Struct Agent 

pub struct Agent<Deps = (), Output = String> { /* private fields */ }

The main agent type.

An agent wraps a model and provides:

• System prompts and instructions
• Tool registration and execution
• Structured output parsing and validation
• Retry logic for failures
• Usage tracking and limits

Type Parameters

• Deps: Dependencies injected into tools and instruction functions.
• Output: The output type (default: String).

Implementations

impl<Deps, Output> Agent<Deps, Output>

where Deps: Send + Sync + 'static, Output: Send + Sync + 'static,

pub fn model(&self) -> &dyn Model

Get the model.

pub fn model_arc(&self) -> Arc<dyn Model>

Get the model as an Arc (for cloning into spawned tasks).

pub fn name(&self) -> Option<&str>

Get agent name.

pub fn model_settings(&self) -> &ModelSettings

Get model settings.

pub fn tools(&self) -> Vec<&ToolDefinition>

Get registered tools.

pub fn output_mode(&self) -> OutputMode

Get the output mode.

pub fn has_tools(&self) -> bool

Check if the agent has tools.

pub fn usage_limits(&self) -> Option<&UsageLimits>

Get usage limits.

pub fn parallel_tool_calls(&self) -> bool

Check if parallel tool execution is enabled.

pub fn max_concurrent_tools(&self) -> Option<usize>

Get the maximum number of concurrent tool calls.

pub async fn run( &self, prompt: impl Into<UserContent>, deps: Deps, ) -> Result<AgentRunResult<Output>, AgentRunError>

Run the agent with a prompt.

Arguments

• prompt - The user prompt to send to the model.
• deps - Dependencies to inject into tools and instructions.

Returns

The agent’s output after completing the conversation.

pub async fn run_with_options( &self, prompt: impl Into<UserContent>, deps: Deps, options: RunOptions, ) -> Result<AgentRunResult<Output>, AgentRunError>

Run with options.

pub fn run_sync( &self, prompt: impl Into<UserContent>, deps: Deps, ) -> Result<AgentRunResult<Output>, AgentRunError>

Run synchronously (blocking).

Note: This requires a Tokio runtime to be available.

pub async fn start_run( &self, prompt: impl Into<UserContent>, deps: Deps, options: RunOptions, ) -> Result<AgentRun<'_, Deps, Output>, AgentRunError>

Start a run that can be iterated.

This allows stepping through the agent’s execution manually.

pub async fn run_stream( &self, prompt: impl Into<UserContent>, deps: Deps, ) -> Result<AgentStream, AgentRunError>

Run with streaming output.

pub async fn run_stream_with_options( &self, prompt: impl Into<UserContent>, deps: Deps, options: RunOptions, ) -> Result<AgentStream, AgentRunError>

Run stream with options.

pub fn static_system_prompt(&self) -> &str

Get the static system prompt.

Trait Implementations

impl<Deps, Output> Debug for Agent<Deps, Output>

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

Formats the value using the given formatter.

impl<Deps: Send + Sync + 'static> Default for Agent<Deps, String>

fn default() -> Self

Returns the “default value” for a type.