diff --git a/crates/panorama-app-sdk/src/lib.rs b/crates/panorama-app-sdk/src/lib.rs
index 3476a07..58fbfc0 100644
--- a/crates/panorama-app-sdk/src/lib.rs
+++ b/crates/panorama-app-sdk/src/lib.rs
@@ -1,17 +1,38 @@
 use std::ffi::CString;
 
+use sys::RegisterCallback;
+
 pub mod sys {
   use std::ffi::c_char;
 
+  use crate::RegisterContext;
+
+  pub type RegisterCallback = fn(*mut RegisterContext) -> ();
+
   extern "C" {
-    pub fn register_endpoint(url_len: u64, url: *const c_char);
+    pub fn register_endpoint(
+      url_len: u64,
+      url: *const c_char,
+      callback: *mut RegisterCallback,
+    );
   }
 }
 
-pub fn register_endpoint(url: impl AsRef<str>) {
+pub struct RegisterContext {}
+
+pub fn register_endpoint(
+  url: impl AsRef<str>,
+  callback: fn(&RegisterContext) -> (),
+) {
   let url = url.as_ref();
   let url_cstr = CString::new(url).unwrap();
-  let result =
-    unsafe { sys::register_endpoint(url.len() as u64, url_cstr.into_raw()) };
+  let mut callback2 = |ctx: *mut RegisterContext| callback(&*ctx);
+  let result = unsafe {
+    sys::register_endpoint(
+      url.len() as u64,
+      url_cstr.into_raw(),
+      &mut callback2 as *mut RegisterCallback,
+    )
+  };
   println!("Result: {:?}", result);
 }
diff --git a/crates/panorama-core/src/state/apps.rs b/crates/panorama-core/src/state/apps.rs
index 9cbb708..a9ee076 100644
--- a/crates/panorama-core/src/state/apps.rs
+++ b/crates/panorama-core/src/state/apps.rs
@@ -138,40 +138,6 @@ impl AppState {
       .context("Could not get typed function")?;
     hello.call(&mut store, ()).context("Could not call")?;
 
-    // let mut sources = Sources::new();
-    // sources
-    //   .insert(Source::new("register.rn", register_script).into_diagnostic()?)
-    //   .into_diagnostic()?;
-
-    // let mut diagnostics = Diagnostics::new();
-    // let register_script_unit = prepare(&mut sources)
-    //   .with_diagnostics(&mut diagnostics)
-    //   .build();
-    // if !diagnostics.is_empty() {
-    //   let mut writer = StandardStream::stderr(ColorChoice::Always);
-    //   diagnostics.emit(&mut writer, &sources).into_diagnostic()?;
-    // }
-    // let register_script_unit =
-    //   Arc::new(register_script_unit.into_diagnostic()?);
-
-    // let module = Module::new();
-    // // let mut ctx = Context::new();
-    // let mut ctx = Context::with_default_modules().into_diagnostic()?;
-    // ctx.install(module).into_diagnostic()?;
-
-    // let rt_ctx = ctx.runtime().into_diagnostic()?;
-    // let ctx_arc = Arc::new(rt_ctx);
-    // let mut vm = Vm::new(ctx_arc, register_script_unit);
-
-    // let main = Hash::type_hash(["main"]);
-    // let result = vm
-    //   .execute(main, ())
-    //   .into_diagnostic()?
-    //   .complete()
-    //   .into_result()
-    //   .into_diagnostic()?;
-    // println!("Executed. {result:?}");
-
     Ok(())
   }
 }