Struct HookStartData 

pub struct HookStartData {
    pub hook_invocation_id: String,
    pub hook_type: String,
    pub input: Option<Value>,
    pub parent_tool_call_id: Option<String>,
}

Session event “hook.start”. Hook invocation start details including type and input data

Fields

hook_invocation_id: String

Unique identifier for this hook invocation

hook_type: String

Type of hook being invoked (e.g., “preToolUse”, “postToolUse”, “sessionStart”)

input: Option<Value>

Input data passed to the hook. For postToolUse hooks the retained copy served by session.eventLog.read (and by a resumed session) drops the tool result’s inline contents/uiResource/skillInvocation and replaces duplicated text result fields with a [copilot:elided ...] marker; the live subscription stream still delivers the full value. Canonical tool output remains in the adjacent tool.execution_complete event, while an invoked skill’s authoritative body remains in its skill invocation event.

parent_tool_call_id: Option<String>

Tool call ID of the parent tool invocation when this event originates from a sub-agent

Trait Implementations

impl Clone for HookStartData

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HookStartData

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

Formats the value using the given formatter.

impl Default for HookStartData

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for HookStartData

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for HookStartData

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

where __S: Serializer,

Serialize this value into the given Serde serializer.