feat: add provenance-aware worker history

crates/agen/examples/engine_cancel_demo.rs

@@ -4,7 +4,7 @@
 
 use agen::llm_client::scheme::{Scheme, anthropic::AnthropicScheme};
 use agen::llm_client::transport::{HttpTransport, ResolvedAuth};
-use agen::{Engine, EngineRunExit, StopReason};
+use agen::{Engine, EngineResult, History};
 use std::time::Duration;
 
 #[tokio::main]
@@ -29,6 +29,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let base_url = scheme.default_base_url().to_string();
     let client = HttpTransport::new(scheme, model, base_url, ResolvedAuth::ApiKey(api_key), cap);
     let engine = Engine::new(client);
+    let mut history = History::new();
 
     println!("🚀 Starting Engine...");
     println!("💡 Will cancel after 2 seconds\n");
@@ -45,13 +46,15 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     println!("📡 Sending request to LLM...");
 
-    let output = engine.run("Tell me a very long story about a brave knight. Make it as detailed as possible with many paragraphs.").await;
-    match output.result {
-        EngineRunExit::Finished => println!("✅ Task completed normally"),
-        EngineRunExit::Paused => println!("⏸️  Task paused"),
-        EngineRunExit::Yielded => println!("↩️  Task yielded"),
-        EngineRunExit::Interrupted(StopReason::LimitReached) => {
-            println!("🔒 Turn limit reached")
+    match engine.run(&mut history, "Tell me a very long story about a brave knight. Make it as detailed as possible with many paragraphs.").await {
+        Ok(out) => match out.result {
+            EngineResult::Finished => println!("✅ Task completed normally"),
+            EngineResult::Paused => println!("⏸️  Task paused"),
+            EngineResult::LimitReached => println!("🔒 Turn limit reached"),
+            EngineResult::Yielded => println!("↩️  Task yielded"),
+        },
+        Err(e) => {
+            println!("❌ Task error: {}", e);
         }
         EngineRunExit::Interrupted(reason) => println!("❌ Task interrupted: {reason:?}"),
     }

crates/agen/examples/engine_cli.rs

@@ -39,7 +39,7 @@ use tracing::info;
 use tracing_subscriber::EnvFilter;
 
 use agen::{
-    Engine, EngineRunExit, StopReason,
+    Engine, History,
     interceptor::{Interceptor, PostToolAction, ToolResultInfo},
     llm_client::{
         LlmClient,
@@ -474,11 +474,16 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     engine.set_interceptor(ToolResultPrinterPolicy::new(tool_call_names));
 
+    let mut history = History::new();
+
     // One-shot mode
     if let Some(prompt) = args.prompt {
-        let output = engine.run(&prompt).await;
-        if let EngineRunExit::Interrupted(StopReason::Unexpected(error)) = output.result {
-            eprintln!("\n❌ Error: {error}");
+        match engine.run(&mut history, &prompt).await {
+            Ok(_) => {}
+            Err(e) => {
+                eprintln!("\n❌ Error: {}", e);
+                std::process::exit(1);
+            }
         }
 
         return Ok(());
@@ -497,8 +502,13 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         return Ok(());
     }
 
-    let output = engine.run(first_input).await;
-    let mut locked = output.engine;
+    let mut locked = match engine.run(&mut history, first_input).await {
+        Ok(out) => out.engine,
+        Err(e) => {
+            eprintln!("\n❌ Error: {}", e);
+            return Ok(());
+        }
+    };
 
     loop {
         print!("\n👤 You: ");
@@ -517,8 +527,11 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
             break;
         }
 
-        if let EngineRunExit::Interrupted(StopReason::Unexpected(error)) = locked.run(input).await {
-            eprintln!("\n❌ Error: {error}");
+        match locked.run(&mut history, input).await {
+            Ok(_) => {}
+            Err(e) => {
+                eprintln!("\n❌ Error: {}", e);
+            }
         }
     }