Struct LogMiddleware 

pub struct LogMiddleware;

Logs agent and tool lifecycle events.

When the tracing-support feature is enabled, uses tracing macros for structured logging. Without the feature, all hooks are silent no-ops.

Implementations

impl LogMiddleware

pub fn new() -> Self

Create a new log middleware.

Trait Implementations

impl Default for LogMiddleware

fn default() -> Self

Returns the “default value” for a type.

impl Middleware for LogMiddleware

fn name(&self) -> &str

Unique name for this middleware (used in logging/debugging).

fn before_agent<'life0, 'life1, 'async_trait>( &'life0 self, _ctx: &'life1 InvocationContext, ) -> Pin<Box<dyn Future<Output = Result<(), AgentError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Called before an agent begins execution.

fn after_agent<'life0, 'life1, 'async_trait>( &'life0 self, _ctx: &'life1 InvocationContext, ) -> Pin<Box<dyn Future<Output = Result<(), AgentError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Called after an agent completes execution.

fn before_tool<'life0, 'life1, 'async_trait>( &'life0 self, call: &'life1 FunctionCall, ) -> Pin<Box<dyn Future<Output = Result<(), AgentError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Called before a tool is invoked.

fn after_tool<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, call: &'life1 FunctionCall, _result: &'life2 Value, ) -> Pin<Box<dyn Future<Output = Result<(), AgentError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Called after a tool completes successfully.

fn on_tool_error<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, call: &'life1 FunctionCall, err: &'life2 ToolError, ) -> Pin<Box<dyn Future<Output = Result<(), AgentError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Called when a tool execution fails.

fn on_error<'life0, 'life1, 'async_trait>( &'life0 self, err: &'life1 AgentError, ) -> Pin<Box<dyn Future<Output = Result<(), AgentError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Called when an agent error occurs.

fn on_event<'life0, 'life1, 'async_trait>( &'life0 self, _event: &'life1 AgentEvent, ) -> Pin<Box<dyn Future<Output = Result<(), AgentError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Called when an agent event is emitted.

fn before_model<'life0, 'life1, 'async_trait>( &'life0 self, _request: &'life1 LlmRequest, ) -> Pin<Box<dyn Future<Output = Result<Option<LlmResponse>, AgentError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Called before an LLM model call is made. Return Some(LlmResponse) to skip the LLM call and use the returned response instead (e.g., for caching, guardrails). Return None to proceed.

fn after_model<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, _request: &'life1 LlmRequest, _response: &'life2 LlmResponse, ) -> Pin<Box<dyn Future<Output = Result<Option<LlmResponse>, AgentError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Called after an LLM model call completes. Return Some(LlmResponse) to replace the model’s response (e.g., for output filtering, safety). Return None to use the original response.