Add Rust embedding API

examples/headless_agent.rs

@@ -0,0 +1,33 @@
+use cassady::prelude::*;
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    let session = SessionBuilder::new()
+        .cwd(std::env::current_dir()?)
+        .access_mode(AccessMode::ReadOnly)
+        .build()
+        .await?;
+
+    let mut turn = session
+        .start_turn("Summarize this project in a few sentences.")
+        .await?;
+
+    while let Some(event) = turn.next_event().await? {
+        match event {
+            Event::AssistantChunk(text) => print!("{text}"),
+            Event::ApprovalRequested(request) => {
+                eprintln!(
+                    "approval requested for {}: {}; denying in this example",
+                    request.name, request.reason
+                );
+                turn.deny(&request.request_id)?;
+            }
+            Event::Finished => break,
+            _ => {}
+        }
+    }
+
+    let session = turn.finish().await?;
+    eprintln!("\nResume chat with: cass --resume {}", session.id());
+    Ok(())
+}