,12 @@
+Primary Authors
+===============
+
+* __[Thomas Hii](dukefirehawk.apps@gmail.com)__
+
+    Thomas is the current maintainer of the code base. He has refactored and migrated the 
+    code base to support NNBD.
+
+* __[Tobe O](thosakwe@gmail.com)__
+
+    Tobe has written much of the original code prior to NNBD migration. He has moved on and
+    is no longer involved with the project.
diff --git a/packages/range_header/CHANGELOG.md b/packages/range_header/CHANGELOG.md
new file mode 100644
index 0000000..ee096c7
--- /dev/null
+++ b/packages/range_header/CHANGELOG.md
@@ -0,0 +1,34 @@
+# Change Log
+
+## 4.0.0
+
+* Upgraded from `pendantic` to `lints` linter
+* Published as `belatuk_range_header` package
+
+## 3.0.2
+
+* Updated README
+  
+## 3.0.1
+
+* Resolve static analysis warnings
+
+## 3.0.0
+
+* Migrated to work with Dart SDK 2.12.x NNBD
+
+## 2.0.2
+
+* Fix bug in `toContentRange` that printed invalid indices.
+* Fold header items by default.
+
+## 2.0.1
+
+* Adjust `RangeHeaderTransformer` to properly print the content range of each item,
+when multiple are present.
+
+## 2.0.0
+
+* Dart 2 update.
+* Add `RangeHeaderTransformer`.
+* Overall restructuring/refactoring.
diff --git a/packages/range_header/LICENSE b/packages/range_header/LICENSE
new file mode 100644
index 0000000..e37a346
--- /dev/null
+++ b/packages/range_header/LICENSE
@@ -0,0 +1,29 @@
+BSD 3-Clause License
+
+Copyright (c) 2021, dukefirehawk.com
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
diff --git a/packages/range_header/README.md b/packages/range_header/README.md
new file mode 100644
index 0000000..066bd08
--- /dev/null
+++ b/packages/range_header/README.md
@@ -0,0 +1,40 @@
+# Belatuk Range Header
+
+[![version](https://img.shields.io/badge/pub-v3.0.0-brightgreen)](https://pub.dev/packages/belatuk_range_header)
+[![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
+[![License](https://img.shields.io/github/license/dart-backend/belatuk-common-utilities)](https://github.com/dart-backend/belatuk-common-utilities/packages/range_header/LICENSE)
+
+**Replacement of `package:range_header` with breaking changes to support NNBD.**
+
+Range header parser for belatuk. Can be used by any dart backend.
+
+## Installation
+
+In your `pubspec.yaml`:
+
+```yaml
+dependencies:
+  belatuk_range_header: ^4.0.0
+```
+
+## Usage
+
+```dart
+handleRequest(HttpRequest request) async {
+  // Parse the header
+  var header = RangeHeader.parse(request.headers.value(HttpHeaders.rangeHeader));
+
+  // Optimize/canonicalize it
+  var items = RangeHeader.foldItems(header.items);
+  header = RangeHeader(items);
+
+  // Get info
+  header.items;
+  header.rangeUnit;
+  print(header.items[0].toContentRange(fileSize));
+
+  // Serve the file
+  var transformer = RangeHeaderTransformer(header);
+  await file.openRead().transform(transformer).pipe(request.response);
+}
+```
diff --git a/packages/range_header/analysis_options.yaml b/packages/range_header/analysis_options.yaml
new file mode 100644
index 0000000..ea2c9e9
--- /dev/null
+++ b/packages/range_header/analysis_options.yaml
@@ -0,0 +1 @@
+include: package:lints/recommended.yaml
\ No newline at end of file
diff --git a/packages/range_header/example/main.dart b/packages/range_header/example/main.dart
new file mode 100644
index 0000000..b58239a
--- /dev/null
+++ b/packages/range_header/example/main.dart
@@ -0,0 +1,28 @@
+import 'dart:io';
+import 'package:angel3_range_header/angel3_range_header.dart';
+
+var file = File('some_video.mp4');
+
+void handleRequest(HttpRequest request) async {
+  // Parse the header
+  var header =
+      RangeHeader.parse(request.headers.value(HttpHeaders.rangeHeader)!);
+
+  // Optimize/canonicalize it
+  var items = RangeHeader.foldItems(header.items);
+  header = RangeHeader(items);
+
+  // Get info
+  header.items;
+  header.rangeUnit;
+  header.items.forEach((item) => item.toContentRange(400));
+
+  // Serve the file
+  var transformer =
+      RangeHeaderTransformer(header, 'video/mp4', await file.length());
+  await file
+      .openRead()
+      .cast<List<int>>()
+      .transform(transformer)
+      .pipe(request.response);
+}
diff --git a/packages/range_header/example/server.dart b/packages/range_header/example/server.dart
new file mode 100644
index 0000000..076acd8
--- /dev/null
+++ b/packages/range_header/example/server.dart
@@ -0,0 +1,103 @@
+//import 'package:angel_framework/angel_framework.dart';
+//import 'package:angel_framework/http.dart';
+//import 'package:angel_static/angel_static.dart';
+
+void main() async {
+  /*
+  var app = new Angel();
+  var http = new AngelHttp(app);
+  var fs = const LocalFileSystem();
+  var vDir = new _RangingVirtualDirectory(app, fs.currentDirectory);
+  app.logger = new Logger('range_header')
+    ..onRecord.listen((rec) {
+      print(rec);
+      if (rec.error != null) print(rec.error);
+      if (rec.stackTrace != null) print(rec.stackTrace);
+    });
+  app.mimeTypeResolver
+    ..addExtension('dart', 'text/dart')
+    ..addExtension('lock', 'text/plain')
+    ..addExtension('md', 'text/plain')
+    ..addExtension('packages', 'text/plain')
+    ..addExtension('yaml', 'text/plain')
+    ..addExtension('yml', 'text/plain');
+  app.fallback(vDir.handleRequest);
+  app.fallback((req, res) => throw new AngelHttpException.notFound());
+  await http.startServer('127.0.0.1', 3000);
+  print('Listening at ${http.uri}');
+  */
+}
+/*
+class _RangingVirtualDirectory extends VirtualDirectory {
+  _RangingVirtualDirectory(Angel app, Directory source)
+      : super(app, source.fileSystem,
+            source: source, allowDirectoryListing: true);
+
+  @override
+  Future<bool> serveFile(
+      File file, FileStat stat, RequestContext req, ResponseContext res) async {
+    res.headers[HttpHeaders.acceptRangesHeader] = 'bytes';
+
+    if (req.headers.value(HttpHeaders.rangeHeader)?.startsWith('bytes') ==
+        true) {
+      var header =
+          new RangeHeader.parse(req.headers.value(HttpHeaders.rangeHeader));
+      header = new RangeHeader(RangeHeader.foldItems(header.items));
+
+      if (header.items.length == 1) {
+        var item = header.items[0];
+        Stream<Uint8List> stream;
+        int len = 0, total = await file.length();
+
+        if (item.start == -1) {
+          if (item.end == -1) {
+            len = total;
+            stream = file.openRead();
+          } else {
+            len = item.end + 1;
+            stream = file.openRead(0, item.end + 1);
+          }
+        } else {
+          if (item.end == -1) {
+            len = total - item.start;
+            stream = file.openRead(item.start);
+          } else {
+            len = item.end - item.start + 1;
+            stream = file.openRead(item.start, item.end + 1);
+          }
+        }
+
+        res.contentType = new MediaType.parse(
+            app.mimeTypeResolver.lookup(file.path) ??
+                'application/octet-stream');
+        res.statusCode = HttpStatus.partialContent;
+        res.headers[HttpHeaders.contentLengthHeader] = len.toString();
+        res.headers[HttpHeaders.contentRangeHeader] =
+            'bytes ' + item.toContentRange(total);
+        await stream.cast<List<int>>().pipe(res);
+        return false;
+      } else {
+        var totalFileSize = await file.length();
+        var transformer = new RangeHeaderTransformer(
+            header,
+            app.mimeTypeResolver.lookup(file.path) ??
+                'application/octet-stream',
+            await file.length());
+        res.statusCode = HttpStatus.partialContent;
+        res.headers[HttpHeaders.contentLengthHeader] =
+            transformer.computeContentLength(totalFileSize).toString();
+        res.contentType = new MediaType(
+            'multipart', 'byteranges', {'boundary': transformer.boundary});
+        await file
+            .openRead()
+            .cast<List<int>>()
+            .transform(transformer)
+            .pipe(res);
+        return false;
+      }
+    } else {
+      return await super.serveFile(file, stat, req, res);
+    }
+  }
+}
+*/
diff --git a/packages/range_header/lib/angel3_range_header.dart b/packages/range_header/lib/angel3_range_header.dart
new file mode 100644
index 0000000..ea17d35
--- /dev/null
+++ b/packages/range_header/lib/angel3_range_header.dart
@@ -0,0 +1,4 @@
+export 'src/converter.dart';
+export 'src/exception.dart';
+export 'src/range_header.dart';
+export 'src/range_header_item.dart';
diff --git a/packages/range_header/lib/src/converter.dart b/packages/range_header/lib/src/converter.dart
new file mode 100644
index 0000000..d5c5645
--- /dev/null
+++ b/packages/range_header/lib/src/converter.dart
@@ -0,0 +1,171 @@
+import 'dart:async';
+import 'dart:collection';
+import 'dart:convert';
+import 'dart:io' show BytesBuilder;
+import 'dart:math';
+import 'package:async/async.dart';
+import 'package:charcode/ascii.dart';
+import 'range_header.dart';
+
+/// A [StreamTransformer] that uses a parsed [RangeHeader] and transforms an input stream
+/// into one compatible with the `multipart/byte-ranges` specification.
+class RangeHeaderTransformer
+    extends StreamTransformerBase<List<int>, List<int>> {
+  final RangeHeader header;
+  final String boundary, mimeType;
+  final int totalLength;
+
+  RangeHeaderTransformer(this.header, this.mimeType, this.totalLength,
+      {String? boundary})
+      : boundary = boundary ?? _randomString() {
+    if (header.items.isEmpty) {
+      throw ArgumentError('`header` cannot be null or empty.');
+    }
+  }
+
+  /// Computes the content length that will be written to a response, given a stream of the given [totalFileSize].
+  int computeContentLength(int totalFileSize) {
+    var len = 0;
+
+    for (var item in header.items) {
+      if (item.start == -1) {
+        if (item.end == -1) {
+          len += totalFileSize;
+        } else {
+          //len += item.end + 1;
+          len += item.end + 1;
+        }
+      } else if (item.end == -1) {
+        len += totalFileSize - item.start;
+        //len += totalFileSize - item.start - 1;
+      } else {
+        len += item.end - item.start;
+      }
+
+      // Take into consideration the fact that delimiters are written.
+      len += utf8.encode('--$boundary\r\n').length;
+      len += utf8.encode('Content-Type: $mimeType\r\n').length;
+      len += utf8
+          .encode(
+              'Content-Range: ${header.rangeUnit} ${item.toContentRange(totalLength)}/$totalLength\r\n\r\n')
+          .length;
+      len += 2; // CRLF
+    }
+
+    len += utf8.encode('--$boundary--\r\n').length;
+
+    return len;
+  }
+
+  @override
+  Stream<List<int>> bind(Stream<List<int>> stream) {
+    var ctrl = StreamController<List<int>>();
+
+    Future(() async {
+      var index = 0;
+      var enqueued = Queue<List<int>>();
+      var q = StreamQueue(stream);
+
+      Future<List<int>> absorb(int length) async {
+        var out = BytesBuilder();
+
+        while (out.length < length) {
+          var remaining = length - out.length;
+
+          while (out.length < length && enqueued.isNotEmpty) {
+            remaining = length - out.length;
+            var blob = enqueued.removeFirst();
+
+            if (blob.length > remaining) {
+              enqueued.addFirst(blob.skip(remaining).toList());
+              blob = blob.take(remaining).toList();
+            }
+
+            out.add(blob);
+            index += blob.length;
+          }
+
+          if (out.length < length && await q.hasNext) {
+            var blob = await q.next;
+            remaining = length - out.length;
+
+            if (blob.length > remaining) {
+              enqueued.addFirst(blob.skip(remaining).toList());
+              blob = blob.take(remaining).toList();
+            }
+
+            out.add(blob);
+            index += blob.length;
+          }
+
+          // If we get this far, and the stream is EMPTY, the user requested
+          // too many bytes.
+          if (out.length < length && enqueued.isEmpty && !(await q.hasNext)) {
+            throw StateError(
+                'The range denoted is bigger than the size of the input stream.');
+          }
+        }
+
+        return out.takeBytes();
+      }
+
+      for (var item in header.items) {
+        var chunk = BytesBuilder();
+
+        // Skip until we reach the start index.
+        while (index < item.start) {
+          var remaining = item.start - index;
+          await absorb(remaining);
+        }
+
+        // Next, absorb until we reach the end.
+        if (item.end == -1) {
+          while (enqueued.isNotEmpty) {
+            chunk.add(enqueued.removeFirst());
+          }
+          while (await q.hasNext) {
+            chunk.add(await q.next);
+          }
+        } else {
+          var remaining = item.end - index;
+          chunk.add(await absorb(remaining));
+        }
+
+        // Next, write the boundary and data.
+        ctrl.add(utf8.encode('--$boundary\r\n'));
+        ctrl.add(utf8.encode('Content-Type: $mimeType\r\n'));
+        ctrl.add(utf8.encode(
+            'Content-Range: ${header.rangeUnit} ${item.toContentRange(totalLength)}/$totalLength\r\n\r\n'));
+        ctrl.add(chunk.takeBytes());
+        ctrl.add(const [$cr, $lf]);
+
+        // If this range was unbounded, don't bother looping any further.
+        if (item.end == -1) break;
+      }
+
+      ctrl.add(utf8.encode('--$boundary--\r\n'));
+
+      await ctrl.close();
+    }).catchError((e) {
+      ctrl.addError(e as Object);
+      return null;
+    });
+
+    return ctrl.stream;
+  }
+}
+
+var _rnd = Random();
+String _randomString(
+    {int length = 32,
+    String validChars =
+        'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'}) {
+  var len = _rnd.nextInt((length - 10)) + 10;
+  var buf = StringBuffer();
+
+  while (buf.length < len) {
+    buf.writeCharCode(validChars.codeUnitAt(_rnd.nextInt(validChars.length)));
+  }
+
+  return buf.toString();
+}
diff --git a/packages/range_header/lib/src/exception.dart b/packages/range_header/lib/src/exception.dart
new file mode 100644
index 0000000..c6b3a7b
--- /dev/null
+++ b/packages/range_header/lib/src/exception.dart
@@ -0,0 +1,18 @@
+class RangeHeaderParseException extends FormatException {
+  @override
+  final String message;
+
+  RangeHeaderParseException(this.message);
+
+  @override
+  String toString() => 'Range header parse exception: $message';
+}
+
+class InvalidRangeHeaderException implements Exception {
+  final String message;
+
+  InvalidRangeHeaderException(this.message);
+
+  @override
+  String toString() => 'Range header parse exception: $message';
+}
diff --git a/packages/range_header/lib/src/parser.dart b/packages/range_header/lib/src/parser.dart
new file mode 100644
index 0000000..ecc365c
--- /dev/null
+++ b/packages/range_header/lib/src/parser.dart
@@ -0,0 +1,152 @@
+import 'package:charcode/charcode.dart';
+import 'package:source_span/source_span.dart';
+import 'package:string_scanner/string_scanner.dart';
+import 'exception.dart';
+import 'range_header.dart';
+import 'range_header_impl.dart';
+import 'range_header_item.dart';
+
+final RegExp _rgxInt = RegExp(r'[0-9]+');
+final RegExp _rgxWs = RegExp(r'[ \n\r\t]');
+
+enum TokenType { RANGE_UNIT, COMMA, INT, DASH, EQUALS }
+
+class Token {
+  final TokenType type;
+  final SourceSpan? span;
+
+  Token(this.type, this.span);
+}
+
+List<Token> scan(String text, List<String> allowedRangeUnits) {
+  var tokens = <Token>[];
+  var scanner = SpanScanner(text);
+
+  while (!scanner.isDone) {
+    // Skip whitespace
+    scanner.scan(_rgxWs);
+
+    if (scanner.scanChar($comma)) {
+      tokens.add(Token(TokenType.COMMA, scanner.lastSpan));
+    } else if (scanner.scanChar($dash)) {
+      tokens.add(Token(TokenType.DASH, scanner.lastSpan));
+    } else if (scanner.scan(_rgxInt)) {
+      tokens.add(Token(TokenType.INT, scanner.lastSpan));
+    } else if (scanner.scanChar($equal)) {
+      tokens.add(Token(TokenType.EQUALS, scanner.lastSpan));
+    } else {
+      var matched = false;
+
+      for (var unit in allowedRangeUnits) {
+        if (scanner.scan(unit)) {
+          tokens.add(Token(TokenType.RANGE_UNIT, scanner.lastSpan));
+          matched = true;
+          break;
+        }
+      }
+
+      if (!matched) {
+        var ch = scanner.readChar();
+        throw RangeHeaderParseException(
+            'Unexpected character: "${String.fromCharCode(ch)}"');
+      }
+    }
+  }
+
+  return tokens;
+}
+
+class Parser {
+  Token? _current;
+  int _index = -1;
+  final List<Token> tokens;
+
+  Parser(this.tokens);
+
+  Token? get current => _current;
+
+  bool get done => _index >= tokens.length - 1;
+
+  RangeHeaderParseException _expected(String type) {
+    var offset = current?.span?.start.offset;
+
+    if (offset == null) return RangeHeaderParseException('Expected $type.');
+
+    Token? peek;
+
+    if (_index < tokens.length - 1) peek = tokens[_index + 1];
+
+    if (peek != null && peek.span != null) {
+      return RangeHeaderParseException(
+          'Expected $type at offset $offset, found "${peek.span!.text}" instead. \nSource:\n${peek.span?.highlight() ?? peek.type}');
+    } else {
+      return RangeHeaderParseException(
+          'Expected $type at offset $offset, but the header string ended without one.\nSource:\n${current!.span?.highlight() ?? current!.type}');
+    }
+  }
+
+  bool next(TokenType type) {
+    if (done) return false;
+    var tok = tokens[_index + 1];
+    if (tok.type == type) {
+      _index++;
+      _current = tok;
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+  RangeHeader? parseRangeHeader() {
+    if (next(TokenType.RANGE_UNIT)) {
+      var unit = current!.span!.text;
+      next(TokenType.EQUALS); // Consume =, if any.
+
+      var items = <RangeHeaderItem>[];
+      var item = parseHeaderItem();
+
+      while (item != null) {
+        items.add(item);
+        // Parse comma
+        if (next(TokenType.COMMA)) {
+          item = parseHeaderItem();
+        } else {
+          item = null;
+        }
+      }
+
+      if (items.isEmpty) {
+        throw _expected('range');
+      } else {
+        return RangeHeaderImpl(unit, items);
+      }
+    } else {
+      return null;
+    }
+  }
+
+  RangeHeaderItem? parseHeaderItem() {
+    if (next(TokenType.INT)) {
+      // i.e 500-544, or 600-
+      var start = int.parse(current!.span!.text);
+      if (next(TokenType.DASH)) {
+        if (next(TokenType.INT)) {
+          return RangeHeaderItem(start, int.parse(current!.span!.text));
+        } else {
+          return RangeHeaderItem(start);
+        }
+      } else {
+        throw _expected('"-"');
+      }
+    } else if (next(TokenType.DASH)) {
+      // i.e. -599
+      if (next(TokenType.INT)) {
+        return RangeHeaderItem(-1, int.parse(current!.span!.text));
+      } else {
+        throw _expected('integer');
+      }
+    } else {
+      return null;
+    }
+  }
+}
diff --git a/packages/range_header/lib/src/range_header.dart b/packages/range_header/lib/src/range_header.dart
new file mode 100644
index 0000000..ee0fa4d
--- /dev/null
+++ b/packages/range_header/lib/src/range_header.dart
@@ -0,0 +1,68 @@
+import 'dart:collection';
+import 'exception.dart';
+import 'parser.dart';
+import 'range_header_item.dart';
+import 'range_header_impl.dart';
+
+/// Represents the contents of a parsed `Range` header.
+abstract class RangeHeader {
+  /// Returns an immutable list of the ranges that were parsed.
+  UnmodifiableListView<RangeHeaderItem> get items;
+
+  const factory RangeHeader(Iterable<RangeHeaderItem> items,
+      {String? rangeUnit}) = _ConstantRangeHeader;
+
+  /// Eliminates any overlapping [items], sorts them, and folds them all into the most efficient representation possible.
+  static UnmodifiableListView<RangeHeaderItem> foldItems(
+      Iterable<RangeHeaderItem> items) {
+    var out = <RangeHeaderItem>{};
+
+    for (var item in items) {
+      // Remove any overlapping items, consolidate them.
+      while (out.any((x) => x.overlaps(item))) {
+        var f = out.firstWhere((x) => x.overlaps(item));
+        out.remove(f);
+        item = item.consolidate(f);
+      }
+
+      out.add(item);
+    }
+
+    return UnmodifiableListView(out.toList()..sort());
+  }
+
+  /// Attempts to parse a [RangeHeader] from its [text] representation.
+  ///
+  /// You can optionally pass a custom list of [allowedRangeUnits].
+  /// The default is `['bytes']`.
+  ///
+  /// If [fold] is `true`, the items will be folded into the most compact
+  /// possible representation.
+  ///
+  factory RangeHeader.parse(String text,
+      {Iterable<String>? allowedRangeUnits, bool fold = true}) {
+    var tokens = scan(text, allowedRangeUnits?.toList() ?? ['bytes']);
+    var parser = Parser(tokens);
+    var header = parser.parseRangeHeader();
+    if (header == null) {
+      throw InvalidRangeHeaderException('Header is null');
+    }
+    var items = foldItems(header.items);
+    return RangeHeaderImpl(header.rangeUnit, items);
+  }
+
+  /// Returns this header's range unit. Most commonly, this is `bytes`.
+  String? get rangeUnit;
+}
+
+class _ConstantRangeHeader implements RangeHeader {
+  final Iterable<RangeHeaderItem> items_;
+  @override
+  final String? rangeUnit;
+
+  const _ConstantRangeHeader(this.items_, {this.rangeUnit = 'bytes'});
+
+  @override
+  UnmodifiableListView<RangeHeaderItem> get items =>
+      UnmodifiableListView(items_);
+}
diff --git a/packages/range_header/lib/src/range_header_impl.dart b/packages/range_header/lib/src/range_header_impl.dart
new file mode 100644
index 0000000..865d387
--- /dev/null
+++ b/packages/range_header/lib/src/range_header_impl.dart
@@ -0,0 +1,20 @@
+import 'dart:collection';
+import 'range_header.dart';
+import 'range_header_item.dart';
+
+/// Represents the contents of a parsed `Range` header.
+class RangeHeaderImpl implements RangeHeader {
+  UnmodifiableListView<RangeHeaderItem>? _cached;
+  final List<RangeHeaderItem> _items = [];
+
+  RangeHeaderImpl(this.rangeUnit, [List<RangeHeaderItem> items = const []]) {
+    _items.addAll(items);
+  }
+
+  @override
+  UnmodifiableListView<RangeHeaderItem> get items =>
+      _cached ??= UnmodifiableListView<RangeHeaderItem>(_items);
+
+  @override
+  final String? rangeUnit;
+}
diff --git a/packages/range_header/lib/src/range_header_item.dart b/packages/range_header/lib/src/range_header_item.dart
new file mode 100644
index 0000000..f8e7170
--- /dev/null
+++ b/packages/range_header/lib/src/range_header_item.dart
@@ -0,0 +1,93 @@
+import 'dart:math';
+
+import 'package:quiver/core.dart';
+
+/// Represents an individual range, with an optional start index and optional end index.
+class RangeHeaderItem implements Comparable<RangeHeaderItem> {
+  /// The index at which this chunk begins. May be `-1`.
+  final int start;
+
+  /// The index at which this chunk ends. May be `-1`.
+  final int end;
+
+  const RangeHeaderItem([this.start = -1, this.end = -1]);
+
+  /// Joins two items together into the largest possible range.
+  RangeHeaderItem consolidate(RangeHeaderItem other) {
+    if (!(other.overlaps(this))) {
+      throw ArgumentError('The two ranges do not overlap.');
+    }
+    return RangeHeaderItem(min(start, other.start), max(end, other.end));
+  }
+
+  @override
+  int get hashCode => hash2(start, end);
+
+  @override
+  bool operator ==(other) =>
+      other is RangeHeaderItem && other.start == start && other.end == end;
+
+  bool overlaps(RangeHeaderItem other) {
+    if (other.start <= start) {
+      return other.end < start;
+    } else if (other.start > start) {
+      return other.start <= end;
+    }
+    return false;
+  }
+
+  @override
+  int compareTo(RangeHeaderItem other) {
+    if (other.start > start) {
+      return -1;
+    } else if (other.start == start) {
+      if (other.end == end) {
+        return 0;
+      } else if (other.end < end) {
+        return 1;
+      } else {
+        return -1;
+      }
+    } else if (other.start < start) {
+      return 1;
+    } else {
+      return -1;
+    }
+  }
+
+  @override
+  String toString() {
+    if (start > -1 && end > -1) {
+      return '$start-$end';
+    } else if (start > -1) {
+      return '$start-';
+    } else {
+      return '-$end';
+    }
+  }
+
+  /// Creates a representation of this instance suitable for a `Content-Range` header.
+  ///
+  /// This can only be used if the user request only one range. If not, send a
+  /// `multipart/byteranges` response.
+  ///
+  /// Please adhere to the standard!!!
+  /// http://httpwg.org/specs/rfc7233.html
+
+  String toContentRange([int? totalSize]) {
+    // var maxIndex = totalSize != null ? (totalSize - 1).toString() : '*';
+    var s = start > -1 ? start : 0;
+
+    if (end == -1) {
+      if (totalSize == null) {
+        throw UnsupportedError(
+            'If the end of this range is unknown, `totalSize` must not be null.');
+      } else {
+        // if (end == totalSize - 1) {
+        return '$s-${totalSize - 1}/$totalSize';
+      }
+    }
+
+    return '$s-$end/$totalSize';
+  }
+}
diff --git a/packages/range_header/pubspec.yaml b/packages/range_header/pubspec.yaml
new file mode 100644
index 0000000..25798b5
--- /dev/null
+++ b/packages/range_header/pubspec.yaml
@@ -0,0 +1,18 @@
+name: belatuk_range_header
+version: 4.0.0
+description: Range header parser for Dart. Beyond parsing, a stream transformer is included.
+homepage: https://github.com/dart-backend/belatuk-common-utilities/tree/main/packages/range_header
+environment:
+  sdk: '>=2.12.0 <3.0.0'
+dependencies:
+  async: ^2.6.0
+  charcode: ^1.2.0
+  quiver: ^3.0.1
+  source_span: ^1.8.1
+  string_scanner: ^1.1.0
+dev_dependencies:
+  file: ^6.1.0
+  http_parser: ^4.0.0
+  logging: ^1.0.1
+  test: ^1.17.8
+  lints: ^1.0.0
diff --git a/packages/range_header/test/all_test.dart b/packages/range_header/test/all_test.dart
new file mode 100644
index 0000000..93c4e9f
--- /dev/null
+++ b/packages/range_header/test/all_test.dart
@@ -0,0 +1,95 @@
+import 'package:angel3_range_header/angel3_range_header.dart';
+import 'package:test/test.dart';
+
+final Matcher throwsRangeParseException =
+    throwsA(const TypeMatcher<RangeHeaderParseException>());
+
+final Matcher throwsInvalidRangeHeaderException =
+    throwsA(const TypeMatcher<InvalidRangeHeaderException>());
+
+void main() {
+  group('one item', () {
+    test('start and end', () {
+      var r = RangeHeader.parse('bytes 1-200');
+      expect(r.items, hasLength(1));
+      expect(r.items.first.start, 1);
+      expect(r.items.first.end, 200);
+    });
+
+    test('start only', () {
+      var r = RangeHeader.parse('bytes 1-');
+      expect(r.items, hasLength(1));
+      expect(r.items.first.start, 1);
+      expect(r.items.first.end, -1);
+    });
+
+    test('end only', () {
+      var r = RangeHeader.parse('bytes -200');
+      print(r.items);
+      expect(r.items, hasLength(1));
+      expect(r.items.first.start, -1);
+      expect(r.items.first.end, 200);
+    });
+  });
+
+  group('multiple items', () {
+    test('three items', () {
+      var r = RangeHeader.parse('bytes 1-20, 21-40, 41-60');
+      print(r.items);
+      expect(r.items, hasLength(3));
+      expect(r.items[0].start, 1);
+      expect(r.items[0].end, 20);
+      expect(r.items[1].start, 21);
+      expect(r.items[1].end, 40);
+      expect(r.items[2].start, 41);
+      expect(r.items[2].end, 60);
+    });
+
+    test('one item without end', () {
+      var r = RangeHeader.parse('bytes 1-20, 21-');
+      print(r.items);
+      expect(r.items, hasLength(2));
+      expect(r.items[0].start, 1);
+      expect(r.items[0].end, 20);
+      expect(r.items[1].start, 21);
+      expect(r.items[1].end, -1);
+    });
+  });
+
+  group('failures', () {
+    test('no start with no end', () {
+      expect(() => RangeHeader.parse('-'), throwsInvalidRangeHeaderException);
+    });
+  });
+
+  group('exceptions', () {
+    test('invalid character', () {
+      expect(() => RangeHeader.parse('!!!'), throwsRangeParseException);
+    });
+
+    test('no ranges', () {
+      expect(() => RangeHeader.parse('bytes'), throwsRangeParseException);
+    });
+
+    test('no dash after int', () {
+      expect(() => RangeHeader.parse('bytes 3'), throwsRangeParseException);
+      expect(() => RangeHeader.parse('bytes 3,'), throwsRangeParseException);
+      expect(() => RangeHeader.parse('bytes 3 24'), throwsRangeParseException);
+    });
+
+    test('no int after dash', () {
+      expect(() => RangeHeader.parse('bytes -,'), throwsRangeParseException);
+    });
+  });
+
+  group('complete coverage', () {
+    test('exception toString()', () {
+      var m = RangeHeaderParseException('hey');
+      expect(m.toString(), contains('hey'));
+    });
+  });
+
+  test('content-range', () {
+    expect(RangeHeader.parse('bytes 1-2').items[0].toContentRange(3), '1-2/3');
+  });
+}
diff --git a/packages/symbol_table/README.md b/packages/symbol_table/README.md
index fafc033..f713dba 100644
--- a/packages/symbol_table/README.md
+++ b/packages/symbol_table/README.md
@@ -1,6 +1,6 @@
 # Belatuk Symbol Table
 
-[![version](https://img.shields.io/badge/pub-v3.0.1-brightgreen)](https://pub.dartlang.org/packages/belatuk_symbol_table)
+[![version](https://img.shields.io/badge/pub-v3.0.1-brightgreen)](https://pub.dev/packages/belatuk_symbol_table)
 [![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
 [![License](https://img.shields.io/github/license/dart-backend/belatuk-common-utilities)](https://github.com/dart-backend/belatuk-common-utilities/packages/symbol_table/LICENSE)
 
diff --git a/packages/user_agent/.travis.yml b/packages/user_agent/.travis.yml
new file mode 100644
index 0000000..de2210c
--- /dev/null
+++ b/packages/user_agent/.travis.yml
@@ -0,0 +1 @@
+language: dart
\ No newline at end of file
diff --git a/packages/user_agent/AUTHORS.md b/packages/user_agent/AUTHORS.md
new file mode 100644
index 0000000..ac95ab5
--- /dev/null
+++ b/packages/user_agent/AUTHORS.md
@@ -0,0 +1,12 @@
+Primary Authors
+===============
+
+* __[Thomas Hii](dukefirehawk.apps@gmail.com)__
+
+    Thomas is the current maintainer of the code base. He has refactored and migrated the 
+    code base to support NNBD.
+
+* __[Tobe O](thosakwe@gmail.com)__
+
+    Tobe has written much of the original code prior to NNBD migration. He has moved on and
+    is no longer involved with the project.
diff --git a/packages/user_agent/CHANGELOG.md b/packages/user_agent/CHANGELOG.md
new file mode 100644
index 0000000..3b24416
--- /dev/null
+++ b/packages/user_agent/CHANGELOG.md
@@ -0,0 +1,22 @@
+# Change Log
+
+## 3.0.2
+
+* Upgraded from `pendantic` to `lints` linter
+* Fixed linter warnings
+
+## 3.0.1
+
+* Updated to use non nullable results
+
+## 3.0.0
+
+* Migrated to support Dart SDK 2.12.x NNBD
+
+## 2.0.0
+
+* Dart 2 updates.
+
+## 0.0.1
+
+* Initial version, created by Stagehand
diff --git a/packages/user_agent/LICENSE b/packages/user_agent/LICENSE
new file mode 100644
index 0000000..e37a346
--- /dev/null
+++ b/packages/user_agent/LICENSE
@@ -0,0 +1,29 @@
+BSD 3-Clause License
+
+Copyright (c) 2021, dukefirehawk.com
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
diff --git a/packages/user_agent/README.md b/packages/user_agent/README.md
new file mode 100644
index 0000000..f01f839
--- /dev/null
+++ b/packages/user_agent/README.md
@@ -0,0 +1,26 @@
+# User Agent Analyzer
+
+[![version](https://img.shields.io/badge/pub-v3.0.2-brightgreen)](https://pub.dev/packages/user_agent_analyzer)
+[![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
+[![License](https://img.shields.io/github/license/dart-backend/belatuk-common-utilities)](https://github.com/dart-backend/belatuk-common-utilities/packages/user_agent/LICENSE)
+
+**Replacement of `package:user_agent` with breaking changes to support NNBD.**
+
+A library to identify the type of devices and web browsers based on `User-Agent` string.
+
+Runs anywhere.
+
+```dart
+void main() async {
+    app.get('/', (req, res) async {
+        var ua = UserAgent(req.headers.value('user-agent'));
+
+        if (ua.isChrome) {
+            res.redirect('/upgrade-your-browser');
+            return;
+        } else {
+            // ...
+        }
+    });
+}
+```
diff --git a/packages/user_agent/analysis_options.yaml b/packages/user_agent/analysis_options.yaml
new file mode 100644
index 0000000..ea2c9e9
--- /dev/null
+++ b/packages/user_agent/analysis_options.yaml
@@ -0,0 +1 @@
+include: package:lints/recommended.yaml
\ No newline at end of file
diff --git a/packages/user_agent/example/example.dart b/packages/user_agent/example/example.dart
new file mode 100644
index 0000000..3918e9d
--- /dev/null
+++ b/packages/user_agent/example/example.dart
@@ -0,0 +1,7 @@
+import 'package:user_agent_analyzer/user_agent_analyzer.dart';
+
+void main() {
+  var ua = UserAgent(
+      'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.95 Safari/537.36');
+  print(ua.isChrome);
+}
diff --git a/packages/user_agent/lib/user_agent_analyzer.dart b/packages/user_agent/lib/user_agent_analyzer.dart
new file mode 100644
index 0000000..f86757f
--- /dev/null
+++ b/packages/user_agent/lib/user_agent_analyzer.dart
@@ -0,0 +1,235 @@
+library user_agent_analyzer;
+
+/// Utils for device detection.
+class UserAgent {
+  bool _isChrome = false;
+  bool _isOpera = false;
+  bool _isIE = false;
+  bool _isFirefox = false;
+  bool _isWebKit = false;
+  String? _cachedCssPrefix;
+  String? _cachedPropertyPrefix;
+
+  final String value, _lowerValue;
+
+  static const List<String> knownMobileUserAgentPrefixes = [
+    'w3c ',
+    'w3c-',
+    'acs-',
+    'alav',
+    'alca',
+    'amoi',
+    'audi',
+    'avan',
+    'benq',
+    'bird',
+    'blac',
+    'blaz',
+    'brew',
+    'cell',
+    'cldc',
+    'cmd-',
+    'dang',
+    'doco',
+    'eric',
+    'hipt',
+    'htc_',
+    'inno',
+    'ipaq',
+    'ipod',
+    'jigs',
+    'kddi',
+    'keji',
+    'leno',
+    'lg-c',
+    'lg-d',
+    'lg-g',
+    'lge-',
+    'lg/u',
+    'maui',
+    'maxo',
+    'midp',
+    'mits',
+    'mmef',
+    'mobi',
+    'mot-',
+    'moto',
+    'mwbp',
+    'nec-',
+    'newt',
+    'noki',
+    'palm',
+    'pana',
+    'pant',
+    'phil',
+    'play',
+    'port',
+    'prox',
+    'qwap',
+    'sage',
+    'sams',
+    'sany',
+    'sch-',
+    'sec-',
+    'send',
+    'seri',
+    'sgh-',
+    'shar',
+    'sie-',
+    'siem',
+    'smal',
+    'smar',
+    'sony',
+    'sph-',
+    'symb',
+    't-mo',
+    'teli',
+    'tim-',
+    'tosh',
+    'tsm-',
+    'upg1',
+    'upsi',
+    'vk-v',
+    'voda',
+    'wap-',
+    'wapa',
+    'wapi',
+    'wapp',
+    'wapr',
+    'webc',
+    'winw',
+    'winw',
+    'xda ',
+    'xda-'
+  ];
+
+  static const List<String> knownMobileUserAgentKeywords = [
+    'blackberry',
+    'webos',
+    'ipod',
+    'lge vx',
+    'midp',
+    'maemo',
+    'mmp',
+    'mobile',
+    'netfront',
+    'hiptop',
+    'nintendo DS',
+    'novarra',
+    'openweb',
+    'opera mobi',
+    'opera mini',
+    'palm',
+    'psp',
+    'phone',
+    'smartphone',
+    'symbian',
+    'up.browser',
+    'up.link',
+    'wap',
+    'windows ce'
+  ];
+
+  static const List<String> knownTabletUserAgentKeywords = [
+    'ipad',
+    'playbook',
+    'hp-tablet',
+    'kindle'
+  ];
+
+  UserAgent(this.value) : _lowerValue = value.toLowerCase();
+
+  /// Determines if the user agent string contains the desired string. Case-insensitive.
+  bool contains(String needle) => _lowerValue.contains(needle.toLowerCase());
+
+  bool get isDesktop => isMacOS || (!isMobile && !isTablet);
+
+  bool get isTablet => knownTabletUserAgentKeywords.any(contains);
+
+  bool get isMobile => knownMobileUserAgentKeywords.any(contains);
+
+  bool get isMacOS => contains('Macintosh') || contains('Mac OS X');
+
+  bool get isSafari => contains('Safari');
+
+  bool get isAndroid => contains('android');
+
+  bool get isAndroidPhone => contains('android') && contains('mobile');
+
+  bool get isAndroidTablet => contains('android') && !contains('mobile');
+
+  bool get isWindows => contains('windows');
+
+  bool get isWindowsPhone => isWindows && contains('phone');
+
+  bool get isWindowsTablet => isWindows && contains('touch');
+
+  bool get isBlackberry =>
+      contains('blackberry') || contains('bb10') || contains('rim');
+
+  bool get isBlackberryPhone => isBlackberry && !contains('tablet');
+
+  bool get isBlackberryTablet => isBlackberry && contains('tablet');
+
+  /// Determines if the current device is running Chrome.
+  bool get isChrome {
+    _isChrome = value.contains('Chrome', 0);
+    return _isChrome;
+  }
+
+  /// Determines if the current device is running Opera.
+  bool get isOpera {
+    _isOpera = value.contains('Opera', 0);
+    return _isOpera;
+  }
+
+  /// Determines if the current device is running Internet Explorer.
+  bool get isIE {
+    _isIE = !isOpera && value.contains('Trident/', 0);
+    return _isIE;
+  }
+
+  /// Determines if the current device is running Firefox.
+  bool get isFirefox {
+    _isFirefox = value.contains('Firefox', 0);
+    return _isFirefox;
+  }
+
+  /// Determines if the current device is running WebKit.
+  bool get isWebKit {
+    _isWebKit = !isOpera && value.contains('WebKit', 0);
+    return _isWebKit;
+  }
+
+  /// Gets the CSS property prefix for the current platform.
+  String get cssPrefix {
+    var prefix = _cachedCssPrefix;
+    if (prefix != null) return prefix;
+    if (isFirefox) {
+      prefix = '-moz-';
+    } else if (isIE) {
+      prefix = '-ms-';
+    } else if (isOpera) {
+      prefix = '-o-';
+    } else {
+      prefix = '-webkit-';
+    }
+    return _cachedCssPrefix = prefix;
+  }
+
+  /// Prefix as used for JS property names.
+  String get propertyPrefix {
+    var prefix = _cachedPropertyPrefix;
+    if (prefix != null) return prefix;
+    if (isFirefox) {
+      prefix = 'moz';
+    } else if (isIE) {
+      prefix = 'ms';
+    } else if (isOpera) {
+      prefix = 'o';
+    } else {
+      prefix = 'webkit';
+    }
+    return _cachedPropertyPrefix = prefix;
+  }
+}
diff --git a/packages/user_agent/pubspec.yaml b/packages/user_agent/pubspec.yaml
new file mode 100644
index 0000000..eca7dd5
--- /dev/null
+++ b/packages/user_agent/pubspec.yaml
@@ -0,0 +1,9 @@
+name: user_agent_analyzer
+version: 3.0.2
+description: A library to identify the type of devices and web browsers based on User-Agent string.
+homepage: https://github.com/dart-backend/belatuk-common-utilities/tree/main/packages/user_agent
+environment:
+  sdk: '>=2.12.0 <3.0.0'
+dev_dependencies:
+  test: ^1.17.8
+  lints: ^1.0.0
diff --git a/packages/user_agent/test/user_agent_test.dart b/packages/user_agent/test/user_agent_test.dart
new file mode 100644
index 0000000..4721765
--- /dev/null
+++ b/packages/user_agent/test/user_agent_test.dart
@@ -0,0 +1,30 @@
+// Copyright (c) 2017, thosakwe. All rights reserved. Use of this source code
+// is governed by a BSD-style license that can be found in the LICENSE file.
+
+import 'package:user_agent_analyzer/user_agent_analyzer.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('chrome', () {
+    var ua = UserAgent(
+        'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.95 Safari/537.36');
+    expect([ua.isChrome, ua.isWebKit, ua.isSafari, ua.isDesktop, ua.isMacOS],
+        everyElement(isTrue));
+    expect([ua.isFirefox, ua.isIE, ua.isOpera, ua.isMobile, ua.isTablet],
+        everyElement(isFalse));
+    expect([
+      ua.isAndroid,
+      ua.isAndroidPhone,
+      ua.isAndroidTablet,
+      ua.isBlackberry,
+      ua.isBlackberryPhone,
+      ua.isBlackberryTablet,
+      ua.isWindows,
+      ua.isWindowsPhone,
+      ua.isWindowsTablet
+    ], everyElement(isFalse));
+
+    expect(ua.cssPrefix, equals('-webkit-'));
+    expect(ua.propertyPrefix, equals('webkit'));
+  });
+}