Struct SubagentUpdate 

#[non_exhaustive]
pub struct SubagentUpdate {
    pub session_id: SessionId,
    pub title: MaybeUndefined<String>,
    pub description: MaybeUndefined<String>,
    pub capabilities: MaybeUndefined<SubagentSessionCapabilities>,
    pub state: MaybeUndefined<StateUpdate>,
    pub meta: MaybeUndefined<Map<String, Value>>,
}

UNSTABLE

This capability is not part of the spec yet, and may be removed or changed at any point.

Notification that the enclosing parent session created and owns a child session.

Later updates modify the existing association’s metadata, not its ownership.

Sent on the immediate parent session. The first update for an unknown SubagentUpdate::session_id announces the child and MUST be sent before any live child traffic or live message naming the child as sender or recipient. Parents may message and reuse an announced child across multiple operations. Child events are delivered automatically on the same connection; no child load, resume, or subscription is needed.

Only the subagent session ID is required. Omitted patch fields keep their previous values; null clears them. Clearing capabilities disables child mutations. Clearing state leaves current activity unset/unconfirmed: it does not imply idle, stop work, or create an unknown state snapshot. A concrete state replaces the entire previous state object, not the session. The title and description provide the parent’s display metadata for the child. They do not replace the content of individual messages or operations.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

session_id: SessionId

The opaque session ID identifying the child in all ACP messages.

title: MaybeUndefined<String>

The parent’s human-readable display title for this child. It need not be unique.

Omitted means unchanged; null clears it. If unset, the Client chooses a fallback presentation.

description: MaybeUndefined<String>

The parent’s human-readable description of the child’s role or purpose.

Omitted means unchanged; null clears it. If unset, the Client chooses a fallback presentation. This is current display metadata, not the history of instructions sent to the child.

capabilities: MaybeUndefined<SubagentSessionCapabilities>

Client-initiated session mutations permitted for this subagent session.

Omitted means unchanged; null clears the capability set and disables child mutations. If never supplied, no session mutations are permitted. Read-only operations retain their normal protocol semantics and capability requirements. A concrete object replaces the whole capability set.

state: MaybeUndefined<StateUpdate>

Current state snapshot for the child session.

Omitted means unchanged; null clears the current activity without asserting idle or sending an unknown snapshot. A concrete state replaces the previous state object wholesale. If never supplied, the current activity is unset/unconfirmed.

meta: MaybeUndefined<Map<String, Value>>

The _meta property is reserved by ACP to allow clients and agents to attach additional metadata to their interactions. Implementations MUST NOT make assumptions about values at these keys.

See protocol docs: Extensibility Omitted means unchanged; null removes the metadata.

Implementations

impl SubagentUpdate

pub fn new(session_id: impl Into<SessionId>) -> SubagentUpdate

Available on crate feature unstable_subagents only.

Builds a subagent upsert with only its required session ID set.

pub fn title(self, title: impl IntoMaybeUndefined<String>) -> SubagentUpdate

Available on crate feature unstable_subagents only.

Sets, clears, or omits the parent’s display title patch.

pub fn description( self, description: impl IntoMaybeUndefined<String>, ) -> SubagentUpdate

Available on crate feature unstable_subagents only.

Sets, clears, or omits the parent’s description patch.

pub fn capabilities( self, capabilities: impl IntoMaybeUndefined<SubagentSessionCapabilities>, ) -> SubagentUpdate

Available on crate feature unstable_subagents only.

Replaces, clears, or omits the permitted client-initiated mutations patch.

pub fn state( self, state: impl IntoMaybeUndefined<StateUpdate>, ) -> SubagentUpdate

Available on crate feature unstable_subagents only.

Replaces, clears, or omits the current activity patch.

pub fn meta( self, meta: impl IntoMaybeUndefined<Map<String, Value>>, ) -> SubagentUpdate

Available on crate feature unstable_subagents only.

The _meta property is reserved by ACP to allow clients and agents to attach additional metadata to their interactions. Implementations MUST NOT make assumptions about values at these keys. Sets, clears, or omits this metadata patch.

Trait Implementations

impl Clone for SubagentUpdate

fn clone(&self) -> SubagentUpdate

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SubagentUpdate

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for SubagentUpdate

fn deserialize<__D>( __deserializer: __D, ) -> Result<SubagentUpdate, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl JsonSchema for SubagentUpdate

fn schema_name() -> Cow<'static, str>

The name of the generated JSON Schema.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

fn json_schema(generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

impl PartialEq for SubagentUpdate

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for SubagentUpdate

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for SubagentUpdate