diff --git a/CHANGELOG.md b/CHANGELOG.md
index d48ac86..c3a31f0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,120 @@
 # Changelog
 
+## 0.2.0-beta (2025-06-24)
+
+### A2A Specification Upgrade ([a2a spec v0.1.0](https://github.com/google-a2a/A2A/releases/tag/v0.1.0) -> [a2a spec v0.2.0](https://github.com/google-a2a/A2A/releases/tag/v0.2.0))
+
+#### Protocol Specification Changes
+
+##### 1. Protocol Method Names
+
+- `tasks/send` → `message/send`
+- `tasks/sendSubscribe` → `message/stream`
+- `tasks/pushNotification/set` → `tasks/pushNotificationConfig/set`
+- `tasks/pushNotification/get` → `tasks/pushNotificationConfig/get`
+- Added `agent/authenticatedExtendedCard` method
+- Legacy methods retained for backward compatibility but deprecated
+
+##### 2. A2A Core Data Structure Updates
+
+Following the A2A specification upgrade, core data structures have been updated to align with the new protocol requirements. These changes include modifications to Task, Message, Part structures, file handling mechanisms, task states, agent card configurations, artifacts, and streaming events.
+
+For detailed specification changes, refer to the official A2A specification comparison:
+- **Previous Specification**: [A2A v0.1.0 JSON Schema](https://github.com/google-a2a/A2A/blob/v0.1.0/specification/json/a2a.json)
+- **Current Specification**: [A2A v0.2.0 JSON Schema](https://github.com/google-a2a/A2A/blob/v0.2.0/specification/json/a2a.json)
+
+#### Interface Evolution
+
+TaskProcessor → MessageProcessor:
+```go
+// Old interface
+type TaskProcessor interface {
+    Process(ctx context.Context, taskID string, initialMsg protocol.Message, handle TaskHandle) error
+}
+
+// New interface  
+type MessageProcessor interface {
+    ProcessMessage(ctx context.Context, message protocol.Message, options ProcessOptions, taskHandler TaskHandler) (*MessageProcessingResult, error)
+}
+```
+
+Key Changes:
+- **Processing Model**: Task-driven → Message-driven processing
+- **Parameters**: Removed `taskID`, added `ProcessOptions` for configuration
+- **Return Type**: Simple `error` → Structured `*MessageProcessingResult` 
+- **Handler Interface**: `TaskHandle` → `TaskHandler` (enhanced capabilities)
+
+TaskHandler Interface Enhancement:
+- **Method Evolution**: `GetSessionID()` → `GetContextID()` (A2A spec compliance)
+- **New Capabilities**: Added `BuildTask()`, `GetTask()`, `SubScribeTask()`, `GetMessageHistory()`
+- **Enhanced Parameters**: `AddArtifact()` now supports `taskID`, `isFinal`, `needMoreData`
+
+TaskManager Interface Updates:
+- **New Methods**: Added `OnSendMessage()`, `OnSendMessageStream()` (A2A 0.2.0 methods)
+- **Updated Returns**: `OnResubscribe()` now returns `<-chan protocol.StreamingMessageEvent`
+- **Backward Compatibility**: Legacy methods (`OnSendTask`, `OnSendTaskSubscribe`) deprecated but retained
+
+Constructor Changes:
+- `NewMemoryTaskManager(TaskProcessor)` → `NewMemoryTaskManager(MessageProcessor, ...MemoryTaskManagerOption)`
+
+#### Implementation Updates
+
+- **Memory TaskManager**: Completely restructured for specification compliance
+  - Constructor signature changed: `NewMemoryTaskManager(TaskProcessor)` → `NewMemoryTaskManager(MessageProcessor, ...MemoryTaskManagerOption)`
+  - Internal data structures reorganized:
+    - `Messages` field: `map[string][]Message` → `map[string]Message`
+    - `Tasks` field: `map[string]*Task` → `map[string]*MemoryCancellableTask`
+    - `Subscribers` field: `map[string][]chan<- TaskEvent` → `map[string][]*MemoryTaskSubscriber`
+  - Removed internal mutex fields (`MessagesMutex`, `TasksMutex`, etc.) for simplified synchronization
+  - Added new types: `MemoryCancellableTask`, `MemoryTaskSubscriber`
+  - Added configuration options: `MemoryTaskManagerOption`, `WithConversationTTL`, `WithMaxHistoryLength`
+
+- **Redis TaskManager**: Restructured implementation to support specification requirements
+  - Split into focused modules:
+    - `redis_manager.go` - main TaskManager implementation
+    - `redis_types.go` - Redis-specific type definitions
+    - `redis_options.go` - configuration options
+    - `redis_task_handle.go` - task handle implementation
+  - Removed legacy files: `options.go`, `push_notification.go`, `task.go`, `redis.go`
+  - Fixed `GetSessionID()` method support as required by specification (#30)
+
+- **Interface Updates**: Updated interfaces to match specification requirements
+  - **TaskManager Interface**: Added `OnSendMessage()` and `OnSendMessageStream()` methods
+  - **TaskHandler Interface**: Renamed `GetSessionID()` to `GetContextID()` per specification
+  - **MessageProcessor Interface**: Updated to support new processing requirements
+
+- **Client & Server**: Updated implementations to support new protocol methods
+  - Client updated for new endpoint support
+  - Server route handlers updated for new methods
+  - Request/response handling updated per specification
+
+
+##### Client Code Updates
+
+- Replace `client.SendTask()` calls with `client.SendMessage()`
+- Replace `client.SendTaskSubscribe()` calls with `client.StreamMessage()`
+- Update request/response structures for new Message-based APIs
+
+##### Server Code Updates
+
+- Update route handlers for new method names
+- Implement new `OnSendMessage()` and `OnSendMessageStream()` handlers
+- Update AgentCard configuration for new security fields
+
+#### Deprecated Methods
+
+##### Legacy TaskManager Methods
+
+**OnSendTask()** (Deprecated → Use OnSendMessage()):
+- Legacy method for `tasks/send` protocol method
+- Replaced by `OnSendMessage()` for `message/send` method
+
+**OnSendTaskSubscribe()** (Deprecated → Use OnSendMessageStream()):
+- Legacy method for `tasks/sendSubscribe` protocol method  
+- Replaced by `OnSendMessageStream()` for `message/stream` method
+
+These methods remain functional for backward compatibility but are deprecated in favor of the new A2A 0.2.0 specification methods.
+
 ## 0.0.3 (2025-05-21)
 
 - Add `GetSessionId` to `TaskHandle` (#27)
diff --git a/taskmanager/interface.go b/taskmanager/interface.go
index d0ac122..5cfd9a0 100644
--- a/taskmanager/interface.go
+++ b/taskmanager/interface.go
@@ -133,21 +133,6 @@ type MessageProcessor interface {
 	) (*MessageProcessingResult, error)
 }
 
-// MessageProcessorWithStatusUpdate is an optional interface that can be implemented by TaskProcessor
-// to receive notifications when the task status changes.
-type MessageProcessorWithStatusUpdate interface {
-	MessageProcessor
-	// OnTaskStatusUpdate is called when the task status changes.
-	// It receives the task ID, the new state, and the optional message.
-	// It should return an error if the status update fails.
-	OnTaskStatusUpdate(
-		ctx context.Context,
-		taskID string,
-		state protocol.TaskState,
-		message *protocol.Message,
-	) error
-}
-
 // TaskManager defines the interface for managing A2A task lifecycles based on the protocol.
 // Implementations handle task creation, updates, retrieval, cancellation, and events,
 // delegating the actual processing logic to an injected MessageProcessor.