Enum Message 

pub enum Message {
    System {
        content: String,
    },
    User {
        content: String,
    },
    Assistant {
        content: Option<String>,
        tool_calls: Vec<ToolCall>,
    },
    ToolResult {
        tool_call_id: String,
        content: String,
    },
}

A message in a multi-turn conversation.

Serializes to OpenAI’s chat completions format with "role" as the discriminator. This format is compatible with OpenAI, GLM, vLLM, Ollama, and other OpenAI-compatible APIs.

Variants

System

System prompt that configures agent behavior. Serializes as: {"role": "system", "content": "..."}

Fields

content: String

User

User message (task description, follow-up, etc.). Serializes as: {"role": "user", "content": "..."}

Fields

content: String

Assistant

Assistant response, optionally with tool calls. Serializes as: {"role": "assistant", "content": "...", "tool_calls": [...]}

Fields

content: Option<String>

tool_calls: Vec<ToolCall>

ToolResult

Result of a tool execution, sent back to the LLM. Serializes as: {"role": "tool", "tool_call_id": "...", "content": "..."}

Fields

tool_call_id: String

content: String

Implementations

impl Message

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

Creates a system message.

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

Creates a user message.

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

Creates an assistant message with text content (no tool calls).

pub fn assistant_with_tool_calls(tool_calls: Vec<ToolCall>) -> Self

Creates an assistant message with tool calls (no text content).

pub fn tool_result( tool_call_id: impl Into<String>, content: impl Into<String>, ) -> Self

Creates a tool result message.

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<'de> Deserialize<'de> for Message

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Message

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

where __S: Serializer,

Serialize this value into the given Serde serializer.