diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1ad91b8..8889b87 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,17 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.3.1] - 2026-04-27
+
+### Added
+- Comprehensive code examples in docstrings for all public API classes and functions: `D3Session`, `D3AsyncSession`, `D3PluginClient`, `D3PythonScript`, `D3Function`, `DesignerPlugin`, `PluginException`, `PluginPayload`, and all low-level functions in `api.py`.
+- `scripts/generate_astro_docs.py`: script for generating Astro-compatible API reference documentation.
+
+### Changed
+- Improved `DesignerPlugin` class docstring and expanded `default_init()`, `from_json_file()`, and `service_info` docstrings with full Args/Returns sections and examples.
+- Added explicit notes to `register_module` and `register_all_modules` on `D3Session` and `D3AsyncSession` clarifying that eager registration is only needed in rare cases — sessions already auto-register lazily on `execute()`.
+- `PluginPayload.is_module_payload()` and `debug_string()` now have docstrings.
+
 ## [1.3.0] - 2026-01-06
 
 ### Added
diff --git a/pyproject.toml b/pyproject.toml
index b54eca7..1139a8e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "designer-plugin"
-version = "1.3.0"
+version = "1.3.1"
 description = "Python library for creating Disguise Designer plugins with DNS-SD discovery and remote Python execution"
 authors = [
     { name = "Taegyun Ha", email = "taegyun.ha@disguise.one" },