public interface EventMixin

Jackson mixin interface for configuring JSON serialization of BaseEvent and its subclasses.

EventMixin provides Jackson annotations to enable proper polymorphic serialization and deserialization of the entire agui event hierarchy. This mixin uses type information based on the event's "type" property to maintain type safety during JSON processing.

The mixin configures Jackson to:

Use the "type" property as the type discriminator
Map each event type name to its corresponding Java class
Preserve complete type information during serialization
Reconstruct the correct event subclass during deserialization

Supported event types and their mappings:

Run lifecycle: RUN_STARTED, RUN_FINISHED, RUN_ERROR
Step management: STEP_STARTED, STEP_FINISHED
Message events: TEXT_MESSAGE_START, TEXT_MESSAGE_CONTENT, TEXT_MESSAGE_CHUNK, TEXT_MESSAGE_END
Tool execution: TOOL_CALL_START, TOOL_CALL_ARGS, TOOL_CALL_CHUNK, TOOL_CALL_END, TOOL_CALL_RESULT
Reasoning process: REASONING_START, REASONING_END, REASONING_MESSAGE_START, REASONING_MESSAGE_CONTENT, REASONING_MESSAGE_END, REASONING_MESSAGE_CHUNK, REASONING_ENCRYPTED_VALUE
State management: STATE_SNAPSHOT, STATE_DELTA, MESSAGES_SNAPSHOT
Activity: ACTIVITY_SNAPSHOT, ACTIVITY_DELTA
Generic: CUSTOM, RAW, META_EVENT

This mixin enables seamless JSON serialization of event objects regardless of their specific subclass, making it possible to serialize mixed collections of events and deserialize them back to their original types correctly.

The mixin is applied to BaseEvent and affects all its subclasses through Jackson's inheritance mechanism, providing consistent JSON handling across the entire event hierarchy without requiring modifications to the core event classes.

Example JSON output:


 {
   "type": "TEXT_MESSAGE_START",
   "messageId": "msg-123",
   "role": "assistant",
   "timestamp": "2023-12-01T10:30:00Z"
 }

Interface EventMixin