Struct Message 

pub struct Message {
    pub role: Role,
    pub content: String,
    pub parts: Vec<MessagePart>,
    pub metadata: MessageMetadata,
}

A single message in a conversation.

Each message has a Role, a flat content string (used when sending to providers that do not support structured parts), and an optional list of MessageParts for providers that accept heterogeneous content blocks (e.g. Claude).

The content field is kept in sync with parts via Message::rebuild_content. When building messages from structured parts, always use Message::from_parts — it populates both parts and content.

Examples

use zeph_llm::provider::{Message, MessagePart, Role};

// Simple text-only message
let msg = Message::from_legacy(Role::User, "What is Rust?");
assert_eq!(msg.to_llm_content(), "What is Rust?");

// Structured message with parts
let parts = vec![
    MessagePart::Text { text: "Explain this code.".into() },
];
let msg = Message::from_parts(Role::User, parts);
assert!(!msg.parts.is_empty());

Fields

role: Role

content: String

Flat text representation of this message, derived from parts when structured.

parts: Vec<MessagePart>

metadata: MessageMetadata

Implementations

impl Message

pub fn from_legacy(role: Role, content: impl Into<String>) -> Self

Create a simple text-only message without structured parts.

Use this constructor for system prompts, plain user turns, and assistant messages produced by providers that return a raw string.

pub fn from_parts(role: Role, parts: Vec<MessagePart>) -> Self

Create a message from structured parts, deriving the flat content automatically.

Prefer this constructor when the message contains tool invocations, images, or other non-text content that providers need to render as separate content blocks.

pub fn to_llm_content(&self) -> &str

Return the flat text content of this message, suitable for providers that do not support structured content blocks.

pub fn rebuild_content(&mut self)

Re-synchronize content from parts after in-place mutation.

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 Default for Message

fn default() -> Self

Returns the “default value” for a type.

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.