Struct KernelMessage 

pub struct KernelMessage {
    pub id: String,
    pub from: Pid,
    pub target: MessageTarget,
    pub payload: MessagePayload,
    pub timestamp: DateTime<Utc>,
    pub correlation_id: Option<String>,
    pub trace_id: Option<String>,
}

A typed message envelope for kernel IPC.

Fields

id: String

Unique message identifier.

from: Pid

Sender PID (0 = kernel).

target: MessageTarget

Target for delivery.

payload: MessagePayload

Message payload.

timestamp: DateTime<Utc>

Creation timestamp.

correlation_id: Option<String>

Optional correlation ID for request-response patterns.

When set, this links a response message back to the original request that triggered it. Used by the A2A protocol’s request-response tracking.

trace_id: Option<String>

Distributed trace ID for end-to-end request tracing (K2-G4).

External messages entering the kernel receive a new UUID v4 trace_id. Internal messages inherit the parent’s trace_id via correlation linkage.

Implementations

impl KernelMessage

pub fn new(from: Pid, target: MessageTarget, payload: MessagePayload) -> Self

Create a new kernel message.

Uses an atomic counter for the message ID instead of UUID v4, eliminating crypto-random generation overhead in hot IPC paths.

pub fn with_correlation( from: Pid, target: MessageTarget, payload: MessagePayload, correlation_id: String, ) -> Self

Create a new kernel message with a correlation ID.

pub fn with_trace( from: Pid, target: MessageTarget, payload: MessagePayload, trace_id: String, ) -> Self

Create a new kernel message with a trace ID (for external entry points).

pub fn set_trace_id(self, trace_id: impl Into<String>) -> Self

Set the trace ID on this message (builder pattern).

pub fn ensure_trace_id(self) -> Self

Ensure this message has a trace ID, generating one if missing.

pub fn text(from: Pid, target: MessageTarget, text: impl Into<String>) -> Self

Create a text message.

pub fn signal(from: Pid, target: MessageTarget, signal: KernelSignal) -> Self

Create a signal message.

pub fn tool_call( from: Pid, target: MessageTarget, name: impl Into<String>, args: Value, ) -> Self

Create a tool call message.

pub fn tool_result( from: Pid, target: MessageTarget, call_id: impl Into<String>, result: Value, ) -> Self

Create a tool result message (response to a tool call).

Trait Implementations

impl Clone for KernelMessage

fn clone(&self) -> KernelMessage

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for KernelMessage

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for KernelMessage

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for KernelMessage

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

where __S: Serializer,

Serialize this value into the given Serde serializer.