Enum Message 

pub enum Message {
    Human {
        content: MessageContent,
        id: Option<String>,
    },
    Ai {
        content: MessageContent,
        tool_calls: Vec<ToolCall>,
        id: Option<String>,
        usage: Option<LlmUsage>,
        thinking: Option<String>,
    },
    System {
        content: MessageContent,
        id: Option<String>,
    },
    Tool {
        content: MessageContent,
        tool_call_id: String,
        name: Option<String>,
        id: Option<String>,
        status: String,
    },
    Remove {
        id: String,
    },
}

Message types for the agent system.

Mirrors the LangChain message types: HumanMessage, AIMessage, SystemMessage, ToolMessage, and RemoveMessage.

Variants

Human

A message from the human user.

Fields

content: MessageContent

id: Option<String>

Ai

A message from the AI assistant.

Fields

content: MessageContent

tool_calls: Vec<ToolCall>

id: Option<String>

usage: Option<LlmUsage>

Token usage from the LLM API response, if available.

thinking: Option<String>

Thinking/reasoning content from models that support it (e.g., DeepSeek, o1/o3).

System

A system message providing instructions.

Fields

content: MessageContent

id: Option<String>

Tool

A message containing the result of a tool call.

Fields

content: MessageContent

tool_call_id: String

name: Option<String>

id: Option<String>

status: String

Status of the tool call: “success” or “error”

Remove

A message that removes a previous message by ID.

Fields

id: String

Implementations

impl Message

pub fn text(&self) -> Option<&str>

Get the text content of the message, if any.

pub fn id(&self) -> Option<&str>

Get the message ID, if any.

pub fn has_tool_calls(&self) -> bool

Check if this message has tool calls.

pub fn tool_calls(&self) -> &[ToolCall]

Get tool calls from the message.

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

Create a human message.

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

Create an AI message.

pub fn ai_with_tool_calls( content: impl Into<String>, tool_calls: Vec<ToolCall>, ) -> Self

Create an AI message with tool calls.

pub fn ai_with_usage(content: impl Into<String>, usage: LlmUsage) -> Self

Create an AI message with token usage information.

pub fn ai_with_tool_calls_and_usage( content: impl Into<String>, tool_calls: Vec<ToolCall>, usage: LlmUsage, ) -> Self

Create an AI message with tool calls and token usage.

pub fn usage(&self) -> Option<&LlmUsage>

Get token usage from the message, if available.

pub fn thinking(&self) -> Option<&str>

Get the thinking/reasoning content, if available.

pub fn ai_with_thinking( content: impl Into<String>, thinking: impl Into<String>, ) -> Self

Create an AI message with thinking/reasoning content.

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

Create a system message.

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

Create a tool result message with success status.

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

Create a tool error 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 Display for Message

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

Formats the value using the given formatter.

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.