feat: add Lux extensions for coreth compatibility

- Add PrecompileEnvironment interface for stateful precompiles
- Expand stateconf package with StateDBStateOption configuration
- Fix badgerdb iterator first-item handling
- Add Reader type alias in triedb/database for coreth
- Add NilXxx types in metrics for prometheus gatherer

core/vm/precompile_env.go

@@ -0,0 +1,63 @@
+// Copyright (C) 2020-2025, Lux Industries Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package vm
+
+import (
+	"math/big"
+
+	"github.com/luxfi/geth/common"
+	"github.com/luxfi/geth/core/types"
+	"github.com/luxfi/geth/params"
+)
+
+// PrecompileEnvironment is the interface for precompile execution environment.
+// This is a Lux extension for stateful precompiles that need access to
+// the execution context.
+type PrecompileEnvironment interface {
+	// BlockHeader returns the block header
+	BlockHeader() (*types.Header, error)
+	// Rules returns the chain rules
+	Rules() params.Rules
+	// BlockNumber returns the current block number
+	BlockNumber() *big.Int
+	// BlockTime returns the current block timestamp
+	BlockTime() uint64
+	// Addresses returns the caller and contract addresses
+	Addresses() PrecompileAddresses
+	// ReadOnly returns whether the environment is read-only
+	ReadOnly() bool
+	// ChainConfig returns the chain config
+	ChainConfig() *params.ChainConfig
+	// StateDB returns the state database
+	StateDB() StateDB
+	// ReadOnlyState returns a read-only state view
+	ReadOnlyState() StateDB
+	// UseGas deducts gas from the available gas
+	UseGas(gas uint64) bool
+	// Gas returns the available gas
+	Gas() uint64
+	// Call executes a call to another contract
+	Call(addr common.Address, input []byte, gas uint64, value *big.Int, opts ...CallOption) ([]byte, uint64, error)
+}
+
+// CallOption is an option for Call
+type CallOption func(*CallConfig)
+
+// CallConfig holds call configuration
+type CallConfig struct {
+	ProxyCaller bool
+}
+
+// WithUNSAFECallerAddressProxying returns an option to proxy caller address
+func WithUNSAFECallerAddressProxying() CallOption {
+	return func(c *CallConfig) {
+		c.ProxyCaller = true
+	}
+}
+
+// PrecompileAddresses holds the caller and self addresses for a precompile call
+type PrecompileAddresses struct {
+	Caller common.Address
+	Self   common.Address
+}

ethdb/badgerdb/badgerdb.go

@@ -118,8 +118,9 @@ func (d *Database) NewIterator(prefix []byte, start []byte) ethdb.Iterator {
 	}
 
 	return &iterator{
-		iter: iter,
-		txn:  txn,
+		iter:  iter,
+		txn:   txn,
+		first: true, // First call to Next() should check Valid() without advancing
 	}
 }
 
@@ -186,14 +187,22 @@ func (b *batch) Replay(w ethdb.KeyValueWriter) error {
 
 // iterator implements ethdb.Iterator
 type iterator struct {
-	iter *badger.Iterator
-	txn  *badger.Txn
+	iter  *badger.Iterator
+	txn   *badger.Txn
+	first bool // true if we haven't returned the first item yet
 }
 
 func (i *iterator) Next() bool {
 	if i.iter == nil {
 		return false
 	}
+	// On first call after NewIterator, the iterator is already positioned
+	// at the first item (via Rewind/Seek), so just check Valid()
+	if i.first {
+		i.first = false
+		return i.iter.Valid()
+	}
+	// On subsequent calls, advance and check
 	i.iter.Next()
 	return i.iter.Valid()
 }

libevm/stateconf/stateconf.go

@@ -1,4 +1,112 @@
+// Copyright (C) 2020-2025, Lux Industries Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+// Package stateconf provides configuration types for state database operations.
+// This is a Lux extension for configurable state operations.
 package stateconf
 
-// Stub for stateconf
-type Config struct{}
+import "github.com/luxfi/geth/common"
+
+// StateDBStateOption is an option for state database operations
+type StateDBStateOption func(*StateDBStateConfig)
+
+// StateDBStateConfig holds configuration for state DB operations
+type StateDBStateConfig struct {
+	SkipKeyTransformation bool
+}
+
+// SkipStateKeyTransformation returns an option to skip state key transformation
+func SkipStateKeyTransformation() StateDBStateOption {
+	return func(c *StateDBStateConfig) {
+		c.SkipKeyTransformation = true
+	}
+}
+
+// ApplyStateDBOptions applies the given options to a config
+func ApplyStateDBOptions(opts ...StateDBStateOption) *StateDBStateConfig {
+	config := &StateDBStateConfig{}
+	for _, opt := range opts {
+		opt(config)
+	}
+	return config
+}
+
+// TrieDBUpdateOption is an option for trie database updates
+type TrieDBUpdateOption func(*TrieDBUpdateConfig)
+
+// TrieDBUpdateConfig holds configuration for trie DB updates
+type TrieDBUpdateConfig struct {
+	ParentHash common.Hash
+	BlockHash  common.Hash
+}
+
+// WithTrieDBUpdatePayload returns an option with parent and block hashes
+func WithTrieDBUpdatePayload(parentHash, blockHash common.Hash) TrieDBUpdateOption {
+	return func(c *TrieDBUpdateConfig) {
+		c.ParentHash = parentHash
+		c.BlockHash = blockHash
+	}
+}
+
+// ExtractTrieDBUpdatePayload extracts the payload from options
+func ExtractTrieDBUpdatePayload(opts ...TrieDBUpdateOption) (common.Hash, common.Hash) {
+	config := &TrieDBUpdateConfig{}
+	for _, opt := range opts {
+		opt(config)
+	}
+	return config.ParentHash, config.BlockHash
+}
+
+// SnapshotUpdateOption is an option for snapshot updates
+type SnapshotUpdateOption func(*SnapshotUpdateConfig)
+
+// SnapshotUpdateConfig holds configuration for snapshot updates
+type SnapshotUpdateConfig struct {
+	Payload interface{}
+}
+
+// WithSnapshotUpdatePayload returns an option with the given payload
+func WithSnapshotUpdatePayload(payload interface{}) SnapshotUpdateOption {
+	return func(c *SnapshotUpdateConfig) {
+		c.Payload = payload
+	}
+}
+
+// ExtractSnapshotUpdatePayload extracts the payload from an option
+func ExtractSnapshotUpdatePayload(opt SnapshotUpdateOption) interface{} {
+	config := &SnapshotUpdateConfig{}
+	opt(config)
+	return config.Payload
+}
+
+// CommitOption is an option for state commit operations
+type CommitOption func(*CommitConfig)
+
+// CommitConfig holds configuration for commit operations
+type CommitConfig struct {
+	TrieDBUpdateOpts   []TrieDBUpdateOption
+	SnapshotUpdateOpts []SnapshotUpdateOption
+}
+
+// WithTrieDBUpdateOpts returns a commit option with trie DB update options
+func WithTrieDBUpdateOpts(opts ...TrieDBUpdateOption) CommitOption {
+	return func(c *CommitConfig) {
+		c.TrieDBUpdateOpts = append(c.TrieDBUpdateOpts, opts...)
+	}
+}
+
+// WithSnapshotUpdateOpts returns a commit option with snapshot update options
+func WithSnapshotUpdateOpts(opts ...SnapshotUpdateOption) CommitOption {
+	return func(c *CommitConfig) {
+		c.SnapshotUpdateOpts = append(c.SnapshotUpdateOpts, opts...)
+	}
+}
+
+// ApplyCommitOptions applies commit options and returns config
+func ApplyCommitOptions(opts ...CommitOption) *CommitConfig {
+	config := &CommitConfig{}
+	for _, opt := range opts {
+		opt(config)
+	}
+	return config
+}

metrics/nil.go

@@ -0,0 +1,20 @@
+// Copyright (C) 2019-2025, Lux Industries, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package metrics
+
+// Nil types are empty structs used to detect disabled/nil metrics
+// in type switches (used by prometheus gatherer)
+
+type NilCounter struct{}
+type NilCounterFloat64 struct{}
+type NilEWMA struct{}
+type NilGauge struct{}
+type NilGaugeFloat64 struct{}
+type NilGaugeInfo struct{}
+type NilHealthcheck struct{}
+type NilHistogram struct{}
+type NilMeter struct{}
+type NilResettingTimer struct{}
+type NilSample struct{}
+type NilTimer struct{}

triedb/database/database.go

@@ -68,3 +68,6 @@ type StateDatabase interface {
 	// An error will be returned if the specified state is not available.
 	StateReader(stateRoot common.Hash) (StateReader, error)
 }
+
+// Reader is an alias for NodeReader for compatibility with coreth
+type Reader = NodeReader