diff --git a/packages/genai_primitives/CHANGELOG.md b/packages/genai_primitives/CHANGELOG.md
index 970750892..efcb563aa 100644
--- a/packages/genai_primitives/CHANGELOG.md
+++ b/packages/genai_primitives/CHANGELOG.md
@@ -1,5 +1,9 @@
 # `genai_primitives` Changelog
 
+## 0.2.1
+
+- Update README.md (#693).
+
 ## 0.2.0
 
 - **BREAKING**: Rename Part to StandardPart and BasePart to Part (#683).
diff --git a/packages/genai_primitives/README.md b/packages/genai_primitives/README.md
index a2741b292..6a6672c71 100644
--- a/packages/genai_primitives/README.md
+++ b/packages/genai_primitives/README.md
@@ -4,6 +4,18 @@ This package provides a set of technology-agnostic primitive types and data stru
 
 It includes core definitions such as `ChatMessage`, `Parts`, `ToolDefinition` and other foundational classes that are used across the `genai` ecosystem to ensure consistency and interoperability between different AI providers.
 
+## Core Types
+
+* [`Part`](https://github.com/flutter/genui/blob/main/packages/genai_primitives/lib/src/parts/model.dart): Base type for message parts. Extend this to define custom part types.
+
+* [`Parts`](https://github.com/flutter/genui/blob/main/packages/genai_primitives/lib/src/parts/parts.dart): A collection of `Part` instances with utility methods.
+
+* [`StandardPart`](https://github.com/flutter/genui/blob/main/packages/genai_primitives/lib/src/parts/standard_part.dart): Sealed class extending `Part` with a fixed set of implementations. Used by `ChatMessage` for cross-provider compatibility.
+
+* [`ChatMessage`](https://github.com/flutter/genui/blob/main/packages/genai_primitives/lib/src/chat_message.dart): Represents a chat message compatible with most GenAI providers.
+
+* [`ToolDefinition`](https://github.com/flutter/genui/blob/main/packages/genai_primitives/lib/src/tool_definition.dart): Defines a tool that can be invoked by an LLM.
+
 ## Aliasing
 
 If you need to resolve name conflicts with other packages, alias the package as `genai`:
diff --git a/packages/genai_primitives/pubspec.yaml b/packages/genai_primitives/pubspec.yaml
index be1581148..b55cb7cd0 100644
--- a/packages/genai_primitives/pubspec.yaml
+++ b/packages/genai_primitives/pubspec.yaml
@@ -4,7 +4,7 @@
 
 name: genai_primitives
 description: A set of primitives for working with generative AI.
-version: 0.2.0
+version: 0.2.1
 homepage: https://github.com/flutter/genui/tree/main/packages/genai_primitives
 license: BSD-3-Clause
 issue_tracker: https://github.com/flutter/genui/issues