Struct SessionEvent 

pub struct SessionEvent {
    pub id: String,
    pub timestamp: String,
    pub parent_id: Option<String>,
    pub ephemeral: Option<bool>,
    pub agent_id: Option<String>,
    pub debug_cli_received_at_ms: Option<i64>,
    pub debug_ws_forwarded_at_ms: Option<i64>,
    pub event_type: String,
    pub data: Value,
}

A single event in a session’s timeline.

Events form a linked chain via parent_id. The event_type string identifies the kind (e.g. "assistant.message_delta", "session.idle", "tool.execution_start"). Event-specific payload is in data as untyped JSON.

Fields

id: String

Unique event ID (UUID v4).

timestamp: String

ISO 8601 timestamp.

parent_id: Option<String>

ID of the preceding event in the chain.

ephemeral: Option<bool>

Transient events that are not persisted to disk.

agent_id: Option<String>

Sub-agent instance identifier. Absent for events emitted by the root/main agent and for session-level events.

debug_cli_received_at_ms: Option<i64>

Debug timestamp: when the CLI received this event (ms since epoch).

debug_ws_forwarded_at_ms: Option<i64>

Debug timestamp: when the event was forwarded over WebSocket.

event_type: String

Event type string (e.g. "assistant.message", "session.idle").

data: Value

Event-specific data. Structure depends on event_type.

Implementations

impl SessionEvent

pub fn parsed_type(&self) -> SessionEventType

Parse the string event_type into a typed SessionEventType enum.

Returns SessionEventType::Unknown for unrecognized event types, ensuring forward compatibility with newer CLI versions.

pub fn typed_data<T: DeserializeOwned>(&self) -> Option<T>

Deserialize the event data field into a typed struct.

Returns None if deserialization fails (e.g. unknown event type or schema mismatch). Prefer typed data accessors for specific event types where you need strongly-typed field access.

pub fn is_transient_error(&self) -> bool

model_call errors are transient — the CLI agent loop continues after them and may succeed on the next turn. These should not be treated as session-ending errors.

Trait Implementations

impl Clone for SessionEvent

fn clone(&self) -> SessionEvent

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SessionEvent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for SessionEvent

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for SessionEvent

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.