Enum Message 

pub enum Message {
    System(SystemMessage),
    User(UserMessage),
    Assistant(AssistantMessage),
    Tool(ToolResultInfo),
    Developer(String),
}

A message in a conversation with a language model.

Variants

System(SystemMessage)

A system message providing context or instructions.

User(UserMessage)

A user message containing input from the human.

Assistant(AssistantMessage)

An assistant message containing the model’s response.

Tool(ToolResultInfo)

A tool result message from executing a tool call.

Developer(String)

A developer-specific message for advanced use cases.

Implementations

impl Message

pub fn conversation_builder() -> MessageBuilder<Conversation>

Start a new conversation with an empty message list.

Returns a MessageBuilder<Conversation>, allowing any number of user/assistant calls without forcing an initial system or user message.

Example

use aisdk::core::Message;

let mut msg = Message::conversation_builder();
for _ in 0..10 {
    msg = msg.user("hello");
}
let messages = msg.build();

pub fn builder() -> MessageBuilder

Create a new message builder in the initial state.

Returns a MessageBuilder<Initial> that enforces type-safe order: the first message must be either a system prompt or a user message. After that, the builder transitions to Conversation state and allows free mixing of user/assistant messages but not system prompts.

Example

use aisdk::core::Message;

let msgs = Message::builder()
    .system("You are helpful.")
    .user("Hello!")
    .assistant("Hi there.")
    .build();

impl Message

pub fn from_vercel_ui_message(ui_messages: &[VercelUIMessage]) -> Vec<Message>

Converts a slice of Vercel UI messages to the aisdk::core::Message format.

This function extracts text content from UI message parts and maps roles to the corresponding Message variants. Currently only “text” parts are supported; other part types (e.g., files, tools) are ignored.

Parameters

• ui_messages: A slice of VercelUIMessage to convert.

Returns

A vector of Message instances.

Notes

• Joins multiple text parts into a single string.
• TODO: Add support for file parts (e.g., map to URLs in content).
• TODO: Add support for tool parts (e.g., map to Tool messages).

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<(), Error>

Formats the value using the given formatter.

impl From<TaggedMessage> for Message

fn from(value: TaggedMessage) -> Message

Converts to this type from the input type.