Enum SessionEvent 

#[non_exhaustive]
pub enum SessionEvent {
    Connected,
    TextDelta(String),
    TextComplete(String),
    AudioData(Bytes),
    Media(InlineMedia),
    InputTranscription(String),
    OutputTranscription(String),
    Thought(String),
    ToolCall(Vec<FunctionCall>),
    ToolCallCancelled(Vec<String>),
    InteractionStatus(String),
    TurnComplete,
    GenerationComplete,
    Interrupted,
    PhaseChanged(SessionPhase),
    GoAway(Option<Duration>),
    Disconnected(Option<String>),
    Error(SessionError),
    SessionResumeUpdate(ResumeInfo),
    VoiceActivityStart,
    VoiceActivityEnd,
    Usage(UsageMetadata),
}

Events emitted by the session, consumed by application code.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Connected

Session connected and setup complete.

TextDelta(String)

Incremental text from model response.

TextComplete(String)

Complete text of a finished model turn.

AudioData(Bytes)

Audio data from model response (PCM16 samples, base64-decoded).

Uses [bytes::Bytes] for zero-copy fan-out: cloning a Bytes handle bumps an Arc refcount instead of copying the underlying data.

Media(InlineMedia)

Non-audio media from the model, such as Gemini 3.8 Live Avatar video (video/mp4, 24 FPS, synchronized with the speech in AudioData).

InputTranscription(String)

Input transcription from server.

OutputTranscription(String)

Output transcription from server.

Thought(String)

Thought/reasoning summary from the model (when includeThoughts is enabled).

ToolCall(Vec<FunctionCall>)

Model requested tool calls.

ToolCallCancelled(Vec<String>)

Server cancelled pending tool calls.

InteractionStatus(String)

Progress of a longer interaction (serverContent.interactionStatus), e.g. "IN_PROGRESS" when Gemini 3.8 Live Extended Thinking has said a holding line and will answer in a later turn.

TurnComplete

Model turn is complete (it’s the user’s turn now).

GenerationComplete

Model finished generating its full response.

Fires even if the generation was interrupted — tells you the model’s internal generation pipeline has stopped. Distinct from TurnComplete which is the turn-taking signal.

Interrupted

Model was interrupted by barge-in.

PhaseChanged(SessionPhase)

Session phase changed.

GoAway(Option<Duration>)

Server sent GoAway: it will close the connection after time_left (when it said how long). The transport reconnects on its own; this is the moment to drain buffered audio and expect a resumption handle.

Disconnected(Option<String>)

Session disconnected (with optional reason).

Error(SessionError)

Non-fatal error. The session loop keeps running (reconnecting where the transport allows); match on the SessionError variants to tell a refused setup from a dropped socket.

SessionResumeUpdate(ResumeInfo)

Session resumption update with handle, resumability, and consumed index.

VoiceActivityStart

Server-side voice activity detected (user started speaking).

VoiceActivityEnd

Server-side voice activity ended (user stopped speaking).

Usage(UsageMetadata)

Token usage metadata from server (for context window tracking).

Contains full token breakdown: prompt, response, cached, tool-use, thinking tokens, plus per-modality details.

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<(), Error>

Formats the value using the given formatter.