diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..5bf6b13
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,23 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog] and this project adheres to [Semantic
+Versioning].
+
+[Keep a Changelog]: https://keepachangelog.com/en/1.1.0
+[Semantic Versioning]: https://semver.org/spec/v2.0.0.html
+
+## [Unreleased]
+
+## [0.1.2] - 2026-04-24
+
+### Added
+
+- Initial version of library.
+- Canonical ECS-native forms of hexagonal coordinates, corresponding edges and
+  vertices, and hexagonal grid sizes.
+- Definition of grid sizes from both inradius and circumradius.
+- Optional auto-attachment of Transform components.
+- Definitions for neighboring coords, edges, and vertices for coords, edges,
+  and vertices.