Struct Message 

pub struct Message {
    pub role: Role,
    pub content: Vec<ContentPart>,
    pub tool_calls: Option<Vec<ToolCall>>,
    pub tool_call_id: Option<String>,
    pub name: Option<String>,
}

A single message in the LLM conversation history.

content is now Vec<ContentPart> to support multimodal messages (text + images) and Anthropic-style tool content blocks.

For the common single-text-message case the API still sees a plain string thanks to the custom serialize_content_parts serializer.

Fields

role: Role

content: Vec<ContentPart>

Message body — one or more content parts. Use text_content() to extract plain text.

NOTE: serialization is handled by a custom serializer below.

tool_calls: Option<Vec<ToolCall>>

tool_call_id: Option<String>

name: Option<String>

Implementations

impl Message

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

Create a system message with plain text content.

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

Create a user message with plain text content.

pub fn assistant( content: Option<String>, tool_calls: Option<Vec<ToolCall>>, ) -> Self

Create an assistant message.

content is Option<String> here for backwards compatibility with callers that had content: Option<String>. Pass None when the response contains only tool calls.

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

Create a tool-result message.

pub fn text_content(&self) -> Option<String>

Extract all plain text from this message’s content parts.

Concatenates every ContentPart::Text in order, joining with \n when there are multiple text parts. Returns None if there are no text parts (e.g. a message containing only images or tool results).

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 PartialEq for Message

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Message

fn serialize<S: Serializer>(&self, s: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Message