From faffb193983ff3e0efeb0f79e134e7dc27880a9d Mon Sep 17 00:00:00 2001
From: Fornax <23104993+0xfornax@users.noreply.github.com>
Date: Thu, 22 Oct 2026 13:06:26 -0300
Subject: [PATCH] Remove ProveValidatorBalanceChunk

---
 bindings/megapool/proof-bundle.go             |  3 --
 bindings/megapool/proof-bundle_test.go        |  4 ---
 shared/services/megapools.go                  | 11 -------
 .../eth2/fork/gloas/gloas_proofs_test.go      | 32 -------------------
 4 files changed, 50 deletions(-)

diff --git a/bindings/megapool/proof-bundle.go b/bindings/megapool/proof-bundle.go
index e3ebd67c8..c991b78cc 100644
--- a/bindings/megapool/proof-bundle.go
+++ b/bindings/megapool/proof-bundle.go
@@ -45,7 +45,6 @@ type FinalBalanceProofBundleV2 struct {
 	ValidatorProof                   ValidatorProof           `json:"validatorProof"`
 	SlotProof                        SlotProof                `json:"slotProof"`
 	PreviousNextWithdrawalIndexProof NextWithdrawalIndexProof `json:"previousNextWithdrawalIndexProof"`
-	ValidatorBalanceProof            ValidatorBalanceProof    `json:"validatorBalanceProof"`
 }
 
 // UsesProofBundles selects the transaction format from the deployed manager version.
@@ -158,7 +157,6 @@ func EncodeFinalBalanceProofBundleV2(
 	validatorProof ValidatorProof,
 	slotProof SlotProof,
 	previousNextWithdrawalIndexProof NextWithdrawalIndexProof,
-	validatorBalanceProof ValidatorBalanceProof,
 ) ([]byte, error) {
 	return encodeTuple([]abi.ArgumentMarshaling{
 		{Name: "withdrawalProof", Type: "tuple", Components: withdrawalProofComponents},
@@ -171,7 +169,6 @@ func EncodeFinalBalanceProofBundleV2(
 		ValidatorProof:                   validatorProof,
 		SlotProof:                        slotProof,
 		PreviousNextWithdrawalIndexProof: previousNextWithdrawalIndexProof,
-		ValidatorBalanceProof:            validatorBalanceProof,
 	})
 }
 
diff --git a/bindings/megapool/proof-bundle_test.go b/bindings/megapool/proof-bundle_test.go
index b781a9fec..dcc1793b2 100644
--- a/bindings/megapool/proof-bundle_test.go
+++ b/bindings/megapool/proof-bundle_test.go
@@ -72,10 +72,6 @@ func TestEncodeFinalBalanceProofBundleV2(t *testing.T) {
 			NextWithdrawalIndex: 9,
 			Witnesses:           [][32]byte{{0x66}},
 		},
-		ValidatorBalanceProof{
-			BalanceChunk: [32]byte{0x77},
-			Witnesses:    [][32]byte{{0x88}},
-		},
 	)
 	if err != nil {
 		t.Fatalf("encode: %v", err)
diff --git a/shared/services/megapools.go b/shared/services/megapools.go
index d06eecbe7..457972c98 100644
--- a/shared/services/megapools.go
+++ b/shared/services/megapools.go
@@ -1282,13 +1282,6 @@ func getGloasFinalBalanceProofBundle(bc beacon.Client, ec withdrawalExecutionCli
 	if err != nil {
 		return nil, nil, err
 	}
-	balanceLeafProof, balanceChunk, err := gloasWithdrawalState.ProveValidatorBalanceChunk(validatorIndex)
-	if err != nil {
-		return nil, nil, err
-	}
-	if !gloas.IsZeroValidatorBalance(balanceChunk, validatorIndex) {
-		return nil, nil, fmt.Errorf("validator %d balance chunk is not zero at withdrawal slot %d", validatorIndex, withdrawalSlot)
-	}
 
 	previousSlot := withdrawalSlot - 1
 	nextWithdrawalIndex, nextWithdrawalIndexLeafProof, err := proveNextWithdrawalIndex(previousState)
@@ -1344,10 +1337,6 @@ func getGloasFinalBalanceProofBundle(bc beacon.Client, ec withdrawalExecutionCli
 			NextWithdrawalIndex: nextWithdrawalIndex,
 			Witnesses:           ConvertToFixedSize(concatProofs(nextWithdrawalIndexLeafProof, previousPastRoot, blockHeaderProof)),
 		},
-		megapool.ValidatorBalanceProof{
-			BalanceChunk: balanceChunk,
-			Witnesses:    ConvertToFixedSize(concatProofs(balanceLeafProof, withdrawalPastRoot, blockHeaderProof)),
-		},
 	)
 	if err != nil {
 		return nil, nil, err
diff --git a/shared/types/eth2/fork/gloas/gloas_proofs_test.go b/shared/types/eth2/fork/gloas/gloas_proofs_test.go
index 0dad405e9..a5c07d718 100644
--- a/shared/types/eth2/fork/gloas/gloas_proofs_test.go
+++ b/shared/types/eth2/fork/gloas/gloas_proofs_test.go
@@ -405,38 +405,6 @@ func TestProveNextWithdrawalIndex(t *testing.T) {
 	}
 }
 
-func TestProveValidatorBalanceChunk(t *testing.T) {
-	state := minimalBeaconState()
-	state.Balances = []uint64{1, 0, 3, 4, 5}
-
-	_, chunk, err := state.ProveValidatorBalanceChunk(1)
-	if err != nil {
-		t.Fatalf("ProveValidatorBalanceChunk: %v", err)
-	}
-	if !IsZeroValidatorBalance(chunk, 1) {
-		t.Fatal("expected validator 1 lane to be zero")
-	}
-	if IsZeroValidatorBalance(chunk, 0) {
-		t.Fatal("expected validator 0 lane to be non-zero")
-	}
-
-	stateTree, err := generic.SSZ.GetTree(state)
-	if err != nil {
-		t.Fatalf("GetTree: %v", err)
-	}
-	direct, err := stateTree.Prove(int(GetGeneralizedIndexForBalanceChunk(1)))
-	if err != nil {
-		t.Fatalf("direct Prove: %v", err)
-	}
-	if ok, err := treeproof.VerifyProof(stateTree.Hash(), direct); err != nil || !ok {
-		t.Fatalf("verify balance chunk: ok=%v err=%v", ok, err)
-	}
-
-	if _, _, err := state.ProveValidatorBalanceChunk(uint64(len(state.Balances))); err == nil {
-		t.Fatal("expected out-of-bounds error")
-	}
-}
-
 func TestHistoricalBoundarySplit(t *testing.T) {
 	const w uint64 = 100
 	proofSlot := w + generic.SlotsPerHistoricalRoot