Module event 

Core traits and types.

Always available regardless of feature flags. Includes:

• Agent - The fundamental trait for all agents
• Tool / Toolset - For extending agents with capabilities
• Session / State - For managing conversation context
• Event - For streaming agent responses
• AdkError / Result - Unified error handling Event types representing agent interactions in a conversation.

Structs

Event

Event represents a single interaction in a conversation. This struct embeds LlmResponse to match ADK-Go’s design pattern.

EventActions

Actions to apply as side effects of an event.

EventCompaction

Metadata for a compacted (summarized) event. When context compaction is enabled, older events are summarized into a single compacted event containing this metadata.

ToolCallView

A typed, borrowed view of a single tool call carried by an Event.

ToolResultView

A typed, borrowed view of a single tool result carried by an Event.

Constants

KEY_PREFIX_APP

Key prefix for application-scoped state (persists across sessions).

KEY_PREFIX_TEMP

Key prefix for temporary state (cleared each turn).

KEY_PREFIX_USER

Key prefix for user-scoped state (persists across sessions).

TOOL_PROGRESS_CALL_ID_KEY

Event-level provider_metadata key carrying the originating tool’s function-call id on a tool-progress event.

TOOL_PROGRESS_STREAM_KEY

Event-level provider_metadata key marking a tool-progress event and naming its output stream (e.g. "stdout", "stderr"). Present only on events produced by ToolContext::emit_progress.

Functions

event_belongs_to_branch

Whether an event is visible from a given conversation branch.