Enum Message 

pub enum Message {
    System {
        content: Arc<str>,
    },
    User {
        content: Arc<str>,
    },
    Assistant {
        content: Arc<str>,
        tool_calls: Arc<[ToolCall]>,
    },
    ToolResult {
        tool_call_id: Arc<str>,
        name: Arc<str>,
        content: Arc<str>,
    },
    Event {
        source: Arc<str>,
        kind: Arc<str>,
        content: Arc<str>,
    },
}

One turn of conversation history, preserving the structure a hosted adapter needs to reconstruct valid provider history: visible assistant text, the assistant’s tool calls, tool-call IDs, tool results, and external events.

Variants

System

The system prompt: instructions framing the whole conversation.

Fields

content: Arc<str>

The prompt text.

User

A turn from the user.

Fields

content: Arc<str>

The user’s text.

Assistant

A turn generated by the model: its visible text and any tool calls it made, in the order the provider must replay them.

Fields

content: Arc<str>

Visible assistant text; empty for a tool-call-only turn.

tool_calls: Arc<[ToolCall]>

The tool calls this turn made, correlated to later results by ToolCall::id.

ToolResult

The result of a previous ToolCall, correlated by tool_call_id.

Fields

tool_call_id: Arc<str>

The ToolCall::id this result answers.

name: Arc<str>

Model-facing name of the tool that produced the result.

content: Arc<str>

The tool’s output, as text.

Event

An event from another system rather than the user.

Fields

source: Arc<str>

Identifier of the system that produced the event.

kind: Arc<str>

The kind of event, in the producer’s own vocabulary.

content: Arc<str>

The event payload, as text.

Implementations

impl Message

pub fn system(content: impl Into<Arc<str>>) -> Self

A System message — the framing prompt.

pub fn user(content: impl Into<Arc<str>>) -> Self

A User message.

pub fn assistant(content: impl Into<Arc<str>>) -> Self

An Assistant message with visible text and no tool calls.

pub fn assistant_with_tool_calls( content: impl Into<Arc<str>>, tool_calls: impl Into<Arc<[ToolCall]>>, ) -> Self

An Assistant message carrying visible text and the turn’s tool calls.

Trait Implementations

impl Clone for Message

fn clone(&self) -> Message

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Message

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

Formats the value using the given formatter.

impl Eq for Message

impl From<ModelMessage> for Message

fn from(message: ModelMessage) -> Self

Lift a core ModelMessage — a tool result or an external event — into conversation history.

impl PartialEq for Message

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Message