Struct AgentBuilder 

pub struct AgentBuilder { /* private fields */ }

Implementations

impl AgentBuilder

pub fn new(provider: Arc<dyn LlmProvider>) -> Self

Create a new builder with an LlmProvider.

pub fn event_bus_capacity(self, capacity: usize) -> Self

pub fn session_id_generator( self, generator: Arc<dyn SessionIdGenerator>, ) -> Self

pub fn convert_to_llm(self, cb: ConvertToLlmFn) -> Self

Set a callback to transform messages before they are sent to the LLM.

The default behavior (when None) is to filter out ChatMessage::Custom variants, which most providers don’t understand. Override this to inject custom serialization logic for application-specific message types.

pub fn guard(self, guard: impl ReactLoopGuard + 'static) -> Self

pub fn guard_dyn(self, guard: Arc<dyn ReactLoopGuard>) -> Self

Set a guard from a pre-built Arc<dyn ReactLoopGuard>.

Use this when you need to share the guard reference (e.g. for inspecting recorded calls in tests).

pub fn context_compactor(self, compactor: Arc<dyn ContextCompaction>) -> Self

Set an inline context compactor for the react loop.

When set, the react loop will check token count after each tool turn and compact the session if it exceeds the configured threshold.

pub fn get_guard(&self) -> Option<&Arc<dyn ReactLoopGuard>>

Check if a guard has been set.

Used by agent-works to inject a default guard if none was set.

pub fn system_prompt(self, system_prompt: impl Into<String>) -> Self

pub fn enable_thought(self, enable: bool) -> Self

Set whether to include the reasoning content in LLM responses.

Controls whether the reasoning_content field from the LLM is forwarded to consumers (i.e., “show the thinking process”). See AgentConfig::enable_thought for the distinction from enable_thinking().

pub fn reasoning(self, config: ReasoningConfig) -> Self

pub fn enable_thinking(self, enable: bool) -> Self

Set whether to enable the model’s extended thinking / reasoning mode.

Controls whether the model performs deep reasoning (i.e., “enable thinking mode”). See AgentConfig::enable_thought for the distinction from enable_thought().

pub fn thinking_budget(self, budget: u64) -> Self

pub fn tool_timeout(self, timeout_ms: u64) -> Self

pub fn max_tool_output_chars(self, max_chars: usize) -> Self

pub fn register_tool(self, tool: impl Tool + 'static) -> Self

pub fn register_tool_arc(self, tool: Arc<dyn Tool>) -> Self

pub fn approval_handler(self, handler: Arc<dyn ApprovalHandler>) -> Self

pub fn tool_policy(self, policy: Arc<dyn ToolPolicy>) -> Self

pub fn middleware(self, mw: impl Middleware + 'static) -> Self

pub fn context_window(self, max_tokens: usize) -> Self

pub fn context_window_manager(self, manager: ContextWindowManager) -> Self

pub fn response_format(self, format: ResponseFormat) -> Self

pub fn llm_retry(self, retry: RetryConfig) -> Self

pub fn session_store(self, store: Arc<dyn SessionStore>) -> Self

pub fn error_recovery(self, recovery: Arc<dyn ToolErrorRecovery>) -> Self

pub fn max_sessions(self, max: usize) -> Self

pub fn max_turns_per_session(self, max: usize) -> Self

pub fn execution_max_turns(self, max: u32) -> Self

Cap the number of react-loop iterations allowed for a single run (one user input). Distinct from Self::max_turns_per_session, which caps turns across the whole session. When unset, falls back to DEFAULT_MAX_TURNS (50).

pub fn max_message_tokens(self, max: usize) -> Self

pub fn tool_error_retry_prompt(self, prompt: impl Into<String>) -> Self

pub fn language(self, language: Language) -> Self

pub fn apply_if<T>( self, value: Option<T>, f: impl FnOnce(Self, T) -> Self, ) -> Self

Conditionally chain a builder call: apply f only when value is Some.

Example

let builder = AgentBuilder::new(client)
    .apply_if(config.timeout, |b, t| b.tool_timeout(t))
    .apply_if(config.max_chars, |b, c| b.max_tool_output_chars(c));

pub fn build(self) -> AgentResult<AgentRuntime>