@@ -24,76 +24,12 @@ [Synchronizer]
 SyncLoopInterval = "1s"
 StatsRefreshPeriod = "1s"
 
-    [Synchronizer.StartBlockNum]
-    Rollup = 19
-    Auction = 17
-    WDelayer = 15
-
 [SmartContracts]
 Rollup   = "0x8EEaea23686c319133a7cC110b840d1591d9AeE0"
 Auction  = "0x317113D2593e3efF1FfAE0ba2fF7A61861Df7ae5"
 WDelayer = "0x5E0816F0f8bC560cB2B9e9C87187BeCac8c2021F"
 TokenHEZ = "0x5D94e3e7aeC542aB0F9129B9a7BAdeb5B3Ca0f77"
 TokenHEZName = "Hermez Network Token"
-
-    [Synchronizer.InitialVariables.Auction]
-    DonationAddress = "0x0000000000000000000000000000000000000001"
-    BootCoordinator = "0xb4124cEB3451635DAcedd11767f004d8a28c6eE7"
-    BootCoordinatorURL = "https://boot.coordinator.io"
-    DefaultSlotSetBid = [
-        "10000000000000000000",
-        "10000000000000000000",
-        "10000000000000000000",
-        "10000000000000000000",
-        "10000000000000000000",
-        "10000000000000000000",
-    ]
-    DefaultSlotSetBidSlotNum = 0
-    ClosedAuctionSlots = 2
-    OpenAuctionSlots = 4320
-    AllocationRatio = [4000, 4000, 2000]
-    Outbidding = 1000
-    SlotDeadline = 20
-
-    [Synchronizer.InitialVariables.WDelayer]
-    # HermezRollupAddress        =
-    HermezGovernanceAddress    = "0x0000000000000000000000000000000000000001"
-    EmergencyCouncilAddress    = "0x0000000000000000000000000000000000000001"
-    WithdrawalDelay            = 60
-    EmergencyModeStartingTime  = 0
-    EmergencyMode              = false
-
-    [Synchronizer.InitialVariables.Rollup]
-    FeeAddToken = "10"
-    ForgeL1L2BatchTimeout = 10
-    WithdrawalDelay = 1209600 # 60 * 60 * 24 * 7 * 2
-    SafeMode = false
-        [[Synchronizer.InitialVariables.Rollup.Buckets]]
-        CeilUSD             = 0
-        Withdrawals         = 0
-        BlockWithdrawalRate = 0
-        MaxWithdrawals      = 0
-        [[Synchronizer.InitialVariables.Rollup.Buckets]]
-        CeilUSD             = 0
-        Withdrawals         = 0
-        BlockWithdrawalRate = 0
-        MaxWithdrawals      = 0
-        [[Synchronizer.InitialVariables.Rollup.Buckets]]
-        CeilUSD             = 0
-        Withdrawals         = 0
-        BlockWithdrawalRate = 0
-        MaxWithdrawals      = 0
-        [[Synchronizer.InitialVariables.Rollup.Buckets]]
-        CeilUSD             = 0
-        Withdrawals         = 0
-        BlockWithdrawalRate = 0
-        MaxWithdrawals      = 0
-        [[Synchronizer.InitialVariables.Rollup.Buckets]]
-        CeilUSD             = 0
-        Withdrawals         = 0
-        BlockWithdrawalRate = 0
-        MaxWithdrawals      = 0
-
 
 [Coordinator]
 ForgerAddress = "0x6BB84Cc84D4A34467aD12a2039A312f7029e2071"

@@ -53,7 +53,7 @@ // from the L1Tx values
 func NewL1Tx(tx *L1Tx) (*L1Tx, error) {
 	txTypeOld := tx.Type
 	if err := tx.SetType(); err != nil {
-		return nil, err
+		return nil, tracerr.Wrap(err)
 	}
 	// If original Type doesn't match the correct one, return error
 	if txTypeOld != "" && txTypeOld != tx.Type {
@@ -63,7 +63,7 @@ }
 
 	txIDOld := tx.TxID
 	if err := tx.SetID(); err != nil {
-		return nil, err
+		return nil, tracerr.Wrap(err)
 	}
 	// If original TxID doesn't match the correct one, return error
 	if txIDOld != (TxID{}) && txIDOld != tx.TxID {

@@ -27,7 +27,7 @@ // from the L2Tx values
 func NewL2Tx(tx *L2Tx) (*L2Tx, error) {
 	txTypeOld := tx.Type
 	if err := tx.SetType(); err != nil {
-		return nil, err
+		return nil, tracerr.Wrap(err)
 	}
 	// If original Type doesn't match the correct one, return error
 	if txTypeOld != "" && txTypeOld != tx.Type {
@@ -37,7 +37,7 @@ }
 
 	txIDOld := tx.TxID
 	if err := tx.SetID(); err != nil {
-		return nil, err
+		return nil, tracerr.Wrap(err)
 	}
 	// If original TxID doesn't match the correct one, return error
 	if txIDOld != (TxID{}) && txIDOld != tx.TxID {

@@ -53,7 +53,7 @@ // from the L2Tx values
 func NewPoolL2Tx(tx *PoolL2Tx) (*PoolL2Tx, error) {
 	txTypeOld := tx.Type
 	if err := tx.SetType(); err != nil {
-		return nil, err
+		return nil, tracerr.Wrap(err)
 	}
 	// If original Type doesn't match the correct one, return error
 	if txTypeOld != "" && txTypeOld != tx.Type {
@@ -63,7 +63,7 @@ }
 
 	txIDOld := tx.TxID
 	if err := tx.SetID(); err != nil {
-		return nil, err
+		return nil, tracerr.Wrap(err)
 	}
 	// If original TxID doesn't match the correct one, return error
 	if txIDOld != (TxID{}) && txIDOld != tx.TxID {

@@ -8,7 +8,6 @@
 	"github.com/BurntSushi/toml"
 	ethCommon "github.com/ethereum/go-ethereum/common"
 	"github.com/hermeznetwork/hermez-node/common"
-	"github.com/hermeznetwork/hermez-node/synchronizer"
 	"github.com/hermeznetwork/tracerr"
 	"gopkg.in/go-playground/validator.v9"
 )
@@ -111,10 +110,8 @@ Web3 struct {
 		URL string `validate:"required"`
 	} `validate:"required"`
 	Synchronizer struct {
-		SyncLoopInterval   Duration                         `validate:"required"`
-		StatsRefreshPeriod Duration                         `validate:"required"`
-		StartBlockNum      synchronizer.ConfigStartBlockNum `validate:"required"`
-		InitialVariables   synchronizer.SCVariables         `validate:"required"`
+		SyncLoopInterval   Duration `validate:"required"`
+		StatsRefreshPeriod Duration `validate:"required"`
 	} `validate:"required"`
 	SmartContracts struct {
 		Rollup       ethCommon.Address `validate:"required"`

@@ -185,16 +185,7 @@ func newTestSynchronizer(t *testing.T, ethClient *test.Client, ethClientSetup *test.ClientSetup,
 	modules modules) *synchronizer.Synchronizer {
 	sync, err := synchronizer.NewSynchronizer(ethClient, modules.historyDB, modules.stateDB,
 		synchronizer.Config{
-			StartBlockNum: synchronizer.ConfigStartBlockNum{
-				Rollup:   1,
-				Auction:  1,
-				WDelayer: 1,
-			},
-			InitialVariables: synchronizer.SCVariables{
-				Rollup:   *ethClientSetup.RollupVariables,
-				Auction:  *ethClientSetup.AuctionVariables,
-				WDelayer: *ethClientSetup.WDelayerVariables,
-			},
+			StatsRefreshPeriod: 0 * time.Second,
 		})
 	require.NoError(t, err)
 	return sync
@@ -311,7 +302,11 @@ modules := newTestModules(t)
 	coord := newTestCoordinator(t, forger, ethClient, ethClientSetup, modules)
 	_, err := ethClient.AuctionSetCoordinator(forger, "https://foo.bar")
 	require.NoError(t, err)
-	_, err = ethClient.AuctionBidSimple(2, big.NewInt(9999))
+	bid, ok := new(big.Int).SetString("12000000000000000000", 10)
+	if !ok {
+		panic("bad bid")
+	}
+	_, err = ethClient.AuctionBidSimple(2, bid)
 	require.NoError(t, err)
 
 	modules2 := newTestModules(t)
@@ -359,7 +354,11 @@ modules := newTestModules(t)
 	coord := newTestCoordinator(t, forger, ethClient, ethClientSetup, modules)
 	_, err := ethClient.AuctionSetCoordinator(forger, "https://foo.bar")
 	require.NoError(t, err)
-	_, err = ethClient.AuctionBidSimple(2, big.NewInt(9999))
+	bid, ok := new(big.Int).SetString("11000000000000000000", 10)
+	if !ok {
+		panic("bad bid")
+	}
+	_, err = ethClient.AuctionBidSimple(2, bid)
 	require.NoError(t, err)
 
 	var msg MsgSyncBlock

@@ -69,6 +69,26 @@ OpenAuctionSlots       uint16
 	AllocationRatio        [3]uint16
 }
 
+// AuctionVariables returns the AuctionVariables from the initialize event
+func (ei *AuctionEventInitialize) AuctionVariables(InitialMinimalBidding *big.Int) *common.AuctionVariables {
+	return &common.AuctionVariables{
+		EthBlockNum:        0,
+		DonationAddress:    ei.DonationAddress,
+		BootCoordinator:    ei.BootCoordinatorAddress,
+		BootCoordinatorURL: ei.BootCoordinatorURL,
+		DefaultSlotSetBid: [6]*big.Int{
+			InitialMinimalBidding, InitialMinimalBidding, InitialMinimalBidding,
+			InitialMinimalBidding, InitialMinimalBidding, InitialMinimalBidding,
+		},
+		DefaultSlotSetBidSlotNum: 0,
+		ClosedAuctionSlots:       ei.ClosedAuctionSlots,
+		OpenAuctionSlots:         ei.OpenAuctionSlots,
+		AllocationRatio:          ei.AllocationRatio,
+		Outbidding:               ei.Outbidding,
+		SlotDeadline:             ei.SlotDeadline,
+	}
+}
+
 // AuctionEventNewBid is an event of the Auction Smart Contract
 type AuctionEventNewBid struct {
 	Slot      int64
@@ -235,6 +255,7 @@ //
 
 	AuctionConstants() (*common.AuctionConstants, error)
 	AuctionEventsByBlock(blockNum int64) (*AuctionEvents, *ethCommon.Hash, error)
+	AuctionEventInit() (*AuctionEventInitialize, int64, error)
 }
 
 //
@@ -756,11 +777,11 @@ if err != nil {
 		return nil, 0, tracerr.Wrap(err)
 	}
 	if len(logs) != 1 {
-		return nil, 0, fmt.Errorf("no event of type InitializeHermezAuctionProtocolEvent found")
+		return nil, 0, tracerr.Wrap(fmt.Errorf("no event of type InitializeHermezAuctionProtocolEvent found"))
 	}
 	vLog := logs[0]
 	if vLog.Topics[0] != logAuctionInitialize {
-		return nil, 0, fmt.Errorf("event is not InitializeHermezAuctionProtocolEvent")
+		return nil, 0, tracerr.Wrap(fmt.Errorf("event is not InitializeHermezAuctionProtocolEvent"))
 	}
 
 	var auctionInit AuctionEventInitialize
@@ -768,7 +789,7 @@ if err := c.contractAbi.UnpackIntoInterface(&auctionInit,
 		"InitializeHermezAuctionProtocolEvent", vLog.Data); err != nil {
 		return nil, 0, tracerr.Wrap(err)
 	}
-	return &auctionInit, int64(vLog.BlockNumber), err
+	return &auctionInit, int64(vLog.BlockNumber), tracerr.Wrap(err)
 }
 
 // AuctionEventsByBlock returns the events in a block that happened in the

@@ -59,6 +59,27 @@ FeeAddToken           *big.Int
 	WithdrawalDelay       uint64
 }
 
+// RollupVariables returns the RollupVariables from the initialize event
+func (ei *RollupEventInitialize) RollupVariables() *common.RollupVariables {
+	var buckets [common.RollupConstNumBuckets]common.BucketParams
+	for i := range buckets {
+		buckets[i] = common.BucketParams{
+			CeilUSD:             big.NewInt(0),
+			Withdrawals:         big.NewInt(0),
+			BlockWithdrawalRate: big.NewInt(0),
+			MaxWithdrawals:      big.NewInt(0),
+		}
+	}
+	return &common.RollupVariables{
+		EthBlockNum:           0,
+		FeeAddToken:           ei.FeeAddToken,
+		ForgeL1L2BatchTimeout: int64(ei.ForgeL1L2BatchTimeout),
+		WithdrawalDelay:       ei.WithdrawalDelay,
+		Buckets:               buckets,
+		SafeMode:              false,
+	}
+}
+
 // RollupEventL1UserTx is an event of the Rollup Smart Contract
 type RollupEventL1UserTx struct {
 	// ToForgeL1TxsNum int64 // QueueIndex       *big.Int
@@ -245,6 +266,7 @@
 	RollupConstants() (*common.RollupConstants, error)
 	RollupEventsByBlock(blockNum int64) (*RollupEvents, *ethCommon.Hash, error)
 	RollupForgeBatchArgs(ethCommon.Hash, uint16) (*RollupForgeBatchArgs, *ethCommon.Address, error)
+	RollupEventInit() (*RollupEventInitialize, int64, error)
 }
 
 //
@@ -688,18 +710,18 @@ if err != nil {
 		return nil, 0, tracerr.Wrap(err)
 	}
 	if len(logs) != 1 {
-		return nil, 0, fmt.Errorf("no event of type InitializeHermezEvent found")
+		return nil, 0, tracerr.Wrap(fmt.Errorf("no event of type InitializeHermezEvent found"))
 	}
 	vLog := logs[0]
 	if vLog.Topics[0] != logHermezInitialize {
-		return nil, 0, fmt.Errorf("event is not InitializeHermezEvent")
+		return nil, 0, tracerr.Wrap(fmt.Errorf("event is not InitializeHermezEvent"))
 	}
 
 	var rollupInit RollupEventInitialize
 	if err := c.contractAbi.UnpackIntoInterface(&rollupInit, "InitializeHermezEvent", vLog.Data); err != nil {
 		return nil, 0, tracerr.Wrap(err)
 	}
-	return &rollupInit, int64(vLog.BlockNumber), err
+	return &rollupInit, int64(vLog.BlockNumber), tracerr.Wrap(err)
 }
 
 // RollupEventsByBlock returns the events in a block that happened in the Rollup Smart Contract

@@ -33,6 +33,18 @@ InitialHermezGovernanceAddress ethCommon.Address
 	InitialEmergencyCouncil        ethCommon.Address
 }
 
+// WDelayerVariables returns the WDelayerVariables from the initialize event
+func (ei *WDelayerEventInitialize) WDelayerVariables() *common.WDelayerVariables {
+	return &common.WDelayerVariables{
+		EthBlockNum:                0,
+		HermezGovernanceAddress:    ei.InitialHermezGovernanceAddress,
+		EmergencyCouncilAddress:    ei.InitialEmergencyCouncil,
+		WithdrawalDelay:            ei.InitialWithdrawalDelay,
+		EmergencyModeStartingBlock: 0,
+		EmergencyMode:              false,
+	}
+}
+
 // WDelayerEventDeposit is an event of the WithdrawalDelayer Smart Contract
 type WDelayerEventDeposit struct {
 	Owner            ethCommon.Address
@@ -124,6 +136,7 @@ WDelayerEscapeHatchWithdrawal(to, token ethCommon.Address, amount *big.Int) (*types.Transaction, error)
 
 	WDelayerEventsByBlock(blockNum int64) (*WDelayerEvents, *ethCommon.Hash, error)
 	WDelayerConstants() (*common.WDelayerConstants, error)
+	WDelayerEventInit() (*WDelayerEventInitialize, int64, error)
 }
 
 //
@@ -395,11 +408,11 @@ if err != nil {
 		return nil, 0, tracerr.Wrap(err)
 	}
 	if len(logs) != 1 {
-		return nil, 0, fmt.Errorf("no event of type InitializeWithdrawalDelayerEvent found")
+		return nil, 0, tracerr.Wrap(fmt.Errorf("no event of type InitializeWithdrawalDelayerEvent found"))
 	}
 	vLog := logs[0]
 	if vLog.Topics[0] != logWDelayerInitialize {
-		return nil, 0, fmt.Errorf("event is not InitializeWithdrawalDelayerEvent")
+		return nil, 0, tracerr.Wrap(fmt.Errorf("event is not InitializeWithdrawalDelayerEvent"))
 	}
 
 	var wDelayerInit WDelayerEventInitialize
@@ -407,7 +420,7 @@ if err := c.contractAbi.UnpackIntoInterface(&wDelayerInit, "InitializeWithdrawalDelayerEvent",
 		vLog.Data); err != nil {
 		return nil, 0, tracerr.Wrap(err)
 	}
-	return &wDelayerInit, int64(vLog.BlockNumber), err
+	return &wDelayerInit, int64(vLog.BlockNumber), tracerr.Wrap(err)
 }
 
 // WDelayerEventsByBlock returns the events in a block that happened in the

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"strings"
 	"sync"
 	"time"
 
@@ -120,8 +121,6 @@ return nil, tracerr.Wrap(err)
 	}
 
 	sync, err := synchronizer.NewSynchronizer(client, historyDB, stateDB, synchronizer.Config{
-		StartBlockNum:      cfg.Synchronizer.StartBlockNum,
-		InitialVariables:   cfg.Synchronizer.InitialVariables,
 		StatsRefreshPeriod: cfg.Synchronizer.StatsRefreshPeriod.Duration,
 	})
 	if err != nil {
@@ -390,7 +389,11 @@ blockData, discarded, err := n.sync.Sync2(n.ctx, lastBlock)
 	stats := n.sync.Stats()
 	if err != nil {
 		// case: error
-		log.Errorw("Synchronizer.Sync", "err", err)
+		if strings.Contains(err.Error(), "context canceled") {
+			log.Warnw("Synchronizer.Sync", "err", err)
+		} else {
+			log.Errorw("Synchronizer.Sync", "err", err)
+		}
 		return nil, n.cfg.Synchronizer.SyncLoopInterval.Duration
 	} else if discarded != nil {
 		// case: reorg

@@ -27,7 +27,7 @@
 func (b *bigInt) UnmarshalText(text []byte) error {
 	_, ok := (*big.Int)(b).SetString(string(text), 10)
 	if !ok {
-		return fmt.Errorf("invalid big int: \"%v\"", string(text))
+		return tracerr.Wrap(fmt.Errorf("invalid big int: \"%v\"", string(text)))
 	}
 	return nil
 }
@@ -42,7 +42,7 @@ PiC      [2]*bigInt    `json:"pi_c"`
 		Protocol string        `json:"protocol"`
 	}{}
 	if err := json.Unmarshal(data, &proof); err != nil {
-		return err
+		return tracerr.Wrap(err)
 	}
 	p.PiA[0] = (*big.Int)(proof.PiA[0])
 	p.PiA[1] = (*big.Int)(proof.PiA[1])
@@ -66,7 +66,7 @@ // are in decimal as quoted strings
 func (p *PublicInputs) UnmarshalJSON(data []byte) error {
 	pubInputs := []*bigInt{}
 	if err := json.Unmarshal(data, &pubInputs); err != nil {
-		return err
+		return tracerr.Wrap(err)
 	}
 	*p = make([]*big.Int, len(pubInputs))
 	for i, v := range pubInputs {
@@ -245,7 +245,7 @@ return nil, nil, tracerr.Wrap(err)
 		}
 		return &proof, pubInputs, nil
 	}
-	return nil, nil, fmt.Errorf("status != StatusCodeSuccess, status = %v", status.Status)
+	return nil, nil, tracerr.Wrap(fmt.Errorf("status != StatusCodeSuccess, status = %v", status.Status))
 }
 
 // Cancel cancels any current proof computation
@@ -261,7 +261,7 @@ if err != nil {
 			return tracerr.Wrap(err)
 		}
 		if !status.Status.IsInitialized() {
-			return fmt.Errorf("Proof Server is not initialized")
+			return tracerr.Wrap(fmt.Errorf("Proof Server is not initialized"))
 		}
 		if status.Status.IsReady() {
 			return nil

@@ -17,31 +17,6 @@ "github.com/hermeznetwork/hermez-node/log"
 	"github.com/hermeznetwork/tracerr"
 )
 
-var (
-// ErrNotAbleToSync is used when there is not possible to find a valid block to sync
-// ErrNotAbleToSync = errors.New("it has not been possible to synchronize any block")
-)
-
-// // SyncronizerState describes the synchronization progress of the smart contracts
-// type SyncronizerState struct {
-// 	LastUpdate                time.Time // last time this information was updated
-// 	CurrentBatchNum           BatchNum  // Last batch that was forged on the blockchain
-// 	CurrentBlockNum           uint64    // Last block that was mined on Ethereum
-// 	CurrentToForgeL1TxsNum    uint32
-// 	LastSyncedBatchNum        BatchNum // last batch synchronized by the coordinator
-// 	LastSyncedBlockNum        uint64   // last Ethereum block synchronized by the coordinator
-// 	LastSyncedToForgeL1TxsNum uint32
-// }
-
-// // SyncStatus is returned by the Status method of the Synchronizer
-// type SyncStatus struct {
-// 	CurrentBlock      int64
-// 	CurrentBatch      BatchNum
-// 	CurrentForgerAddr ethCommon.Address
-// 	NextForgerAddr    ethCommon.Address
-// 	Synchronized      bool
-// }
-
 // Stats of the syncrhonizer
 type Stats struct {
 	Eth struct {
@@ -170,12 +145,12 @@ return float64(batchNum) * 100.0 /
 		float64(s.Eth.LastBatch)
 }
 
-// ConfigStartBlockNum sets the first block used to start tracking the smart
+// StartBlockNums sets the first block used to start tracking the smart
 // contracts
-type ConfigStartBlockNum struct {
-	Rollup   int64 `validate:"required"`
-	Auction  int64 `validate:"required"`
-	WDelayer int64 `validate:"required"`
+type StartBlockNums struct {
+	Rollup   int64
+	Auction  int64
+	WDelayer int64
 }
 
 // SCVariables joins all the smart contract variables in a single struct
@@ -202,8 +177,8 @@ }
 
 // Config is the Synchronizer configuration
 type Config struct {
-	StartBlockNum      ConfigStartBlockNum
-	InitialVariables   SCVariables
+	// StartBlockNum StartBlockNum
+	// InitialVariables   SCVariables
 	StatsRefreshPeriod time.Duration
 }
 
@@ -217,6 +192,7 @@ consts        SCConsts
 	historyDB     *historydb.HistoryDB
 	stateDB       *statedb.StateDB
 	cfg           Config
+	initVars      SCVariables
 	startBlockNum int64
 	vars          SCVariables
 	stats         *StatsHolder
@@ -242,27 +218,38 @@ if err != nil {
 		return nil, tracerr.Wrap(fmt.Errorf("NewSynchronizer ethClient.WDelayerConstants(): %w",
 			err))
 	}
+	consts := SCConsts{
+		Rollup:   *rollupConstants,
+		Auction:  *auctionConstants,
+		WDelayer: *wDelayerConstants,
+	}
 
+	initVars, startBlockNums, err := getInitialVariables(ethClient, &consts)
+	if err != nil {
+		return nil, tracerr.Wrap(err)
+	}
+	log.Infow("Synchronizer syncing from smart contract blocks",
+		"rollup", startBlockNums.Rollup,
+		"auction", startBlockNums.Auction,
+		"wdelayer", startBlockNums.WDelayer,
+	)
 	// Set startBlockNum to the minimum between Auction, Rollup and
 	// WDelayer StartBlockNum
-	startBlockNum := cfg.StartBlockNum.Auction
-	if cfg.StartBlockNum.Rollup < startBlockNum {
-		startBlockNum = cfg.StartBlockNum.Rollup
+	startBlockNum := startBlockNums.Auction
+	if startBlockNums.Rollup < startBlockNum {
+		startBlockNum = startBlockNums.Rollup
 	}
-	if cfg.StartBlockNum.WDelayer < startBlockNum {
-		startBlockNum = cfg.StartBlockNum.WDelayer
+	if startBlockNums.WDelayer < startBlockNum {
+		startBlockNum = startBlockNums.WDelayer
 	}
 	stats := NewStatsHolder(startBlockNum, cfg.StatsRefreshPeriod)
 	s := &Synchronizer{
-		ethClient: ethClient,
-		consts: SCConsts{
-			Rollup:   *rollupConstants,
-			Auction:  *auctionConstants,
-			WDelayer: *wDelayerConstants,
-		},
+		ethClient:     ethClient,
+		consts:        consts,
 		historyDB:     historyDB,
 		stateDB:       stateDB,
 		cfg:           cfg,
+		initVars:      *initVars,
 		startBlockNum: startBlockNum,
 		stats:         stats,
 	}
@@ -596,22 +583,54 @@
 	return block.Num, nil
 }
 
+func getInitialVariables(ethClient eth.ClientInterface,
+	consts *SCConsts) (*SCVariables, *StartBlockNums, error) {
+	rollupInit, rollupInitBlock, err := ethClient.RollupEventInit()
+	if err != nil {
+		return nil, nil, tracerr.Wrap(err)
+	}
+	auctionInit, auctionInitBlock, err := ethClient.AuctionEventInit()
+	if err != nil {
+		return nil, nil, tracerr.Wrap(err)
+	}
+	wDelayerInit, wDelayerInitBlock, err := ethClient.WDelayerEventInit()
+	if err != nil {
+		return nil, nil, tracerr.Wrap(err)
+	}
+	rollupVars := rollupInit.RollupVariables()
+	auctionVars := auctionInit.AuctionVariables(consts.Auction.InitialMinimalBidding)
+	wDelayerVars := wDelayerInit.WDelayerVariables()
+	return &SCVariables{
+			Rollup:   *rollupVars,
+			Auction:  *auctionVars,
+			WDelayer: *wDelayerVars,
+		}, &StartBlockNums{
+			Rollup:   rollupInitBlock,
+			Auction:  auctionInitBlock,
+			WDelayer: wDelayerInitBlock,
+		}, nil
+}
+
 func (s *Synchronizer) resetState(block *common.Block) error {
 	rollup, auction, wDelayer, err := s.historyDB.GetSCVars()
 	// If SCVars are not in the HistoryDB, this is probably the first run
 	// of the Synchronizer: store the initial vars taken from config
 	if tracerr.Unwrap(err) == sql.ErrNoRows {
-		rollup = &s.cfg.InitialVariables.Rollup
-		auction = &s.cfg.InitialVariables.Auction
-		wDelayer = &s.cfg.InitialVariables.WDelayer
+		vars := s.initVars
 		log.Info("Setting initial SCVars in HistoryDB")
-		if err = s.historyDB.SetInitialSCVars(rollup, auction, wDelayer); err != nil {
+		if err = s.historyDB.SetInitialSCVars(&vars.Rollup, &vars.Auction, &vars.WDelayer); err != nil {
 			return tracerr.Wrap(fmt.Errorf("historyDB.SetInitialSCVars: %w", err))
 		}
+		s.vars.Rollup = *vars.Rollup.Copy()
+		s.vars.Auction = *vars.Auction.Copy()
+		s.vars.WDelayer = *vars.WDelayer.Copy()
+	} else if err != nil {
+		return tracerr.Wrap(err)
+	} else {
+		s.vars.Rollup = *rollup
+		s.vars.Auction = *auction
+		s.vars.WDelayer = *wDelayer
 	}
-	s.vars.Rollup = *rollup
-	s.vars.Auction = *auction
-	s.vars.WDelayer = *wDelayer
 
 	batchNum, err := s.historyDB.GetLastBatchNum()
 	if err != nil && tracerr.Unwrap(err) != sql.ErrNoRows {
@@ -786,7 +805,7 @@
 		// Set TxID, BlockNum, BatchNum and Position to the forged L2Txs
 		for i := range l2Txs {
 			if err := l2Txs[i].SetID(); err != nil {
-				return nil, err
+				return nil, tracerr.Wrap(err)
 			}
 			l2Txs[i].EthBlockNum = blockNum
 			l2Txs[i].BatchNum = batchNum

@@ -9,6 +9,7 @@ "math/big"
 	"os"
 	"sort"
 	"testing"
+	"time"
 
 	ethCommon "github.com/ethereum/go-ethereum/common"
 	"github.com/hermeznetwork/hermez-node/common"
@@ -300,16 +301,7 @@ client := test.NewClient(true, &timer, &ethCommon.Address{}, clientSetup)
 
 	// Create Synchronizer
 	s, err := NewSynchronizer(client, historyDB, stateDB, Config{
-		StartBlockNum: ConfigStartBlockNum{
-			Rollup:   1,
-			Auction:  1,
-			WDelayer: 1,
-		},
-		InitialVariables: SCVariables{
-			Rollup:   *clientSetup.RollupVariables,
-			Auction:  *clientSetup.AuctionVariables,
-			WDelayer: *clientSetup.WDelayerVariables,
-		},
+		StatsRefreshPeriod: 0 * time.Second,
 	})
 	require.NoError(t, err)
 

@@ -301,10 +301,20 @@ HermezGovernanceAddress: governanceAddress,
 		HermezAuctionContract:   ethCommon.HexToAddress("0x8E442975805fb1908f43050c9C1A522cB0e28D7b"),
 		WithdrawDelayerContract: ethCommon.HexToAddress("0x5CB7979cBdbf65719BEE92e4D15b7b7Ed3D79114"),
 	}
+	var buckets [common.RollupConstNumBuckets]common.BucketParams
+	for i := range buckets {
+		buckets[i] = common.BucketParams{
+			CeilUSD:             big.NewInt(0),
+			Withdrawals:         big.NewInt(0),
+			BlockWithdrawalRate: big.NewInt(0),
+			MaxWithdrawals:      big.NewInt(0),
+		}
+	}
 	rollupVariables := &common.RollupVariables{
 		FeeAddToken:           big.NewInt(11),
 		ForgeL1L2BatchTimeout: 9,
 		WithdrawalDelay:       80,
+		Buckets:               buckets,
 	}
 	auctionConstants := &common.AuctionConstants{
 		BlocksPerSlot:         40,
@@ -319,8 +329,9 @@ DonationAddress:    ethCommon.HexToAddress("0x61Ed87CF0A1496b49A420DA6D84B58196b98f2e7"),
 		BootCoordinator:    ethCommon.HexToAddress("0xE39fEc6224708f0772D2A74fd3f9055A90E0A9f2"),
 		BootCoordinatorURL: "https://boot.coordinator.com",
 		DefaultSlotSetBid: [6]*big.Int{
-			big.NewInt(1000), big.NewInt(1100), big.NewInt(1200),
-			big.NewInt(1300), big.NewInt(1400), big.NewInt(1500)},
+			initialMinimalBidding, initialMinimalBidding, initialMinimalBidding,
+			initialMinimalBidding, initialMinimalBidding, initialMinimalBidding,
+		},
 		ClosedAuctionSlots: 2,
 		OpenAuctionSlots:   4320,
 		AllocationRatio:    [3]uint16{4000, 4000, 2000},
@@ -1064,6 +1075,16 @@ }
 	return &block.Rollup.Events, &block.Eth.Hash, nil
 }
 
+// RollupEventInit returns the initialize event with its corresponding block number
+func (c *Client) RollupEventInit() (*eth.RollupEventInitialize, int64, error) {
+	vars := c.blocks[0].Rollup.Vars
+	return &eth.RollupEventInitialize{
+		ForgeL1L2BatchTimeout: uint8(vars.ForgeL1L2BatchTimeout),
+		FeeAddToken:           vars.FeeAddToken,
+		WithdrawalDelay:       vars.WithdrawalDelay,
+	}, 1, nil
+}
+
 // RollupForgeBatchArgs returns the arguments used in a ForgeBatch call in the Rollup Smart Contract in the given transaction
 func (c *Client) RollupForgeBatchArgs(ethTxHash ethCommon.Hash, l1UserTxsLen uint16) (*eth.RollupForgeBatchArgs, *ethCommon.Address, error) {
 	c.rw.RLock()
@@ -1511,6 +1532,21 @@ }
 	return &block.Auction.Events, &block.Eth.Hash, nil
 }
 
+// AuctionEventInit returns the initialize event with its corresponding block number
+func (c *Client) AuctionEventInit() (*eth.AuctionEventInitialize, int64, error) {
+	vars := c.blocks[0].Auction.Vars
+	return &eth.AuctionEventInitialize{
+		DonationAddress:        vars.DonationAddress,
+		BootCoordinatorAddress: vars.BootCoordinator,
+		BootCoordinatorURL:     vars.BootCoordinatorURL,
+		Outbidding:             vars.Outbidding,
+		SlotDeadline:           vars.SlotDeadline,
+		ClosedAuctionSlots:     vars.ClosedAuctionSlots,
+		OpenAuctionSlots:       vars.OpenAuctionSlots,
+		AllocationRatio:        vars.AllocationRatio,
+	}, 1, nil
+}
+
 //
 // WDelayer
 //
@@ -1720,6 +1756,16 @@
 	return c.wDelayerConstants, nil
 }
 
+// WDelayerEventInit returns the initialize event with its corresponding block number
+func (c *Client) WDelayerEventInit() (*eth.WDelayerEventInitialize, int64, error) {
+	vars := c.blocks[0].WDelayer.Vars
+	return &eth.WDelayerEventInitialize{
+		InitialWithdrawalDelay:         vars.WithdrawalDelay,
+		InitialHermezGovernanceAddress: vars.HermezGovernanceAddress,
+		InitialEmergencyCouncil:        vars.EmergencyCouncilAddress,
+	}, 1, nil
+}
+
 // CtlAddBlocks adds block data to the smarts contracts.  The added blocks will
 // appear as mined.  Not thread safe.
 func (c *Client) CtlAddBlocks(blocks []common.BlockData) (err error) {
@@ -1731,14 +1777,14 @@ rollup := nextBlock.Rollup
 		auction := nextBlock.Auction
 		for _, token := range block.Rollup.AddedTokens {
 			if _, err := c.RollupAddTokenSimple(token.EthAddr, rollup.Vars.FeeAddToken); err != nil {
-				return err
+				return tracerr.Wrap(err)
 			}
 		}
 		for _, tx := range block.Rollup.L1UserTxs {
 			c.CtlSetAddr(tx.FromEthAddr)
 			if _, err := c.RollupL1UserTxERC20ETH(tx.FromBJJ, int64(tx.FromIdx), tx.DepositAmount, tx.Amount,
 				uint32(tx.TokenID), int64(tx.ToIdx)); err != nil {
-				return err
+				return tracerr.Wrap(err)
 			}
 		}
 		c.CtlSetAddr(auction.Vars.BootCoordinator)
@@ -1758,7 +1804,7 @@ ProofA:      [2]*big.Int{},    // Intentionally empty
 				ProofB:      [2][2]*big.Int{}, // Intentionally empty
 				ProofC:      [2]*big.Int{},    // Intentionally empty
 			}); err != nil {
-				return err
+				return tracerr.Wrap(err)
 			}
 		}
 		// Mine block and sync

@@ -883,7 +883,7 @@ position++
 				tc.extra.nonces[tx.FromIdx]++
 				tx.Nonce = tc.extra.nonces[tx.FromIdx]
 				if err := tx.SetID(); err != nil {
-					return err
+					return tracerr.Wrap(err)
 				}
 				nTx, err := common.NewL2Tx(tx)
 				if err != nil {