diff --git a/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp.rs b/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp.rs
index 618658847..8f025d9cf 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp.rs
@@ -7,8 +7,7 @@ use ceno_emul::{
 use ff_ext::ExtensionField;
 use generic_array::typenum::Unsigned;
 use gkr_iop::{
-    ProtocolBuilder, ProtocolWitnessGenerator,
-    gkr::{GKRCircuit, layer::Layer},
+    ProtocolBuilder, ProtocolWitnessGenerator, gkr::GKRCircuit,
     utils::lk_multiplicity::Multiplicity,
 };
 use itertools::{Itertools, izip};
@@ -291,9 +290,7 @@ fn build_fp_op_circuit<E: ExtensionField, P: FpOpField + NumWords>(
             .collect::<Result<Vec<WriteMEM>, _>>()?,
     );
 
-    let (out_evals, mut chip) = layout.finalize(cb);
-    let layer = Layer::from_circuit_builder(cb, layer_name.to_string(), out_evals);
-    chip.add_layer(layer);
+    let chip = layout.finalize(layer_name.to_string(), cb);
 
     Ok((
         EcallFpOpConfig {
diff --git a/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_add.rs b/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_add.rs
index 583058357..1bf07548d 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_add.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_add.rs
@@ -6,8 +6,7 @@ use ceno_emul::{
 use ff_ext::ExtensionField;
 use generic_array::typenum::Unsigned;
 use gkr_iop::{
-    ProtocolBuilder, ProtocolWitnessGenerator,
-    gkr::{GKRCircuit, layer::Layer},
+    ProtocolBuilder, ProtocolWitnessGenerator, gkr::GKRCircuit,
     utils::lk_multiplicity::Multiplicity,
 };
 use itertools::{Itertools, izip};
@@ -209,9 +208,7 @@ fn build_fp2_add_circuit<E: ExtensionField, P: FpOpField + Fp2AddSpec + NumWords
             .collect::<Result<Vec<WriteMEM>, _>>()?,
     );
 
-    let (out_evals, mut chip) = layout.finalize(cb);
-    let layer = Layer::from_circuit_builder(cb, "fp2_add".to_string(), out_evals);
-    chip.add_layer(layer);
+    let chip = layout.finalize("fp2_add".to_string(), cb);
 
     Ok((
         EcallFp2AddConfig {
diff --git a/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_mul.rs b/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_mul.rs
index bfcf118d3..563b63599 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_mul.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_mul.rs
@@ -6,8 +6,7 @@ use ceno_emul::{
 use ff_ext::ExtensionField;
 use generic_array::typenum::Unsigned;
 use gkr_iop::{
-    ProtocolBuilder, ProtocolWitnessGenerator,
-    gkr::{GKRCircuit, layer::Layer},
+    ProtocolBuilder, ProtocolWitnessGenerator, gkr::GKRCircuit,
     utils::lk_multiplicity::Multiplicity,
 };
 use itertools::{Itertools, izip};
@@ -207,9 +206,7 @@ fn build_fp2_mul_circuit<E: ExtensionField, P: FpOpField + Fp2MulSpec + NumWords
             .collect::<Result<Vec<WriteMEM>, _>>()?,
     );
 
-    let (out_evals, mut chip) = layout.finalize(cb);
-    let layer = Layer::from_circuit_builder(cb, "fp2_mul".to_string(), out_evals);
-    chip.add_layer(layer);
+    let chip = layout.finalize("fp2_mul".to_string(), cb);
 
     Ok((
         EcallFp2MulConfig {
diff --git a/ceno_zkvm/src/instructions/riscv/ecall/keccak.rs b/ceno_zkvm/src/instructions/riscv/ecall/keccak.rs
index b5adda675..b130e9c11 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/keccak.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/keccak.rs
@@ -7,7 +7,7 @@ use ceno_emul::{
 use ff_ext::ExtensionField;
 use gkr_iop::{
     ProtocolBuilder, ProtocolWitnessGenerator,
-    gkr::{GKRCircuit, booleanhypercube::BooleanHypercube, layer::Layer},
+    gkr::{GKRCircuit, booleanhypercube::BooleanHypercube},
     utils::lk_multiplicity::Multiplicity,
 };
 use itertools::{Itertools, izip};
@@ -132,10 +132,7 @@ impl<E: ExtensionField> Instruction<E> for KeccakInstruction<E> {
             })
             .collect::<Result<Vec<WriteMEM>, _>>()?;
 
-        let (out_evals, mut chip) = layout.finalize(cb);
-
-        let layer = Layer::from_circuit_builder(cb, Self::name(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize(Self::name(), cb);
 
         let circuit = chip.gkr_circuit();
 
diff --git a/ceno_zkvm/src/instructions/riscv/ecall/sha_extend.rs b/ceno_zkvm/src/instructions/riscv/ecall/sha_extend.rs
index bd9253a97..f9e143e3d 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/sha_extend.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/sha_extend.rs
@@ -5,8 +5,7 @@ use ceno_emul::{
 };
 use ff_ext::{ExtensionField, FieldInto};
 use gkr_iop::{
-    ProtocolBuilder, ProtocolWitnessGenerator,
-    gkr::{GKRCircuit, layer::Layer},
+    ProtocolBuilder, ProtocolWitnessGenerator, gkr::GKRCircuit,
     utils::lk_multiplicity::Multiplicity,
 };
 use itertools::{Itertools, izip};
@@ -130,10 +129,7 @@ impl<E: ExtensionField> Instruction<E> for ShaExtendInstruction<E> {
             vm_state.ts,
         )?);
 
-        let (out_evals, mut chip) = layout.finalize(cb);
-
-        let layer = Layer::from_circuit_builder(cb, Self::name(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize(Self::name(), cb);
 
         let circuit = chip.gkr_circuit();
 
diff --git a/ceno_zkvm/src/instructions/riscv/ecall/uint256.rs b/ceno_zkvm/src/instructions/riscv/ecall/uint256.rs
index 83fdba78a..fae2bb342 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/uint256.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/uint256.rs
@@ -7,8 +7,7 @@ use ceno_emul::{
 use ff_ext::ExtensionField;
 use generic_array::typenum::Unsigned;
 use gkr_iop::{
-    ProtocolBuilder, ProtocolWitnessGenerator,
-    gkr::{GKRCircuit, layer::Layer},
+    ProtocolBuilder, ProtocolWitnessGenerator, gkr::GKRCircuit,
     utils::lk_multiplicity::Multiplicity,
 };
 use itertools::{Itertools, chain, izip};
@@ -177,10 +176,7 @@ impl<E: ExtensionField> Instruction<E> for Uint256MulInstruction<E> {
             .collect::<Result<Vec<WriteMEM>, _>>()?,
         );
 
-        let (out_evals, mut chip) = layout.finalize(cb);
-
-        let layer = Layer::from_circuit_builder(cb, "uint256_mul".to_string(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize("uint256_mul".to_string(), cb);
 
         let circuit = chip.gkr_circuit();
 
@@ -501,10 +497,7 @@ impl<E: ExtensionField, Spec: Uint256InvSpec> Instruction<E> for Uint256InvInstr
             })
             .collect::<Result<Vec<WriteMEM>, _>>()?;
 
-        let (out_evals, mut chip) = layout.finalize(cb);
-
-        let layer = Layer::from_circuit_builder(cb, Spec::name(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize(Spec::name(), cb);
 
         let circuit = chip.gkr_circuit();
 
diff --git a/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_add.rs b/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_add.rs
index e5e1566e2..e8687f7f9 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_add.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_add.rs
@@ -7,8 +7,7 @@ use ceno_emul::{
 use ff_ext::ExtensionField;
 use generic_array::{GenericArray, typenum::Unsigned};
 use gkr_iop::{
-    ProtocolBuilder, ProtocolWitnessGenerator,
-    gkr::{GKRCircuit, layer::Layer},
+    ProtocolBuilder, ProtocolWitnessGenerator, gkr::GKRCircuit,
     utils::lk_multiplicity::Multiplicity,
 };
 use itertools::{Itertools, izip};
@@ -177,10 +176,7 @@ impl<E: ExtensionField, EC: EllipticCurve> Instruction<E>
                 .collect::<Result<Vec<WriteMEM>, _>>()?,
         );
 
-        let (out_evals, mut chip) = layout.finalize(cb);
-
-        let layer = Layer::from_circuit_builder(cb, "weierstrass_add".to_string(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize("weierstrass_add".to_string(), cb);
 
         let circuit = chip.gkr_circuit();
 
diff --git a/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_decompress.rs b/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_decompress.rs
index efead1b9e..f211e9afb 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_decompress.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_decompress.rs
@@ -7,8 +7,7 @@ use ceno_emul::{
 use ff_ext::ExtensionField;
 use generic_array::{GenericArray, typenum::Unsigned};
 use gkr_iop::{
-    ProtocolBuilder, ProtocolWitnessGenerator,
-    gkr::{GKRCircuit, layer::Layer},
+    ProtocolBuilder, ProtocolWitnessGenerator, gkr::GKRCircuit,
     utils::lk_multiplicity::Multiplicity,
 };
 use itertools::{Itertools, izip};
@@ -178,11 +177,7 @@ impl<E: ExtensionField, EC: EllipticCurve + WeierstrassParameters> Instruction<E
             .collect::<Result<Vec<WriteMEM>, _>>()?,
         );
 
-        let (out_evals, mut chip) = layout.finalize(cb);
-
-        let layer =
-            Layer::from_circuit_builder(cb, "weierstrass_decompress".to_string(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize("weierstrass_decompress".to_string(), cb);
 
         let circuit = chip.gkr_circuit();
 
diff --git a/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_double.rs b/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_double.rs
index 3b47da936..db1d79fc2 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_double.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/weierstrass_double.rs
@@ -7,8 +7,7 @@ use ceno_emul::{
 use ff_ext::ExtensionField;
 use generic_array::{GenericArray, typenum::Unsigned};
 use gkr_iop::{
-    ProtocolBuilder, ProtocolWitnessGenerator,
-    gkr::{GKRCircuit, layer::Layer},
+    ProtocolBuilder, ProtocolWitnessGenerator, gkr::GKRCircuit,
     utils::lk_multiplicity::Multiplicity,
 };
 use itertools::{Itertools, izip};
@@ -150,10 +149,7 @@ impl<E: ExtensionField, EC: EllipticCurve + WeierstrassParameters> Instruction<E
             })
             .collect::<Result<Vec<WriteMEM>, _>>()?;
 
-        let (out_evals, mut chip) = layout.finalize(cb);
-
-        let layer = Layer::from_circuit_builder(cb, "weierstrass_double".to_string(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize("weierstrass_double".to_string(), cb);
 
         let circuit = chip.gkr_circuit();
 
diff --git a/ceno_zkvm/src/precompiles/bitwise_keccakf.rs b/ceno_zkvm/src/precompiles/bitwise_keccakf.rs
index c6ad508dc..9f8415da4 100644
--- a/ceno_zkvm/src/precompiles/bitwise_keccakf.rs
+++ b/ceno_zkvm/src/precompiles/bitwise_keccakf.rs
@@ -18,7 +18,7 @@ use transcript::{BasicTranscript, Transcript};
 use witness::{InstancePaddingStrategy, RowMajorMatrix};
 
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator,
+    ProtocolBuilder, ProtocolWitnessGenerator,
     chip::Chip,
     circuit_builder::{CircuitBuilder, ConstraintSystem},
     cpu::{CpuBackend, CpuProver},
@@ -776,7 +776,7 @@ impl<E: ExtensionField> KeccakLayout<E> {
 impl<E: ExtensionField> ProtocolBuilder<E> for KeccakLayout<E> {
     type Params = KeccakParams;
 
-    fn finalize(&mut self, _cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, _name: String, _cb: &mut CircuitBuilder<E>) -> Chip<E> {
         unimplemented!()
     }
 
diff --git a/ceno_zkvm/src/precompiles/fptower/fp.rs b/ceno_zkvm/src/precompiles/fptower/fp.rs
index 9d6901eca..63a89f61e 100644
--- a/ceno_zkvm/src/precompiles/fptower/fp.rs
+++ b/ceno_zkvm/src/precompiles/fptower/fp.rs
@@ -28,8 +28,8 @@ use derive::AlignedBorrow;
 use ff_ext::ExtensionField;
 use generic_array::{GenericArray, sequence::GenericSequence};
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator, chip::Chip,
-    circuit_builder::CircuitBuilder, error::CircuitBuilderError, selector::SelectorType,
+    ProtocolBuilder, ProtocolWitnessGenerator, chip::Chip, circuit_builder::CircuitBuilder,
+    default_out_eval_groups, error::CircuitBuilderError, gkr::layer::Layer, selector::SelectorType,
 };
 use itertools::Itertools;
 use multilinear_extensions::{Expression, ToExpr, WitIn, util::max_usable_threads};
@@ -224,7 +224,7 @@ impl<E: ExtensionField, P: FpOpField> ProtocolBuilder<E> for FpOpLayout<E, P> {
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
         self.n_structural_witin = cb.cs.num_structural_witin as usize;
@@ -234,20 +234,11 @@ impl<E: ExtensionField, P: FpOpField> ProtocolBuilder<E> for FpOpLayout<E, P> {
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                (0..r_len).collect_vec(),
-                (r_len..r_len + w_len).collect_vec(),
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 }
 
@@ -299,7 +290,7 @@ mod tests {
     use gkr_iop::{
         circuit_builder::{CircuitBuilder, ConstraintSystem},
         cpu::{CpuBackend, CpuProver},
-        gkr::{GKRProverOutput, layer::Layer},
+        gkr::GKRProverOutput,
         selector::SelectorContext,
     };
     use itertools::Itertools;
@@ -330,9 +321,7 @@ mod tests {
         let mut cb = CircuitBuilder::<E>::new(&mut cs);
         let mut layout =
             FpOpLayout::<E, P>::build_layer_logic(&mut cb, ()).expect("build_layer_logic failed");
-        let (out_evals, mut chip) = layout.finalize(&mut cb);
-        let layer = Layer::from_circuit_builder(&cb, "fp_op".to_string(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize("fp_op".to_string(), &mut cb);
         let gkr_circuit = chip.gkr_circuit();
 
         let instances = (0..count)
diff --git a/ceno_zkvm/src/precompiles/fptower/fp2_addsub.rs b/ceno_zkvm/src/precompiles/fptower/fp2_addsub.rs
index 55e53fc88..85c56e430 100644
--- a/ceno_zkvm/src/precompiles/fptower/fp2_addsub.rs
+++ b/ceno_zkvm/src/precompiles/fptower/fp2_addsub.rs
@@ -28,8 +28,8 @@ use derive::AlignedBorrow;
 use ff_ext::ExtensionField;
 use generic_array::{GenericArray, sequence::GenericSequence};
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator, chip::Chip,
-    circuit_builder::CircuitBuilder, error::CircuitBuilderError, selector::SelectorType,
+    ProtocolBuilder, ProtocolWitnessGenerator, chip::Chip, circuit_builder::CircuitBuilder,
+    default_out_eval_groups, error::CircuitBuilderError, gkr::layer::Layer, selector::SelectorType,
 };
 use itertools::Itertools;
 use multilinear_extensions::{Expression, ToExpr, WitIn, util::max_usable_threads};
@@ -248,7 +248,7 @@ impl<E: ExtensionField, P: FpOpField> ProtocolBuilder<E> for Fp2AddSubAssignLayo
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
         self.n_structural_witin = cb.cs.num_structural_witin as usize;
@@ -258,20 +258,11 @@ impl<E: ExtensionField, P: FpOpField> ProtocolBuilder<E> for Fp2AddSubAssignLayo
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                (0..r_len).collect_vec(),
-                (r_len..r_len + w_len).collect_vec(),
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 }
 
@@ -326,7 +317,7 @@ mod tests {
     use gkr_iop::{
         circuit_builder::{CircuitBuilder, ConstraintSystem},
         cpu::{CpuBackend, CpuProver},
-        gkr::{GKRProverOutput, layer::Layer},
+        gkr::GKRProverOutput,
         selector::SelectorContext,
     };
     use itertools::Itertools;
@@ -357,9 +348,7 @@ mod tests {
         let mut cb = CircuitBuilder::<E>::new(&mut cs);
         let mut layout = Fp2AddSubAssignLayout::<E, P>::build_layer_logic(&mut cb, ())
             .expect("build_layer_logic failed");
-        let (out_evals, mut chip) = layout.finalize(&mut cb);
-        let layer = Layer::from_circuit_builder(&cb, "fp2_addsub".to_string(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize("fp2_addsub".to_string(), &mut cb);
         let gkr_circuit = chip.gkr_circuit();
 
         let instances = (0..count)
diff --git a/ceno_zkvm/src/precompiles/fptower/fp2_mul.rs b/ceno_zkvm/src/precompiles/fptower/fp2_mul.rs
index adddd1fb0..6d8288710 100644
--- a/ceno_zkvm/src/precompiles/fptower/fp2_mul.rs
+++ b/ceno_zkvm/src/precompiles/fptower/fp2_mul.rs
@@ -28,8 +28,8 @@ use derive::AlignedBorrow;
 use ff_ext::ExtensionField;
 use generic_array::{GenericArray, sequence::GenericSequence};
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator, chip::Chip,
-    circuit_builder::CircuitBuilder, error::CircuitBuilderError, selector::SelectorType,
+    ProtocolBuilder, ProtocolWitnessGenerator, chip::Chip, circuit_builder::CircuitBuilder,
+    default_out_eval_groups, error::CircuitBuilderError, gkr::layer::Layer, selector::SelectorType,
 };
 use itertools::Itertools;
 use multilinear_extensions::{Expression, ToExpr, WitIn, util::max_usable_threads};
@@ -277,7 +277,7 @@ impl<E: ExtensionField, P: FpOpField> ProtocolBuilder<E> for Fp2MulAssignLayout<
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
         self.n_structural_witin = cb.cs.num_structural_witin as usize;
@@ -287,20 +287,11 @@ impl<E: ExtensionField, P: FpOpField> ProtocolBuilder<E> for Fp2MulAssignLayout<
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                (0..r_len).collect_vec(),
-                (r_len..r_len + w_len).collect_vec(),
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 }
 
@@ -355,7 +346,7 @@ mod tests {
     use gkr_iop::{
         circuit_builder::{CircuitBuilder, ConstraintSystem},
         cpu::{CpuBackend, CpuProver},
-        gkr::{GKRProverOutput, layer::Layer},
+        gkr::GKRProverOutput,
         selector::SelectorContext,
     };
     use itertools::Itertools;
@@ -386,9 +377,7 @@ mod tests {
         let mut cb = CircuitBuilder::<E>::new(&mut cs);
         let mut layout = Fp2MulAssignLayout::<E, P>::build_layer_logic(&mut cb, ())
             .expect("build_layer_logic failed");
-        let (out_evals, mut chip) = layout.finalize(&mut cb);
-        let layer = Layer::from_circuit_builder(&cb, "fp2_mul".to_string(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize("fp2_mul".to_string(), &mut cb);
         let gkr_circuit = chip.gkr_circuit();
 
         let instances = (0..count)
diff --git a/ceno_zkvm/src/precompiles/lookup_keccakf.rs b/ceno_zkvm/src/precompiles/lookup_keccakf.rs
index 0394bc573..4fed156dc 100644
--- a/ceno_zkvm/src/precompiles/lookup_keccakf.rs
+++ b/ceno_zkvm/src/precompiles/lookup_keccakf.rs
@@ -1,10 +1,11 @@
 use ceno_emul::{ByteAddr, Cycle, MemOp, StepRecord};
 use ff_ext::ExtensionField;
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator,
+    ProtocolBuilder, ProtocolWitnessGenerator,
     chip::Chip,
     circuit_builder::{CircuitBuilder, ConstraintSystem, expansion_expr, rotation_split},
     cpu::{CpuBackend, CpuProver},
+    default_out_eval_groups,
     error::{BackendError, CircuitBuilderError},
     gkr::{
         GKRCircuit, GKRProof, GKRProverOutput,
@@ -512,7 +513,7 @@ impl<E: ExtensionField> ProtocolBuilder<E> for KeccakLayout<E> {
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
 
@@ -522,24 +523,11 @@ impl<E: ExtensionField> ProtocolBuilder<E> for KeccakLayout<E> {
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                // r_record
-                (0..r_len).collect_vec(),
-                // w_record
-                (r_len..r_len + w_len).collect_vec(),
-                // lk_record
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                // zero_record
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 
     fn n_committed(&self) -> usize {
@@ -974,10 +962,7 @@ pub fn setup_gkr_circuit<E: ExtensionField>()
         })
         .collect::<Result<Vec<WriteMEM>, _>>()?;
 
-    let (out_evals, mut chip) = layout.finalize(&mut cb);
-
-    let layer = Layer::from_circuit_builder(&cb, "lookup_keccak".to_string(), out_evals);
-    chip.add_layer(layer);
+    let chip = layout.finalize("lookup_keccak".to_string(), &mut cb);
 
     Ok((
         TestKeccakLayout {
diff --git a/ceno_zkvm/src/precompiles/sha256/extend.rs b/ceno_zkvm/src/precompiles/sha256/extend.rs
index 565a85b1c..21b442835 100644
--- a/ceno_zkvm/src/precompiles/sha256/extend.rs
+++ b/ceno_zkvm/src/precompiles/sha256/extend.rs
@@ -27,8 +27,8 @@ use std::{array, borrow::BorrowMut, mem::size_of};
 use derive::AlignedBorrow;
 use ff_ext::{ExtensionField, SmallField};
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator, chip::Chip,
-    circuit_builder::CircuitBuilder, error::CircuitBuilderError, selector::SelectorType,
+    ProtocolBuilder, ProtocolWitnessGenerator, chip::Chip, circuit_builder::CircuitBuilder,
+    default_out_eval_groups, error::CircuitBuilderError, gkr::layer::Layer, selector::SelectorType,
 };
 use itertools::Itertools;
 use multilinear_extensions::{Expression, ToExpr, WitIn, util::max_usable_threads};
@@ -266,7 +266,7 @@ impl<E: ExtensionField> ProtocolBuilder<E> for ShaExtendLayout<E> {
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
         self.n_structural_witin = cb.cs.num_structural_witin as usize;
@@ -276,20 +276,11 @@ impl<E: ExtensionField> ProtocolBuilder<E> for ShaExtendLayout<E> {
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                (0..r_len).collect_vec(),
-                (r_len..r_len + w_len).collect_vec(),
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 }
 
@@ -367,7 +358,7 @@ mod tests {
     use ff_ext::BabyBearExt4;
     use gkr_iop::{
         cpu::{CpuBackend, CpuProver},
-        gkr::{GKRProverOutput, layer::Layer},
+        gkr::GKRProverOutput,
         selector::SelectorContext,
     };
     use itertools::Itertools;
@@ -388,9 +379,7 @@ mod tests {
         let mut cb = CircuitBuilder::<E>::new(&mut cs);
         let mut layout =
             ShaExtendLayout::<E>::build_layer_logic(&mut cb, ()).expect("build_layer_logic failed");
-        let (out_evals, mut chip) = layout.finalize(&mut cb);
-        let layer = Layer::from_circuit_builder(&cb, "sha_extend".to_string(), out_evals);
-        chip.add_layer(layer);
+        let chip = layout.finalize("sha_extend".to_string(), &mut cb);
         let gkr_circuit = chip.gkr_circuit();
 
         let mut rng = StdRng::seed_from_u64(1);
diff --git a/ceno_zkvm/src/precompiles/uint256.rs b/ceno_zkvm/src/precompiles/uint256.rs
index e1d2cc7ba..3664b9a59 100644
--- a/ceno_zkvm/src/precompiles/uint256.rs
+++ b/ceno_zkvm/src/precompiles/uint256.rs
@@ -39,9 +39,10 @@ use derive::AlignedBorrow;
 use ff_ext::{ExtensionField, SmallField};
 use generic_array::{GenericArray, sequence::GenericSequence};
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator,
+    ProtocolBuilder, ProtocolWitnessGenerator,
     chip::Chip,
     cpu::{CpuBackend, CpuProver},
+    default_out_eval_groups,
     error::{BackendError, CircuitBuilderError},
     gkr::{GKRCircuit, GKRProof, GKRProverOutput, layer::Layer, mock::MockProver},
     selector::{SelectorContext, SelectorType},
@@ -279,7 +280,7 @@ impl<E: ExtensionField> ProtocolBuilder<E> for Uint256MulLayout<E> {
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
         self.n_structural_witin = cb.cs.num_structural_witin as usize;
@@ -290,24 +291,11 @@ impl<E: ExtensionField> ProtocolBuilder<E> for Uint256MulLayout<E> {
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                // r_record
-                (0..r_len).collect_vec(),
-                // w_record
-                (r_len..r_len + w_len).collect_vec(),
-                // lk_record
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                // zero_record
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 
     fn n_committed(&self) -> usize {
@@ -523,7 +511,7 @@ impl<E: ExtensionField, Spec: Uint256InvSpec> ProtocolBuilder<E> for Uint256InvL
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
         self.n_structural_witin = cb.cs.num_structural_witin as usize;
@@ -534,24 +522,11 @@ impl<E: ExtensionField, Spec: Uint256InvSpec> ProtocolBuilder<E> for Uint256InvL
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                // r_record
-                (0..r_len).collect_vec(),
-                // w_record
-                (r_len..r_len + w_len).collect_vec(),
-                // lk_record
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                // zero_record
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 
     fn n_committed(&self) -> usize {
@@ -691,10 +666,7 @@ pub fn setup_uint256mul_gkr_circuit<E: ExtensionField>()
         })
         .collect::<Result<Vec<_>, _>>()?;
 
-    let (out_evals, mut chip) = layout.finalize(&mut cb);
-
-    let layer = Layer::from_circuit_builder(&cb, "weierstrass_add".to_string(), out_evals);
-    chip.add_layer(layer);
+    let chip = layout.finalize("weierstrass_add".to_string(), &mut cb);
 
     Ok((
         TestUint256MulLayout {
diff --git a/ceno_zkvm/src/precompiles/weierstrass/weierstrass_add.rs b/ceno_zkvm/src/precompiles/weierstrass/weierstrass_add.rs
index 48ae4eb81..1bd025e60 100644
--- a/ceno_zkvm/src/precompiles/weierstrass/weierstrass_add.rs
+++ b/ceno_zkvm/src/precompiles/weierstrass/weierstrass_add.rs
@@ -30,10 +30,11 @@ use derive::AlignedBorrow;
 use ff_ext::{ExtensionField, SmallField};
 use generic_array::{GenericArray, sequence::GenericSequence, typenum::Unsigned};
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator,
+    ProtocolBuilder, ProtocolWitnessGenerator,
     chip::Chip,
     circuit_builder::{CircuitBuilder, ConstraintSystem},
     cpu::{CpuBackend, CpuProver},
+    default_out_eval_groups,
     error::{BackendError, CircuitBuilderError},
     gkr::{GKRCircuit, GKRProof, GKRProverOutput, layer::Layer, mock::MockProver},
     selector::{SelectorContext, SelectorType},
@@ -324,7 +325,7 @@ impl<E: ExtensionField, EC: EllipticCurve> ProtocolBuilder<E>
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
         self.n_structural_witin = cb.cs.num_structural_witin as usize;
@@ -335,24 +336,11 @@ impl<E: ExtensionField, EC: EllipticCurve> ProtocolBuilder<E>
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                // r_record
-                (0..r_len).collect_vec(),
-                // w_record
-                (r_len..r_len + w_len).collect_vec(),
-                // lk_record
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                // zero_record
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 
     fn n_committed(&self) -> usize {
@@ -501,10 +489,7 @@ pub fn setup_gkr_circuit<E: ExtensionField, EC: EllipticCurve>()
             .collect::<Result<Vec<WriteMEM>, _>>()?,
     );
 
-    let (out_evals, mut chip) = layout.finalize(&mut cb);
-
-    let layer = Layer::from_circuit_builder(&cb, "weierstrass_add".to_string(), out_evals);
-    chip.add_layer(layer);
+    let chip = layout.finalize("weierstrass_add".to_string(), &mut cb);
 
     Ok((
         TestWeierstrassAddLayout {
diff --git a/ceno_zkvm/src/precompiles/weierstrass/weierstrass_decompress.rs b/ceno_zkvm/src/precompiles/weierstrass/weierstrass_decompress.rs
index 8f7075917..ca3ad11b7 100644
--- a/ceno_zkvm/src/precompiles/weierstrass/weierstrass_decompress.rs
+++ b/ceno_zkvm/src/precompiles/weierstrass/weierstrass_decompress.rs
@@ -30,10 +30,11 @@ use derive::AlignedBorrow;
 use ff_ext::{ExtensionField, SmallField};
 use generic_array::{GenericArray, sequence::GenericSequence, typenum::Unsigned};
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator,
+    ProtocolBuilder, ProtocolWitnessGenerator,
     chip::Chip,
     circuit_builder::{CircuitBuilder, ConstraintSystem},
     cpu::{CpuBackend, CpuProver},
+    default_out_eval_groups,
     error::{BackendError, CircuitBuilderError},
     gkr::{GKRCircuit, GKRProof, GKRProverOutput, layer::Layer, mock::MockProver},
     selector::{SelectorContext, SelectorType},
@@ -334,7 +335,7 @@ impl<E: ExtensionField, EC: EllipticCurve + WeierstrassParameters> ProtocolBuild
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
         self.n_structural_witin = cb.cs.num_structural_witin as usize;
@@ -345,24 +346,11 @@ impl<E: ExtensionField, EC: EllipticCurve + WeierstrassParameters> ProtocolBuild
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                // r_record
-                (0..r_len).collect_vec(),
-                // w_record
-                (r_len..r_len + w_len).collect_vec(),
-                // lk_record
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                // zero_record
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 
     fn n_committed(&self) -> usize {
@@ -499,10 +487,7 @@ pub fn setup_gkr_circuit<E: ExtensionField, EC: EllipticCurve + WeierstrassParam
         .collect::<Result<Vec<WriteMEM>, _>>()?,
     );
 
-    let (out_evals, mut chip) = layout.finalize(&mut cb);
-
-    let layer = Layer::from_circuit_builder(&cb, "weierstrass_decompress".to_string(), out_evals);
-    chip.add_layer(layer);
+    let chip = layout.finalize("weierstrass_decompress".to_string(), &mut cb);
 
     Ok((
         TestWeierstrassDecompressLayout {
diff --git a/ceno_zkvm/src/precompiles/weierstrass/weierstrass_double.rs b/ceno_zkvm/src/precompiles/weierstrass/weierstrass_double.rs
index e1b111d92..1362e19ad 100644
--- a/ceno_zkvm/src/precompiles/weierstrass/weierstrass_double.rs
+++ b/ceno_zkvm/src/precompiles/weierstrass/weierstrass_double.rs
@@ -30,10 +30,11 @@ use derive::AlignedBorrow;
 use ff_ext::{ExtensionField, SmallField};
 use generic_array::{GenericArray, sequence::GenericSequence, typenum::Unsigned};
 use gkr_iop::{
-    OutEvalGroups, ProtocolBuilder, ProtocolWitnessGenerator,
+    ProtocolBuilder, ProtocolWitnessGenerator,
     chip::Chip,
     circuit_builder::{CircuitBuilder, ConstraintSystem},
     cpu::{CpuBackend, CpuProver},
+    default_out_eval_groups,
     error::{BackendError, CircuitBuilderError},
     gkr::{GKRCircuit, GKRProof, GKRProverOutput, layer::Layer, mock::MockProver},
     selector::{SelectorContext, SelectorType},
@@ -352,7 +353,7 @@ impl<E: ExtensionField, EC: EllipticCurve + WeierstrassParameters> ProtocolBuild
         Ok(layout)
     }
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>) {
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E> {
         self.n_fixed = cb.cs.num_fixed;
         self.n_committed = cb.cs.num_witin as usize;
         self.n_structural_witin = cb.cs.num_structural_witin as usize;
@@ -363,24 +364,11 @@ impl<E: ExtensionField, EC: EllipticCurve + WeierstrassParameters> ProtocolBuild
         cb.cs.lk_selector = Some(self.selector_type_layout.sel_all.clone());
         cb.cs.zero_selector = Some(self.selector_type_layout.sel_all.clone());
 
-        let w_len = cb.cs.w_expressions.len();
-        let r_len = cb.cs.r_expressions.len();
-        let lk_len = cb.cs.lk_expressions.len();
-        let zero_len =
-            cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
-        (
-            [
-                // r_record
-                (0..r_len).collect_vec(),
-                // w_record
-                (r_len..r_len + w_len).collect_vec(),
-                // lk_record
-                (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
-                // zero_record
-                (0..zero_len).collect_vec(),
-            ],
-            Chip::new_from_cb(cb),
-        )
+        let out_evals = default_out_eval_groups(cb);
+        let mut chip = Chip::new_from_cb(cb);
+        let layer = Layer::from_circuit_builder(cb, name, out_evals);
+        chip.add_layer(layer);
+        chip
     }
 
     fn n_committed(&self) -> usize {
@@ -506,10 +494,7 @@ pub fn setup_gkr_circuit<E: ExtensionField, EC: EllipticCurve + WeierstrassParam
         })
         .collect::<Result<Vec<WriteMEM>, _>>()?;
 
-    let (out_evals, mut chip) = layout.finalize(&mut cb);
-
-    let layer = Layer::from_circuit_builder(&cb, "weierstrass_double".to_string(), out_evals);
-    chip.add_layer(layer);
+    let chip = layout.finalize("weierstrass_double".to_string(), &mut cb);
 
     Ok((
         TestWeierstrassDoubleLayout {
diff --git a/gkr_iop/src/lib.rs b/gkr_iop/src/lib.rs
index 933e92c14..bfd2ec877 100644
--- a/gkr_iop/src/lib.rs
+++ b/gkr_iop/src/lib.rs
@@ -5,6 +5,7 @@ use crate::{
 };
 use either::Either;
 use ff_ext::ExtensionField;
+use itertools::Itertools;
 use multilinear_extensions::{Expression, impl_expr_from_unsigned, mle::ArcMultilinearExtension};
 use std::marker::PhantomData;
 use strum_macros::EnumIter;
@@ -41,7 +42,7 @@ pub trait ProtocolBuilder<E: ExtensionField>: Sized {
         params: Self::Params,
     ) -> Result<Self, CircuitBuilderError>;
 
-    fn finalize(&mut self, cb: &mut CircuitBuilder<E>) -> (OutEvalGroups, Chip<E>);
+    fn finalize(&mut self, name: String, cb: &mut CircuitBuilder<E>) -> Chip<E>;
 
     fn n_committed(&self) -> usize {
         todo!()
@@ -78,6 +79,21 @@ pub struct ProtocolProver<E: ExtensionField, Trans: Transcript<E>, PCS>(
     PhantomData<(E, Trans, PCS)>,
 );
 
+pub fn default_out_eval_groups<E: ExtensionField>(cb: &CircuitBuilder<E>) -> OutEvalGroups {
+    let r_len = cb.cs.r_expressions.len() + cb.cs.r_table_expressions.len();
+    let w_len = cb.cs.w_expressions.len() + cb.cs.w_table_expressions.len();
+    let lk_len = cb.cs.lk_expressions.len() + cb.cs.lk_table_expressions.len() * 2;
+    let zero_len =
+        cb.cs.assert_zero_expressions.len() + cb.cs.assert_zero_sumcheck_expressions.len();
+
+    [
+        (0..r_len).collect_vec(),
+        (r_len..r_len + w_len).collect_vec(),
+        (r_len + w_len..r_len + w_len + lk_len).collect_vec(),
+        (0..zero_len).collect_vec(),
+    ]
+}
+
 // TODO: the following trait consists of `commit_phase1`, `commit_phase2`,
 // `gkr_phase` and `opening_phase`.
 pub struct ProtocolVerifier<E: ExtensionField, Trans: Transcript<E>, PCS>(