Struct CallbackManager 

pub struct CallbackManager { /* private fields */ }

Callback manager that handles multiple handlers

Dispatch events to all registered handlers. Prefer the dispatch_* methods over poking handlers() directly: the dispatch methods guarantee every handler is invoked in order and (when a Tracer is attached via with_tracer) also publish each run as a tracing span.

Implementations

impl CallbackManager

pub fn new() -> Self

Create a new callback manager

pub fn add_handler(self, handler: Arc<dyn CallbackHandler>) -> Self

Add a callback handler

pub fn with_tracer(self, tracer: Arc<Tracer>) -> Self

Attach a Tracer so every dispatched run is also published as a tracing span (Q6: minimal merge between callbacks and the tracing tree).

With a tracer attached, dispatch_*_start starts a span named after the run and dispatch_*_end/dispatch_*_error ends it. Nested runs become parent/child spans via the tracer’s task-local span stack.

pub fn handlers(&self) -> &[Arc<dyn CallbackHandler>]

Get all handlers

pub fn is_empty(&self) -> bool

Check if there are any handlers

pub fn merge_with(&self, other: &CallbackManager) -> CallbackManager

Merge other’s handlers into a new manager, keeping this manager’s handlers first and appending other’s (Q8: config merges append callback handlers instead of replacing them wholesale).

self’s tracer wins; if self has none, other’s tracer is used. The active trace-span table starts empty in the merged manager.

impl CallbackManager

pub async fn dispatch_run_start(&self, run: &RunTree)

Dispatch on_run_start to all handlers.

pub async fn dispatch_run_end(&self, run: &RunTree)

Dispatch on_run_end to all handlers.

pub async fn dispatch_run_error(&self, run: &RunTree, error: &str)

Dispatch on_run_error to all handlers.

pub async fn dispatch_chain_start(&self, run: &RunTree, inputs: &Value)

Dispatch on_chain_start to all handlers.

pub async fn dispatch_chain_end(&self, run: &RunTree, outputs: &Value)

Dispatch on_chain_end to all handlers.

pub async fn dispatch_chain_error(&self, run: &RunTree, error: &str)

Dispatch on_chain_error to all handlers.

pub async fn dispatch_llm_start(&self, run: &RunTree, messages: &[Message])

Dispatch on_llm_start to all handlers.

pub async fn dispatch_llm_end(&self, run: &RunTree, response: &str)

Dispatch on_llm_end to all handlers.

pub async fn dispatch_llm_error(&self, run: &RunTree, error: &str)

Dispatch on_llm_error to all handlers.

pub async fn dispatch_llm_new_token(&self, run: &RunTree, token: &str)

Dispatch on_llm_new_token to all handlers.

pub async fn dispatch_llm_thinking(&self, run: &RunTree, thinking: &str)

Dispatch on_llm_thinking to all handlers.

pub async fn dispatch_tool_start( &self, run: &RunTree, tool_name: &str, input: &str, )

Dispatch on_tool_start to all handlers.

pub async fn dispatch_tool_end(&self, run: &RunTree, output: &str)

Dispatch on_tool_end to all handlers.

pub async fn dispatch_tool_error(&self, run: &RunTree, error: &str)

Dispatch on_tool_error to all handlers.

pub async fn dispatch_retriever_start(&self, run: &RunTree, query: &str)

Dispatch on_retriever_start to all handlers.

pub async fn dispatch_retriever_end(&self, run: &RunTree, documents: &[Value])

Dispatch on_retriever_end to all handlers.

pub async fn dispatch_retriever_error(&self, run: &RunTree, error: &str)

Dispatch on_retriever_error to all handlers.

Trait Implementations

impl Clone for CallbackManager

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CallbackManager

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

Formats the value using the given formatter.

impl Default for CallbackManager

fn default() -> Self

Returns the “default value” for a type.