> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ag-ui.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Events

> Java event types used by the Agent User Interaction Protocol

# Events

All events live in `com.agui.core.event` and share `BaseEvent` with a `type` and `timestamp`.

## Lifecycle Events

* `RunStartedEvent`
* `RunFinishedEvent`
* `RunErrorEvent`
* `StepStartedEvent`
* `StepFinishedEvent`

## Text Message Events

* `TextMessageStartEvent` — Begin of a streamed assistant message
* `TextMessageContentEvent` — Incremental content chunks (`delta`)
* `TextMessageEndEvent` — Message finished

## Tool Call Events

* `ToolCallStartEvent`
* `ToolCallArgsEvent`
* `ToolCallEndEvent`
* `ToolCallResultEvent`

## State Management Events

* `StateSnapshotEvent`
* `StateDeltaEvent`
* `MessagesSnapshotEvent`

## Special Events

* `RawEvent` — Raw payload passthrough
* `CustomEvent` — Application-specific event

See also: `AgentSubscriber` callbacks in the client docs for handling these events.