Struct UserMessage 

pub struct UserMessage {
    pub message: MessageContent,
    pub session_id: Option<Uuid>,
    pub parent_tool_use_id: Option<String>,
    pub uuid: Option<String>,
    pub timestamp: Option<String>,
    pub tool_use_result: Option<Value>,
    pub subagent_type: Option<String>,
    pub task_description: Option<String>,
}

User message

Fields

message: MessageContent

session_id: Option<Uuid>

parent_tool_use_id: Option<String>

Parent tool use ID for nested agent messages

uuid: Option<String>

Message-level unique identifier

timestamp: Option<String>

CLI-emitted ISO-8601 timestamp for the message (present on echoed tool results).

tool_use_result: Option<Value>

Structured tool result data echoed by the CLI alongside the tool_result content block. The shape depends on which tool produced it (e.g. for AskUserQuestion it is { questions, answers }; for Bash it is { stdout, stderr, exit_code, ... }). Stored as raw JSON to preserve wire fidelity; use UserMessage::tool_use_result_as to parse into a typed shape when you know which tool was invoked.

subagent_type: Option<String>

Subagent type, when this user message is the prompt echoed into a local_agent subagent (e.g. general-purpose).

task_description: Option<String>

Short description of the subagent task, present alongside subagent_type.

Implementations

impl UserMessage

pub fn tool_use_result_as<T: DeserializeOwned>( &self, ) -> Option<Result<T, Error>>

Parse the tool_use_result field into a caller-specified type.

Returns None if tool_use_result is absent, otherwise returns the deserialization result. The caller must know which tool produced the result and supply a matching type — e.g. for AskUserQuestion use AskUserQuestionInput, whose questions + answers fields match the wire result shape.

pub fn subagent_result(&self) -> Option<SubagentResult>

Parse the tool_use_result as a subagent (Task) run result.

When this user message echoes the result of a Task tool call, the CLI attaches a structured tool_use_result carrying the subagent’s token, timing, and tool-use accounting. Returns None when the field is absent or does not parse as a SubagentResult.

Summing SubagentResult::total_tokens across every Task result in a session yields the subagent token rollup the CLI renders as subagent_tokens in its terminal <usage> block.

Trait Implementations

impl Clone for UserMessage

fn clone(&self) -> UserMessage

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for UserMessage

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for UserMessage

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for UserMessage

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

where __S: Serializer,

Serialize this value into the given Serde serializer.