From ea5213d4b3a42a86c637d709c48cad007eae1f9e Mon Sep 17 00:00:00 2001
From: Alan Lawrence <alan.lawrence@quantinuum.com>
Date: Wed, 12 Jun 2024 14:09:41 +0100
Subject: [PATCH] refactor!: Remove NodeType and input_extensions (#1183)

Following #1142 the `input_extensions` are unused, so remove the storage
for them

BREAKING CHANGE: * `add_child_op`(`_with_parent`), etc., gone; use
`add_child_node`(`_with_parent`) with an (impl Into-)OpType.
* `get_nodetype` gone - use `get_optype`.
* `NodeType` gone - use `OpType` directly.
* Various (Into<)Option<ExtensionSet> params removed from builder
methods especially {cfg_,dfg_}builder.
* `input_extensions` removed from serialization schema.
---
 hugr-core/src/builder.rs                      |   6 +-
 hugr-core/src/builder/build_traits.rs         |  76 +---
 hugr-core/src/builder/cfg.rs                  |  18 +-
 hugr-core/src/builder/conditional.rs          |  16 +-
 hugr-core/src/builder/dataflow.rs             |  84 ++--
 hugr-core/src/builder/module.rs               |  19 +-
 hugr-core/src/builder/tail_loop.rs            |   7 +-
 hugr-core/src/hugr.rs                         | 121 +-----
 hugr-core/src/hugr/hugrmut.rs                 |  21 +-
 hugr-core/src/hugr/internal.rs                |  10 +-
 hugr-core/src/hugr/rewrite/inline_dfg.rs      |   8 +-
 hugr-core/src/hugr/rewrite/outline_cfg.rs     |   4 +-
 hugr-core/src/hugr/rewrite/replace.rs         |  10 +-
 hugr-core/src/hugr/rewrite/simple_replace.rs  |   1 -
 hugr-core/src/hugr/serialize.rs               |  21 +-
 hugr-core/src/hugr/serialize/test.rs          |  15 +-
 hugr-core/src/hugr/validate.rs                |   9 +-
 hugr-core/src/hugr/validate/test.rs           | 105 ++---
 hugr-core/src/hugr/views.rs                   |  19 +-
 hugr-core/src/hugr/views/descendants.rs       |   7 +-
 hugr-core/src/hugr/views/root_checked.rs      |  20 +-
 hugr-core/src/hugr/views/sibling.rs           |  14 +-
 hugr-core/src/ops/constant.rs                 |   2 +-
 hugr-core/src/ops/custom.rs                   |   7 +-
 hugr-passes/src/const_fold/test.rs            |   3 +-
 hugr-py/src/hugr/serialization/ops.py         |   1 -
 hugr/src/hugr.rs                              |   4 +-
 .../schema/hugr_schema_strict_v1.json         | 375 ------------------
 specification/schema/hugr_schema_v1.json      | 375 ------------------
 .../schema/testing_hugr_schema_strict_v1.json | 375 ------------------
 .../schema/testing_hugr_schema_v1.json        | 375 ------------------
 31 files changed, 196 insertions(+), 1932 deletions(-)

diff --git a/hugr-core/src/builder.rs b/hugr-core/src/builder.rs
index 787decc07..56ded9129 100644
--- a/hugr-core/src/builder.rs
+++ b/hugr-core/src/builder.rs
@@ -220,7 +220,7 @@ pub enum BuilderWiringError {
 pub(crate) mod test {
     use rstest::fixture;
 
-    use crate::hugr::{views::HugrView, HugrMut, NodeType};
+    use crate::hugr::{views::HugrView, HugrMut};
     use crate::ops;
     use crate::std_extensions::arithmetic::float_ops::FLOAT_OPS_REGISTRY;
     use crate::types::{FunctionType, PolyFuncType, Type};
@@ -278,9 +278,9 @@ pub(crate) mod test {
     /// inference. Using DFGBuilder will default to a root node with an open
     /// extension variable
     pub(crate) fn closed_dfg_root_hugr(signature: FunctionType) -> Hugr {
-        let mut hugr = Hugr::new(NodeType::new_pure(ops::DFG {
+        let mut hugr = Hugr::new(ops::DFG {
             signature: signature.clone(),
-        }));
+        });
         hugr.add_node_with_parent(
             hugr.root(),
             ops::Input {
diff --git a/hugr-core/src/builder/build_traits.rs b/hugr-core/src/builder/build_traits.rs
index 9279a6ba5..1b4945afc 100644
--- a/hugr-core/src/builder/build_traits.rs
+++ b/hugr-core/src/builder/build_traits.rs
@@ -14,7 +14,6 @@ use super::{
 use super::{BuilderWiringError, FunctionBuilder};
 
 use crate::{
-    hugr::NodeType,
     ops::handle::{ConstID, DataflowOpID, FuncID, NodeHandle},
     types::EdgeKind,
 };
@@ -45,12 +44,7 @@ pub trait Container {
     /// Immutable reference to HUGR being built
     fn hugr(&self) -> &Hugr;
     /// Add an [`OpType`] as the final child of the container.
-    fn add_child_op(&mut self, op: impl Into<OpType>) -> Node {
-        let parent = self.container_node();
-        self.hugr_mut().add_node_with_parent(parent, op)
-    }
-    /// Add a [`NodeType`] as the final child of the container.
-    fn add_child_node(&mut self, node: NodeType) -> Node {
+    fn add_child_node(&mut self, node: impl Into<OpType>) -> Node {
         let parent = self.container_node();
         self.hugr_mut().add_node_with_parent(parent, node)
     }
@@ -71,8 +65,7 @@ pub trait Container {
     /// This function will return an error if there is an error in adding the
     /// [`OpType::Const`] node.
     fn add_constant(&mut self, constant: impl Into<ops::Const>) -> ConstID {
-        self.add_child_node(NodeType::new_pure(constant.into()))
-            .into()
+        self.add_child_node(constant.into()).into()
     }
 
     /// Add a [`ops::FuncDefn`] node and returns a builder to define the function
@@ -88,13 +81,12 @@ pub trait Container {
         signature: PolyFuncType,
     ) -> Result<FunctionBuilder<&mut Hugr>, BuildError> {
         let body = signature.body().clone();
-        let f_node = self.add_child_node(NodeType::new_pure(ops::FuncDefn {
+        let f_node = self.add_child_node(ops::FuncDefn {
             name: name.into(),
             signature,
-        }));
+        });
 
-        let db =
-            DFGBuilder::create_with_io(self.hugr_mut(), f_node, body, Some(ExtensionSet::new()))?;
+        let db = DFGBuilder::create_with_io(self.hugr_mut(), f_node, body)?;
         Ok(FunctionBuilder::from_dfg_builder(db))
     }
 
@@ -182,7 +174,7 @@ pub trait Dataflow: Container {
     fn input_wires(&self) -> Outputs {
         self.input().outputs()
     }
-    /// Add a dataflow op to the sibling graph, wiring up the `input_wires` to the
+    /// Add a dataflow [`OpType`] to the sibling graph, wiring up the `input_wires` to the
     /// incoming ports of the resulting node.
     ///
     /// # Errors
@@ -190,21 +182,7 @@ pub trait Dataflow: Container {
     /// Returns a [`BuildError::OperationWiring`] error if the `input_wires` cannot be connected.
     fn add_dataflow_op(
         &mut self,
-        op: impl Into<OpType>,
-        input_wires: impl IntoIterator<Item = Wire>,
-    ) -> Result<BuildHandle<DataflowOpID>, BuildError> {
-        self.add_dataflow_node(NodeType::new_auto(op), input_wires)
-    }
-
-    /// Add a dataflow [`NodeType`] to the sibling graph, wiring up the `input_wires` to the
-    /// incoming ports of the resulting node.
-    ///
-    /// # Errors
-    ///
-    /// Returns a [`BuildError::OperationWiring`] error if the `input_wires` cannot be connected.
-    fn add_dataflow_node(
-        &mut self,
-        nodetype: NodeType,
+        nodetype: impl Into<OpType>,
         input_wires: impl IntoIterator<Item = Wire>,
     ) -> Result<BuildHandle<DataflowOpID>, BuildError> {
         let outs = add_node_with_wires(self, nodetype, input_wires)?;
@@ -297,16 +275,14 @@ pub trait Dataflow: Container {
     fn dfg_builder(
         &mut self,
         signature: FunctionType,
-        input_extensions: Option<ExtensionSet>,
         input_wires: impl IntoIterator<Item = Wire>,
     ) -> Result<DFGBuilder<&mut Hugr>, BuildError> {
         let op = ops::DFG {
             signature: signature.clone(),
         };
-        let nodetype = NodeType::new(op, input_extensions.clone());
-        let (dfg_n, _) = add_node_with_wires(self, nodetype, input_wires)?;
+        let (dfg_n, _) = add_node_with_wires(self, op, input_wires)?;
 
-        DFGBuilder::create_with_io(self.hugr_mut(), dfg_n, signature, input_extensions)
+        DFGBuilder::create_with_io(self.hugr_mut(), dfg_n, signature)
     }
 
     /// Return a builder for a [`crate::ops::CFG`] node,
@@ -322,7 +298,6 @@ pub trait Dataflow: Container {
     fn cfg_builder(
         &mut self,
         inputs: impl IntoIterator<Item = (Type, Wire)>,
-        input_extensions: impl Into<Option<ExtensionSet>>,
         output_types: TypeRow,
         extension_delta: ExtensionSet,
     ) -> Result<CFGBuilder<&mut Hugr>, BuildError> {
@@ -332,13 +307,10 @@ pub trait Dataflow: Container {
 
         let (cfg_node, _) = add_node_with_wires(
             self,
-            NodeType::new(
-                ops::CFG {
-                    signature: FunctionType::new(inputs.clone(), output_types.clone())
-                        .with_extension_delta(extension_delta),
-                },
-                input_extensions.into(),
-            ),
+            ops::CFG {
+                signature: FunctionType::new(inputs.clone(), output_types.clone())
+                    .with_extension_delta(extension_delta),
+            },
             input_wires,
         )?;
         CFGBuilder::create(self.hugr_mut(), cfg_node, inputs, output_types)
@@ -348,9 +320,8 @@ pub trait Dataflow: Container {
     /// Adds a [`OpType::LoadConstant`] node.
     fn load_const(&mut self, cid: &ConstID) -> Wire {
         let const_node = cid.node();
-        let nodetype = self.hugr().get_nodetype(const_node);
+        let nodetype = self.hugr().get_optype(const_node);
         let op: ops::Const = nodetype
-            .op()
             .clone()
             .try_into()
             .expect("ConstID does not refer to Const op.");
@@ -394,7 +365,7 @@ pub trait Dataflow: Container {
         exts: &ExtensionRegistry,
     ) -> Result<Wire, BuildError> {
         let func_node = fid.node();
-        let func_op = self.hugr().get_nodetype(func_node).op();
+        let func_op = self.hugr().get_optype(func_node);
         let func_sig = match func_op {
             OpType::FuncDefn(ops::FuncDefn { signature, .. })
             | OpType::FuncDecl(ops::FuncDecl { signature, .. }) => signature.clone(),
@@ -643,26 +614,23 @@ pub trait Dataflow: Container {
 /// invalid edge.
 fn add_node_with_wires<T: Dataflow + ?Sized>(
     data_builder: &mut T,
-    nodetype: impl Into<NodeType>,
+    nodetype: impl Into<OpType>,
     inputs: impl IntoIterator<Item = Wire>,
 ) -> Result<(Node, usize), BuildError> {
-    let nodetype: NodeType = nodetype.into();
+    let op = nodetype.into();
     // Check there are no row variables, as that would prevent us
     // from indexing into the node's ports in order to wire up
-    nodetype
-        .op_signature()
+    op.dataflow_signature()
         .as_ref()
         .and_then(FunctionType::find_rowvar)
         .map_or(Ok(()), |(idx, _)| {
             Err(SignatureError::RowVarWhereTypeExpected { idx })
         })?;
-    let num_outputs = nodetype.op().value_output_count();
-    let op_node = data_builder.add_child_node(nodetype.clone());
+    let num_outputs = op.value_output_count();
+    let op_node = data_builder.add_child_node(op.clone());
 
-    wire_up_inputs(inputs, op_node, data_builder).map_err(|error| BuildError::OperationWiring {
-        op: nodetype.into_op(),
-        error,
-    })?;
+    wire_up_inputs(inputs, op_node, data_builder)
+        .map_err(|error| BuildError::OperationWiring { op, error })?;
 
     Ok((op_node, num_outputs))
 }
diff --git a/hugr-core/src/builder/cfg.rs b/hugr-core/src/builder/cfg.rs
index 1ac852b45..c7ae975ae 100644
--- a/hugr-core/src/builder/cfg.rs
+++ b/hugr-core/src/builder/cfg.rs
@@ -13,10 +13,7 @@ use crate::{
 use crate::{hugr::views::HugrView, types::TypeRow};
 
 use crate::Node;
-use crate::{
-    hugr::{HugrMut, NodeType},
-    type_row, Hugr,
-};
+use crate::{hugr::HugrMut, type_row, Hugr};
 
 /// Builder for a [`crate::ops::CFG`] child control
 /// flow graph.
@@ -158,7 +155,7 @@ impl CFGBuilder<Hugr> {
             signature: signature.clone(),
         };
 
-        let base = Hugr::new(NodeType::new_open(cfg_op));
+        let base = Hugr::new(cfg_op);
         let cfg_node = base.root();
         CFGBuilder::create(base, cfg_node, signature.input, signature.output)
     }
@@ -336,12 +333,7 @@ impl<B: AsMut<Hugr> + AsRef<Hugr>> BlockBuilder<B> {
     fn create(base: B, block_n: Node) -> Result<Self, BuildError> {
         let block_op = base.get_optype(block_n).as_dataflow_block().unwrap();
         let signature = block_op.inner_signature();
-        let inp_ex = base
-            .as_ref()
-            .get_nodetype(block_n)
-            .input_extensions()
-            .cloned();
-        let db = DFGBuilder::create_with_io(base, block_n, signature, inp_ex)?;
+        let db = DFGBuilder::create_with_io(base, block_n, signature)?;
         Ok(BlockBuilder::from_dfg_builder(db))
     }
 
@@ -363,7 +355,6 @@ impl BlockBuilder<Hugr> {
     /// Initialize a [`DataflowBlock`] rooted HUGR builder
     pub fn new(
         inputs: impl Into<TypeRow>,
-        input_extensions: impl Into<Option<ExtensionSet>>,
         sum_rows: impl IntoIterator<Item = TypeRow>,
         other_outputs: impl Into<TypeRow>,
         extension_delta: ExtensionSet,
@@ -378,7 +369,7 @@ impl BlockBuilder<Hugr> {
             extension_delta,
         };
 
-        let base = Hugr::new(NodeType::new(op, input_extensions));
+        let base = Hugr::new(op);
         let root = base.root();
         Self::create(base, root)
     }
@@ -418,7 +409,6 @@ pub(crate) mod test {
                 let cfg_id = {
                     let mut cfg_builder = func_builder.cfg_builder(
                         vec![(NAT, int)],
-                        None,
                         type_row![NAT],
                         ExtensionSet::new(),
                     )?;
diff --git a/hugr-core/src/builder/conditional.rs b/hugr-core/src/builder/conditional.rs
index e39c88451..ec9566f5f 100644
--- a/hugr-core/src/builder/conditional.rs
+++ b/hugr-core/src/builder/conditional.rs
@@ -16,11 +16,7 @@ use super::{
 };
 
 use crate::Node;
-use crate::{
-    extension::ExtensionSet,
-    hugr::{HugrMut, NodeType},
-    Hugr,
-};
+use crate::{extension::ExtensionSet, hugr::HugrMut, Hugr};
 
 use std::collections::HashSet;
 
@@ -130,7 +126,7 @@ impl<B: AsMut<Hugr> + AsRef<Hugr>> ConditionalBuilder<B> {
             if let Some(&sibling_node) = self.case_nodes[case + 1..].iter().flatten().next() {
                 self.hugr_mut().add_node_before(sibling_node, case_op)
             } else {
-                self.add_child_op(case_op)
+                self.add_child_node(case_op)
             };
 
         self.case_nodes[case] = Some(case_node);
@@ -139,7 +135,6 @@ impl<B: AsMut<Hugr> + AsRef<Hugr>> ConditionalBuilder<B> {
             self.hugr_mut(),
             case_node,
             FunctionType::new(inputs, outputs).with_extension_delta(extension_delta),
-            None,
         )?;
 
         Ok(CaseBuilder::from_dfg_builder(dfg_builder))
@@ -177,8 +172,7 @@ impl ConditionalBuilder<Hugr> {
             outputs,
             extension_delta,
         };
-        // TODO: Allow input extensions to be specified
-        let base = Hugr::new(NodeType::new_open(op));
+        let base = Hugr::new(op);
         let conditional_node = base.root();
 
         Ok(ConditionalBuilder {
@@ -196,9 +190,9 @@ impl CaseBuilder<Hugr> {
         let op = ops::Case {
             signature: signature.clone(),
         };
-        let base = Hugr::new(NodeType::new_open(op));
+        let base = Hugr::new(op);
         let root = base.root();
-        let dfg_builder = DFGBuilder::create_with_io(base, root, signature, None)?;
+        let dfg_builder = DFGBuilder::create_with_io(base, root, signature)?;
 
         Ok(CaseBuilder::from_dfg_builder(dfg_builder))
     }
diff --git a/hugr-core/src/builder/dataflow.rs b/hugr-core/src/builder/dataflow.rs
index 67865e13a..f5c8db00f 100644
--- a/hugr-core/src/builder/dataflow.rs
+++ b/hugr-core/src/builder/dataflow.rs
@@ -4,12 +4,12 @@ use super::{BuildError, Container, Dataflow, DfgID, FuncID};
 
 use std::marker::PhantomData;
 
-use crate::hugr::{HugrView, NodeType, ValidationError};
+use crate::hugr::{HugrView, ValidationError};
 use crate::ops;
 
 use crate::types::{FunctionType, PolyFuncType};
 
-use crate::extension::{ExtensionRegistry, ExtensionSet};
+use crate::extension::ExtensionRegistry;
 use crate::Node;
 use crate::{hugr::HugrMut, Hugr};
 
@@ -27,7 +27,6 @@ impl<T: AsMut<Hugr> + AsRef<Hugr>> DFGBuilder<T> {
         mut base: T,
         parent: Node,
         signature: FunctionType,
-        input_extensions: Option<ExtensionSet>,
     ) -> Result<Self, BuildError> {
         let num_in_wires = signature.input().len();
         let num_out_wires = signature.output().len();
@@ -49,15 +48,8 @@ impl<T: AsMut<Hugr> + AsRef<Hugr>> DFGBuilder<T> {
         let output = ops::Output {
             types: signature.output().clone(),
         };
-        base.as_mut()
-            .add_node_with_parent(parent, NodeType::new(input, input_extensions.clone()));
-        base.as_mut().add_node_with_parent(
-            parent,
-            NodeType::new(
-                output,
-                input_extensions.map(|inp| inp.union(signature.extension_reqs)),
-            ),
-        );
+        base.as_mut().add_node_with_parent(parent, input);
+        base.as_mut().add_node_with_parent(parent, output);
 
         Ok(Self {
             base,
@@ -79,9 +71,9 @@ impl DFGBuilder<Hugr> {
         let dfg_op = ops::DFG {
             signature: signature.clone(),
         };
-        let base = Hugr::new(NodeType::new_open(dfg_op));
+        let base = Hugr::new(dfg_op);
         let root = base.root();
-        DFGBuilder::create_with_io(base, root, signature, None)
+        DFGBuilder::create_with_io(base, root, signature)
     }
 }
 
@@ -153,10 +145,10 @@ impl FunctionBuilder<Hugr> {
             name: name.into(),
         };
 
-        let base = Hugr::new(NodeType::new_pure(op));
+        let base = Hugr::new(op);
         let root = base.root();
 
-        let db = DFGBuilder::create_with_io(base, root, body, Some(ExtensionSet::new()))?;
+        let db = DFGBuilder::create_with_io(base, root, body)?;
         Ok(Self::from_dfg_builder(db))
     }
 }
@@ -209,8 +201,11 @@ pub(crate) mod test {
     use crate::builder::build_traits::DataflowHugr;
     use crate::builder::{BuilderWiringError, DataflowSubContainer, ModuleBuilder};
     use crate::extension::prelude::{BOOL_T, USIZE_T};
-    use crate::extension::{ExtensionId, SignatureError, EMPTY_REG, PRELUDE_REGISTRY};
+    use crate::extension::{
+        ExtensionId, ExtensionSet, SignatureError, EMPTY_REG, PRELUDE_REGISTRY,
+    };
     use crate::hugr::validate::InterGraphEdgeError;
+    use crate::ops::OpTrait;
     use crate::ops::{handle::NodeHandle, Lift, Noop, OpTag};
 
     use crate::std_extensions::logic::test::and_op;
@@ -239,11 +234,8 @@ pub(crate) mod test {
 
                 let q_out = func_builder.add_dataflow_op(h_gate(), vec![qb])?;
 
-                let inner_builder = func_builder.dfg_builder(
-                    FunctionType::new(type_row![NAT], type_row![NAT]),
-                    None,
-                    [int],
-                )?;
+                let inner_builder = func_builder
+                    .dfg_builder(FunctionType::new(type_row![NAT], type_row![NAT]), [int])?;
                 let inner_id = n_identity(inner_builder)?;
 
                 func_builder.finish_with_outputs(inner_id.outputs().chain(q_out.outputs()))?
@@ -348,7 +340,7 @@ pub(crate) mod test {
             let i1 = noop.out_wire(0);
 
             let mut nested =
-                f_build.dfg_builder(FunctionType::new(type_row![], type_row![BIT]), None, [])?;
+                f_build.dfg_builder(FunctionType::new(type_row![], type_row![BIT]), [])?;
 
             let id = nested.add_dataflow_op(Noop { ty: BIT }, [i1])?;
 
@@ -371,8 +363,7 @@ pub(crate) mod test {
         let noop = f_build.add_dataflow_op(Noop { ty: QB }, [i1])?;
         let i1 = noop.out_wire(0);
 
-        let mut nested =
-            f_build.dfg_builder(FunctionType::new(type_row![], type_row![QB]), None, [])?;
+        let mut nested = f_build.dfg_builder(FunctionType::new(type_row![], type_row![QB]), [])?;
 
         let id_res = nested.add_dataflow_op(Noop { ty: QB }, [i1]);
 
@@ -450,7 +441,7 @@ pub(crate) mod test {
             .with_extension_delta(ab_extensions.clone());
 
         // A box which adds extensions A and B, via child Lift nodes
-        let mut add_ab = parent.dfg_builder(add_ab_sig, Some(ExtensionSet::new()), [w])?;
+        let mut add_ab = parent.dfg_builder(add_ab_sig, [w])?;
         let [w] = add_ab.input_wires_arr();
 
         let lift_a = add_ab.add_dataflow_op(
@@ -462,14 +453,11 @@ pub(crate) mod test {
         )?;
         let [w] = lift_a.outputs_arr();
 
-        let lift_b = add_ab.add_dataflow_node(
-            NodeType::new(
-                Lift {
-                    type_row: type_row![BIT],
-                    new_extension: xb,
-                },
-                ExtensionSet::from_iter([xa]),
-            ),
+        let lift_b = add_ab.add_dataflow_op(
+            Lift {
+                type_row: type_row![BIT],
+                new_extension: xb,
+            },
             [w],
         )?;
         let [w] = lift_b.outputs_arr();
@@ -479,16 +467,13 @@ pub(crate) mod test {
 
         // Add another node (a sibling to add_ab) which adds extension C
         // via a child lift node
-        let mut add_c = parent.dfg_builder(add_c_sig, Some(ab_extensions.clone()), [w])?;
+        let mut add_c = parent.dfg_builder(add_c_sig, [w])?;
         let [w] = add_c.input_wires_arr();
-        let lift_c = add_c.add_dataflow_node(
-            NodeType::new(
-                Lift {
-                    type_row: type_row![BIT],
-                    new_extension: xc,
-                },
-                ab_extensions,
-            ),
+        let lift_c = add_c.add_dataflow_op(
+            Lift {
+                type_row: type_row![BIT],
+                new_extension: xc,
+            },
             [w],
         )?;
         let wires: Vec<Wire> = lift_c.outputs().collect();
@@ -504,10 +489,10 @@ pub(crate) mod test {
     fn non_cfg_ancestor() -> Result<(), BuildError> {
         let unit_sig = FunctionType::new(type_row![Type::UNIT], type_row![Type::UNIT]);
         let mut b = DFGBuilder::new(unit_sig.clone())?;
-        let b_child = b.dfg_builder(unit_sig.clone(), None, [b.input().out_wire(0)])?;
+        let b_child = b.dfg_builder(unit_sig.clone(), [b.input().out_wire(0)])?;
         let b_child_in_wire = b_child.input().out_wire(0);
         b_child.finish_with_outputs([])?;
-        let b_child_2 = b.dfg_builder(unit_sig.clone(), None, [])?;
+        let b_child_2 = b.dfg_builder(unit_sig.clone(), [])?;
 
         // DFG block has edge coming a sibling block, which is only valid for
         // CFGs
@@ -528,17 +513,16 @@ pub(crate) mod test {
     fn no_relation_edge() -> Result<(), BuildError> {
         let unit_sig = FunctionType::new(type_row![Type::UNIT], type_row![Type::UNIT]);
         let mut b = DFGBuilder::new(unit_sig.clone())?;
-        let mut b_child = b.dfg_builder(unit_sig.clone(), None, [b.input().out_wire(0)])?;
-        let b_child_child =
-            b_child.dfg_builder(unit_sig.clone(), None, [b_child.input().out_wire(0)])?;
+        let mut b_child = b.dfg_builder(unit_sig.clone(), [b.input().out_wire(0)])?;
+        let b_child_child = b_child.dfg_builder(unit_sig.clone(), [b_child.input().out_wire(0)])?;
         let b_child_child_in_wire = b_child_child.input().out_wire(0);
 
         b_child_child.finish_with_outputs([])?;
         b_child.finish_with_outputs([])?;
 
-        let mut b_child_2 = b.dfg_builder(unit_sig.clone(), None, [])?;
+        let mut b_child_2 = b.dfg_builder(unit_sig.clone(), [])?;
         let b_child_2_child =
-            b_child_2.dfg_builder(unit_sig.clone(), None, [b_child_2.input().out_wire(0)])?;
+            b_child_2.dfg_builder(unit_sig.clone(), [b_child_2.input().out_wire(0)])?;
 
         let res = b_child_2_child.finish_with_outputs([b_child_child_in_wire]);
 
diff --git a/hugr-core/src/builder/module.rs b/hugr-core/src/builder/module.rs
index 9866ab326..d5fbf3823 100644
--- a/hugr-core/src/builder/module.rs
+++ b/hugr-core/src/builder/module.rs
@@ -13,11 +13,9 @@ use crate::types::{PolyFuncType, Type, TypeBound};
 
 use crate::ops::handle::{AliasID, FuncID, NodeHandle};
 
-use crate::Node;
+use crate::{Hugr, Node};
 use smol_str::SmolStr;
 
-use crate::{hugr::NodeType, Hugr};
-
 /// Builder for a HUGR module.
 #[derive(Debug, Clone, PartialEq)]
 pub struct ModuleBuilder<T>(pub(super) T);
@@ -86,13 +84,10 @@ impl<T: AsMut<Hugr> + AsRef<Hugr>> ModuleBuilder<T> {
             .clone();
         let body = signature.body().clone();
         self.hugr_mut()
-            .replace_op(
-                f_node,
-                NodeType::new_pure(ops::FuncDefn { name, signature }),
-            )
+            .replace_op(f_node, ops::FuncDefn { name, signature })
             .expect("Replacing a FuncDecl node with a FuncDefn should always be valid");
 
-        let db = DFGBuilder::create_with_io(self.hugr_mut(), f_node, body, None)?;
+        let db = DFGBuilder::create_with_io(self.hugr_mut(), f_node, body)?;
         Ok(FunctionBuilder::from_dfg_builder(db))
     }
 
@@ -108,10 +103,10 @@ impl<T: AsMut<Hugr> + AsRef<Hugr>> ModuleBuilder<T> {
         signature: PolyFuncType,
     ) -> Result<FuncID<false>, BuildError> {
         // TODO add param names to metadata
-        let declare_n = self.add_child_node(NodeType::new_pure(ops::FuncDecl {
+        let declare_n = self.add_child_node(ops::FuncDecl {
             signature,
             name: name.into(),
-        }));
+        });
 
         Ok(declare_n.into())
     }
@@ -133,7 +128,7 @@ impl<T: AsMut<Hugr> + AsRef<Hugr>> ModuleBuilder<T> {
         // every 0-input node.
         let name: SmolStr = name.into();
         let bound = typ.least_upper_bound();
-        let node = self.add_child_op(ops::AliasDefn {
+        let node = self.add_child_node(ops::AliasDefn {
             name: name.clone(),
             definition: typ,
         });
@@ -151,7 +146,7 @@ impl<T: AsMut<Hugr> + AsRef<Hugr>> ModuleBuilder<T> {
         bound: TypeBound,
     ) -> Result<AliasID<false>, BuildError> {
         let name: SmolStr = name.into();
-        let node = self.add_child_op(ops::AliasDecl {
+        let node = self.add_child_node(ops::AliasDecl {
             name: name.clone(),
             bound,
         });
diff --git a/hugr-core/src/builder/tail_loop.rs b/hugr-core/src/builder/tail_loop.rs
index 2bee9bcfa..fc7eeb864 100644
--- a/hugr-core/src/builder/tail_loop.rs
+++ b/hugr-core/src/builder/tail_loop.rs
@@ -1,7 +1,7 @@
 use crate::extension::ExtensionSet;
 use crate::ops;
 
-use crate::hugr::{views::HugrView, NodeType};
+use crate::hugr::views::HugrView;
 use crate::types::{FunctionType, TypeRow};
 use crate::{Hugr, Node};
 
@@ -22,7 +22,7 @@ impl<B: AsMut<Hugr> + AsRef<Hugr>> TailLoopBuilder<B> {
         tail_loop: &ops::TailLoop,
     ) -> Result<Self, BuildError> {
         let signature = FunctionType::new(tail_loop.body_input_row(), tail_loop.body_output_row());
-        let dfg_build = DFGBuilder::create_with_io(base, loop_node, signature, None)?;
+        let dfg_build = DFGBuilder::create_with_io(base, loop_node, signature)?;
 
         Ok(TailLoopBuilder::from_dfg_builder(dfg_build))
     }
@@ -83,8 +83,7 @@ impl TailLoopBuilder<Hugr> {
             rest: inputs_outputs.into(),
             extension_delta,
         };
-        // TODO: Allow input extensions to be specified
-        let base = Hugr::new(NodeType::new_open(tail_loop.clone()));
+        let base = Hugr::new(tail_loop.clone());
         let root = base.root();
         Self::create_with_io(base, root, &tail_loop)
     }
diff --git a/hugr-core/src/hugr.rs b/hugr-core/src/hugr.rs
index 0ab25f7ba..25aa28214 100644
--- a/hugr-core/src/hugr.rs
+++ b/hugr-core/src/hugr.rs
@@ -25,14 +25,12 @@ use thiserror::Error;
 
 pub use self::views::{HugrView, RootTagged};
 use crate::core::NodeIndex;
-use crate::extension::{ExtensionRegistry, ExtensionSet};
+use crate::extension::ExtensionRegistry;
 use crate::ops::custom::resolve_extension_ops;
-use crate::ops::{OpTag, OpTrait, OpType, DEFAULT_OPTYPE};
-use crate::types::FunctionType;
+use crate::ops::OpTag;
+pub use crate::ops::{OpType, DEFAULT_OPTYPE};
 use crate::{Direction, Node};
 
-use delegate::delegate;
-
 /// The Hugr data structure.
 #[derive(Clone, Debug, PartialEq)]
 pub struct Hugr {
@@ -46,115 +44,15 @@ pub struct Hugr {
     root: portgraph::NodeIndex,
 
     /// Operation types for each node.
-    op_types: UnmanagedDenseMap<portgraph::NodeIndex, NodeType>,
+    op_types: UnmanagedDenseMap<portgraph::NodeIndex, OpType>,
 
     /// Node metadata
     metadata: UnmanagedDenseMap<portgraph::NodeIndex, Option<NodeMetadataMap>>,
 }
 
-#[derive(Clone, Debug, Default, PartialEq, serde::Serialize, serde::Deserialize)]
-/// The type of a node on a graph. In addition to the [`OpType`], it also
-/// describes the extensions inferred to be used by the node.
-pub struct NodeType {
-    /// The underlying OpType
-    op: OpType,
-    /// The extensions that the signature has been specialised to
-    input_extensions: Option<ExtensionSet>,
-}
-
-/// The default NodeType, with open extensions
-pub const DEFAULT_NODETYPE: NodeType = NodeType {
-    op: DEFAULT_OPTYPE,
-    input_extensions: None, // Default for any Option
-};
-
-impl NodeType {
-    /// Create a new optype with some ExtensionSet
-    pub fn new(op: impl Into<OpType>, input_extensions: impl Into<Option<ExtensionSet>>) -> Self {
-        NodeType {
-            op: op.into(),
-            input_extensions: input_extensions.into(),
-        }
-    }
-
-    /// Instantiate an OpType with no input extensions
-    pub fn new_pure(op: impl Into<OpType>) -> Self {
-        NodeType {
-            op: op.into(),
-            input_extensions: Some(ExtensionSet::new()),
-        }
-    }
-
-    /// Instantiate an OpType with an unknown set of input extensions
-    /// (to be inferred later)
-    pub fn new_open(op: impl Into<OpType>) -> Self {
-        NodeType {
-            op: op.into(),
-            input_extensions: None,
-        }
-    }
-
-    /// Instantiate an [OpType] with the default set of input extensions
-    /// for that OpType.
-    pub fn new_auto(op: impl Into<OpType>) -> Self {
-        let op = op.into();
-        if OpTag::ModuleOp.is_superset(op.tag()) {
-            Self::new_pure(op)
-        } else {
-            Self::new_open(op)
-        }
-    }
-
-    /// Get the function type from the embedded op
-    pub fn op_signature(&self) -> Option<FunctionType> {
-        self.op.dataflow_signature()
-    }
-
-    /// The input extensions defined for this node.
-    ///
-    /// The output extensions will correspond to the input extensions plus any
-    /// extension delta defined by the operation type.
-    ///
-    /// If the input extensions are not known, this will return None.
-    pub fn input_extensions(&self) -> Option<&ExtensionSet> {
-        self.input_extensions.as_ref()
-    }
-
-    /// Gets the underlying [OpType] i.e. without any [input_extensions]
-    ///
-    /// [input_extensions]: NodeType::input_extensions
-    pub fn op(&self) -> &OpType {
-        &self.op
-    }
-
-    /// Returns the underlying [OpType] i.e. without any [input_extensions]
-    ///
-    /// [input_extensions]: NodeType::input_extensions
-    pub fn into_op(self) -> OpType {
-        self.op
-    }
-
-    delegate! {
-        to self.op {
-            /// Tag identifying the operation.
-            pub fn tag(&self) -> OpTag;
-            /// Returns the number of inputs ports for the operation.
-            pub fn input_count(&self) -> usize;
-            /// Returns the number of outputs ports for the operation.
-            pub fn output_count(&self) -> usize;
-        }
-    }
-}
-
-impl<T: Into<OpType>> From<T> for NodeType {
-    fn from(value: T) -> Self {
-        NodeType::new_auto(value.into())
-    }
-}
-
 impl Default for Hugr {
     fn default() -> Self {
-        Self::new(NodeType::new_pure(crate::ops::Module))
+        Self::new(crate::ops::Module)
     }
 }
 
@@ -181,8 +79,8 @@ pub type NodeMetadataMap = serde_json::Map<String, NodeMetadata>;
 /// Public API for HUGRs.
 impl Hugr {
     /// Create a new Hugr, with a single root node.
-    pub fn new(root_node: NodeType) -> Self {
-        Self::with_capacity(root_node, 0, 0)
+    pub fn new(root_node: impl Into<OpType>) -> Self {
+        Self::with_capacity(root_node.into(), 0, 0)
     }
 
     /// Resolve extension ops, infer extensions used, and pass the closure into validation
@@ -210,8 +108,7 @@ impl Hugr {
 /// Internal API for HUGRs, not intended for use by users.
 impl Hugr {
     /// Create a new Hugr, with a single root node and preallocated capacity.
-    // TODO: Make this take a NodeType
-    pub(crate) fn with_capacity(root_node: NodeType, nodes: usize, ports: usize) -> Self {
+    pub(crate) fn with_capacity(root_node: OpType, nodes: usize, ports: usize) -> Self {
         let mut graph = MultiPortGraph::with_capacity(nodes, ports);
         let hierarchy = Hierarchy::new();
         let mut op_types = UnmanagedDenseMap::with_capacity(nodes);
@@ -236,7 +133,7 @@ impl Hugr {
     }
 
     /// Add a node to the graph.
-    pub(crate) fn add_node(&mut self, nodetype: NodeType) -> Node {
+    pub(crate) fn add_node(&mut self, nodetype: OpType) -> Node {
         let node = self
             .graph
             .add_node(nodetype.input_count(), nodetype.output_count());
diff --git a/hugr-core/src/hugr/hugrmut.rs b/hugr-core/src/hugr/hugrmut.rs
index c06d87fd5..08d852249 100644
--- a/hugr-core/src/hugr/hugrmut.rs
+++ b/hugr-core/src/hugr/hugrmut.rs
@@ -7,7 +7,7 @@ use portgraph::view::{NodeFilter, NodeFiltered};
 use portgraph::{LinkMut, NodeIndex, PortMut, PortView, SecondaryMap};
 
 use crate::hugr::views::SiblingSubgraph;
-use crate::hugr::{HugrView, Node, NodeType, RootTagged};
+use crate::hugr::{HugrView, Node, OpType, RootTagged};
 use crate::hugr::{NodeMetadata, Rewrite};
 use crate::{Hugr, IncomingPort, OutgoingPort, Port, PortIndex};
 
@@ -74,7 +74,7 @@ pub trait HugrMut: HugrMutInternals {
     ///
     /// If the parent is not in the graph.
     #[inline]
-    fn add_node_with_parent(&mut self, parent: Node, op: impl Into<NodeType>) -> Node {
+    fn add_node_with_parent(&mut self, parent: Node, op: impl Into<OpType>) -> Node {
         panic_invalid_node(self, parent);
         self.hugr_mut().add_node_with_parent(parent, op)
     }
@@ -87,7 +87,7 @@ pub trait HugrMut: HugrMutInternals {
     ///
     /// If the sibling is not in the graph, or if the sibling is the root node.
     #[inline]
-    fn add_node_before(&mut self, sibling: Node, nodetype: impl Into<NodeType>) -> Node {
+    fn add_node_before(&mut self, sibling: Node, nodetype: impl Into<OpType>) -> Node {
         panic_invalid_non_root(self, sibling);
         self.hugr_mut().add_node_before(sibling, nodetype)
     }
@@ -100,7 +100,7 @@ pub trait HugrMut: HugrMutInternals {
     ///
     /// If the sibling is not in the graph, or if the sibling is the root node.
     #[inline]
-    fn add_node_after(&mut self, sibling: Node, op: impl Into<NodeType>) -> Node {
+    fn add_node_after(&mut self, sibling: Node, op: impl Into<OpType>) -> Node {
         panic_invalid_non_root(self, sibling);
         self.hugr_mut().add_node_after(sibling, op)
     }
@@ -237,7 +237,7 @@ fn translate_indices(node_map: HashMap<NodeIndex, NodeIndex>) -> HashMap<Node, N
 
 /// Impl for non-wrapped Hugrs. Overwrites the recursive default-impls to directly use the hugr.
 impl<T: RootTagged<RootHandle = Node> + AsMut<Hugr>> HugrMut for T {
-    fn add_node_with_parent(&mut self, parent: Node, node: impl Into<NodeType>) -> Node {
+    fn add_node_with_parent(&mut self, parent: Node, node: impl Into<OpType>) -> Node {
         let node = self.as_mut().add_node(node.into());
         self.as_mut()
             .hierarchy
@@ -246,7 +246,7 @@ impl<T: RootTagged<RootHandle = Node> + AsMut<Hugr>> HugrMut for T {
         node
     }
 
-    fn add_node_before(&mut self, sibling: Node, nodetype: impl Into<NodeType>) -> Node {
+    fn add_node_before(&mut self, sibling: Node, nodetype: impl Into<OpType>) -> Node {
         let node = self.as_mut().add_node(nodetype.into());
         self.as_mut()
             .hierarchy
@@ -255,7 +255,7 @@ impl<T: RootTagged<RootHandle = Node> + AsMut<Hugr>> HugrMut for T {
         node
     }
 
-    fn add_node_after(&mut self, sibling: Node, op: impl Into<NodeType>) -> Node {
+    fn add_node_after(&mut self, sibling: Node, op: impl Into<OpType>) -> Node {
         let node = self.as_mut().add_node(op.into());
         self.as_mut()
             .hierarchy
@@ -341,7 +341,7 @@ impl<T: RootTagged<RootHandle = Node> + AsMut<Hugr>> HugrMut for T {
         let (new_root, node_map) = insert_hugr_internal(self.as_mut(), root, other);
         // Update the optypes and metadata, copying them from the other graph.
         for (&node, &new_node) in node_map.iter() {
-            let nodetype = other.get_nodetype(node.into());
+            let nodetype = other.get_optype(node.into());
             self.as_mut().op_types.set(new_node, nodetype.clone());
             let meta = other.base_hugr().metadata.get(node);
             self.as_mut().metadata.set(new_node, meta.clone());
@@ -372,7 +372,7 @@ impl<T: RootTagged<RootHandle = Node> + AsMut<Hugr>> HugrMut for T {
         let node_map = insert_subgraph_internal(self.as_mut(), root, other, &portgraph);
         // Update the optypes and metadata, copying them from the other graph.
         for (&node, &new_node) in node_map.iter() {
-            let nodetype = other.get_nodetype(node.into());
+            let nodetype = other.get_optype(node.into());
             self.as_mut().op_types.set(new_node, nodetype.clone());
             let meta = other.base_hugr().metadata.get(node);
             self.as_mut().metadata.set(new_node, meta.clone());
@@ -534,8 +534,7 @@ mod test {
         );
 
         {
-            let f_in =
-                hugr.add_node_with_parent(f, NodeType::new_pure(ops::Input::new(type_row![NAT])));
+            let f_in = hugr.add_node_with_parent(f, ops::Input::new(type_row![NAT]));
             let f_out = hugr.add_node_with_parent(f, ops::Output::new(type_row![NAT, NAT]));
             let noop = hugr.add_node_with_parent(f, Noop { ty: NAT });
 
diff --git a/hugr-core/src/hugr/internal.rs b/hugr-core/src/hugr/internal.rs
index 3cf2b9c63..b8ac050c3 100644
--- a/hugr-core/src/hugr/internal.rs
+++ b/hugr-core/src/hugr/internal.rs
@@ -5,10 +5,11 @@ use std::ops::Range;
 use portgraph::{LinkView, MultiPortGraph, PortMut, PortView};
 
 use crate::ops::handle::NodeHandle;
+use crate::ops::OpTrait;
 use crate::{Direction, Hugr, Node};
 
 use super::hugrmut::{panic_invalid_node, panic_invalid_non_root};
-use super::{HugrError, NodeType, RootTagged};
+use super::{HugrError, OpType, RootTagged};
 
 /// Trait for accessing the internals of a Hugr(View).
 ///
@@ -138,8 +139,9 @@ pub trait HugrMutInternals: RootTagged {
     /// # Panics
     ///
     /// If the node is not in the graph.
-    fn replace_op(&mut self, node: Node, op: NodeType) -> Result<NodeType, HugrError> {
+    fn replace_op(&mut self, node: Node, op: impl Into<OpType>) -> Result<OpType, HugrError> {
         panic_invalid_node(self, node);
+        let op = op.into();
         if node == self.root() && !Self::RootHandle::TAG.is_superset(op.tag()) {
             return Err(HugrError::InvalidTag {
                 required: Self::RootHandle::TAG,
@@ -206,9 +208,9 @@ impl<T: RootTagged<RootHandle = Node> + AsMut<Hugr>> HugrMutInternals for T {
             .expect("Inserting a newly-created node into the hierarchy should never fail.");
     }
 
-    fn replace_op(&mut self, node: Node, op: NodeType) -> Result<NodeType, HugrError> {
+    fn replace_op(&mut self, node: Node, op: impl Into<OpType>) -> Result<OpType, HugrError> {
         // We know RootHandle=Node here so no need to check
         let cur = self.hugr_mut().op_types.get_mut(node.pg_index());
-        Ok(std::mem::replace(cur, op))
+        Ok(std::mem::replace(cur, op.into()))
     }
 }
diff --git a/hugr-core/src/hugr/rewrite/inline_dfg.rs b/hugr-core/src/hugr/rewrite/inline_dfg.rs
index adba1170f..b98e57bf5 100644
--- a/hugr-core/src/hugr/rewrite/inline_dfg.rs
+++ b/hugr-core/src/hugr/rewrite/inline_dfg.rs
@@ -201,7 +201,6 @@ mod test {
         let inner = {
             let mut inner = outer.dfg_builder(
                 FunctionType::new_endo(vec![int_ty.clone()]).with_extension_delta(delta),
-                None,
                 [a],
             )?;
             let [a] = inner.input_wires_arr();
@@ -261,11 +260,7 @@ mod test {
             .add_dataflow_op(test_quantum_extension::h_gate(), [p])?
             .outputs_arr();
         let swap = {
-            let swap = h.dfg_builder(
-                FunctionType::new_endo(type_row![QB_T, QB_T]),
-                None,
-                [p_h, q],
-            )?;
+            let swap = h.dfg_builder(FunctionType::new_endo(type_row![QB_T, QB_T]), [p_h, q])?;
             let [a, b] = swap.input_wires_arr();
             swap.finish_with_outputs([b, a])?
         };
@@ -363,7 +358,6 @@ mod test {
         let h_b = outer.add_dataflow_op(test_quantum_extension::h_gate(), [b])?;
         let mut inner = outer.dfg_builder(
             FunctionType::new_endo(type_row![QB_T]).with_extension_delta(float_types::EXTENSION_ID),
-            None,
             h_b.outputs(),
         )?;
         let [i] = inner.input_wires_arr();
diff --git a/hugr-core/src/hugr/rewrite/outline_cfg.rs b/hugr-core/src/hugr/rewrite/outline_cfg.rs
index 335a7a44d..5880708e0 100644
--- a/hugr-core/src/hugr/rewrite/outline_cfg.rs
+++ b/hugr-core/src/hugr/rewrite/outline_cfg.rs
@@ -125,10 +125,8 @@ impl Rewrite for OutlineCfg {
 
         // 2. new_block contains input node, sub-cfg, exit node all connected
         let (new_block, cfg_node) = {
-            let input_extensions = h.get_nodetype(entry).input_extensions().cloned();
             let mut new_block_bldr = BlockBuilder::new(
                 inputs.clone(),
-                input_extensions.clone(),
                 vec![type_row![]],
                 outputs.clone(),
                 extension_delta.clone(),
@@ -136,7 +134,7 @@ impl Rewrite for OutlineCfg {
             .unwrap();
             let wires_in = inputs.iter().cloned().zip(new_block_bldr.input_wires());
             let cfg = new_block_bldr
-                .cfg_builder(wires_in, input_extensions, outputs, extension_delta)
+                .cfg_builder(wires_in, outputs, extension_delta)
                 .unwrap();
             let cfg = cfg.finish_sub_container().unwrap();
             let unit_sum = new_block_bldr.add_constant(ops::Value::unary_unit_sum());
diff --git a/hugr-core/src/hugr/rewrite/replace.rs b/hugr-core/src/hugr/rewrite/replace.rs
index 9cc028053..08bea175c 100644
--- a/hugr-core/src/hugr/rewrite/replace.rs
+++ b/hugr-core/src/hugr/rewrite/replace.rs
@@ -455,7 +455,7 @@ mod test {
     };
     use crate::hugr::internal::HugrMutInternals;
     use crate::hugr::rewrite::replace::WhichHugr;
-    use crate::hugr::{HugrMut, NodeType, Rewrite};
+    use crate::hugr::{HugrMut, Rewrite};
     use crate::ops::custom::{CustomOp, OpaqueOp};
     use crate::ops::dataflow::DataflowOpTrait;
     use crate::ops::handle::{BasicBlockID, ConstID, NodeHandle};
@@ -523,9 +523,9 @@ mod test {
 
         // Replacement: one BB with two DFGs inside.
         // Use Hugr rather than Builder because DFGs must be empty (not even Input/Output).
-        let mut replacement = Hugr::new(NodeType::new_open(ops::CFG {
+        let mut replacement = Hugr::new(ops::CFG {
             signature: FunctionType::new_endo(just_list.clone()),
-        }));
+        });
         let r_bb = replacement.add_node_with_parent(
             replacement.root(),
             DataflowBlock {
@@ -676,14 +676,14 @@ mod test {
         let case1 = case1.finish_with_outputs(foo.outputs())?.node();
         let mut case2 = cond.case_builder(1)?;
         let bar = case2.add_dataflow_op(mk_op("bar"), case2.input_wires())?;
-        let mut baz_dfg = case2.dfg_builder(utou.clone(), None, bar.outputs())?;
+        let mut baz_dfg = case2.dfg_builder(utou.clone(), bar.outputs())?;
         let baz = baz_dfg.add_dataflow_op(mk_op("baz"), baz_dfg.input_wires())?;
         let baz_dfg = baz_dfg.finish_with_outputs(baz.outputs())?;
         let case2 = case2.finish_with_outputs(baz_dfg.outputs())?.node();
         let cond = cond.finish_sub_container()?;
         let h = h.finish_hugr_with_outputs(cond.outputs(), &PRELUDE_REGISTRY)?;
 
-        let mut r_hugr = Hugr::new(NodeType::new_open(h.get_optype(cond.node()).clone()));
+        let mut r_hugr = Hugr::new(h.get_optype(cond.node()).clone());
         let r1 = r_hugr.add_node_with_parent(
             r_hugr.root(),
             Case {
diff --git a/hugr-core/src/hugr/rewrite/simple_replace.rs b/hugr-core/src/hugr/rewrite/simple_replace.rs
index 387b97b76..a70c275aa 100644
--- a/hugr-core/src/hugr/rewrite/simple_replace.rs
+++ b/hugr-core/src/hugr/rewrite/simple_replace.rs
@@ -244,7 +244,6 @@ pub(in crate::hugr::rewrite) mod test {
 
             let mut inner_builder = func_builder.dfg_builder(
                 FunctionType::new(type_row![QB, QB], type_row![QB, QB]),
-                None,
                 [qb0, qb1],
             )?;
             let inner_graph = {
diff --git a/hugr-core/src/hugr/serialize.rs b/hugr-core/src/hugr/serialize.rs
index a93eb2070..f5554094b 100644
--- a/hugr-core/src/hugr/serialize.rs
+++ b/hugr-core/src/hugr/serialize.rs
@@ -5,8 +5,7 @@ use std::collections::HashMap;
 use thiserror::Error;
 
 use crate::core::NodeIndex;
-use crate::extension::ExtensionSet;
-use crate::hugr::{Hugr, NodeType};
+use crate::hugr::Hugr;
 use crate::ops::OpType;
 use crate::{Node, PortIndex};
 use portgraph::hierarchy::AttachError;
@@ -48,7 +47,6 @@ impl<T> Versioned<T> {
 #[derive(Clone, Serialize, Deserialize, PartialEq, Debug)]
 struct NodeSer {
     parent: Node,
-    input_extensions: Option<ExtensionSet>,
     #[serde(flatten)]
     op: OpType,
 }
@@ -143,12 +141,11 @@ impl TryFrom<&Hugr> for SerHugrV1 {
         let mut metadata = vec![None; hugr.node_count()];
         for n in hugr.nodes() {
             let parent = node_rekey[&hugr.get_parent(n).unwrap_or(n)];
-            let opt = hugr.get_nodetype(n);
+            let opt = hugr.get_optype(n);
             let new_node = node_rekey[&n].index();
             nodes[new_node] = Some(NodeSer {
                 parent,
-                input_extensions: opt.input_extensions.clone(),
-                op: opt.op.clone(),
+                op: opt.clone(),
             });
             metadata[new_node].clone_from(hugr.metadata.get(n.pg_index()));
         }
@@ -205,7 +202,6 @@ impl TryFrom<SerHugrV1> for Hugr {
         let mut nodes = nodes.into_iter();
         let NodeSer {
             parent: root_parent,
-            input_extensions,
             op: root_type,
         } = nodes.next().unwrap();
         if root_parent.index() != 0 {
@@ -213,17 +209,10 @@ impl TryFrom<SerHugrV1> for Hugr {
         }
         // if there are any unconnected ports or copy nodes the capacity will be
         // an underestimate
-        let mut hugr = Hugr::with_capacity(
-            NodeType::new(root_type, input_extensions),
-            nodes.len(),
-            edges.len() * 2,
-        );
+        let mut hugr = Hugr::with_capacity(root_type, nodes.len(), edges.len() * 2);
 
         for node_ser in nodes {
-            hugr.add_node_with_parent(
-                node_ser.parent,
-                NodeType::new(node_ser.op, node_ser.input_extensions),
-            );
+            hugr.add_node_with_parent(node_ser.parent, node_ser.op);
         }
 
         if let Some(metadata) = metadata {
diff --git a/hugr-core/src/hugr/serialize/test.rs b/hugr-core/src/hugr/serialize/test.rs
index fdd58e398..712c871b4 100644
--- a/hugr-core/src/hugr/serialize/test.rs
+++ b/hugr-core/src/hugr/serialize/test.rs
@@ -5,7 +5,7 @@ use crate::builder::{
 };
 use crate::extension::prelude::{BOOL_T, PRELUDE_ID, QB_T, USIZE_T};
 use crate::extension::simple_op::MakeRegisteredOp;
-use crate::extension::{test::SimpleOpDef, EMPTY_REG, PRELUDE_REGISTRY};
+use crate::extension::{test::SimpleOpDef, ExtensionSet, EMPTY_REG, PRELUDE_REGISTRY};
 use crate::hugr::internal::HugrMutInternals;
 use crate::ops::custom::{ExtensionOp, OpaqueOp};
 use crate::ops::{self, dataflow::IOTrait, Input, Module, Noop, Output, Value, DFG};
@@ -226,11 +226,11 @@ fn simpleser() {
     let mut h = Hierarchy::new();
     let mut op_types = UnmanagedDenseMap::new();
 
-    op_types[root] = NodeType::new_open(gen_optype(&g, root));
+    op_types[root] = gen_optype(&g, root);
 
     for n in [a, b, c] {
         h.push_child(n, root).unwrap();
-        op_types[n] = NodeType::new_pure(gen_optype(&g, n));
+        op_types[n] = gen_optype(&g, n);
     }
 
     let hugr = Hugr {
@@ -469,7 +469,6 @@ fn roundtrip_polyfunctype(#[case] poly_func_type: PolyFuncType) {
 fn roundtrip_optype(#[case] optype: impl Into<OpType> + std::fmt::Debug) {
     check_testing_roundtrip(NodeSer {
         parent: portgraph::NodeIndex::new(0).into(),
-        input_extensions: None,
         op: optype.into(),
     });
 }
@@ -477,7 +476,6 @@ fn roundtrip_optype(#[case] optype: impl Into<OpType> + std::fmt::Debug) {
 mod proptest {
     use super::check_testing_roundtrip;
     use super::{NodeSer, SimpleOpDef};
-    use crate::extension::ExtensionSet;
     use crate::ops::{OpType, Value};
     use crate::types::{PolyFuncType, Type};
     use proptest::prelude::*;
@@ -488,14 +486,9 @@ mod proptest {
         fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy {
             (
                 (0..i32::MAX as usize).prop_map(|x| portgraph::NodeIndex::new(x).into()),
-                any::<Option<ExtensionSet>>(),
                 any::<OpType>(),
             )
-                .prop_map(|(parent, input_extensions, op)| NodeSer {
-                    parent,
-                    input_extensions,
-                    op,
-                })
+                .prop_map(|(parent, op)| NodeSer { parent, op })
                 .boxed()
         }
     }
diff --git a/hugr-core/src/hugr/validate.rs b/hugr-core/src/hugr/validate.rs
index ce6532ab0..be2e06003 100644
--- a/hugr-core/src/hugr/validate.rs
+++ b/hugr-core/src/hugr/validate.rs
@@ -19,7 +19,6 @@ use crate::types::{EdgeKind, FunctionType};
 use crate::{Direction, Hugr, Node, Port};
 
 use super::views::{HierarchyView, HugrView, SiblingGraph};
-use super::NodeType;
 
 /// Structure keeping track of pre-computed information used in the validation
 /// process.
@@ -152,8 +151,7 @@ impl<'a, 'b> ValidationContext<'a, 'b> {
     /// - Matching the number of ports with the signature
     /// - Dataflow ports are correct. See `validate_df_port`
     fn validate_node(&self, node: Node) -> Result<(), ValidationError> {
-        let node_type = self.hugr.get_nodetype(node);
-        let op_type = &node_type.op;
+        let op_type = self.hugr.get_optype(node);
 
         // The Hugr can have only one root node.
         if node == self.hugr.root() {
@@ -210,7 +208,7 @@ impl<'a, 'b> ValidationContext<'a, 'b> {
             })?;
 
         // Thirdly that the node has correct children
-        self.validate_children(node, node_type)?;
+        self.validate_children(node, op_type)?;
 
         Ok(())
     }
@@ -315,8 +313,7 @@ impl<'a, 'b> ValidationContext<'a, 'b> {
     /// Check operation-specific constraints.
     ///
     /// These are flags defined for each operation type as an [`OpValidityFlags`] object.
-    fn validate_children(&self, node: Node, node_type: &NodeType) -> Result<(), ValidationError> {
-        let op_type = &node_type.op;
+    fn validate_children(&self, node: Node, op_type: &OpType) -> Result<(), ValidationError> {
         let flags = op_type.validity_flags();
 
         if self.hugr.hierarchy.child_count(node.pg_index()) > 0 {
diff --git a/hugr-core/src/hugr/validate/test.rs b/hugr-core/src/hugr/validate/test.rs
index 47c197416..d4d311170 100644
--- a/hugr-core/src/hugr/validate/test.rs
+++ b/hugr-core/src/hugr/validate/test.rs
@@ -77,7 +77,7 @@ fn invalid_root() {
         Err(ValidationError::NoParent { node }) => assert_eq!(node, other)
     );
     b.set_parent(other, root);
-    b.replace_op(other, NodeType::new_pure(declare_op)).unwrap();
+    b.replace_op(other, declare_op).unwrap();
     b.add_ports(other, Direction::Outgoing, 1);
     assert_eq!(b.validate(&EMPTY_REG), Ok(()));
 
@@ -96,7 +96,7 @@ fn invalid_root() {
 fn leaf_root() {
     let leaf_op: OpType = Noop { ty: USIZE_T }.into();
 
-    let b = Hugr::new(NodeType::new_pure(leaf_op));
+    let b = Hugr::new(leaf_op);
     assert_eq!(b.validate(&EMPTY_REG), Ok(()));
 }
 
@@ -107,7 +107,7 @@ fn dfg_root() {
     }
     .into();
 
-    let mut b = Hugr::new(NodeType::new_pure(dfg_op));
+    let mut b = Hugr::new(dfg_op);
     let root = b.root();
     add_df_children(&mut b, root, 1);
     assert_eq!(b.update_validate(&EMPTY_REG), Ok(()));
@@ -175,36 +175,26 @@ fn df_children_restrictions() {
         .unwrap();
 
     // Replace the output operation of the df subgraph with a copy
-    b.replace_op(output, NodeType::new_pure(Noop { ty: NAT }))
-        .unwrap();
+    b.replace_op(output, Noop { ty: NAT }).unwrap();
     assert_matches!(
         b.validate(&EMPTY_REG),
         Err(ValidationError::InvalidInitialChild { parent, .. }) => assert_eq!(parent, def)
     );
 
     // Revert it back to an output, but with the wrong number of ports
-    b.replace_op(
-        output,
-        NodeType::new_pure(ops::Output::new(type_row![BOOL_T])),
-    )
-    .unwrap();
+    b.replace_op(output, ops::Output::new(type_row![BOOL_T]))
+        .unwrap();
     assert_matches!(
         b.validate(&EMPTY_REG),
         Err(ValidationError::InvalidChildren { parent, source: ChildrenValidationError::IOSignatureMismatch { child, .. }, .. })
             => {assert_eq!(parent, def); assert_eq!(child, output.pg_index())}
     );
-    b.replace_op(
-        output,
-        NodeType::new_pure(ops::Output::new(type_row![BOOL_T, BOOL_T])),
-    )
-    .unwrap();
+    b.replace_op(output, ops::Output::new(type_row![BOOL_T, BOOL_T]))
+        .unwrap();
 
     // After fixing the output back, replace the copy with an output op
-    b.replace_op(
-        copy,
-        NodeType::new_pure(ops::Output::new(type_row![BOOL_T, BOOL_T])),
-    )
-    .unwrap();
+    b.replace_op(copy, ops::Output::new(type_row![BOOL_T, BOOL_T]))
+        .unwrap();
     assert_matches!(
         b.validate(&EMPTY_REG),
         Err(ValidationError::InvalidChildren { parent, source: ChildrenValidationError::InternalIOChildren { child, .. }, .. })
@@ -265,7 +255,6 @@ fn no_ext_edge_into_func() -> Result<(), Box<dyn std::error::Error>> {
 
     let mut dfg = h.dfg_builder(
         FunctionType::new(vec![], Type::new_function(b2b.clone())),
-        None,
         [],
     )?;
     let mut func = dfg.define_function("AndWithOuter", b2b.clone().into())?;
@@ -694,16 +683,13 @@ fn no_outer_row_variables(#[case] connect: bool) -> Result<(), Box<dyn std::erro
     let tv = Type::new_row_var_use(0, TypeBound::Copyable);
     let fun_ty = Type::new_function(FunctionType::new(USIZE_T, tv.clone()));
     let results = if connect { vec![tv.clone()] } else { vec![] };
-    let mut fb = Hugr::new(
-        FuncDefn {
-            name: "bad_eval".to_string(),
-            signature: PolyFuncType::new(
-                [TypeParam::new_list(TypeBound::Copyable)],
-                FunctionType::new(fun_ty.clone(), results.clone()),
-            ),
-        }
-        .into(),
-    );
+    let mut fb = Hugr::new(FuncDefn {
+        name: "bad_eval".to_string(),
+        signature: PolyFuncType::new(
+            [TypeParam::new_list(TypeBound::Copyable)],
+            FunctionType::new(fun_ty.clone(), results.clone()),
+        ),
+    });
     let inp = fb.add_node_with_parent(
         fb.root(),
         ops::Input {
@@ -879,9 +865,9 @@ fn cfg_children_restrictions() {
     b.validate(&EMPTY_REG).unwrap();
     b.replace_op(
         copy,
-        NodeType::new_pure(ops::CFG {
+        ops::CFG {
             signature: FunctionType::new(type_row![BOOL_T], type_row![BOOL_T]),
-        }),
+        },
     )
     .unwrap();
     assert_matches!(
@@ -942,25 +928,22 @@ fn cfg_children_restrictions() {
     // Change the types in the BasicBlock node to work on qubits instead of bits
     b.replace_op(
         block,
-        NodeType::new_pure(ops::DataflowBlock {
+        ops::DataflowBlock {
             inputs: type_row![QB_T],
             sum_rows: vec![type_row![]],
             other_outputs: type_row![QB_T],
             extension_delta: ExtensionSet::new(),
-        }),
+        },
     )
     .unwrap();
     let mut block_children = b.hierarchy.children(block.pg_index());
     let block_input = block_children.next().unwrap().into();
     let block_output = block_children.next_back().unwrap().into();
-    b.replace_op(
-        block_input,
-        NodeType::new_pure(ops::Input::new(type_row![QB_T])),
-    )
-    .unwrap();
+    b.replace_op(block_input, ops::Input::new(type_row![QB_T]))
+        .unwrap();
     b.replace_op(
         block_output,
-        NodeType::new_pure(ops::Output::new(type_row![Type::new_unit_sum(1), QB_T])),
+        ops::Output::new(type_row![Type::new_unit_sum(1), QB_T]),
     )
     .unwrap();
     assert_matches!(
@@ -1035,30 +1018,27 @@ mod extension_tests {
         let parent = parent_f(
             FunctionType::new_endo(USIZE_T).with_extension_delta(parent_extensions.clone()),
         );
-        let mut hugr = Hugr::new(NodeType::new_pure(parent));
+        let mut hugr = Hugr::new(parent);
 
         let input = hugr.add_node_with_parent(
             hugr.root(),
-            NodeType::new_pure(ops::Input {
+            ops::Input {
                 types: type_row![USIZE_T],
-            }),
+            },
         );
         let output = hugr.add_node_with_parent(
             hugr.root(),
-            NodeType::new(
-                ops::Output {
-                    types: type_row![USIZE_T],
-                },
-                Some(XB.into()),
-            ),
+            ops::Output {
+                types: type_row![USIZE_T],
+            },
         );
 
         let lift = hugr.add_node_with_parent(
             hugr.root(),
-            NodeType::new_pure(ops::Lift {
+            ops::Lift {
                 type_row: type_row![USIZE_T],
                 new_extension: XB,
-            }),
+            },
         );
 
         hugr.connect(input, 0, lift, 0);
@@ -1127,7 +1107,7 @@ mod extension_tests {
             outputs: type_row![USIZE_T],
             extension_delta: parent_extensions.clone(),
         };
-        let mut hugr = Hugr::new(NodeType::new_pure(parent));
+        let mut hugr = Hugr::new(parent);
 
         // First case with no delta should be ok in all cases. Second one may not be.
         let [_, child] = [None, Some(XB)].map(|case_ext| {
@@ -1142,28 +1122,25 @@ mod extension_tests {
 
             let input = hugr.add_node_with_parent(
                 case,
-                NodeType::new_pure(ops::Input {
+                ops::Input {
                     types: type_row![USIZE_T],
-                }),
+                },
             );
             let output = hugr.add_node_with_parent(
                 case,
-                NodeType::new(
-                    ops::Output {
-                        types: type_row![USIZE_T],
-                    },
-                    Some(case_exts),
-                ),
+                ops::Output {
+                    types: type_row![USIZE_T],
+                },
             );
             let res = match case_ext {
                 None => input,
                 Some(new_ext) => {
                     let lift = hugr.add_node_with_parent(
                         case,
-                        NodeType::new_pure(ops::Lift {
+                        ops::Lift {
                             type_row: type_row![USIZE_T],
                             new_extension: new_ext,
-                        }),
+                        },
                     );
                     hugr.connect(input, 0, lift, 0);
                     lift
@@ -1227,7 +1204,7 @@ mod extension_tests {
     }
 
     fn make_bb(t: Type, es: ExtensionSet) -> DFGWrapper<Hugr, BasicBlockID> {
-        BlockBuilder::new(t.clone(), None, vec![t.into()], type_row![], es).unwrap()
+        BlockBuilder::new(t.clone(), vec![t.into()], type_row![], es).unwrap()
     }
 
     fn make_tailloop(t: Type, es: ExtensionSet) -> DFGWrapper<Hugr, BuildHandle<TailLoopID>> {
diff --git a/hugr-core/src/hugr/views.rs b/hugr-core/src/hugr/views.rs
index 607f88768..6371e7772 100644
--- a/hugr-core/src/hugr/views.rs
+++ b/hugr-core/src/hugr/views.rs
@@ -26,8 +26,7 @@ use portgraph::{multiportgraph, LinkView, PortView};
 
 use super::internal::HugrInternals;
 use super::{
-    Hugr, HugrError, HugrMut, NodeMetadata, NodeMetadataMap, NodeType, ValidationError,
-    DEFAULT_NODETYPE,
+    Hugr, HugrError, HugrMut, NodeMetadata, NodeMetadataMap, ValidationError, DEFAULT_OPTYPE,
 };
 use crate::extension::ExtensionRegistry;
 use crate::ops::handle::NodeHandle;
@@ -80,8 +79,8 @@ pub trait HugrView: HugrInternals {
 
     /// Return the type of the HUGR root node.
     #[inline]
-    fn root_type(&self) -> &NodeType {
-        let node_type = self.get_nodetype(self.root());
+    fn root_type(&self) -> &OpType {
+        let node_type = self.get_optype(self.root());
         // Sadly no way to do this at present
         // debug_assert!(Self::RootHandle::can_hold(node_type.tag()));
         node_type
@@ -119,15 +118,9 @@ pub trait HugrView: HugrInternals {
     /// Returns the operation type of a node.
     #[inline]
     fn get_optype(&self, node: Node) -> &OpType {
-        &self.get_nodetype(node).op
-    }
-
-    /// Returns the type of a node.
-    #[inline]
-    fn get_nodetype(&self, node: Node) -> &NodeType {
         match self.contains_node(node) {
             true => self.base_hugr().op_types.get(node.pg_index()),
-            false => &DEFAULT_NODETYPE,
+            false => &DEFAULT_OPTYPE,
         }
     }
 
@@ -323,8 +316,8 @@ pub trait HugrView: HugrInternals {
     /// If the node isn't a dataflow parent, then return None
     #[inline]
     fn get_io(&self, node: Node) -> Option<[Node; 2]> {
-        let op = self.get_nodetype(node);
-        // Nodes outside the view have no children (and a non-DataflowParent NodeType::default())
+        let op = self.get_optype(node);
+        // Nodes outside the view have no children (and a non-DataflowParent OpType::default())
         if OpTag::DataflowParent.is_superset(op.tag()) {
             self.children(node).take(2).collect_vec().try_into().ok()
         } else {
diff --git a/hugr-core/src/hugr/views/descendants.rs b/hugr-core/src/hugr/views/descendants.rs
index bee6dbd26..264890a31 100644
--- a/hugr-core/src/hugr/views/descendants.rs
+++ b/hugr-core/src/hugr/views/descendants.rs
@@ -231,11 +231,8 @@ pub(super) mod test {
             let q_out = func_builder.add_dataflow_op(h_gate(), vec![qb])?;
 
             let inner_id = {
-                let inner_builder = func_builder.dfg_builder(
-                    FunctionType::new(type_row![NAT], type_row![NAT]),
-                    None,
-                    [int],
-                )?;
+                let inner_builder = func_builder
+                    .dfg_builder(FunctionType::new(type_row![NAT], type_row![NAT]), [int])?;
                 let w = inner_builder.input_wires();
                 inner_builder.finish_with_outputs(w)
             }?;
diff --git a/hugr-core/src/hugr/views/root_checked.rs b/hugr-core/src/hugr/views/root_checked.rs
index d8d52a7ae..668fdb83d 100644
--- a/hugr-core/src/hugr/views/root_checked.rs
+++ b/hugr-core/src/hugr/views/root_checked.rs
@@ -72,16 +72,17 @@ mod test {
     use super::RootChecked;
     use crate::extension::ExtensionSet;
     use crate::hugr::internal::HugrMutInternals;
-    use crate::hugr::{HugrError, HugrMut, NodeType};
+    use crate::hugr::{HugrError, HugrMut};
     use crate::ops::handle::{BasicBlockID, CfgID, DataflowParentID, DfgID};
-    use crate::ops::{DataflowBlock, MakeTuple, OpTag};
+    use crate::ops::{DataflowBlock, MakeTuple, OpTag, OpType};
     use crate::{ops, type_row, types::FunctionType, Hugr, HugrView};
 
     #[test]
     fn root_checked() {
-        let root_type = NodeType::new_pure(ops::DFG {
+        let root_type: OpType = ops::DFG {
             signature: FunctionType::new(vec![], vec![]),
-        });
+        }
+        .into();
         let mut h = Hugr::new(root_type.clone());
         let cfg_v = RootChecked::<&Hugr, CfgID>::try_new(&h);
         assert_eq!(
@@ -94,12 +95,13 @@ mod test {
         let mut dfg_v = RootChecked::<&mut Hugr, DfgID>::try_new(&mut h).unwrap();
         // That is a HugrMutInternal, so we can try:
         let root = dfg_v.root();
-        let bb = NodeType::new_pure(DataflowBlock {
+        let bb: OpType = DataflowBlock {
             inputs: type_row![],
             other_outputs: type_row![],
             sum_rows: vec![type_row![]],
             extension_delta: ExtensionSet::new(),
-        });
+        }
+        .into();
         let r = dfg_v.replace_op(root, bb.clone());
         assert_eq!(
             r,
@@ -109,7 +111,7 @@ mod test {
             })
         );
         // That didn't do anything:
-        assert_eq!(dfg_v.get_nodetype(root), &root_type);
+        assert_eq!(dfg_v.get_optype(root), &root_type);
 
         // Make a RootChecked that allows any DataflowParent
         // We won't be able to do this by widening the bound:
@@ -124,12 +126,12 @@ mod test {
         let mut dfp_v = RootChecked::<&mut Hugr, DataflowParentID>::try_new(&mut h).unwrap();
         let r = dfp_v.replace_op(root, bb.clone());
         assert_eq!(r, Ok(root_type));
-        assert_eq!(dfp_v.get_nodetype(root), &bb);
+        assert_eq!(dfp_v.get_optype(root), &bb);
         // Just check we can create a nested instance (narrowing the bound)
         let mut bb_v = RootChecked::<_, BasicBlockID>::try_new(dfp_v).unwrap();
 
         // And it's a HugrMut:
-        let nodetype = NodeType::new_pure(MakeTuple { tys: type_row![] });
+        let nodetype = MakeTuple { tys: type_row![] };
         bb_v.add_node_with_parent(bb_v.root(), nodetype);
     }
 }
diff --git a/hugr-core/src/hugr/views/sibling.rs b/hugr-core/src/hugr/views/sibling.rs
index 25bc477a4..662764e6c 100644
--- a/hugr-core/src/hugr/views/sibling.rs
+++ b/hugr-core/src/hugr/views/sibling.rs
@@ -381,9 +381,9 @@ mod test {
     use crate::builder::test::simple_dfg_hugr;
     use crate::builder::{Container, Dataflow, DataflowSubContainer, HugrBuilder, ModuleBuilder};
     use crate::extension::PRELUDE_REGISTRY;
-    use crate::hugr::NodeType;
     use crate::ops::handle::{CfgID, DataflowParentID, DfgID, FuncID};
     use crate::ops::{dataflow::IOTrait, Input, OpTag, Output};
+    use crate::ops::{OpTrait, OpType};
     use crate::type_row;
     use crate::types::{FunctionType, Type};
 
@@ -411,7 +411,7 @@ mod test {
         let mut module_builder = ModuleBuilder::new();
         let fty = FunctionType::new(type_row![NAT], type_row![NAT]);
         let mut fbuild = module_builder.define_function("main", fty.clone().into())?;
-        let dfg = fbuild.dfg_builder(fty, None, fbuild.input_wires())?;
+        let dfg = fbuild.dfg_builder(fty, fbuild.input_wires())?;
         let ins = dfg.input_wires();
         let sub_dfg = dfg.finish_with_outputs(ins)?;
         let fun = fbuild.finish_with_outputs(sub_dfg.outputs())?;
@@ -455,7 +455,7 @@ mod test {
         );
 
         let mut sib_mut = SiblingMut::<DfgID>::try_new(&mut simple_dfg_hugr, root).unwrap();
-        let bad_nodetype = NodeType::new_open(crate::ops::CFG { signature });
+        let bad_nodetype: OpType = crate::ops::CFG { signature }.into();
         assert_eq!(
             sib_mut.replace_op(sib_mut.root(), bad_nodetype.clone()),
             Err(HugrError::InvalidTag {
@@ -472,13 +472,13 @@ mod test {
     #[rstest]
     fn sibling_mut_covariance(mut simple_dfg_hugr: Hugr) {
         let root = simple_dfg_hugr.root();
-        let case_nodetype = NodeType::new_open(crate::ops::Case {
-            signature: simple_dfg_hugr.root_type().op_signature().unwrap(),
-        });
+        let case_nodetype = crate::ops::Case {
+            signature: simple_dfg_hugr.root_type().dataflow_signature().unwrap(),
+        };
         let mut sib_mut = SiblingMut::<DfgID>::try_new(&mut simple_dfg_hugr, root).unwrap();
         // As expected, we cannot replace the root with a Case
         assert_eq!(
-            sib_mut.replace_op(root, case_nodetype.clone()),
+            sib_mut.replace_op(root, case_nodetype),
             Err(HugrError::InvalidTag {
                 required: OpTag::Dfg,
                 actual: OpTag::Case
diff --git a/hugr-core/src/ops/constant.rs b/hugr-core/src/ops/constant.rs
index ea55908fa..7975c40fe 100644
--- a/hugr-core/src/ops/constant.rs
+++ b/hugr-core/src/ops/constant.rs
@@ -274,7 +274,7 @@ fn mono_fn_type(h: &Hugr) -> Result<FunctionType, ConstTypeError> {
         }
     }
     Err(ConstTypeError::NotMonomorphicFunction {
-        hugr_root_type: h.root_type().op().clone(),
+        hugr_root_type: h.root_type().clone(),
     })
 }
 
diff --git a/hugr-core/src/ops/custom.rs b/hugr-core/src/ops/custom.rs
index d97a8202c..8f4e3f19c 100644
--- a/hugr-core/src/ops/custom.rs
+++ b/hugr-core/src/ops/custom.rs
@@ -12,7 +12,7 @@ use {
 
 use crate::extension::{ConstFoldResult, ExtensionId, ExtensionRegistry, OpDef, SignatureError};
 use crate::hugr::internal::HugrMutInternals;
-use crate::hugr::{HugrView, NodeType};
+use crate::hugr::HugrView;
 use crate::types::EdgeKind;
 use crate::types::{type_param::TypeArg, FunctionType};
 use crate::{ops, Hugr, IncomingPort, Node};
@@ -362,10 +362,9 @@ pub fn resolve_extension_ops(
     }
     // Only now can we perform the replacements as the 'for' loop was borrowing 'h' preventing use from using it mutably
     for (n, op) in replacements {
-        let node_type = NodeType::new(op, h.get_nodetype(n).input_extensions().cloned());
         debug_assert_eq!(h.get_optype(n).tag(), OpTag::Leaf);
-        debug_assert_eq!(node_type.tag(), OpTag::Leaf);
-        h.replace_op(n, node_type).unwrap();
+        debug_assert_eq!(op.tag(), OpTag::Leaf);
+        h.replace_op(n, op).unwrap();
     }
     Ok(())
 }
diff --git a/hugr-passes/src/const_fold/test.rs b/hugr-passes/src/const_fold/test.rs
index b5c0913bd..b116853ab 100644
--- a/hugr-passes/src/const_fold/test.rs
+++ b/hugr-passes/src/const_fold/test.rs
@@ -231,7 +231,6 @@ fn orphan_output() {
     //
     // We arange things so that the `or` folds away first, leaving the not
     // with no outputs.
-    use hugr_core::hugr::NodeType;
     use hugr_core::ops::handle::NodeHandle;
 
     let mut build = DFGBuilder::new(FunctionType::new(type_row![], vec![BOOL_T])).unwrap();
@@ -252,7 +251,7 @@ fn orphan_output() {
 
     // we delete the original Not and create a new One. This means it will be
     // traversed by `constant_fold_pass` after the Or.
-    let new_not = h.add_node_with_parent(parent, NodeType::new_auto(NotOp));
+    let new_not = h.add_node_with_parent(parent, NotOp);
     h.connect(true_wire.node(), true_wire.source(), new_not, 0);
     h.disconnect(or_node, IncomingPort::from(1));
     h.connect(new_not, 0, or_node, 1);
diff --git a/hugr-py/src/hugr/serialization/ops.py b/hugr-py/src/hugr/serialization/ops.py
index e96dfa733..60242b77d 100644
--- a/hugr-py/src/hugr/serialization/ops.py
+++ b/hugr-py/src/hugr/serialization/ops.py
@@ -29,7 +29,6 @@ class BaseOp(ABC, ConfiguredBaseModel):
 
     # Parent node index of node the op belongs to, used only at serialization time
     parent: NodeID
-    input_extensions: ExtensionSet | None = Field(default=None)
 
     def insert_port_types(self, in_types: TypeRow, out_types: TypeRow) -> None:
         """Hook to insert type information from the input and output ports into the
diff --git a/hugr/src/hugr.rs b/hugr/src/hugr.rs
index c2b6a70b7..cdf4fe42b 100644
--- a/hugr/src/hugr.rs
+++ b/hugr/src/hugr.rs
@@ -3,6 +3,6 @@
 // Exports everything except the `internal` module.
 pub use hugr_core::hugr::{
     hugrmut, rewrite, serialize, validate, views, Hugr, HugrError, HugrView, IdentList,
-    InvalidIdentifier, NodeMetadata, NodeMetadataMap, NodeType, Rewrite, RootTagged,
-    SimpleReplacement, SimpleReplacementError, ValidationError, DEFAULT_NODETYPE,
+    InvalidIdentifier, NodeMetadata, NodeMetadataMap, OpType, Rewrite, RootTagged,
+    SimpleReplacement, SimpleReplacementError, ValidationError, DEFAULT_OPTYPE,
 };
diff --git a/specification/schema/hugr_schema_strict_v1.json b/specification/schema/hugr_schema_strict_v1.json
index 08f948996..87c29ac88 100644
--- a/specification/schema/hugr_schema_strict_v1.json
+++ b/specification/schema/hugr_schema_strict_v1.json
@@ -35,21 +35,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "AliasDecl",
                     "default": "AliasDecl",
@@ -82,21 +67,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "AliasDefn",
                     "default": "AliasDefn",
@@ -211,21 +181,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CFG",
                     "default": "CFG",
@@ -253,21 +208,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Call",
                     "default": "Call",
@@ -308,21 +248,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CallIndirect",
                     "default": "CallIndirect",
@@ -350,21 +275,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Case",
                     "default": "Case",
@@ -392,21 +302,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Conditional",
                     "default": "Conditional",
@@ -463,21 +358,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Const",
                     "default": "Const",
@@ -524,21 +404,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CustomOp",
                     "default": "CustomOp",
@@ -588,21 +453,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "DFG",
                     "default": "DFG",
@@ -630,21 +480,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "DataflowBlock",
                     "default": "DataflowBlock",
@@ -701,21 +536,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "ExitBlock",
                     "default": "ExitBlock",
@@ -825,21 +645,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "FuncDecl",
                     "default": "FuncDecl",
@@ -873,21 +678,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "FuncDefn",
                     "default": "FuncDefn",
@@ -1025,21 +815,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Input",
                     "default": "Input",
@@ -1071,21 +846,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Lift",
                     "default": "Lift",
@@ -1145,21 +905,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "LoadConstant",
                     "default": "LoadConstant",
@@ -1188,21 +933,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "LoadFunction",
                     "default": "LoadFunction",
@@ -1243,21 +973,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "MakeTuple",
                     "default": "MakeTuple",
@@ -1289,21 +1004,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Module",
                     "default": "Module",
@@ -1328,21 +1028,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Noop",
                     "default": "Noop",
@@ -1575,21 +1260,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Output",
                     "default": "Output",
@@ -1771,21 +1441,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Tag",
                     "default": "Tag",
@@ -1826,21 +1481,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "TailLoop",
                     "default": "TailLoop",
@@ -2175,21 +1815,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "UnpackTuple",
                     "default": "UnpackTuple",
diff --git a/specification/schema/hugr_schema_v1.json b/specification/schema/hugr_schema_v1.json
index 8399c4feb..24d59c149 100644
--- a/specification/schema/hugr_schema_v1.json
+++ b/specification/schema/hugr_schema_v1.json
@@ -35,21 +35,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "AliasDecl",
                     "default": "AliasDecl",
@@ -82,21 +67,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "AliasDefn",
                     "default": "AliasDefn",
@@ -211,21 +181,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CFG",
                     "default": "CFG",
@@ -253,21 +208,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Call",
                     "default": "Call",
@@ -308,21 +248,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CallIndirect",
                     "default": "CallIndirect",
@@ -350,21 +275,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Case",
                     "default": "Case",
@@ -392,21 +302,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Conditional",
                     "default": "Conditional",
@@ -463,21 +358,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Const",
                     "default": "Const",
@@ -524,21 +404,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CustomOp",
                     "default": "CustomOp",
@@ -588,21 +453,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "DFG",
                     "default": "DFG",
@@ -630,21 +480,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "DataflowBlock",
                     "default": "DataflowBlock",
@@ -701,21 +536,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "ExitBlock",
                     "default": "ExitBlock",
@@ -825,21 +645,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "FuncDecl",
                     "default": "FuncDecl",
@@ -873,21 +678,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "FuncDefn",
                     "default": "FuncDefn",
@@ -1025,21 +815,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Input",
                     "default": "Input",
@@ -1071,21 +846,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Lift",
                     "default": "Lift",
@@ -1145,21 +905,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "LoadConstant",
                     "default": "LoadConstant",
@@ -1188,21 +933,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "LoadFunction",
                     "default": "LoadFunction",
@@ -1243,21 +973,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "MakeTuple",
                     "default": "MakeTuple",
@@ -1289,21 +1004,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Module",
                     "default": "Module",
@@ -1328,21 +1028,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Noop",
                     "default": "Noop",
@@ -1575,21 +1260,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Output",
                     "default": "Output",
@@ -1771,21 +1441,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Tag",
                     "default": "Tag",
@@ -1826,21 +1481,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "TailLoop",
                     "default": "TailLoop",
@@ -2175,21 +1815,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "UnpackTuple",
                     "default": "UnpackTuple",
diff --git a/specification/schema/testing_hugr_schema_strict_v1.json b/specification/schema/testing_hugr_schema_strict_v1.json
index 567c481dd..0199ce591 100644
--- a/specification/schema/testing_hugr_schema_strict_v1.json
+++ b/specification/schema/testing_hugr_schema_strict_v1.json
@@ -35,21 +35,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "AliasDecl",
                     "default": "AliasDecl",
@@ -82,21 +67,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "AliasDefn",
                     "default": "AliasDefn",
@@ -211,21 +181,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CFG",
                     "default": "CFG",
@@ -253,21 +208,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Call",
                     "default": "Call",
@@ -308,21 +248,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CallIndirect",
                     "default": "CallIndirect",
@@ -350,21 +275,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Case",
                     "default": "Case",
@@ -392,21 +302,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Conditional",
                     "default": "Conditional",
@@ -463,21 +358,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Const",
                     "default": "Const",
@@ -524,21 +404,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CustomOp",
                     "default": "CustomOp",
@@ -588,21 +453,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "DFG",
                     "default": "DFG",
@@ -630,21 +480,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "DataflowBlock",
                     "default": "DataflowBlock",
@@ -701,21 +536,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "ExitBlock",
                     "default": "ExitBlock",
@@ -846,21 +666,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "FuncDecl",
                     "default": "FuncDecl",
@@ -894,21 +699,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "FuncDefn",
                     "default": "FuncDefn",
@@ -1046,21 +836,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Input",
                     "default": "Input",
@@ -1092,21 +867,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Lift",
                     "default": "Lift",
@@ -1166,21 +926,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "LoadConstant",
                     "default": "LoadConstant",
@@ -1209,21 +954,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "LoadFunction",
                     "default": "LoadFunction",
@@ -1264,21 +994,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "MakeTuple",
                     "default": "MakeTuple",
@@ -1310,21 +1025,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Module",
                     "default": "Module",
@@ -1349,21 +1049,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Noop",
                     "default": "Noop",
@@ -1652,21 +1337,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Output",
                     "default": "Output",
@@ -1848,21 +1518,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Tag",
                     "default": "Tag",
@@ -1903,21 +1558,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "TailLoop",
                     "default": "TailLoop",
@@ -2252,21 +1892,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "UnpackTuple",
                     "default": "UnpackTuple",
diff --git a/specification/schema/testing_hugr_schema_v1.json b/specification/schema/testing_hugr_schema_v1.json
index 47ed10526..f06ad5300 100644
--- a/specification/schema/testing_hugr_schema_v1.json
+++ b/specification/schema/testing_hugr_schema_v1.json
@@ -35,21 +35,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "AliasDecl",
                     "default": "AliasDecl",
@@ -82,21 +67,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "AliasDefn",
                     "default": "AliasDefn",
@@ -211,21 +181,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CFG",
                     "default": "CFG",
@@ -253,21 +208,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Call",
                     "default": "Call",
@@ -308,21 +248,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CallIndirect",
                     "default": "CallIndirect",
@@ -350,21 +275,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Case",
                     "default": "Case",
@@ -392,21 +302,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Conditional",
                     "default": "Conditional",
@@ -463,21 +358,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Const",
                     "default": "Const",
@@ -524,21 +404,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "CustomOp",
                     "default": "CustomOp",
@@ -588,21 +453,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "DFG",
                     "default": "DFG",
@@ -630,21 +480,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "DataflowBlock",
                     "default": "DataflowBlock",
@@ -701,21 +536,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "ExitBlock",
                     "default": "ExitBlock",
@@ -846,21 +666,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "FuncDecl",
                     "default": "FuncDecl",
@@ -894,21 +699,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "FuncDefn",
                     "default": "FuncDefn",
@@ -1046,21 +836,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Input",
                     "default": "Input",
@@ -1092,21 +867,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Lift",
                     "default": "Lift",
@@ -1166,21 +926,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "LoadConstant",
                     "default": "LoadConstant",
@@ -1209,21 +954,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "LoadFunction",
                     "default": "LoadFunction",
@@ -1264,21 +994,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "MakeTuple",
                     "default": "MakeTuple",
@@ -1310,21 +1025,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Module",
                     "default": "Module",
@@ -1349,21 +1049,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Noop",
                     "default": "Noop",
@@ -1652,21 +1337,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Output",
                     "default": "Output",
@@ -1848,21 +1518,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "Tag",
                     "default": "Tag",
@@ -1903,21 +1558,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "TailLoop",
                     "default": "TailLoop",
@@ -2252,21 +1892,6 @@
                     "title": "Parent",
                     "type": "integer"
                 },
-                "input_extensions": {
-                    "anyOf": [
-                        {
-                            "items": {
-                                "type": "string"
-                            },
-                            "type": "array"
-                        },
-                        {
-                            "type": "null"
-                        }
-                    ],
-                    "default": null,
-                    "title": "Input Extensions"
-                },
                 "op": {
                     "const": "UnpackTuple",
                     "default": "UnpackTuple",