Trait Memory 

pub trait Memory: Send + Sync {
    // Required methods
    fn add_message(
        &self,
        message: &Message,
    ) -> impl Future<Output = Result<()>> + Send;
    fn get_messages(&self) -> impl Future<Output = Result<Vec<Message>>> + Send;
    fn clear(&self) -> impl Future<Output = Result<()>> + Send;

    // Provided method
    fn with_messages<R, F>(
        &self,
        f: F,
    ) -> impl Future<Output = Result<R>> + Send
       where F: FnOnce(&[Message]) -> R + Send,
             R: Send { ... }
}

Trait for conversation memory backends. Stores and retrieves messages for agent context.

Required Methods

fn add_message( &self, message: &Message, ) -> impl Future<Output = Result<()>> + Send

Appends a message to the history. Order is preserved.

Takes a borrow so callers that keep the message (the agent runner appends it to its working log after persisting) don’t clone it per iteration. Backends that store owned messages clone internally; serializing backends (Redis, SQLite) never need ownership at all.

fn get_messages(&self) -> impl Future<Output = Result<Vec<Message>>> + Send

Returns all stored messages in order. Used to build context for the model.

fn clear(&self) -> impl Future<Output = Result<()>> + Send

Removes all messages. Use when starting a new conversation.

Provided Methods

fn with_messages<R, F>(&self, f: F) -> impl Future<Output = Result<R>> + Send

where F: FnOnce(&[Message]) -> R + Send, R: Send,

Runs f over the stored messages without handing out an owned copy.

The default implementation falls back to Memory::get_messages (one full clone); in-process backends override it to borrow their storage under the lock, so read-only consumers (serializing history to disk, measuring it, rendering it) don’t pay an O(history) deep copy per call.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors