Struct Agent

pub struct Agent { /* private fields */ }

Agents are the main interface for building agentic systems.

Construct agents by calling the builder, setting an llm, configure hooks, tools and other customizations.

Important defaults

• The default context is the DefaultContext, executing tools locally with the LocalExecutor.
• A default stop tool is provided for agents to explicitly stop if needed
• The default SystemPrompt instructs the agent with chain of thought and some common safeguards, but is otherwise quite bare. In a lot of cases this can be sufficient.

Implementations

impl Agent

pub fn builder() -> AgentBuilder

Build a new agent

pub fn default_tools() -> HashSet<Box<dyn Tool>>

Default tools for the agent that it always includes Right now this is the stop tool, which allows the agent to stop itself.

pub async fn query( &mut self, query: impl Into<Prompt>, ) -> Result<(), AgentError>

Run the agent with a user message. The agent will loop completions, make tool calls, until no new messages are available.

Errors

Errors if anything goes wrong, see AgentError for more details.

pub async fn query_once( &mut self, query: impl Into<Prompt>, ) -> Result<(), AgentError>

Run the agent with a user message once.

Errors

Errors if anything goes wrong, see AgentError for more details.

pub async fn run(&mut self) -> Result<(), AgentError>

Run the agent with without user message. The agent will loop completions, make tool calls, until no new messages are available.

Errors

Errors if anything goes wrong, see AgentError for more details.

pub async fn run_once(&mut self) -> Result<(), AgentError>

Run the agent with without user message. The agent will loop completions, make tool calls, until

Errors

Errors if anything goes wrong, see AgentError for more details.

pub async fn history(&self) -> Result<Vec<ChatMessage>, AgentError>

Retrieve the message history of the agent

Errors

Error if the message history cannot be retrieved, e.g. if the context is not set up or a connection fails

pub async fn add_message(&self, message: ChatMessage) -> Result<(), AgentError>

Add a message to the agent’s context

This will trigger a OnNewMessage hook if its present.

If you want to add a message without triggering the hook, use the context directly.

Errors

Errors if the message cannot be added to the context. With the default in memory context that is not supposed to happen.

pub async fn stop(&mut self, reason: impl Into<StopReason>)

Tell the agent to stop. It will finish it’s current loop and then stop.

pub async fn stop_with_error(&mut self, error: &AgentError)

pub fn context(&self) -> &dyn AgentContext

Access the agent’s context

pub fn is_running(&self) -> bool

The agent is still running

pub fn is_stopped(&self) -> bool

The agent stopped

pub fn is_pending(&self) -> bool

The agent has not (ever) started

pub fn tools(&self) -> &HashSet<Box<dyn Tool>>

Get a list of tools available to the agent

pub fn state(&self) -> &State

pub fn stop_reason(&self) -> Option<&StopReason>

Trait Implementations

impl Clone for Agent

fn clone(&self) -> Agent

Returns a duplicate of the value.

const fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Agent

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

Formats the value using the given formatter.