Struct AgentBuilder 

pub struct AgentBuilder { /* private fields */ }

Builder for Agent.

Implementations

impl AgentBuilder

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

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

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

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

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

pub fn temperature(self, temperature: f32) -> Self

pub fn max_tokens(self, max_tokens: u32) -> Self

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

Request a structured-output response format (e.g. a JSON schema).

pub fn tool(self, tool: ToolDefinition) -> Self

Add a tool available to the agent.

pub fn tools(self, tools: impl IntoIterator<Item = ToolDefinition>) -> Self

Add multiple tools.

pub fn tool_source(self, source: Arc<dyn ToolSource>) -> Self

Register a dynamic tool source (e.g. an MCP server wrapper), resolved fresh on every run and appended after the agent’s static/context/ per-run tools (dedup by name against those and any earlier-registered source; first registrant wins). Call repeatedly to register more than one source. See ToolSource, resolved internally by every Agent run.

pub fn context_provider(self, provider: Arc<dyn ContextProvider>) -> Self

Add a single context provider (repeatable; providers run in registration order, agent providers after any thread-level ones).

pub fn context_providers(self, providers: Vec<Arc<dyn ContextProvider>>) -> Self

Set the context provider list, replacing any previously registered.

pub fn with_compaction( self, strategy: impl CompactionStrategy + 'static, ) -> Self

Attach conversation-history compaction, via a CompactionProvider wrapping strategy (with the default ApproxTokenizer; use AgentBuilder::context_provider with CompactionProvider::with_tokenizer for a custom tokenizer).

Registered as one of the agent’s own context providers, which Agent::combined_providers always runs after the session’s — including the auto-attached (or explicitly attached) HistoryProvider, which lives on the session — so compaction sees, and can shrink, the full history-prepended message list for the run. Not calling this leaves the default behavior unchanged: the full history is sent every run.

pub fn middleware(self, mw: Arc<AgentMiddleware>) -> Self

Add an agent middleware.

pub fn chat_middleware(self, mw: Arc<ChatMiddleware>) -> Self

Add a chat middleware, run around the underlying chat-client call on every request (repeatable, like AgentBuilder::middleware). See the chat-client call pipeline for exactly what it can observe and mutate.

pub fn function_middleware(self, mw: Arc<FunctionMiddleware>) -> Self

Add a function-invocation middleware, run around every local tool call (repeatable). Plumbed down into the FunctionInvokingChatClient this builder wraps the underlying client with.

pub fn observability_config(self, config: ObservabilityConfig) -> Self

Set the ObservabilityConfig for the execute_tool spans this agent’s tool loop emits — content capture and the GenAI semantic-convention version.

The builder wraps the caller’s client in a FunctionInvokingChatClient itself, so this is the only way to reach that wrapper’s own config. Pass the same value given to an ObservableChatClient around the same client, so one trace reports one convention version across its chat and tool spans. Left unset, the tool loop reads the environment, as it always has.

pub fn chat_options(self, options: ChatOptions) -> Self

Override the whole chat options object (advanced).

pub fn build(self) -> Agent

Build the agent.