diff --git a/CHANGELOG.md b/CHANGELOG.md
index 87e2bd48..969d58f7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,16 +1,59 @@
 # Changelog
 All notable changes to Crinja will be documented in this file.
 
+## 0.4.0 (2018-10-16)
+
+This release comes with some refactorings of the public API to make it easier to use.
+Most prominently, annotation based autogenerator for exposing object properties to the Crinja runtime were added.
+
+```cr
+require "crinja"
+
+class User
+  include Crinja::Object::Auto
+
+  @[Crinja::Attribute]
+  def name : String
+    "john paul"
+  end
+end
+
+Crinja.new.from_string("{{ user.name }}").render({"user" => User.new}) # => "john paul"
+```
+
+Autogeneration of `crinja_call` will be left for the next release.
+
+Most other changes involve the CI infrastructure, with Circle CI taking over the main load from travis.
+
+* **(breaking-change)** Replaced `Crinja::PyObject` by `Crinja::Object` and renamed hook methods to `crinja_attribute` and `crinja_call`. `getitem` hook has been removed.
+* **(breaking-change)** Added `Crinja::Object::Auto` for generating automatic bindings for `crinja_attribute` (previously provided by `Crinja::PyObject.getattr`). The behaviour can be configured using annotations `Crinja::Attribute` and `Crinja::Attributes`.
+* **(breaking-change)** Renamed `Crinja::Callable::Arguments` to `Crinja::Arguments`. The API has been simplified by removing unused setters.
+* **(breaking-change)** Removed `Crinja::Arguments#[](key : Symbol)`. Use a string key instead.
+* **(breaking-change)** Renamed `Crinja::Callable::Arguments::UnknownArgumentException` to `Crinja::Arguments.:UnknownArgumentError`.
+* **(breaking-change)** Renamed `Crinja::Callable::Arguments::ArgumentError` to `Crinja::Arguments::Error`.
+* **(breaking-change)** Renamed `Crinja::PyTuple` to `Crinja::Tuple`.
+* **(breaking-change)** Updated `BakedFileLoader` for compatibility with `baked_file_system 0.9.6`
+* Upgraded to Crystal 0.26.1.
+* Fixed number filters (`int` and `float`) to not rely on raising an error.
+* Fixed `generate-docs` script.
+* Added `Makefile`.
+* Added Circle CI integration with nighly builds testing with Crystal nightly.
+* Added integration tests for usage examples (`./examples`) in travis-ci and Circle CI.
+* Added automatic docs generation to circle CI workflow and removed it from travis-ci.
+* Added formatter checks to CI checks.
+* Added preliminary Windows support by removing dependency on `xml`.
+* Added this changelog.
+* Improved reference to exmples in README.
+
 ## 0.3.0 (2018-06-29)
 
 This release updated Crinja to work with Crystal 0.25.1
 
 Notable changes:
 
-* Renamed `Crinja::Environment` to just `Crinja`
-* Removed `Crinja::Type` in favour of `Crinja::Value` to avoid recursive aliases and reduce a lot of `.as(Type)` castings all over the place. This change was similar to `JSON::Type` -> `JSON::Any` in Crystal 0.25.0.
-* Removed `Crinja::Bindings`. Some methods are obsolete with `Crinja::Value`, others moved to `Crinja` namespace.
-* Added automatic testing of usage examples (`./examples`) on travis-ci
+* **(breaking-change)** Renamed `Crinja::Environment` to just `Crinja`
+* **(breaking-change)** Removed `Crinja::Type` in favour of `Crinja::Value` to avoid recursive aliases and reduce a lot of `.as(Type)` castings all over the place. This change was similar to `JSON::Type` -> `JSON::Any` in Crystal 0.25.0.
+* **(breaking-change)** Removed `Crinja::Bindings`. Some methods are obsolete with `Crinja::Value`, others moved to `Crinja` namespace.
 * Added dedicated documentation of [*Template Syntax*](https://github.com/straight-shoota/crinja/blob/5b1a3c30fac48f8bfccab5043fbda209f7859046/TEMPLATE_SYNTAX.md)
 
 ## 0.2.1 (2018-01-01)
diff --git a/shard.yml b/shard.yml
index 1d47e147..c1e42bf8 100644
--- a/shard.yml
+++ b/shard.yml
@@ -1,11 +1,16 @@
 name: crinja
-version: 0.3.0
+version: 0.4.0
 license: Apache-2.0
-crystal: 0.25.1
+crystal: 0.26.1
 
 authors:
   - Johannes Müller <straightshoota@gmail.com>
 
+description: |
+  Implementation of Jinja2 runtime template language in Crystal
+
+  https://straight-shoota.github.io/crinja/
+
 targets:
   crinja:
     main: src/cli.cr