Enum AgentEvent 

pub enum AgentEvent {
    RunStarted {},
    MessageDelta {
        message_id: MessageId,
        content_index: u32,
        delta: EventDelta,
    },
    ToolCallRequested {
        tool_call_id: ToolCallId,
        tool_name: String,
        arguments: Value,
    },
    ApprovalRequested {
        approval_id: ApprovalId,
        tool_call_id: ToolCallId,
        capabilities: Vec<String>,
        resources: Vec<String>,
        expires_at: ProtocolTimestamp,
    },
    ToolExecutionProgress {
        tool_call_id: ToolCallId,
        message: String,
        completed_units: u64,
        total_units: Option<u64>,
    },
    ToolExecutionPreview {
        tool_call_id: ToolCallId,
        presentation: ToolPresentation,
    },
    HostedToolStarted {
        tool_call_id: ToolCallId,
        tool_name: String,
    },
    HostedToolCompleted {
        tool_call_id: ToolCallId,
        tool_name: String,
        arguments: Value,
        outcome: HostedToolOutcome,
        source_count: u32,
    },
    ModelRetryScheduled {
        message_id: MessageId,
        attempt: u32,
        max_retries: u32,
        delay_ms: u64,
    },
    ModelRetryStarted {
        message_id: MessageId,
        attempt: u32,
        max_retries: u32,
    },
    TurnCheckpointed {},
    SessionCompacted {
        summary_message_id: MessageId,
        compacted_through_message_id: MessageId,
    },
    SessionForked {
        source_branch_id: BranchId,
        branch_id: BranchId,
        from_message_id: MessageId,
    },
    RunFinished {
        status: RunStatus,
        usage: Option<Usage>,
        cost: Option<ExactCost>,
    },
}

A provider- and UI-neutral observable runtime event.

Variants

RunStarted

A run started.

MessageDelta

A streaming message fragment was produced.

Fields

message_id: MessageId

Message receiving the fragment.

content_index: u32

Zero-based content-block index.

delta: EventDelta

Bounded content fragment.

ToolCallRequested

A complete tool call was requested by the model.

Fields

tool_call_id: ToolCallId

Canonical tool-call identifier.

tool_name: String

Registered tool name.

arguments: Value

Validated JSON object arguments.

ApprovalRequested

A tool call requires approval.

Fields

approval_id: ApprovalId

Approval request identifier.

tool_call_id: ToolCallId

Tool call awaiting approval.

capabilities: Vec<String>

Bounded required capability names.

resources: Vec<String>

Bounded affected resource identifiers.

expires_at: ProtocolTimestamp

Decision deadline.

ToolExecutionProgress

Non-durable tool progress suitable for UI display.

Fields

tool_call_id: ToolCallId

Tool call reporting progress.

message: String

English technical progress diagnostic.

completed_units: u64

Completed work units.

total_units: Option<u64>

Total work units when known.

ToolExecutionPreview

A trusted tool computed a bounded preview before a pending approval.

Fields

tool_call_id: ToolCallId

Tool call the preview describes.

presentation: ToolPresentation

Typed UI-only data produced from the tool’s current workspace view.

HostedToolStarted

A provider-hosted tool started inside the active model response.

Fields

tool_call_id: ToolCallId

Kernel-owned activity identifier.

tool_name: String

Stable hosted tool name.

HostedToolCompleted

A provider-hosted tool completed inside the active model response.

Fields

tool_call_id: ToolCallId

Kernel-owned activity identifier.

tool_name: String

Stable hosted tool name.

arguments: Value

Validated provider-neutral arguments, without continuation state.

outcome: HostedToolOutcome

Normalized terminal outcome.

source_count: u32

Number of normalized sources retained in the eventual durable block.

ModelRetryScheduled

A retryable model failure is waiting before another provider request.

Fields

message_id: MessageId

Ephemeral assistant message whose failed partial output is discarded.

attempt: u32

One-based retry number.

max_retries: u32

Maximum retry count, excluding the initial request.

delay_ms: u64

Selected bounded delay in milliseconds.

ModelRetryStarted

A scheduled retry completed its backoff and is starting another request.

Fields

message_id: MessageId

Ephemeral assistant message reused by the next attempt.

attempt: u32

One-based retry number.

max_retries: u32

Maximum retry count, excluding the initial request.

TurnCheckpointed

A turn reached a durable checkpoint.

SessionCompacted

Session history was compacted through a source message.

Fields

summary_message_id: MessageId

Summary message introduced by compaction.

compacted_through_message_id: MessageId

Last source message covered by the summary.

SessionForked

A new branch was forked from an existing branch/message.

Fields

source_branch_id: BranchId

Source branch identifier.

branch_id: BranchId

New branch identifier.

from_message_id: MessageId

Message at the fork point.

RunFinished

A run reached a terminal state.

Fields

status: RunStatus

Terminal run status.

usage: Option<Usage>

Provider-neutral usage when available.

cost: Option<ExactCost>

Exact billable cost when available.

Implementations

impl AgentEvent

pub const fn event_type(&self) -> AgentEventType

Returns the stable event discriminator.

Trait Implementations

impl Clone for AgentEvent

fn clone(&self) -> AgentEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AgentEvent

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for AgentEvent

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for AgentEvent

fn eq(&self, other: &AgentEvent) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for AgentEvent

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for AgentEvent