aether_core/events/
agent_event.rs

1use schemars::JsonSchema;
2use serde::{Deserialize, Serialize};
3
4use super::{ContextEvent, MessageEvent, ModelEvent, StreamState, ToolEvent, TurnEvent, TurnOutcome};
5
6/// A canonical event on the agent's output stream.
7#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
8#[serde(tag = "category", content = "event", rename_all = "snake_case")]
9#[allow(clippy::large_enum_variant)]
10pub enum AgentEvent {
11    Message(MessageEvent),
12    Tool(ToolEvent),
13    Turn(TurnEvent),
14    Context(ContextEvent),
15    Model(ModelEvent),
16    SessionUsage(llm::SessionUsageEvent),
17}
18
19impl AgentEvent {
20    pub fn text(message_id: &str, chunk: &str, state: StreamState) -> Self {
21        Self::Message(MessageEvent::Text {
22            message_id: message_id.into(),
23            chunk: chunk.into(),
24            is_complete: state.is_complete(),
25        })
26    }
27
28    pub fn thought(message_id: &str, chunk: &str, state: StreamState) -> Self {
29        Self::Message(MessageEvent::Thought {
30            message_id: message_id.into(),
31            chunk: chunk.into(),
32            is_complete: state.is_complete(),
33        })
34    }
35
36    pub fn turn_ended(outcome: TurnOutcome) -> Self {
37        Self::Turn(TurnEvent::Ended { outcome })
38    }
39
40    /// Human-readable text content of this event, if any.
41    pub fn content(&self) -> Option<String> {
42        match self {
43            Self::Message(MessageEvent::Text { chunk, .. } | MessageEvent::Thought { chunk, .. }) => {
44                Some(chunk.clone())
45            }
46            Self::Tool(ToolEvent::Result { result, .. } | ToolEvent::TaskCompleted { result, .. }) => {
47                Some(result.result.clone())
48            }
49            Self::Tool(ToolEvent::Error { error } | ToolEvent::TaskFailed { error, .. }) => Some(error.error.clone()),
50            Self::Tool(ToolEvent::TaskCreated { task_id, .. }) => Some(task_id.clone()),
51            Self::Tool(ToolEvent::TaskStatus { task_id, status, status_message, .. }) => {
52                Some(status_message.as_ref().map_or_else(
53                    || format!("{task_id}: {status}"),
54                    |message| format!("{task_id}: {status} - {message}"),
55                ))
56            }
57            Self::Tool(ToolEvent::TaskCancelled { task_id, .. }) => Some(format!("{task_id}: cancelled")),
58            Self::Context(ContextEvent::CompactionResult { summary, .. }) => Some(summary.clone()),
59            _ => None,
60        }
61    }
62
63    /// The turn's terminal outcome, if this event ends a turn.
64    pub fn turn_outcome(&self) -> Option<&TurnOutcome> {
65        match self {
66            Self::Turn(TurnEvent::Ended { outcome }) => Some(outcome),
67            _ => None,
68        }
69    }
70}
71
72#[cfg(test)]
73mod tests {
74    use super::*;
75    use crate::events::{CompactionOutcome, LlmCallOutcome};
76    use llm::{ContextUsage, LlmCallPurpose};
77
78    #[test]
79    fn serializes_nested_event_contract() {
80        let event = AgentEvent::text("m1", "hello", StreamState::Complete);
81        assert_eq!(
82            serde_json::to_value(event).unwrap(),
83            serde_json::json!({"category":"message","event":{"type":"text","message_id":"m1","chunk":"hello","is_complete":true}})
84        );
85    }
86
87    #[test]
88    fn nested_events_roundtrip() {
89        let events = [
90            AgentEvent::text("m", "text", StreamState::Complete),
91            AgentEvent::Tool(ToolEvent::DefinitionsUpdated { tools: vec![] }),
92            AgentEvent::Turn(TurnEvent::LlmCallEnded {
93                purpose: LlmCallPurpose::Chat,
94                outcome: LlmCallOutcome::Cancelled,
95            }),
96            AgentEvent::Context(ContextEvent::UsageUpdated { usage: ContextUsage::default() }),
97            AgentEvent::Context(ContextEvent::CompactionEnded { outcome: CompactionOutcome::Completed }),
98            AgentEvent::Model(ModelEvent::Switched { previous: "a".into(), new: "b".into() }),
99            AgentEvent::SessionUsage(llm::testing::session_usage_event(1, llm::TokenUsage::new(1, 2))),
100            AgentEvent::Tool(ToolEvent::DisplayUpdate {
101                request: llm::ToolCallRequest { id: "call".into(), name: "read".into(), arguments: "{}".into() },
102                meta: mcp_utils::display_meta::ToolDisplayMeta::new("Read file", "main.rs").into(),
103            }),
104            AgentEvent::Tool(ToolEvent::SubAgentProgress {
105                request: llm::ToolCallRequest { id: "call".into(), name: "spawn".into(), arguments: "{}".into() },
106                payload: Box::new(crate::events::SubAgentProgressPayload {
107                    task_id: "task_0".into(),
108                    agent_name: "explorer".into(),
109                    event: AgentEvent::turn_ended(TurnOutcome::Completed),
110                }),
111            }),
112        ];
113        for event in events {
114            let json = serde_json::to_string(&event).unwrap();
115            assert_eq!(serde_json::from_str::<AgentEvent>(&json).unwrap(), event);
116        }
117    }
118
119    #[test]
120    fn turn_outcome_returns_outcome_only_for_turn_end() {
121        assert_eq!(AgentEvent::turn_ended(TurnOutcome::Completed).turn_outcome(), Some(&TurnOutcome::Completed));
122        assert_eq!(AgentEvent::text("m", "text", StreamState::Complete).turn_outcome(), None);
123        assert_eq!(AgentEvent::Turn(TurnEvent::Started { content: vec![] }).turn_outcome(), None);
124    }
125}
aether_core/events/agent_event.rs

aether_core/events/
agent_event.rs
