Struct SimpleEventSink 

pub struct SimpleEventSink;

Simple event sink that prints to stdout.

A minimal sink for CLI tools, debugging, or batch processing. Prints LLM text output directly to stdout with basic formatting.

Limitations

This sink is non-interactive and cannot handle:

• Permission requests: Use with AutoApprovePolicy to auto-approve
• User interactions: Use with AutoApprovePolicy to auto-cancel

If you need interactive permission prompts or user questions, use ChannelEventSink with a proper frontend (TUI, WebSocket, etc.).

Output Format

Event	Output
TextChunk	Prints text directly (no newline)
Complete	Prints newline
Error	Prints to stderr with “Error: “ prefix
ToolExecuting	Prints “[Tool: name]”
ToolCompleted	Prints errors only
PermissionRequired	Warning - use AutoApprovePolicy
UserInteractionRequired	Warning - use AutoApprovePolicy
Other events	Silently ignored

Example

use agent_core_runtime::agent::{
    AgentCore, SimpleEventSink, ChannelInputSource, AutoApprovePolicy
};

// Simple CLI agent - must use AutoApprovePolicy
agent.run_with_frontend(
    SimpleEventSink::new(),
    input_source,
    AutoApprovePolicy::new(),  // Required for non-interactive sink
)?;

Implementations

impl SimpleEventSink

pub fn new() -> Self

Create a new simple event sink.

Trait Implementations

impl Clone for SimpleEventSink

fn clone(&self) -> SimpleEventSink

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for SimpleEventSink

fn default() -> SimpleEventSink

Returns the “default value” for a type.

impl EventSink for SimpleEventSink

fn send(&self, event: UiMessage) -> Result<(), SendError>

Send an event to the consumer (non-blocking).

fn clone_box(&self) -> Box<dyn EventSink>

Clone this sink into a boxed trait object.

fn send_async( &self, event: UiMessage, ) -> Pin<Box<dyn Future<Output = Result<(), SendError>> + Send + '_>>

Send an event to the consumer (async, with backpressure).