diff --git a/Cargo.lock b/Cargo.lock
index d875cdf..a6ae50a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1124,7 +1124,6 @@ dependencies = [
  "ordered-float",
  "regex",
  "rust-embed",
- "rust_decimal",
  "some_executor 0.4.0",
  "substack",
  "test_executors",
@@ -1201,6 +1200,7 @@ dependencies = [
  "orchid-base",
  "orchid-extension",
  "ordered-float",
+ "rust_decimal",
  "tokio",
 ]
 
diff --git a/SWAP.md b/SWAP.md
index f74cbe1..0603be1 100644
--- a/SWAP.md
+++ b/SWAP.md
@@ -1,9 +1,5 @@
 ## Async conversion
 
-convert host to async non-send
-
-demonstrate operation with existing lex-hello example
-
 consider converting extension's SysCtx to a typed context bag
 
 align fn atom and macros on both sides with new design. No global state.
diff --git a/orchid-base/Cargo.toml b/orchid-base/Cargo.toml
index a6cb15a..4944ceb 100644
--- a/orchid-base/Cargo.toml
+++ b/orchid-base/Cargo.toml
@@ -23,7 +23,6 @@ orchid-api-traits = { version = "0.1.0", path = "../orchid-api-traits" }
 ordered-float = "4.6.0"
 regex = "1.11.1"
 rust-embed = "8.5.0"
-rust_decimal = "1.36.0"
 some_executor = "0.4.0"
 substack = "1.1.1"
 test_executors = "0.3.2"
diff --git a/orchid-base/src/interner.rs b/orchid-base/src/interner.rs
index c0c4afa..6e70360 100644
--- a/orchid-base/src/interner.rs
+++ b/orchid-base/src/interner.rs
@@ -98,7 +98,7 @@ impl Interned for String {
 impl InternMarker for api::TStr {
 	type Interned = String;
 	async fn resolve(self, i: &Interner) -> Tok<Self::Interned> {
-		Tok::new(Rc::new(i.master.as_ref().unwrap().request(api::ExternStr(self)).await), self)
+		Tok::new(Rc::new(i.0.master.as_ref().unwrap().request(api::ExternStr(self)).await), self)
 	}
 	fn get_id(self) -> NonZeroU64 { self.0 }
 	fn from_id(id: NonZeroU64) -> Self { Self(id) }
@@ -125,7 +125,7 @@ impl Interned for Vec<Tok<String>> {
 impl InternMarker for api::TStrv {
 	type Interned = Vec<Tok<String>>;
 	async fn resolve(self, i: &Interner) -> Tok<Self::Interned> {
-		let rep = i.master.as_ref().unwrap().request(api::ExternStrv(self)).await;
+		let rep = i.0.master.as_ref().unwrap().request(api::ExternStrv(self)).await;
 		let data = futures::future::join_all(rep.into_iter().map(|m| i.ex(m))).await;
 		Tok::new(Rc::new(data), self)
 	}
@@ -217,24 +217,26 @@ pub struct TypedInterners {
 }
 
 #[derive(Default)]
-pub struct Interner {
+pub struct InternerData {
 	interners: Mutex<TypedInterners>,
 	master: Option<Box<dyn DynRequester<Transfer = api::IntReq>>>,
 }
+#[derive(Clone, Default)]
+pub struct Interner(Rc<InternerData>);
 impl Interner {
 	pub fn new_master() -> Self { Self::default() }
 	pub fn new_replica(req: impl DynRequester<Transfer = api::IntReq> + 'static) -> Self {
-		Self { master: Some(Box::new(req)), interners: Mutex::default() }
+		Self(Rc::new(InternerData { master: Some(Box::new(req)), interners: Mutex::default() }))
 	}
 	/// Intern some data; query its identifier if not known locally
 	pub async fn i<T: Interned>(&self, t: &(impl Internable<Interned = T> + ?Sized)) -> Tok<T> {
 		let data = t.get_owned();
-		let mut g = self.interners.lock().await;
+		let mut g = self.0.interners.lock().await;
 		let typed = T::bimap(&mut g);
 		if let Some(tok) = typed.by_value(&data) {
 			return tok;
 		}
-		let marker = match &self.master {
+		let marker = match &self.0.master {
 			Some(c) => data.clone().intern(&**c).await,
 			None =>
 				T::Marker::from_id(NonZeroU64::new(ID.fetch_add(1, atomic::Ordering::Relaxed)).unwrap()),
@@ -245,29 +247,29 @@ impl Interner {
 	}
 	/// Extern an identifier; query the data it represents if not known locally
 	pub async fn ex<M: InternMarker>(&self, marker: M) -> Tok<M::Interned> {
-		if let Some(tok) = M::Interned::bimap(&mut *self.interners.lock().await).by_marker(marker) {
+		if let Some(tok) = M::Interned::bimap(&mut *self.0.interners.lock().await).by_marker(marker) {
 			return tok;
 		}
-		assert!(self.master.is_some(), "ID not in local interner and this is master");
+		assert!(self.0.master.is_some(), "ID not in local interner and this is master");
 		let token = marker.resolve(self).await;
-		M::Interned::bimap(&mut *self.interners.lock().await).insert(token.clone());
+		M::Interned::bimap(&mut *self.0.interners.lock().await).insert(token.clone());
 		token
 	}
 	pub async fn sweep_replica(&self) -> api::Retained {
-		assert!(self.master.is_some(), "Not a replica");
-		let mut g = self.interners.lock().await;
+		assert!(self.0.master.is_some(), "Not a replica");
+		let mut g = self.0.interners.lock().await;
 		api::Retained { strings: g.strings.sweep_replica(), vecs: g.vecs.sweep_replica() }
 	}
 	pub async fn sweep_master(&self, retained: api::Retained) {
-		assert!(self.master.is_none(), "Not master");
-		let mut g = self.interners.lock().await;
+		assert!(self.0.master.is_none(), "Not master");
+		let mut g = self.0.interners.lock().await;
 		g.strings.sweep_master(retained.strings.into_iter().collect());
 		g.vecs.sweep_master(retained.vecs.into_iter().collect());
 	}
 }
 impl fmt::Debug for Interner {
 	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-		write!(f, "Interner{{ replica: {} }}", self.master.is_none())
+		write!(f, "Interner{{ replica: {} }}", self.0.master.is_none())
 	}
 }
 
diff --git a/orchid-base/src/number.rs b/orchid-base/src/number.rs
index 527da4a..a902a79 100644
--- a/orchid-base/src/number.rs
+++ b/orchid-base/src/number.rs
@@ -1,9 +1,7 @@
 use std::num::IntErrorKind;
 use std::ops::Range;
 
-use num_traits::ToPrimitive;
 use ordered_float::NotNan;
-use rust_decimal::Decimal;
 
 use crate::error::{OrcErr, mk_err};
 use crate::interner::Interner;
@@ -12,24 +10,17 @@ use crate::location::Pos;
 /// A number, either floating point or unsigned int, parsed by Orchid.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum Numeric {
-	/// A nonnegative integer
-	Uint(u64),
+	/// An integer
+	Int(i64),
 	/// A binary float other than NaN
 	Float(NotNan<f64>),
-	/// A decimal number
-	Decimal(Decimal),
 }
 impl Numeric {
-	pub fn decimal(num: i64, scale: u32) -> Self { Self::Decimal(Decimal::new(num, scale)) }
 	pub fn float(value: f64) -> Self { Self::Float(NotNan::new(value).unwrap()) }
 	pub fn to_f64(self) -> NotNan<f64> {
 		match self {
 			Self::Float(f) => f,
-			Self::Decimal(d) => {
-				let f = d.to_f64().expect("This is apparently always possible");
-				NotNan::new(f).expect("decimal was nan")
-			},
-			Self::Uint(i) => NotNan::new(i as f64).expect("int cannot be NaN"),
+			Self::Int(i) => NotNan::new(i as f64).expect("int cannot be NaN"),
 		}
 	}
 }
@@ -77,31 +68,31 @@ pub async fn num_to_err(NumError { kind, range }: NumError, offset: u32, i: &Int
 
 /// Parse a numbre literal out of text
 pub fn parse_num(string: &str) -> Result<Numeric, NumError> {
-	let overflow_err = NumError { range: 0..string.len(), kind: NumErrorKind::Overflow };
+	let overflow_e = NumError { range: 0..string.len(), kind: NumErrorKind::Overflow };
 	let (radix, noprefix, pos) = (string.strip_prefix("0x").map(|s| (16u8, s, 2)))
 		.or_else(|| string.strip_prefix("0b").map(|s| (2u8, s, 2)))
 		.or_else(|| string.strip_prefix("0o").map(|s| (8u8, s, 2)))
 		.unwrap_or((10u8, string, 0));
 	eprintln!("({radix}, {noprefix}, {pos})");
 	// identity
-	let (base, exponent) = match noprefix.split_once('p') {
+	let (base_s, exponent) = match noprefix.split_once('p') {
 		Some((b, e)) => {
 			let (s, d, len) = e.strip_prefix('-').map_or((1, e, 0), |ue| (-1, ue, 1));
 			(b, s * int_parse(d, 10, pos + b.len() + 1 + len)? as i32)
 		},
 		None => (noprefix, 0),
 	};
-	eprintln!("({base},{exponent})");
-	match base.split_once('.') {
+	eprintln!("({base_s},{exponent})");
+	match base_s.split_once('.') {
 		None => {
-			let base_usize = int_parse(base, radix, pos)?;
+			let base = int_parse(base_s, radix, pos)?;
 			if let Ok(pos_exp) = u32::try_from(exponent) {
 				if let Some(radical) = u64::from(radix).checked_pow(pos_exp) {
-					let number = base_usize.checked_mul(radical).ok_or(overflow_err)?;
-					return Ok(Numeric::Uint(number));
+					let num = base.checked_mul(radical).and_then(|m| m.try_into().ok()).ok_or(overflow_e)?;
+					return Ok(Numeric::Int(num));
 				}
 			}
-			let f = (base_usize as f64) * (radix as f64).powi(exponent);
+			let f = (base as f64) * (radix as f64).powi(exponent);
 			let err = NumError { range: 0..string.len(), kind: NumErrorKind::NaN };
 			Ok(Numeric::Float(NotNan::new(f).map_err(|_| err)?))
 		},
@@ -109,25 +100,9 @@ pub fn parse_num(string: &str) -> Result<Numeric, NumError> {
 			let whole_n = int_parse(whole, radix, pos)?;
 			let part_n = int_parse(part, radix, pos + whole.len() + 1)?;
 			let scale = part.chars().filter(|c| *c != '_').count() as u32;
-			if radix == 10 {
-				let scaled_unit = 10u64.checked_pow(scale).ok_or(overflow_err.clone())?;
-				let scaled_n = i128::from(whole_n) * i128::from(scaled_unit) + i128::from(part_n);
-				let decimal = Decimal::from_i128_with_scale(scaled_n, scale);
-				let p = if let Ok(uexp) = u32::try_from(exponent) {
-					let e_multiplier = 10i64.checked_pow(uexp).ok_or(overflow_err)?;
-					Decimal::new(e_multiplier, 0)
-				} else {
-					let inv_oom = u32::try_from(-exponent).map_err(|_| overflow_err)?;
-					eprintln!("inv_oom: {inv_oom}");
-					Decimal::new(1, inv_oom)
-				};
-				eprintln!("({scaled_n}, {scale}, {p})");
-				Ok(Numeric::Decimal(decimal * p))
-			} else {
-				let real_val = whole_n as f64 + (part_n as f64 / (radix as f64).powi(scale as i32));
-				let f = real_val * (radix as f64).powi(exponent);
-				Ok(Numeric::Float(NotNan::new(f).expect("None of the inputs are NaN")))
-			}
+			let real_val = whole_n as f64 + (part_n as f64 / (radix as f64).powi(scale as i32));
+			let f = real_val * (radix as f64).powi(exponent);
+			Ok(Numeric::Float(NotNan::new(f).expect("None of the inputs are NaN")))
 		},
 	}
 }
@@ -168,7 +143,7 @@ mod test {
 
 	#[test]
 	fn just_ints() {
-		let test = |s, n| assert_eq!(parse_num(s), Ok(Numeric::Uint(n)));
+		let test = |s, n| assert_eq!(parse_num(s), Ok(Numeric::Int(n)));
 		test("12345", 12345);
 		test("0xcafebabe", 0xcafebabe);
 		test("0o751", 0o751);
@@ -178,11 +153,11 @@ mod test {
 	#[test]
 	fn decimals() {
 		let test = |s, n| assert_eq!(parse_num(s), Ok(n));
-		test("3.1417", Numeric::decimal(31417, 4));
+		test("3.1417", Numeric::float(3.1417));
 		test("0xf.cafe", Numeric::float(0xf as f64 + 0xcafe as f64 / 0x10000 as f64));
-		test("34p3", Numeric::Uint(34000));
-		test("0x2p3", Numeric::Uint(0x2 * 0x1000));
-		test("1.5p3", Numeric::decimal(1500, 0));
+		test("34p3", Numeric::Int(34000));
+		test("0x2p3", Numeric::Int(0x2 * 0x1000));
+		test("1.5p3", Numeric::float(1500.0));
 		test("0x2.5p3", Numeric::float((0x25 * 0x100) as f64));
 	}
 }
diff --git a/orchid-extension/src/atom.rs b/orchid-extension/src/atom.rs
index bccda8e..439cc48 100644
--- a/orchid-extension/src/atom.rs
+++ b/orchid-extension/src/atom.rs
@@ -42,6 +42,13 @@ pub trait AtomicVariant {}
 pub trait Atomic: 'static + Sized {
 	type Variant: AtomicVariant;
 	type Data: Clone + Coding + Sized + 'static;
+	/// Register handlers for IPC calls. If this atom implements [Supports], you
+	/// should register your implementations here. If this atom doesn't
+	/// participate in IPC at all, use the below body.
+	/// ```
+	/// MethodSetBuilder::new()
+	/// ```
+	// this method isn't default-implemented to prevent bugs from forgetting to register IPC requests.
 	fn reg_reqs() -> MethodSetBuilder<Self>;
 }
 impl<A: Atomic> AtomCard for A {
@@ -106,9 +113,9 @@ impl ForeignAtom<'static> {
 		ForeignAtom { _life: PhantomData, atom, ctx: handle.ctx.clone(), expr: Some(handle), pos }
 	}
 	pub async fn request<M: AtomMethod>(&self, m: M) -> Option<M::Response> {
-		let rep = (self.ctx.reqnot.request(api::Fwd(
+		let rep = (self.ctx.reqnot().request(api::Fwd(
 			self.atom.clone(),
-			Sym::parse(M::NAME, &self.ctx.i).await.unwrap().tok().to_api(),
+			Sym::parse(M::NAME, self.ctx.i()).await.unwrap().tok().to_api(),
 			enc_vec(&m).await,
 		)))
 		.await?;
@@ -125,7 +132,7 @@ impl fmt::Debug for ForeignAtom<'_> {
 }
 impl Format for ForeignAtom<'_> {
 	async fn print<'a>(&'a self, _c: &'a (impl FmtCtx + ?Sized + 'a)) -> FmtUnit {
-		FmtUnit::from_api(&self.ctx.reqnot.request(api::ExtAtomPrint(self.atom.clone())).await)
+		FmtUnit::from_api(&self.ctx.reqnot().request(api::ExtAtomPrint(self.atom.clone())).await)
 	}
 }
 impl AtomRepr for ForeignAtom<'_> {
@@ -145,7 +152,7 @@ pub struct NotTypAtom {
 impl NotTypAtom {
 	pub async fn mk_err(&self) -> OrcErr {
 		mk_err(
-			self.ctx.i.i("Not the expected type").await,
+			self.ctx.i().i("Not the expected type").await,
 			format!("This expression is not a {}", self.typ.name()),
 			[self.pos.clone().into()],
 		)
@@ -192,7 +199,7 @@ impl<A: AtomCard> MethodSetBuilder<A> {
 			handlers: stream::from_iter(self.handlers.iter())
 				.then(|(k, v)| {
 					clone!(ctx; async move {
-						(Sym::parse(k, &ctx.i).await.unwrap(), v.clone())
+						(Sym::parse(k, ctx.i()).await.unwrap(), v.clone())
 					})
 				})
 				.collect()
@@ -257,9 +264,9 @@ impl<A: AtomicFeatures> TypAtom<'_, A> {
 	pub async fn request<M: AtomMethod>(&self, req: M) -> M::Response
 	where A: Supports<M> {
 		M::Response::decode(Pin::new(
-			&mut &(self.data.ctx.reqnot.request(api::Fwd(
+			&mut &(self.data.ctx.reqnot().request(api::Fwd(
 				self.data.atom.clone(),
-				Sym::parse(M::NAME, &self.data.ctx.i).await.unwrap().tok().to_api(),
+				Sym::parse(M::NAME, self.data.ctx.i()).await.unwrap().tok().to_api(),
 				enc_vec(&req).await,
 			)))
 			.await
@@ -275,7 +282,7 @@ impl<A: AtomicFeatures> Deref for TypAtom<'_, A> {
 
 pub struct AtomCtx<'a>(pub &'a [u8], pub Option<api::AtomId>, pub SysCtx);
 impl FmtCtx for AtomCtx<'_> {
-	fn i(&self) -> &Interner { &self.2.i }
+	fn i(&self) -> &Interner { self.2.i() }
 }
 
 pub trait AtomDynfo: 'static {
diff --git a/orchid-extension/src/atom_owned.rs b/orchid-extension/src/atom_owned.rs
index 9815577..8336b67 100644
--- a/orchid-extension/src/atom_owned.rs
+++ b/orchid-extension/src/atom_owned.rs
@@ -28,20 +28,23 @@ use crate::atom::{
 };
 use crate::expr::{Expr, ExprHandle};
 use crate::gen_expr::{GExpr, bot};
-use crate::system::SysCtx;
+use crate::system::{SysCtx, SysCtxEntry};
+use crate::system_ctor::CtedObj;
 
 pub struct OwnedVariant;
 impl AtomicVariant for OwnedVariant {}
 impl<A: OwnedAtom + Atomic<Variant = OwnedVariant>> AtomicFeaturesImpl<OwnedVariant> for A {
 	fn _factory(self) -> AtomFactory {
 		AtomFactory::new(move |ctx| async move {
-			let serial = ctx.obj_store.0.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+			let serial =
+				ctx.get_or_default::<ObjStore>().next_id.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
 			let atom_id = api::AtomId(NonZero::new(serial + 1).unwrap());
-			let (typ_id, _) = get_info::<A>(ctx.cted.inst().card());
+			let (typ_id, _) = get_info::<A>(ctx.get::<CtedObj>().inst().card());
 			let mut data = enc_vec(&typ_id).await;
 			self.encode(Pin::<&mut Vec<u8>>::new(&mut data)).await;
-			ctx.obj_store.1.read().await.insert(atom_id, Box::new(self));
-			api::Atom { drop: Some(atom_id), data, owner: ctx.id }
+			ctx.get_or_default::<ObjStore>().objects.read().await.insert(atom_id, Box::new(self));
+			eprintln!("Created atom {:?} of type {}", atom_id, type_name::<A>());
+			api::Atom { drop: Some(atom_id), data, owner: ctx.sys_id() }
 		})
 	}
 	fn _info() -> Self::_Info { OwnedAtomDynfo { msbuild: A::reg_reqs(), ms: OnceCell::new() } }
@@ -55,8 +58,9 @@ pub(crate) struct AtomReadGuard<'a> {
 }
 impl<'a> AtomReadGuard<'a> {
 	async fn new(id: api::AtomId, ctx: &'a SysCtx) -> Self {
-		let guard = ctx.obj_store.1.read().await;
-		assert!(guard.get(&id).is_some(), "Received invalid atom ID: {}", id.0);
+		let guard = ctx.get_or_default::<ObjStore>().objects.read().await;
+		let valid = guard.iter().map(|i| i.0).collect_vec();
+		assert!(guard.get(&id).is_some(), "Received invalid atom ID: {:?} not in {:?}", id, valid);
 		Self { id, guard }
 	}
 }
@@ -66,7 +70,7 @@ impl Deref for AtomReadGuard<'_> {
 }
 
 pub(crate) async fn take_atom(id: api::AtomId, ctx: &SysCtx) -> Box<dyn DynOwnedAtom> {
-	let mut g = ctx.obj_store.1.write().await;
+	let mut g = ctx.get_or_default::<ObjStore>().objects.write().await;
 	g.remove(&id).unwrap_or_else(|| panic!("Received invalid atom ID: {}", id.0))
 }
 
@@ -219,7 +223,7 @@ pub trait OwnedAtom: Atomic<Variant = OwnedVariant> + Any + Clone + 'static {
 	fn val(&self) -> impl Future<Output = Cow<'_, Self::Data>>;
 	#[allow(unused_variables)]
 	fn call_ref(&self, arg: ExprHandle) -> impl Future<Output = GExpr> {
-		async move { bot([err_not_callable(&arg.ctx.i).await]) }
+		async move { bot([err_not_callable(arg.ctx.i()).await]) }
 	}
 	fn call(self, arg: ExprHandle) -> impl Future<Output = GExpr> {
 		async {
@@ -231,7 +235,7 @@ pub trait OwnedAtom: Atomic<Variant = OwnedVariant> + Any + Clone + 'static {
 	}
 	#[allow(unused_variables)]
 	fn command(self, ctx: SysCtx) -> impl Future<Output = OrcRes<Option<GExpr>>> {
-		async move { Err(err_not_command(&ctx.i).await.into()) }
+		async move { Err(err_not_command(ctx.i()).await.into()) }
 	}
 	#[allow(unused_variables)]
 	fn free(self, ctx: SysCtx) -> impl Future<Output = ()> { async {} }
@@ -313,4 +317,9 @@ impl<T: OwnedAtom> DynOwnedAtom for T {
 	}
 }
 
-pub type ObjStore = Rc<(AtomicU64, RwLock<MemoMap<api::AtomId, Box<dyn DynOwnedAtom>>>)>;
+#[derive(Default)]
+struct ObjStore {
+	next_id: AtomicU64,
+	objects: RwLock<MemoMap<api::AtomId, Box<dyn DynOwnedAtom>>>,
+}
+impl SysCtxEntry for ObjStore {}
diff --git a/orchid-extension/src/atom_thin.rs b/orchid-extension/src/atom_thin.rs
index 33f0629..6742ae6 100644
--- a/orchid-extension/src/atom_thin.rs
+++ b/orchid-extension/src/atom_thin.rs
@@ -19,16 +19,17 @@ use crate::atom::{
 use crate::expr::ExprHandle;
 use crate::gen_expr::{GExpr, bot};
 use crate::system::SysCtx;
+use crate::system_ctor::CtedObj;
 
 pub struct ThinVariant;
 impl AtomicVariant for ThinVariant {}
 impl<A: ThinAtom + Atomic<Variant = ThinVariant>> AtomicFeaturesImpl<ThinVariant> for A {
 	fn _factory(self) -> AtomFactory {
 		AtomFactory::new(move |ctx| async move {
-			let (id, _) = get_info::<A>(ctx.cted.inst().card());
+			let (id, _) = get_info::<A>(ctx.get::<CtedObj>().inst().card());
 			let mut buf = enc_vec(&id).await;
 			self.encode(Pin::new(&mut buf)).await;
-			api::Atom { drop: None, data: buf, owner: ctx.id }
+			api::Atom { drop: None, data: buf, owner: ctx.sys_id() }
 		})
 	}
 	fn _info() -> Self::_Info { ThinAtomDynfo { msbuild: Self::reg_reqs(), ms: OnceCell::new() } }
@@ -106,7 +107,7 @@ impl<T: ThinAtom> AtomDynfo for ThinAtomDynfo<T> {
 	fn drop<'a>(&'a self, AtomCtx(buf, _, ctx): AtomCtx<'a>) -> LocalBoxFuture<'a, ()> {
 		async move {
 			let string_self = T::decode(Pin::new(&mut &buf[..])).await.print(ctx.clone()).await;
-			writeln!(ctx.logger, "Received drop signal for non-drop atom {string_self:?}");
+			writeln!(ctx.logger(), "Received drop signal for non-drop atom {string_self:?}");
 		}
 		.boxed_local()
 	}
@@ -117,11 +118,11 @@ pub trait ThinAtom:
 {
 	#[allow(unused_variables)]
 	fn call(&self, arg: ExprHandle) -> impl Future<Output = GExpr> {
-		async move { bot([err_not_callable(&arg.ctx.i).await]) }
+		async move { bot([err_not_callable(arg.ctx.i()).await]) }
 	}
 	#[allow(unused_variables)]
 	fn command(&self, ctx: SysCtx) -> impl Future<Output = OrcRes<Option<GExpr>>> {
-		async move { Err(err_not_command(&ctx.i).await.into()) }
+		async move { Err(err_not_command(ctx.i()).await.into()) }
 	}
 	#[allow(unused_variables)]
 	fn print(&self, ctx: SysCtx) -> impl Future<Output = FmtUnit> {
diff --git a/orchid-extension/src/conv.rs b/orchid-extension/src/conv.rs
index 0d7cbaa..0130e7b 100644
--- a/orchid-extension/src/conv.rs
+++ b/orchid-extension/src/conv.rs
@@ -34,10 +34,10 @@ async fn err_type(pos: Pos, i: &Interner) -> OrcErr {
 impl<A: AtomicFeatures> TryFromExpr for TypAtom<'_, A> {
 	async fn try_from_expr(expr: Expr) -> OrcRes<Self> {
 		match expr.atom().await {
-			Err(ex) => Err(err_not_atom(ex.data().await.pos.clone(), &ex.ctx().i).await.into()),
+			Err(ex) => Err(err_not_atom(ex.data().await.pos.clone(), ex.ctx().i()).await.into()),
 			Ok(f) => match downcast_atom::<A>(f).await {
 				Ok(a) => Ok(a),
-				Err(f) => Err(err_type(f.pos(), &f.ctx().i).await.into()),
+				Err(f) => Err(err_type(f.pos(), f.ctx().i()).await.into()),
 			},
 		}
 	}
diff --git a/orchid-extension/src/entrypoint.rs b/orchid-extension/src/entrypoint.rs
index 7a36099..f12aed4 100644
--- a/orchid-extension/src/entrypoint.rs
+++ b/orchid-extension/src/entrypoint.rs
@@ -15,7 +15,7 @@ use futures::future::{LocalBoxFuture, join_all};
 use futures::{FutureExt, StreamExt};
 use hashbrown::HashMap;
 use itertools::Itertools;
-use orchid_api::ApplyMacro;
+use orchid_api::{ApplyMacro, ExtMsgSet};
 use orchid_api_traits::{Decode, Encode, enc_vec};
 use orchid_base::builtin::{ExtPort, Spawner};
 use orchid_base::char_filter::{char_filter_match, char_filter_union, mk_char_filter};
@@ -32,14 +32,14 @@ use trait_set::trait_set;
 
 use crate::api;
 use crate::atom::{AtomCtx, AtomDynfo, AtomTypeId};
-use crate::atom_owned::{ObjStore, take_atom};
+use crate::atom_owned::take_atom;
 use crate::fs::VirtFS;
 use crate::lexer::{LexContext, err_cascade, err_not_applicable};
 use crate::macros::{Rule, RuleCtx};
 use crate::msg::{recv_parent_msg, send_parent_msg};
 use crate::system::{SysCtx, atom_by_idx};
 use crate::system_ctor::{CtedObj, DynSystemCtor};
-use crate::tree::{GenTok, GenTokTree, LazyMemberFactory, TIACtxImpl, do_extra};
+use crate::tree::{GenTok, GenTokTree, LazyMemberFactory, TreeIntoApiCtxImpl, do_extra};
 
 pub type ExtReq<'a> = RequestHandle<'a, api::ExtMsgSet>;
 pub type ExtReqNot = ReqNot<api::ExtMsgSet>;
@@ -61,11 +61,11 @@ pub enum MemberRecord {
 }
 
 pub struct SystemRecord {
-	cted: CtedObj,
 	vfses: HashMap<api::VfsId, &'static dyn VirtFS>,
 	declfs: api::EagerVfs,
 	lazy_members: HashMap<api::TreeId, MemberRecord>,
 	rules: HashMap<api::MacroId, Rc<Rule>>,
+	ctx: SysCtx,
 }
 
 trait_set! {
@@ -78,14 +78,13 @@ trait_set! {
 }
 
 pub async fn with_atom_record<'a, F: Future<Output = SysCtx>, T>(
-	get_sys_ctx: &impl Fn(api::SysId, ReqNot<api::ExtMsgSet>) -> F,
-	reqnot: ReqNot<api::ExtMsgSet>,
+	get_sys_ctx: &impl Fn(api::SysId) -> F,
 	atom: &'a api::Atom,
 	cb: impl WARCallback<'a, T>,
 ) -> T {
 	let mut data = &atom.data[..];
-	let ctx = get_sys_ctx(atom.owner, reqnot).await;
-	let inst = ctx.cted.inst();
+	let ctx = get_sys_ctx(atom.owner).await;
+	let inst = ctx.get::<CtedObj>().inst();
 	let id = AtomTypeId::decode(Pin::new(&mut data)).await;
 	let atom_record = atom_by_idx(inst.card(), id.clone()).expect("Atom ID reserved");
 	cb(atom_record, ctx, id, data).await
@@ -108,6 +107,7 @@ pub struct ExtensionOwner {
 	rn: ReqNot<api::ExtMsgSet>,
 	out_recv: Receiver<Vec<u8>>,
 	out_send: Sender<Vec<u8>>,
+	ext_header: api::ExtensionHeader,
 }
 
 impl ExtPort for ExtensionOwner {
@@ -125,6 +125,12 @@ impl ExtPort for ExtensionOwner {
 		.boxed_local()
 	}
 }
+impl ExtensionOwner {
+	pub fn ext_header(&self) -> &api::ExtensionHeader { &self.ext_header }
+	// pub async fn new(data: ExtensionData, spawner: Spawner, header:
+	// api::HostHeader) -> Self { 	let decls =
+	// }
+}
 
 pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 	let api::HostHeader { log_strategy, msg_logs } =
@@ -134,7 +140,7 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 		.map(|(id, sys)| (u16::try_from(id).expect("more than u16max system ctors"), sys))
 		.map(|(id, sys)| sys.decl(api::SysDeclId(NonZero::new(id + 1).unwrap())))
 		.collect_vec();
-	let systems = Rc::new(Mutex::new(HashMap::<api::SysId, SystemRecord>::new()));
+	let systems_lock = Rc::new(Mutex::new(HashMap::<api::SysId, SystemRecord>::new()));
 	api::ExtensionHeader { name: data.name.to_string(), systems: decls.clone() }
 		.encode(Pin::new(&mut buf))
 		.await;
@@ -143,41 +149,48 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 	let exiting = Arc::new(AtomicBool::new(false));
 	let logger = Logger::new(log_strategy);
 	let msg_logger = Logger::new(msg_logs);
-	let interner_cell = Rc::new(RefCell::new(None::<Rc<Interner>>));
+	let interner_cell = Rc::new(RefCell::new(None::<Interner>));
 	let interner_weak = Rc::downgrade(&interner_cell);
-	let obj_store = ObjStore::default();
-	let mk_ctx = clone!(
-		logger, systems, spawner, obj_store, interner_weak;
-		move |id: api::SysId, reqnot: ReqNot<api::ExtMsgSet>| {
-			clone!(logger, systems, spawner, obj_store, interner_weak; async move {
-				let cted = systems.lock().await[&id].cted.clone();
-				let interner_cell = (interner_weak.upgrade())
-					.expect("mk_ctx called after Interner rc dropped");
-				let i = (interner_cell.borrow().clone())
-					.expect("mk_ctx called before interner initialized");
-				SysCtx { id, cted, logger, reqnot, spawner, obj_store, i: i.clone() }
-			}.boxed_local())
-	});
+	let systems_weak = Rc::downgrade(&systems_lock);
+	let get_ctx = clone!(systems_weak; move |id: api::SysId| clone!(systems_weak; async move {
+		let systems =
+			systems_weak.upgrade().expect("System table dropped before request processing done");
+		let x = systems.lock().await.get(&id).expect("System not found").ctx.clone();
+		x
+	}));
+	let init_ctx = {
+		clone!(systems_weak, interner_weak, spawner, logger);
+		move |id: api::SysId, cted: CtedObj, reqnot: ReqNot<ExtMsgSet>| {
+			clone!(systems_weak, interner_weak, spawner, logger; async move {
+				let interner_rc =
+					interner_weak.upgrade().expect("System construction order while shutting down");
+				let i = interner_rc.borrow().clone().expect("mk_ctx called very early, no interner!");
+				SysCtx::new(id, i, reqnot, spawner, logger, cted)
+			})
+		}
+	};
 	let rn = ReqNot::<api::ExtMsgSet>::new(
 		msg_logger.clone(),
 		move |a, _| async move { send_parent_msg(a).await.unwrap() }.boxed_local(),
-		clone!(systems, exiting, mk_ctx; move |n, reqnot| {
-			clone!(systems, exiting, mk_ctx; async move {
+		clone!(systems_weak, exiting, get_ctx; move |n, reqnot| {
+			clone!(systems_weak, exiting, get_ctx; async move {
 				match n {
 					api::HostExtNotif::Exit => exiting.store(true, Ordering::Relaxed),
 					api::HostExtNotif::SystemDrop(api::SystemDrop(sys_id)) =>
-						mem::drop(systems.lock().await.remove(&sys_id)),
+						if let Some(rc) = systems_weak.upgrade() {
+							mem::drop(rc.lock().await.remove(&sys_id))
+						},
 					api::HostExtNotif::AtomDrop(api::AtomDrop(sys_id, atom)) => {
-						let ctx = mk_ctx(sys_id, reqnot).await;
+						let ctx = get_ctx(sys_id).await;
 						take_atom(atom, &ctx).await.dyn_free(ctx.clone()).await
 					}
 				}
 			}.boxed_local())
 		}),
 		{
-			clone!(systems, logger, mk_ctx, interner_weak, obj_store, spawner, decls, msg_logger);
+			clone!(logger, get_ctx, init_ctx, systems_weak, interner_weak, spawner, decls, msg_logger);
 			move |hand, req| {
-				clone!(systems, logger, mk_ctx, interner_weak, obj_store, spawner, decls, msg_logger);
+				clone!(logger, get_ctx, init_ctx, systems_weak, interner_weak, spawner, decls, msg_logger);
 				async move {
 					let interner_cell = interner_weak.upgrade().expect("Interner dropped before request");
 					let i = interner_cell.borrow().clone().expect("Request arrived before interner set");
@@ -197,21 +210,13 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 								});
 							let lazy_mems = Mutex::new(HashMap::new());
 							let rules = Mutex::new(HashMap::new());
-							let ctx = SysCtx {
-								cted: cted.clone(),
-								id: new_sys.id,
-								logger: logger.clone(),
-								reqnot: hand.reqnot(),
-								i: i.clone(),
-								obj_store: obj_store.clone(),
-								spawner: spawner.clone(),
-							};
+							let ctx = init_ctx(new_sys.id, cted.clone(), hand.reqnot()).await;
 							let const_root = stream::from_iter(cted.inst().dyn_env())
 								.then(|(k, v)| {
 									let (req, lazy_mems, rules) = (&hand, &lazy_mems, &rules);
 									clone!(i, ctx; async move {
 										let name = i.i(&k).await.to_api();
-										let value = v.into_api(&mut TIACtxImpl {
+										let value = v.into_api(&mut TreeIntoApiCtxImpl {
 											lazy_members: &mut *lazy_mems.lock().await,
 											rules: &mut *rules.lock().await,
 											sys: ctx,
@@ -229,17 +234,19 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 							let record = SystemRecord {
 								declfs,
 								vfses,
-								cted,
+								ctx,
 								lazy_members: lazy_mems.into_inner(),
 								rules: rules.into_inner(),
 							};
+							let systems = systems_weak.upgrade().expect("System constructed during shutdown");
 							systems.lock().await.insert(new_sys.id, record);
 							hand
 								.handle(&new_sys, &api::SystemInst { lex_filter, const_root, line_types: vec![] })
 								.await
 						},
 						api::HostExtReq::GetMember(get_tree @ api::GetMember(sys_id, tree_id)) => {
-							let sys_ctx = mk_ctx(sys_id, hand.reqnot()).await;
+							let sys_ctx = get_ctx(sys_id).await;
+							let systems = systems_weak.upgrade().expect("Member queried during shutdown");
 							let mut systems_g = systems.lock().await;
 							let SystemRecord { lazy_members, rules, .. } =
 								systems_g.get_mut(&sys_id).expect("System not found");
@@ -248,8 +255,8 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 								Some(MemberRecord::Res) => panic!("This tree has already been transmitted"),
 								Some(MemberRecord::Gen(path, cb)) => (path, cb),
 							};
-							let tree = cb.build(Sym::new(path.clone(), &i).await.unwrap()).await;
-							let mut tia_ctx = TIACtxImpl {
+							let tree = cb.build(Sym::new(path.clone(), &i).await.unwrap(), sys_ctx.clone()).await;
+							let mut tia_ctx = TreeIntoApiCtxImpl {
 								sys: sys_ctx,
 								path: Substack::Bottom,
 								basepath: &path,
@@ -260,32 +267,33 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 							hand.handle(&get_tree, &tree.into_api(&mut tia_ctx).await).await
 						},
 						api::HostExtReq::VfsReq(api::VfsReq::GetVfs(get_vfs @ api::GetVfs(sys_id))) => {
+							let systems = systems_weak.upgrade().expect("VFS root requested during shutdown");
 							let systems_g = systems.lock().await;
 							hand.handle(&get_vfs, &systems_g[&sys_id].declfs).await
 						},
 						api::HostExtReq::SysReq(api::SysReq::SysFwded(fwd)) => {
 							let api::SysFwded(sys_id, payload) = fwd;
-							let ctx = mk_ctx(sys_id, hand.reqnot()).await;
-							let sys = ctx.cted.inst();
+							let ctx = get_ctx(sys_id).await;
+							let sys = ctx.cted().inst();
 							sys.dyn_request(hand, payload).await
 						},
 						api::HostExtReq::VfsReq(api::VfsReq::VfsRead(vfs_read)) => {
 							let api::VfsRead(sys_id, vfs_id, path) = &vfs_read;
-							let ctx = mk_ctx(*sys_id, hand.reqnot()).await;
+							let ctx = get_ctx(*sys_id).await;
+							let systems = systems_weak.upgrade().expect("VFS requested during shutdoown");
 							let systems_g = systems.lock().await;
 							let path = join_all(path.iter().map(|t| Tok::from_api(*t, &i))).await;
 							let vfs = systems_g[sys_id].vfses[vfs_id].load(&path, ctx).await;
 							hand.handle(&vfs_read, &vfs).await
 						},
 						api::HostExtReq::LexExpr(lex @ api::LexExpr { sys, text, pos, id }) => {
-							let systems_g = systems.lock().await;
-							let lexers = systems_g[&sys].cted.inst().dyn_lexers();
-							mem::drop(systems_g);
+							let sys_ctx = get_ctx(sys).await;
 							let text = Tok::from_api(text, &i).await;
 							let ctx = LexContext { sys, id, pos, reqnot: hand.reqnot(), text: &text, i: &i };
 							let trigger_char = text.chars().nth(pos as usize).unwrap();
 							let err_na = err_not_applicable(&i).await;
 							let err_cascade = err_cascade(&i).await;
+							let lexers = sys_ctx.cted().inst().dyn_lexers();
 							for lx in lexers.iter().filter(|l| char_filter_match(l.char_filter(), trigger_char)) {
 								match lx.lex(&text[pos as usize..], &ctx).await {
 									Err(e) if e.any(|e| *e == err_na) => continue,
@@ -294,10 +302,9 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 										return hand.handle(&lex, &eopt).await;
 									},
 									Ok((s, expr)) => {
-										let ctx = mk_ctx(sys, hand.reqnot()).await;
 										let expr = expr
 											.to_api(&mut |f, r| {
-												clone!(ctx; async move { do_extra(f, r, ctx).await }).boxed_local()
+												clone!(sys_ctx; async move { do_extra(f, r, sys_ctx).await }).boxed_local()
 											})
 											.await;
 										let pos = (text.len() - s.len()) as u32;
@@ -310,8 +317,8 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 						},
 						api::HostExtReq::ParseLine(pline) => {
 							let api::ParseLine { exported, comments, sys, line } = &pline;
-							let mut ctx = mk_ctx(*sys, hand.reqnot()).await;
-							let parsers = ctx.cted.inst().dyn_parsers();
+							let mut ctx = get_ctx(*sys).await;
+							let parsers = ctx.cted().inst().dyn_parsers();
 							let comments = join_all(comments.iter().map(|c| Comment::from_api(c, &i))).await;
 							let line: Vec<GenTokTree> = ttv_from_api(line, &mut ctx, &i).await;
 							let snip = Snippet::new(line.first().expect("Empty line"), &line, &i);
@@ -337,7 +344,7 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 						api::HostExtReq::AtomReq(atom_req) => {
 							let atom = atom_req.get_atom();
 							let atom_req = atom_req.clone();
-							with_atom_record(&mk_ctx, hand.reqnot(), atom, move |nfo, ctx, id, buf| {
+							with_atom_record(&get_ctx, atom, move |nfo, ctx, id, buf| {
 								async move {
 									let actx = AtomCtx(buf, atom.drop, ctx.clone());
 									match &atom_req {
@@ -389,16 +396,16 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 						api::HostExtReq::DeserAtom(deser) => {
 							let api::DeserAtom(sys, buf, refs) = &deser;
 							let mut read = &mut &buf[..];
-							let ctx = mk_ctx(*sys, hand.reqnot()).await;
+							let ctx = get_ctx(*sys).await;
 							let id = AtomTypeId::decode(Pin::new(&mut read)).await;
-							let inst = ctx.cted.inst();
+							let inst = ctx.cted().inst();
 							let nfo = atom_by_idx(inst.card(), id).expect("Deserializing atom with invalid ID");
 							hand.handle(&deser, &nfo.deserialize(ctx.clone(), read, refs).await).await
 						},
 						orchid_api::HostExtReq::ApplyMacro(am) => {
 							let tok = hand.will_handle_as(&am);
 							let ApplyMacro { id, params, run_id, sys } = am;
-							let sys_ctx = mk_ctx(sys, hand.reqnot()).await;
+							let sys_ctx = get_ctx(sys).await;
 							let mut ctx =
 								RuleCtx { args: ahash::HashMap::default(), run_id, sys: sys_ctx.clone() };
 							for (k, v) in params {
@@ -408,6 +415,7 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 								);
 							}
 							let err_cascade = err_cascade(&i).await;
+							let systems = systems_weak.upgrade().expect("macro call during shutdown");
 							let systems_g = systems.lock().await;
 							let rule = &systems_g[&sys].rules[&id];
 							match (rule.apply)(ctx).await {
@@ -432,7 +440,7 @@ pub async fn extension_main_logic(data: ExtensionData, spawner: Spawner) {
 			}
 		},
 	);
-	*interner_cell.borrow_mut() = Some(Rc::new(Interner::new_replica(rn.clone().map())));
+	*interner_cell.borrow_mut() = Some(Interner::new_replica(rn.clone().map()));
 	while !exiting.load(Ordering::Relaxed) {
 		let rcvd = recv_parent_msg().await.unwrap();
 		spawner(Box::pin(clone!(rn; async move { rn.receive(&rcvd).await })))
diff --git a/orchid-extension/src/expr.rs b/orchid-extension/src/expr.rs
index 701efd6..18c1f88 100644
--- a/orchid-extension/src/expr.rs
+++ b/orchid-extension/src/expr.rs
@@ -23,7 +23,7 @@ impl ExprHandle {
 	pub(crate) fn from_args(ctx: SysCtx, tk: api::ExprTicket) -> Self { Self { ctx, tk } }
 	pub fn get_ctx(&self) -> SysCtx { self.ctx.clone() }
 	pub async fn clone(&self) -> Self {
-		self.ctx.reqnot.notify(api::Acquire(self.ctx.id, self.tk)).await;
+		self.ctx.reqnot().notify(api::Acquire(self.ctx.sys_id(), self.tk)).await;
 		Self { ctx: self.ctx.clone(), tk: self.tk }
 	}
 }
@@ -34,9 +34,9 @@ impl fmt::Debug for ExprHandle {
 }
 impl Drop for ExprHandle {
 	fn drop(&mut self) {
-		let notif = api::Release(self.ctx.id, self.tk);
-		let SysCtx { reqnot, spawner, .. } = self.ctx.clone();
-		spawner(Box::pin(async move { reqnot.notify(notif).await }))
+		let notif = api::Release(self.ctx.sys_id(), self.tk);
+		let reqnot = self.ctx.reqnot().clone();
+		self.ctx.spawner()(Box::pin(async move { reqnot.notify(notif).await }))
 	}
 }
 
@@ -53,13 +53,13 @@ impl Expr {
 
 	pub async fn data(&self) -> &ExprData {
 		(self.data.get_or_init(async {
-			let details = self.handle.ctx.reqnot.request(api::Inspect { target: self.handle.tk }).await;
-			let pos = Pos::from_api(&details.location, &self.handle.ctx.i).await;
+			let details = self.handle.ctx.reqnot().request(api::Inspect { target: self.handle.tk }).await;
+			let pos = Pos::from_api(&details.location, self.handle.ctx.i()).await;
 			let kind = match details.kind {
 				api::InspectedKind::Atom(a) =>
 					ExprKind::Atom(ForeignAtom::new(self.handle.clone(), a, pos.clone())),
 				api::InspectedKind::Bottom(b) =>
-					ExprKind::Bottom(OrcErrv::from_api(&b, &self.handle.ctx.i).await),
+					ExprKind::Bottom(OrcErrv::from_api(&b, self.handle.ctx.i()).await),
 				api::InspectedKind::Opaque => ExprKind::Opaque,
 			};
 			ExprData { pos, kind }
@@ -83,7 +83,7 @@ impl Format for Expr {
 			ExprKind::Opaque => "OPAQUE".to_string().into(),
 			ExprKind::Bottom(b) => format!("Bottom({b})").into(),
 			ExprKind::Atom(a) =>
-				FmtUnit::from_api(&self.handle.ctx.reqnot.request(ExtAtomPrint(a.atom.clone())).await),
+				FmtUnit::from_api(&self.handle.ctx.reqnot().request(ExtAtomPrint(a.atom.clone())).await),
 		}
 	}
 }
diff --git a/orchid-extension/src/func_atom.rs b/orchid-extension/src/func_atom.rs
index aa7d5f2..69e397d 100644
--- a/orchid-extension/src/func_atom.rs
+++ b/orchid-extension/src/func_atom.rs
@@ -13,7 +13,6 @@ use never::Never;
 use orchid_api_traits::Encode;
 use orchid_base::clone;
 use orchid_base::error::OrcRes;
-use orchid_base::format::{FmtCtxImpl, Format, take_first};
 use orchid_base::name::Sym;
 use trait_set::trait_set;
 
@@ -22,7 +21,7 @@ use crate::atom_owned::{DeserializeCtx, OwnedAtom, OwnedVariant};
 use crate::conv::ToExpr;
 use crate::expr::{Expr, ExprHandle};
 use crate::gen_expr::GExpr;
-use crate::system::SysCtx;
+use crate::system::{SysCtx, SysCtxEntry};
 
 trait_set! {
 	trait FunCB = Fn(Vec<Expr>) -> LocalBoxFuture<'static, OrcRes<GExpr>> + 'static;
@@ -33,9 +32,9 @@ pub trait ExprFunc<I, O>: Clone + 'static {
 	fn apply(&self, v: Vec<Expr>) -> impl Future<Output = OrcRes<GExpr>>;
 }
 
-thread_local! {
-	static FUNS: Rc<Mutex<HashMap<Sym, (u8, Rc<dyn FunCB>)>>> = Rc::default();
-}
+#[derive(Default)]
+struct FunsCtx(Mutex<HashMap<Sym, (u8, Rc<dyn FunCB>)>>);
+impl SysCtxEntry for FunsCtx {}
 
 /// An Atom representing a partially applied named native function. These
 /// partial calls are serialized into the name of the native function and the
@@ -50,9 +49,9 @@ pub(crate) struct Fun {
 	fun: Rc<dyn FunCB>,
 }
 impl Fun {
-	pub async fn new<I, O, F: ExprFunc<I, O>>(path: Sym, f: F) -> Self {
-		let funs = FUNS.with(|funs| funs.clone());
-		let mut fung = funs.lock().await;
+	pub async fn new<I, O, F: ExprFunc<I, O>>(path: Sym, ctx: SysCtx, f: F) -> Self {
+		let funs: &FunsCtx = ctx.get_or_default();
+		let mut fung = funs.0.lock().await;
 		let fun = if let Some(x) = fung.get(&path) {
 			x.1.clone()
 		} else {
@@ -89,8 +88,8 @@ impl OwnedAtom for Fun {
 	}
 	async fn deserialize(mut ctx: impl DeserializeCtx, args: Self::Refs) -> Self {
 		let sys = ctx.sys();
-		let path = Sym::from_api(ctx.decode().await, &sys.i).await;
-		let (arity, fun) = FUNS.with(|f| f.clone()).lock().await.get(&path).unwrap().clone();
+		let path = Sym::from_api(ctx.decode().await, sys.i()).await;
+		let (arity, fun) = sys.get_or_default::<FunsCtx>().0.lock().await.get(&path).unwrap().clone();
 		Self { args, arity, path, fun }
 	}
 	async fn print(&self, _: SysCtx) -> orchid_base::format::FmtUnit {
diff --git a/orchid-extension/src/macros.rs b/orchid-extension/src/macros.rs
index bb507a2..dbd102f 100644
--- a/orchid-extension/src/macros.rs
+++ b/orchid-extension/src/macros.rs
@@ -4,10 +4,11 @@ use ahash::HashMap;
 use futures::future::{LocalBoxFuture, join_all};
 use itertools::Itertools;
 use never::Never;
+use orchid_api::ExtMsgSet;
 use orchid_base::error::OrcRes;
 use orchid_base::interner::Tok;
 use orchid_base::macros::{MTree, mtreev_from_api, mtreev_to_api};
-use orchid_base::reqnot::Requester;
+use orchid_base::reqnot::{ReqNot, Requester};
 use trait_set::trait_set;
 
 use crate::api;
@@ -44,11 +45,11 @@ impl<'a> RuleCtx<'a> {
 			run_id: self.run_id,
 			query: mtreev_to_api(tree, &mut |b| match *b {}).await,
 		};
-		let Some(treev) = self.sys.reqnot.request(req).await else {
-			return Err(err_cascade(&self.sys.i).await.into());
+		let Some(treev) = self.sys.get::<ReqNot<ExtMsgSet>>().request(req).await else {
+			return Err(err_cascade(self.sys.i()).await.into());
 		};
 		static ATOM_MSG: &str = "Returned atom from Rule recursion";
-		Ok(mtreev_from_api(&treev, &self.sys.i, &mut |_| panic!("{ATOM_MSG}")).await)
+		Ok(mtreev_from_api(&treev, self.sys.i(), &mut |_| panic!("{ATOM_MSG}")).await)
 	}
 	pub fn getv(&mut self, key: &Tok<String>) -> Vec<MTree<'a, Never>> {
 		self.args.remove(key).expect("Key not found")
@@ -78,7 +79,7 @@ impl Rule {
 	pub(crate) async fn into_api(self, ctx: &mut impl TreeIntoApiCtx) -> api::MacroRule {
 		api::MacroRule {
 			comments: join_all(self.comments.iter().map(|c| async {
-				api::Comment { text: ctx.sys().i.i(c).await.to_api(), location: api::Location::Inherit }
+				api::Comment { text: ctx.sys().i().i(c).await.to_api(), location: api::Location::Inherit }
 			}))
 			.await,
 			location: api::Location::Inherit,
diff --git a/orchid-extension/src/system.rs b/orchid-extension/src/system.rs
index 7b390aa..c9524a6 100644
--- a/orchid-extension/src/system.rs
+++ b/orchid-extension/src/system.rs
@@ -1,5 +1,5 @@
-use core::fmt;
-use std::any::{TypeId, type_name};
+use std::any::{Any, TypeId, type_name};
+use std::fmt;
 use std::future::Future;
 use std::num::NonZero;
 use std::pin::Pin;
@@ -7,6 +7,8 @@ use std::rc::Rc;
 
 use futures::future::LocalBoxFuture;
 use hashbrown::HashMap;
+use memo_map::MemoMap;
+use orchid_api::ExtMsgSet;
 use orchid_api_traits::{Coding, Decode};
 use orchid_base::boxed_iter::BoxedIter;
 use orchid_base::builtin::Spawner;
@@ -16,7 +18,6 @@ use orchid_base::reqnot::{Receipt, ReqNot};
 
 use crate::api;
 use crate::atom::{AtomCtx, AtomDynfo, AtomTypeId, AtomicFeatures, ForeignAtom, TypAtom, get_info};
-use crate::atom_owned::ObjStore;
 use crate::entrypoint::ExtReq;
 use crate::fs::DeclFs;
 use crate::func_atom::Fun;
@@ -116,11 +117,11 @@ where A: AtomicFeatures {
 	let mut data = &foreign.atom.data[..];
 	let ctx = foreign.ctx.clone();
 	let value = AtomTypeId::decode(Pin::new(&mut data)).await;
-	let own_inst = ctx.cted.inst();
-	let owner = if ctx.id == foreign.atom.owner {
+	let own_inst = ctx.get::<CtedObj>().inst();
+	let owner = if *ctx.get::<api::SysId>() == foreign.atom.owner {
 		own_inst.card()
 	} else {
-		(ctx.cted.deps().find(|s| s.id() == foreign.atom.owner))
+		(ctx.get::<CtedObj>().deps().find(|s| s.id() == foreign.atom.owner))
 			.ok_or_else(|| foreign.clone())?
 			.get_card()
 	};
@@ -133,18 +134,80 @@ where A: AtomicFeatures {
 	Ok(TypAtom { value, data: foreign })
 }
 
+// #[derive(Clone)]
+// pub struct SysCtx {
+// 	pub reqnot: ReqNot<api::ExtMsgSet>,
+// 	pub spawner: Spawner,
+// 	pub id: api::SysId,
+// 	pub cted: CtedObj,
+// 	pub logger: Logger,
+// 	pub obj_store: ObjStore,
+// 	pub i: Rc<Interner>,
+// }
+// impl fmt::Debug for SysCtx {
+// 	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+// 		write!(f, "SysCtx({:?})", self.id)
+// 	}
+// }
+
 #[derive(Clone)]
-pub struct SysCtx {
-	pub reqnot: ReqNot<api::ExtMsgSet>,
-	pub spawner: Spawner,
-	pub id: api::SysId,
-	pub cted: CtedObj,
-	pub logger: Logger,
-	pub obj_store: ObjStore,
-	pub i: Rc<Interner>,
+pub struct SysCtx(Rc<MemoMap<TypeId, Box<dyn Any>>>);
+impl SysCtx {
+	pub fn new(
+		id: api::SysId,
+		i: Interner,
+		reqnot: ReqNot<ExtMsgSet>,
+		spawner: Spawner,
+		logger: Logger,
+		cted: CtedObj,
+	) -> Self {
+		let this = Self(Rc::new(MemoMap::new()));
+		this.add(id).add(i).add(reqnot).add(spawner).add(logger).add(cted);
+		this
+	}
+	pub fn add<T: SysCtxEntry>(&self, t: T) -> &Self {
+		assert!(self.0.insert(TypeId::of::<T>(), Box::new(t)), "Key already exists");
+		self
+	}
+	pub fn get_or_insert<T: SysCtxEntry>(&self, f: impl FnOnce() -> T) -> &T {
+		(self.0.get_or_insert_owned(TypeId::of::<T>(), || Box::new(f())).downcast_ref())
+			.expect("Keyed by TypeId")
+	}
+	pub fn get_or_default<T: SysCtxEntry + Default>(&self) -> &T {
+		self.get_or_insert(|| {
+			let rc_id = self.0.as_ref() as *const _ as *const () as usize;
+			eprintln!("Default-initializing {} in {}", type_name::<T>(), rc_id);
+			T::default()
+		})
+	}
+	pub fn try_get<T: SysCtxEntry>(&self) -> Option<&T> {
+		Some(self.0.get(&TypeId::of::<T>())?.downcast_ref().expect("Keyed by TypeId"))
+	}
+	pub fn get<T: SysCtxEntry>(&self) -> &T {
+		self.try_get().unwrap_or_else(|| panic!("Context {} missing", type_name::<T>()))
+	}
+	/// Shorthand to get the [Interner] instance
+	pub fn i(&self) -> &Interner { self.get::<Interner>() }
+	/// Shorthand to get the messaging link
+	pub fn reqnot(&self) -> &ReqNot<ExtMsgSet> { self.get::<ReqNot<ExtMsgSet>>() }
+	/// Shorthand to get the system ID
+	pub fn sys_id(&self) -> api::SysId { *self.get::<api::SysId>() }
+	/// Shorthand to get the task spawner callback
+	pub fn spawner(&self) -> &Spawner { self.get::<Spawner>() }
+	/// Shorthand to get the logger
+	pub fn logger(&self) -> &Logger { self.get::<Logger>() }
+	/// Shorthand to get the constructed system object
+	pub fn cted(&self) -> &CtedObj { self.get::<CtedObj>() }
 }
 impl fmt::Debug for SysCtx {
-	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-		write!(f, "SysCtx({:?})", self.id)
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		write!(f, "SysCtx({:?})", self.sys_id())
 	}
 }
+pub trait SysCtxEntry: 'static + Sized {}
+impl SysCtxEntry for api::SysId {}
+impl SysCtxEntry for ReqNot<api::ExtMsgSet> {}
+impl SysCtxEntry for Spawner {}
+impl SysCtxEntry for CtedObj {}
+impl SysCtxEntry for Logger {}
+impl SysCtxEntry for Interner {}
diff --git a/orchid-extension/src/tree.rs b/orchid-extension/src/tree.rs
index dc3b49e..4918491 100644
--- a/orchid-extension/src/tree.rs
+++ b/orchid-extension/src/tree.rs
@@ -46,7 +46,7 @@ pub struct GenItem {
 impl GenItem {
 	pub async fn into_api(self, ctx: &mut impl TreeIntoApiCtx) -> api::Item {
 		let kind = match self.kind {
-			GenItemKind::Export(n) => api::ItemKind::Export(ctx.sys().i.i::<String>(&n).await.to_api()),
+			GenItemKind::Export(n) => api::ItemKind::Export(ctx.sys().i().i::<String>(&n).await.to_api()),
 			GenItemKind::Member(mem) => api::ItemKind::Member(mem.into_api(ctx).await),
 			GenItemKind::Import(cn) => api::ItemKind::Import(cn.tok().to_api()),
 			GenItemKind::Macro(priority, gen_rules) => {
@@ -60,7 +60,7 @@ impl GenItem {
 		let comments = join_all(self.comments.iter().map(|c| async {
 			api::Comment {
 				location: api::Location::Inherit,
-				text: ctx.sys().i.i::<String>(c).await.to_api(),
+				text: ctx.sys().i().i::<String>(c).await.to_api(),
 			}
 		}))
 		.await;
@@ -92,8 +92,8 @@ pub fn root_mod(
 	(name.to_string(), kind)
 }
 pub fn fun<I, O>(exported: bool, name: &str, xf: impl ExprFunc<I, O>) -> Vec<GenItem> {
-	let fac = LazyMemberFactory::new(move |sym| async {
-		return MemKind::Const(build_lambdas(Fun::new(sym, xf).await, 0));
+	let fac = LazyMemberFactory::new(move |sym, ctx| async {
+		return MemKind::Const(build_lambdas(Fun::new(sym, ctx, xf).await, 0));
 		fn build_lambdas(fun: Fun, i: u64) -> GExpr {
 			if i < fun.arity().into() {
 				return lambda(i, [build_lambdas(fun, i + 1)]);
@@ -129,16 +129,16 @@ pub fn comments<'a>(
 
 trait_set! {
 	trait LazyMemberCallback =
-		FnOnce(Sym) -> LocalBoxFuture<'static, MemKind> + DynClone
+		FnOnce(Sym, SysCtx) -> LocalBoxFuture<'static, MemKind> + DynClone
 }
 pub struct LazyMemberFactory(Box<dyn LazyMemberCallback>);
 impl LazyMemberFactory {
 	pub fn new<F: Future<Output = MemKind> + 'static>(
-		cb: impl FnOnce(Sym) -> F + Clone + 'static,
+		cb: impl FnOnce(Sym, SysCtx) -> F + Clone + 'static,
 	) -> Self {
-		Self(Box::new(|s| cb(s).boxed_local()))
+		Self(Box::new(|s, ctx| cb(s, ctx).boxed_local()))
 	}
-	pub async fn build(self, path: Sym) -> MemKind { (self.0)(path).await }
+	pub async fn build(self, path: Sym, ctx: SysCtx) -> MemKind { (self.0)(path, ctx).await }
 }
 impl Clone for LazyMemberFactory {
 	fn clone(&self) -> Self { Self(clone_box(&*self.0)) }
@@ -157,7 +157,7 @@ pub struct GenMember {
 }
 impl GenMember {
 	pub async fn into_api(self, ctx: &mut impl TreeIntoApiCtx) -> api::Member {
-		let name = ctx.sys().i.i::<String>(&self.name).await;
+		let name = ctx.sys().i().i::<String>(&self.name).await;
 		api::Member {
 			kind: self.kind.into_api(&mut ctx.push_path(name.clone())).await,
 			name: name.to_api(),
@@ -197,7 +197,7 @@ pub trait TreeIntoApiCtx {
 	fn req(&self) -> &impl ReqHandlish;
 }
 
-pub struct TIACtxImpl<'a, 'b, RH: ReqHandlish> {
+pub struct TreeIntoApiCtxImpl<'a, 'b, RH: ReqHandlish> {
 	pub sys: SysCtx,
 	pub basepath: &'a [Tok<String>],
 	pub path: Substack<'a, Tok<String>>,
@@ -206,10 +206,10 @@ pub struct TIACtxImpl<'a, 'b, RH: ReqHandlish> {
 	pub req: &'a RH,
 }
 
-impl<RH: ReqHandlish> TreeIntoApiCtx for TIACtxImpl<'_, '_, RH> {
+impl<RH: ReqHandlish> TreeIntoApiCtx for TreeIntoApiCtxImpl<'_, '_, RH> {
 	fn sys(&self) -> SysCtx { self.sys.clone() }
 	fn push_path(&mut self, seg: Tok<String>) -> impl TreeIntoApiCtx {
-		TIACtxImpl {
+		TreeIntoApiCtxImpl {
 			req: self.req,
 			lazy_members: self.lazy_members,
 			rules: self.rules,
diff --git a/orchid-host/src/extension.rs b/orchid-host/src/extension.rs
index a5e1c59..9e88e53 100644
--- a/orchid-host/src/extension.rs
+++ b/orchid-host/src/extension.rs
@@ -35,7 +35,7 @@ pub struct ReqPair<R: Request>(R, Sender<R::Response>);
 #[derive(destructure)]
 pub struct ExtensionData {
 	ctx: Ctx,
-	init: ExtInit,
+	init: Rc<ExtInit>,
 	reqnot: ReqNot<api::HostMsgSet>,
 	systems: Vec<SystemCtor>,
 	logger: Logger,
@@ -55,114 +55,140 @@ impl Drop for ExtensionData {
 pub struct Extension(Rc<ExtensionData>);
 impl Extension {
 	pub fn new(init: ExtInit, logger: Logger, msg_logger: Logger, ctx: Ctx) -> io::Result<Self> {
-		Ok(Self(Rc::new_cyclic(|weak: &Weak<ExtensionData>| ExtensionData {
-			exprs: ExprStore::default(),
-			ctx: ctx.clone(),
-			systems: (init.systems.iter().cloned())
-				.map(|decl| SystemCtor { decl, ext: WeakExtension(weak.clone()) })
-				.collect(),
-			logger: logger.clone(),
-			init,
-			next_pars: RefCell::new(NonZeroU64::new(1).unwrap()),
-			lex_recur: Mutex::default(),
-			mac_recur: Mutex::default(),
-			reqnot: ReqNot::new(
-				msg_logger,
-				clone!(weak; move |sfn, _| clone!(weak; async move {
+		Ok(Self(Rc::new_cyclic(|weak: &Weak<ExtensionData>| {
+			let init = Rc::new(init);
+			(ctx.spawn)(clone!(init, weak, ctx; Box::pin(async move {
+				let reqnot_opt = weak.upgrade().map(|rc| rc.reqnot.clone());
+				if let Some(reqnot) = reqnot_opt {
+					let mut repeat = true;
+					while repeat {
+						repeat = false;
+						(init.recv(Box::new(|msg| {
+							repeat = true;
+							Box::pin(clone!(reqnot, ctx; async move {
+								let msg = msg.to_vec();
+								let reqnot = reqnot.clone();
+								(ctx.spawn)(Box::pin(async move {
+									reqnot.receive(&msg).await;
+								}))
+							}))
+						})))
+						.await;
+					}
+				}
+			})));
+			ExtensionData {
+				exprs: ExprStore::default(),
+				ctx: ctx.clone(),
+				systems: (init.systems.iter().cloned())
+					.map(|decl| SystemCtor { decl, ext: WeakExtension(weak.clone()) })
+					.collect(),
+				logger: logger.clone(),
+				init,
+				next_pars: RefCell::new(NonZeroU64::new(1).unwrap()),
+				lex_recur: Mutex::default(),
+				mac_recur: Mutex::default(),
+				reqnot: ReqNot::new(
+					msg_logger,
+					clone!(weak; move |sfn, _| clone!(weak; async move {
 					let data = weak.upgrade().unwrap();
 					data.init.send(sfn).await
 				}.boxed_local())),
-				clone!(weak; move |notif, _| {
-					clone!(weak; Box::pin(async move {
-					let this = Extension(weak.upgrade().unwrap());
-					match notif {
-						api::ExtHostNotif::ExprNotif(api::ExprNotif::Acquire(acq)) => {
-							let target = this.0.exprs.get_expr(acq.1).expect("Invalid ticket");
-							this.0.exprs.give_expr(target)
-						}
-						api::ExtHostNotif::ExprNotif(api::ExprNotif::Release(rel)) => {
-							this.assert_own_sys(rel.0).await;
-							this.0.exprs.take_expr(rel.1)
-						}
-						api::ExtHostNotif::ExprNotif(api::ExprNotif::Move(mov)) => {
-							this.assert_own_sys(mov.dec).await;
-							let recp = this.ctx().system_inst(mov.inc).await.expect("invallid recipient sys id");
-							let expr = this.0.exprs.get_expr(mov.expr).expect("invalid ticket");
-							recp.ext().0.exprs.give_expr(expr);
-							this.0.exprs.take_expr(mov.expr);
-						},
-						api::ExtHostNotif::Log(api::Log(str)) => this.logger().log(str),
-					}
-				}))}),
-				{
-					clone!(weak, ctx);
-					move |hand, req| {
-						clone!(weak, ctx);
-						Box::pin(async move {
-							let this = Self(weak.upgrade().unwrap());
-							writeln!(this.reqnot().logger(), "Host received request {req:?}");
-							let i = this.ctx().i.clone();
-							match req {
-								api::ExtHostReq::Ping(ping) => hand.handle(&ping, &()).await,
-								api::ExtHostReq::IntReq(intreq) => match intreq {
-									api::IntReq::InternStr(s) => hand.handle(&s, &i.i(&*s.0).await.to_api()).await,
-									api::IntReq::InternStrv(v) => {
-										let tokens = join_all(v.0.iter().map(|m| i.ex(*m))).await;
-										hand.handle(&v, &i.i(&tokens).await.to_api()).await
-									},
-									api::IntReq::ExternStr(si) =>
-										hand.handle(&si, &Tok::<String>::from_api(si.0, &i).await.rc()).await,
-									api::IntReq::ExternStrv(vi) => {
-										let markerv = (i.ex(vi.0).await.iter()).map(|t| t.to_api()).collect_vec();
-										hand.handle(&vi, &markerv).await
-									},
-								},
-								api::ExtHostReq::Fwd(ref fw @ api::Fwd(ref atom, ref key, ref body)) => {
-									let sys = ctx.system_inst(atom.owner).await.expect("owner of live atom dropped");
-									let reply =
-										sys.reqnot().request(api::Fwded(fw.0.clone(), *key, body.clone())).await;
-									hand.handle(fw, &reply).await
-								},
-								api::ExtHostReq::SysFwd(ref fw @ api::SysFwd(id, ref body)) => {
-									let sys = ctx.system_inst(id).await.unwrap();
-									hand.handle(fw, &sys.request(body.clone()).await).await
-								},
-								api::ExtHostReq::SubLex(sl) => {
-									let (rep_in, rep_out) = channel::bounded(1);
-									{
-										let lex_g = this.0.lex_recur.lock().await;
-										let req_in = lex_g.get(&sl.id).expect("Sublex for nonexistent lexid");
-										req_in.send(ReqPair(sl.clone(), rep_in)).await.unwrap();
-									}
-									hand.handle(&sl, &rep_out.recv().await.unwrap()).await
-								},
-								api::ExtHostReq::ExprReq(api::ExprReq::Inspect(ins @ api::Inspect { target })) => {
-									let expr = this.exprs().get_expr(target).expect("Invalid ticket");
-									hand
-										.handle(&ins, &api::Inspected {
-											refcount: expr.strong_count() as u32,
-											location: expr.pos().to_api(),
-											kind: expr.to_api().await,
-										})
-										.await
-								},
-								api::ExtHostReq::RunMacros(rm) => {
-									let (rep_in, rep_out) = channel::bounded(1);
-									let lex_g = this.0.mac_recur.lock().await;
-									let req_in = lex_g.get(&rm.run_id).expect("Sublex for nonexistent lexid");
-									req_in.send(ReqPair(rm.clone(), rep_in)).await.unwrap();
-									hand.handle(&rm, &rep_out.recv().await.unwrap()).await
-								},
-								api::ExtHostReq::ExtAtomPrint(ref eap @ api::ExtAtomPrint(ref atom)) => {
-									let atom = AtomHand::new(atom.clone(), &ctx).await;
-									let unit = atom.print(&FmtCtxImpl { i: &this.ctx().i }).await;
-									hand.handle(eap, &unit.to_api()).await
-								},
+					clone!(weak; move |notif, _| {
+						clone!(weak; Box::pin(async move {
+						let this = Extension(weak.upgrade().unwrap());
+						match notif {
+							api::ExtHostNotif::ExprNotif(api::ExprNotif::Acquire(acq)) => {
+								let target = this.0.exprs.get_expr(acq.1).expect("Invalid ticket");
+								this.0.exprs.give_expr(target)
 							}
-						})
-					}
-				},
-			),
+							api::ExtHostNotif::ExprNotif(api::ExprNotif::Release(rel)) => {
+								this.assert_own_sys(rel.0).await;
+								this.0.exprs.take_expr(rel.1)
+							}
+							api::ExtHostNotif::ExprNotif(api::ExprNotif::Move(mov)) => {
+								this.assert_own_sys(mov.dec).await;
+								let recp = this.ctx().system_inst(mov.inc).await.expect("invallid recipient sys id");
+								let expr = this.0.exprs.get_expr(mov.expr).expect("invalid ticket");
+								recp.ext().0.exprs.give_expr(expr);
+								this.0.exprs.take_expr(mov.expr);
+							},
+							api::ExtHostNotif::Log(api::Log(str)) => this.logger().log(str),
+						}
+					}))}),
+					{
+						clone!(weak, ctx);
+						move |hand, req| {
+							clone!(weak, ctx);
+							Box::pin(async move {
+								let this = Self(weak.upgrade().unwrap());
+								writeln!(this.reqnot().logger(), "Host received request {req:?}");
+								let i = this.ctx().i.clone();
+								match req {
+									api::ExtHostReq::Ping(ping) => hand.handle(&ping, &()).await,
+									api::ExtHostReq::IntReq(intreq) => match intreq {
+										api::IntReq::InternStr(s) => hand.handle(&s, &i.i(&*s.0).await.to_api()).await,
+										api::IntReq::InternStrv(v) => {
+											let tokens = join_all(v.0.iter().map(|m| i.ex(*m))).await;
+											hand.handle(&v, &i.i(&tokens).await.to_api()).await
+										},
+										api::IntReq::ExternStr(si) =>
+											hand.handle(&si, &Tok::<String>::from_api(si.0, &i).await.rc()).await,
+										api::IntReq::ExternStrv(vi) => {
+											let markerv = (i.ex(vi.0).await.iter()).map(|t| t.to_api()).collect_vec();
+											hand.handle(&vi, &markerv).await
+										},
+									},
+									api::ExtHostReq::Fwd(ref fw @ api::Fwd(ref atom, ref key, ref body)) => {
+										let sys =
+											ctx.system_inst(atom.owner).await.expect("owner of live atom dropped");
+										let reply =
+											sys.reqnot().request(api::Fwded(fw.0.clone(), *key, body.clone())).await;
+										hand.handle(fw, &reply).await
+									},
+									api::ExtHostReq::SysFwd(ref fw @ api::SysFwd(id, ref body)) => {
+										let sys = ctx.system_inst(id).await.unwrap();
+										hand.handle(fw, &sys.request(body.clone()).await).await
+									},
+									api::ExtHostReq::SubLex(sl) => {
+										let (rep_in, rep_out) = channel::bounded(1);
+										{
+											let lex_g = this.0.lex_recur.lock().await;
+											let req_in = lex_g.get(&sl.id).expect("Sublex for nonexistent lexid");
+											req_in.send(ReqPair(sl.clone(), rep_in)).await.unwrap();
+										}
+										hand.handle(&sl, &rep_out.recv().await.unwrap()).await
+									},
+									api::ExtHostReq::ExprReq(api::ExprReq::Inspect(
+										ins @ api::Inspect { target },
+									)) => {
+										let expr = this.exprs().get_expr(target).expect("Invalid ticket");
+										hand
+											.handle(&ins, &api::Inspected {
+												refcount: expr.strong_count() as u32,
+												location: expr.pos().to_api(),
+												kind: expr.to_api().await,
+											})
+											.await
+									},
+									api::ExtHostReq::RunMacros(rm) => {
+										let (rep_in, rep_out) = channel::bounded(1);
+										let lex_g = this.0.mac_recur.lock().await;
+										let req_in = lex_g.get(&rm.run_id).expect("Sublex for nonexistent lexid");
+										req_in.send(ReqPair(rm.clone(), rep_in)).await.unwrap();
+										hand.handle(&rm, &rep_out.recv().await.unwrap()).await
+									},
+									api::ExtHostReq::ExtAtomPrint(ref eap @ api::ExtAtomPrint(ref atom)) => {
+										let atom = AtomHand::new(atom.clone(), &ctx).await;
+										let unit = atom.print(&FmtCtxImpl { i: &this.ctx().i }).await;
+										hand.handle(eap, &unit.to_api()).await
+									},
+								}
+							})
+						}
+					},
+				),
+			}
 		})))
 	}
 	pub(crate) fn reqnot(&self) -> &ReqNot<HostMsgSet> { &self.0.reqnot }
@@ -212,20 +238,6 @@ impl Extension {
 		.await;
 		ret.transpose()
 	}
-	pub async fn recv_one(&self) {
-		let reqnot = self.0.reqnot.clone();
-		let ctx = self.ctx().clone();
-		(self.0.init.recv(Box::new(move |msg| {
-			Box::pin(async move {
-				let msg = msg.to_vec();
-				let reqnot = reqnot.clone();
-				(ctx.spawn)(Box::pin(async move {
-					reqnot.receive(&msg).await;
-				}))
-			})
-		})))
-		.await;
-	}
 	pub fn system_drop(&self, id: api::SysId) {
 		let rc = self.clone();
 		(self.ctx().spawn)(Box::pin(async move {
diff --git a/orchid-host/src/subprocess.rs b/orchid-host/src/subprocess.rs
index dfb06dd..e0b7aad 100644
--- a/orchid-host/src/subprocess.rs
+++ b/orchid-host/src/subprocess.rs
@@ -1,7 +1,5 @@
 use std::cell::RefCell;
-use std::path::PathBuf;
 use std::pin::Pin;
-use std::thread;
 
 use async_process::{self, Child, ChildStdin, ChildStdout};
 use async_std::io::{self, BufReadExt, BufReader};
@@ -22,8 +20,6 @@ pub async fn ext_command(
 	msg_logs: Logger,
 	ctx: Ctx,
 ) -> io::Result<ExtInit> {
-	let prog_pbuf = PathBuf::from(cmd.get_program());
-	let prog = prog_pbuf.file_stem().unwrap_or(cmd.get_program()).to_string_lossy().to_string();
 	let mut child = async_process::Command::from(cmd)
 		.stdin(async_process::Stdio::piped())
 		.stdout(async_process::Stdio::piped())
@@ -36,18 +32,16 @@ pub async fn ext_command(
 	let mut stdout = child.stdout.take().unwrap();
 	let header = api::ExtensionHeader::decode(Pin::new(&mut stdout)).await;
 	let child_stderr = child.stderr.take().unwrap();
-	thread::Builder::new().name(format!("stderr-fwd:{prog}")).spawn(move || {
-		async_std::task::block_on(async move {
-			let mut reader = BufReader::new(child_stderr);
-			loop {
-				let mut buf = String::new();
-				if 0 == reader.read_line(&mut buf).await.unwrap() {
-					break;
-				}
-				logger.log(buf.strip_suffix('\n').expect("Readline implies this"));
+	(ctx.spawn)(Box::pin(async move {
+		let mut reader = BufReader::new(child_stderr);
+		loop {
+			let mut buf = String::new();
+			if 0 == reader.read_line(&mut buf).await.unwrap() {
+				break;
 			}
-		})
-	})?;
+			logger.log(buf.strip_suffix('\n').expect("Readline implies this"));
+		}
+	}));
 	Ok(ExtInit {
 		header,
 		port: Box::new(Subprocess {
@@ -87,6 +81,7 @@ impl ExtPort for Subprocess {
 			match recv_msg(self.stdout.lock().await.as_mut()).await {
 				Ok(msg) => cb(&msg).await,
 				Err(e) if e.kind() == io::ErrorKind::BrokenPipe => (),
+				Err(e) if e.kind() == io::ErrorKind::UnexpectedEof => (),
 				Err(e) => panic!("Failed to read from stdout: {}, {e}", e.kind()),
 			}
 		})
diff --git a/orchid-std/Cargo.toml b/orchid-std/Cargo.toml
index 9762ea7..46affd6 100644
--- a/orchid-std/Cargo.toml
+++ b/orchid-std/Cargo.toml
@@ -16,4 +16,5 @@ orchid-api-traits = { version = "0.1.0", path = "../orchid-api-traits" }
 orchid-base = { version = "0.1.0", path = "../orchid-base" }
 orchid-extension = { version = "0.1.0", path = "../orchid-extension" }
 ordered-float = "4.6.0"
+rust_decimal = "1.36.0"
 tokio = { version = "1.43.0", features = ["full"] }
diff --git a/orchid-std/src/number/num_atom.rs b/orchid-std/src/number/num_atom.rs
index 78228b1..c64bcde 100644
--- a/orchid-std/src/number/num_atom.rs
+++ b/orchid-std/src/number/num_atom.rs
@@ -1,6 +1,7 @@
 use orchid_api_derive::Coding;
 use orchid_base::error::OrcRes;
 use orchid_base::format::FmtUnit;
+use orchid_base::number::Numeric;
 use orchid_extension::atom::{
 	AtomFactory, Atomic, AtomicFeatures, MethodSetBuilder, ToAtom, TypAtom,
 };
@@ -9,6 +10,7 @@ use orchid_extension::conv::TryFromExpr;
 use orchid_extension::expr::Expr;
 use orchid_extension::system::SysCtx;
 use ordered_float::NotNan;
+use rust_decimal::prelude::Zero;
 
 #[derive(Clone, Debug, Coding)]
 pub struct Int(pub i64);
@@ -38,27 +40,56 @@ impl ThinAtom for Float {
 }
 impl TryFromExpr for Float {
 	async fn try_from_expr(expr: Expr) -> OrcRes<Self> {
-		TypAtom::<Float>::try_from_expr(expr).await.map(|t| t.value)
+		Ok(Self(Num::try_from_expr(expr).await?.0.to_f64()))
 	}
 }
 
-pub enum Numeric {
-	Int(i64),
-	Float(NotNan<f64>),
-}
-impl TryFromExpr for Numeric {
+pub struct Num(pub Numeric);
+impl TryFromExpr for Num {
 	async fn try_from_expr(expr: Expr) -> OrcRes<Self> {
-		match Int::try_from_expr(expr.clone()).await {
-			Ok(t) => Ok(Numeric::Int(t.0)),
-			Err(e) => Float::try_from_expr(expr).await.map(|t| Numeric::Float(t.0)).map_err(|e2| e + e2),
+		let e = match Int::try_from_expr(expr.clone()).await {
+			Ok(t) => return Ok(Num(Numeric::Int(t.0))),
+			Err(e) => e,
+		};
+		match TypAtom::<Float>::try_from_expr(expr).await {
+			Ok(t) => Ok(Num(Numeric::Float(t.0))),
+			Err(e2) => Err(e + e2),
 		}
 	}
 }
-impl ToAtom for Numeric {
+impl ToAtom for Num {
 	fn to_atom_factory(self) -> AtomFactory {
-		match self {
-			Self::Float(f) => Float(f).factory(),
-			Self::Int(i) => Int(i).factory(),
+		match self.0 {
+			Numeric::Float(f) => Float(f).factory(),
+			Numeric::Int(i) => Int(i).factory(),
 		}
 	}
 }
+
+/// A homogenous fixed length number array that forces all of its elements into
+/// the weakest element type. This describes the argument casting behaviour of
+/// most numeric operations.
+pub enum HomoArray<const N: usize> {
+	Int([i64; N]),
+	Float([NotNan<f64>; N]),
+}
+impl<const N: usize> HomoArray<N> {
+	pub fn new(n: [Numeric; N]) -> Self {
+		let mut ints = [0i64; N];
+		for i in 0..N {
+			if let Numeric::Int(val) = n[i] {
+				ints[i] = val
+			} else {
+				let mut floats = [NotNan::zero(); N];
+				for (i, int) in ints.iter().take(i).enumerate() {
+					floats[i] = NotNan::new(*int as f64).expect("i64 cannot convert to f64 NaN");
+				}
+				for j in i..N {
+					floats[j] = n[j].to_f64();
+				}
+				return Self::Float(floats);
+			}
+		}
+		Self::Int(ints)
+	}
+}
diff --git a/orchid-std/src/number/num_lexer.rs b/orchid-std/src/number/num_lexer.rs
index a30277f..e154a9d 100644
--- a/orchid-std/src/number/num_lexer.rs
+++ b/orchid-std/src/number/num_lexer.rs
@@ -1,13 +1,12 @@
 use std::ops::RangeInclusive;
 
 use orchid_base::error::OrcRes;
-use orchid_base::number::{Numeric, num_to_err, parse_num};
-use orchid_extension::atom::AtomicFeatures;
+use orchid_base::number::{num_to_err, parse_num};
+use orchid_extension::atom::ToAtom;
 use orchid_extension::lexer::{LexContext, Lexer};
 use orchid_extension::tree::{GenTok, GenTokTree};
-use ordered_float::NotNan;
 
-use super::num_atom::{Float, Int};
+use super::num_atom::Num;
 
 #[derive(Default)]
 pub struct NumLexer;
@@ -17,9 +16,7 @@ impl Lexer for NumLexer {
 		let ends_at = all.find(|c: char| !c.is_ascii_hexdigit() && !"xX._pP".contains(c));
 		let (chars, tail) = all.split_at(ends_at.unwrap_or(all.len()));
 		let fac = match parse_num(chars) {
-			Ok(Numeric::Float(f)) => Float(f).factory(),
-			Ok(Numeric::Uint(uint)) => Int(uint.try_into().unwrap()).factory(),
-			Ok(Numeric::Decimal(dec)) => Float(NotNan::new(dec.try_into().unwrap()).unwrap()).factory(),
+			Ok(numeric) => Num(numeric).to_atom_factory(),
 			Err(e) => return Err(num_to_err(e, ctx.pos(all), ctx.i).await.into()),
 		};
 		Ok((tail, GenTok::X(fac).at(ctx.pos(all)..ctx.pos(tail))))
diff --git a/orchid-std/src/std.rs b/orchid-std/src/std.rs
index c4789fb..821e4a1 100644
--- a/orchid-std/src/std.rs
+++ b/orchid-std/src/std.rs
@@ -1,6 +1,7 @@
 use std::rc::Rc;
 
 use never::Never;
+use orchid_base::number::Numeric;
 use orchid_base::reqnot::Receipt;
 use orchid_extension::atom::{AtomDynfo, AtomicFeatures};
 use orchid_extension::entrypoint::ExtReq;
@@ -8,9 +9,10 @@ use orchid_extension::fs::DeclFs;
 use orchid_extension::system::{System, SystemCard};
 use orchid_extension::system_ctor::SystemCtor;
 use orchid_extension::tree::{MemKind, comments, fun, module, root_mod};
+use ordered_float::NotNan;
 
 use crate::OrcString;
-use crate::number::num_atom::{Float, Int};
+use crate::number::num_atom::{Float, HomoArray, Int, Num};
 use crate::number::num_lexer::NumLexer;
 use crate::string::str_atom::{IntStrAtom, StrAtom};
 use crate::string::str_lexer::StringLexer;
@@ -37,11 +39,39 @@ impl System for StdSystem {
 	fn parsers() -> Vec<orchid_extension::parser::ParserObj> { vec![] }
 	fn vfs() -> DeclFs { DeclFs::Mod(&[]) }
 	fn env() -> Vec<(String, MemKind)> {
-		vec![root_mod("std", [], [module(true, "string", [], [comments(
-			["Concatenate two strings"],
-			fun(true, "concat", |left: OrcString<'static>, right: OrcString<'static>| async move {
-				StrAtom::new(Rc::new(left.get_string().await.to_string() + &right.get_string().await))
-			}),
-		)])])]
+		vec![root_mod("std", [], [
+			module(true, "string", [], [comments(
+				["Concatenate two strings"],
+				fun(true, "concat", |left: OrcString<'static>, right: OrcString<'static>| async move {
+					StrAtom::new(Rc::new(left.get_string().await.to_string() + &right.get_string().await))
+				}),
+			)]),
+			module(true, "number", [], [
+				fun(true, "add", |a: Num, b: Num| async move {
+					Num(match HomoArray::new([a.0, b.0]) {
+						HomoArray::Int([a, b]) => Numeric::Int(a + b),
+						HomoArray::Float([a, b]) => Numeric::Float(a + b),
+					})
+				}),
+				fun(true, "neg", |a: Num| async move {
+					Num(match a.0 {
+						Numeric::Int(i) => Numeric::Int(-i),
+						Numeric::Float(f) => Numeric::Float(-f),
+					})
+				}),
+				fun(true, "mul", |a: Num, b: Num| async move {
+					Num(match HomoArray::new([a.0, b.0]) {
+						HomoArray::Int([a, b]) => Numeric::Int(a * b),
+						HomoArray::Float([a, b]) => Numeric::Float(a * b),
+					})
+				}),
+				fun(true, "idiv", |a: Int, b: Int| async move { Int(a.0 / b.0) }),
+				fun(true, "imod", |a: Int, b: Int| async move { Int(a.0 % b.0) }),
+				fun(true, "fdiv", |a: Float, b: Float| async move { Float(a.0 / b.0) }),
+				fun(true, "fmod", |a: Float, b: Float| async move {
+					Float(a.0 - NotNan::new((a.0 / b.0).trunc()).unwrap() * b.0)
+				}),
+			]),
+		])]
 	}
 }
diff --git a/orchid-std/src/string/str_atom.rs b/orchid-std/src/string/str_atom.rs
index 35c06dd..157392c 100644
--- a/orchid-std/src/string/str_atom.rs
+++ b/orchid-std/src/string/str_atom.rs
@@ -74,7 +74,7 @@ impl OwnedAtom for IntStrAtom {
 	}
 	async fn deserialize(mut ctx: impl DeserializeCtx, _: ()) -> Self {
 		let s = ctx.decode::<String>().await;
-		Self(ctx.sys().i.i(&s).await)
+		Self(ctx.sys().i().i(&s).await)
 	}
 }
 
@@ -92,7 +92,7 @@ pub enum OrcStringKind<'a> {
 impl OrcString<'_> {
 	pub async fn get_string(&self) -> Rc<String> {
 		match &self.kind {
-			OrcStringKind::Int(tok) => self.ctx.i.ex(**tok).await.rc(),
+			OrcStringKind::Int(tok) => self.ctx.i().ex(**tok).await.rc(),
 			OrcStringKind::Val(atom) => atom.request(StringGetVal).await,
 		}
 	}
@@ -106,7 +106,7 @@ impl TryFromExpr for OrcString<'static> {
 		let ctx = expr.ctx();
 		match TypAtom::<IntStrAtom>::try_from_expr(expr).await {
 			Ok(t) => Ok(OrcString { ctx: t.data.ctx(), kind: OrcStringKind::Int(t) }),
-			Err(e) => Err(mk_errv(ctx.i.i("A string was expected").await, "", e.pos_iter())),
+			Err(e) => Err(mk_errv(ctx.i().i("A string was expected").await, "", e.pos_iter())),
 		}
 	}
 }
diff --git a/orcx/src/main.rs b/orcx/src/main.rs
index dbe26b2..b38c96b 100644
--- a/orcx/src/main.rs
+++ b/orcx/src/main.rs
@@ -9,7 +9,6 @@ use async_stream::try_stream;
 use camino::Utf8PathBuf;
 use clap::{Parser, Subcommand};
 use futures::{Stream, TryStreamExt, io};
-use orchid_base::clone;
 use orchid_base::error::ReporterImpl;
 use orchid_base::format::{FmtCtxImpl, Format, take_first};
 use orchid_base::location::Pos;
@@ -74,7 +73,6 @@ fn get_all_extensions<'a>(
 			let init = ext_command(Command::new(exe.as_os_str()), logger.clone(), msg_logger.clone(), ctx.clone()).await
 				.unwrap();
 			let ext = Extension::new(init, logger.clone(), msg_logger.clone(), ctx.clone())?;
-			spawn_local(clone!(ext; async move { loop { ext.recv_one().await }}));
 			yield ext
 		}
 	}
@@ -168,12 +166,8 @@ async fn main() -> io::Result<ExitCode> {
 					if args.verbose {
 						println!("lexed: {}", take_first(&ttv_fmt(&lexemes, &FmtCtxImpl { i }).await, true));
 					}
-					let mtreev = parse_mtree(
-						Snippet::new(&lexemes[0], &lexemes, i),
-						Substack::Bottom.push(i.i("orcx").await).push(i.i("input").await),
-					)
-					.await
-					.unwrap();
+					let mtreev =
+						parse_mtree(Snippet::new(&lexemes[0], &lexemes, i), Substack::Bottom).await.unwrap();
 					if args.verbose {
 						let fmt = mtreev_fmt(&mtreev, &FmtCtxImpl { i }).await;
 						println!("parsed: {}", take_first(&fmt, true));