op-program: Update cli flags to support multiple chains (#13740)

* op-program: Validate that we have L2 chain configs for each rollup

* op-program: Update CLI flags to support specifying multiple L2 chains

* op-program: Allow custom l2 chain ID flag

op-program/host/cmd/main_test.go

@@ -3,11 +3,14 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"math/big"
 	"os"
 	"strconv"
+	"strings"
 	"testing"
 
 	"github.com/ethereum-optimism/optimism/op-node/chaincfg"
+	"github.com/ethereum-optimism/optimism/op-node/rollup"
 	"github.com/ethereum-optimism/optimism/op-program/chainconfig"
 	"github.com/ethereum-optimism/optimism/op-program/client/boot"
 	"github.com/ethereum-optimism/optimism/op-program/host/config"
@@ -90,12 +93,10 @@ func TestNetwork(t *testing.T) {
 		verifyArgsInvalid(t, "invalid network: \"bar\"", replaceRequiredArg("--network", "bar"))
 	})
 
-	t.Run("Required", func(t *testing.T) {
-		verifyArgsInvalid(t, "flag rollup.config or network is required", addRequiredArgsExcept("--network"))
-	})
-
-	t.Run("DisallowNetworkAndRollupConfig", func(t *testing.T) {
-		verifyArgsInvalid(t, "cannot specify both rollup.config and network", addRequiredArgs("--rollup.config=foo"))
+	t.Run("AllowNetworkAndRollupConfig", func(t *testing.T) {
+		configFile, rollupCfg := writeRollupConfigWithChainID(t, 4297842)
+		cfg := configForArgs(t, addRequiredArgs("--rollup.config", configFile))
+		require.Equal(t, []*rollup.Config{chaincfg.OPSepolia(), rollupCfg}, cfg.Rollups)
 	})
 
 	t.Run("RollupConfig", func(t *testing.T) {
@@ -107,6 +108,15 @@ func TestNetwork(t *testing.T) {
 		require.Equal(t, *chaincfg.OPSepolia(), *cfg.Rollups[0])
 	})
 
+	t.Run("Multiple", func(t *testing.T) {
+		cfg := configForArgs(t, addRequiredArgsExcept("--network", "--network=op-mainnet,op-sepolia"))
+		require.Len(t, cfg.Rollups, 2)
+		opMainnetCfg, err := chaincfg.GetRollupConfig("op-mainnet")
+		require.NoError(t, err)
+		require.Equal(t, *opMainnetCfg, *cfg.Rollups[0])
+		require.Equal(t, *chaincfg.OPSepolia(), *cfg.Rollups[1])
+	})
+
 	for _, name := range chaincfg.AvailableNetworks() {
 		name := name
 		expected, err := chaincfg.GetRollupConfig(name)
@@ -141,17 +151,20 @@ func TestDataFormat(t *testing.T) {
 }
 
 func TestL2(t *testing.T) {
-	expected := "https://example.com:8545"
-	cfg := configForArgs(t, addRequiredArgs("--l2", expected))
-	require.Equal(t, []string{expected}, cfg.L2URLs)
-}
+	t.Run("Single", func(t *testing.T) {
+		expected := "https://example.com:8545"
+		cfg := configForArgs(t, addRequiredArgs("--l2", expected))
+		require.Equal(t, []string{expected}, cfg.L2URLs)
+	})
 
-func TestL2Genesis(t *testing.T) {
-	t.Run("RequiredWithCustomNetwork", func(t *testing.T) {
-		rollupCfgFile := writeValidRollupConfig(t)
-		verifyArgsInvalid(t, "flag l2.genesis is required", addRequiredArgsExcept("--network", "--rollup.config", rollupCfgFile))
+	t.Run("Multiple", func(t *testing.T) {
+		expected := []string{"https://example.com:8545", "https://example.com:9000"}
+		cfg := configForArgs(t, addRequiredArgs("--l2", strings.Join(expected, ",")))
+		require.Equal(t, expected, cfg.L2URLs)
 	})
+}
 
+func TestL2Genesis(t *testing.T) {
 	t.Run("Valid", func(t *testing.T) {
 		rollupCfgFile := writeValidRollupConfig(t)
 		genesisFile := writeValidGenesis(t)
@@ -165,6 +178,31 @@ func TestL2Genesis(t *testing.T) {
 	})
 }
 
+func TestMultipleNetworkConfigs(t *testing.T) {
+	t.Run("MultipleCustomChains", func(t *testing.T) {
+		rollupFile1, rollupCfg1 := writeRollupConfigWithChainID(t, 1)
+		rollupFile2, rollupCfg2 := writeRollupConfigWithChainID(t, 2)
+		genesisFile1, chainCfg1 := writeGenesisFileWithChainID(t, 1)
+		genesisFile2, chainCfg2 := writeGenesisFileWithChainID(t, 2)
+		cfg := configForArgs(t, addRequiredArgsExcept("--network",
+			"--rollup.config", rollupFile1+","+rollupFile2,
+			"--l2.genesis", genesisFile1+","+genesisFile2))
+		require.Equal(t, []*rollup.Config{rollupCfg1, rollupCfg2}, cfg.Rollups)
+		require.Equal(t, []*params.ChainConfig{chainCfg1, chainCfg2}, cfg.L2ChainConfigs)
+	})
+
+	t.Run("MixNetworkAndCustomChains", func(t *testing.T) {
+		rollupFile, rollupCfg := writeRollupConfigWithChainID(t, 1)
+		genesisFile, chainCfg := writeGenesisFileWithChainID(t, 1)
+		cfg := configForArgs(t, addRequiredArgsExcept("--network",
+			"--network", "op-sepolia",
+			"--rollup.config", rollupFile,
+			"--l2.genesis", genesisFile))
+		require.Equal(t, []*rollup.Config{chaincfg.OPSepolia(), rollupCfg}, cfg.Rollups)
+		require.Equal(t, []*params.ChainConfig{chainconfig.OPSepoliaChainConfig(), chainCfg}, cfg.L2ChainConfigs)
+	})
+}
+
 func TestL2ChainID(t *testing.T) {
 	t.Run("DefaultToNetworkChainID", func(t *testing.T) {
 		cfg := configForArgs(t, replaceRequiredArg("--network", "op-mainnet"))
@@ -187,11 +225,24 @@ func TestL2ChainID(t *testing.T) {
 			"--l2.custom"))
 		require.Equal(t, boot.CustomChainIDIndicator, cfg.L2ChainID)
 	})
+
+	t.Run("ZeroWhenMultipleL2ChainsSpecified", func(t *testing.T) {
+		cfg := configForArgs(t, addRequiredArgsExcept("--network", "--network", "op-sepolia,op-mainnet"))
+		require.Zero(t, cfg.L2ChainID)
+	})
 }
 
 func TestL2Head(t *testing.T) {
-	t.Run("Required", func(t *testing.T) {
-		verifyArgsInvalid(t, "flag l2.head is required", addRequiredArgsExcept("--l2.head"))
+	t.Run("RequiredWithOutputRoot", func(t *testing.T) {
+		verifyArgsInvalid(t, "flag l2.head is required when l2.outputroot is specified", addRequiredArgsExcept("--l2.head"))
+	})
+
+	t.Run("NotAllowedWithAgreedPrestate", func(t *testing.T) {
+		req := requiredArgs()
+		delete(req, "--l2.head")
+		delete(req, "--l2.outputroot")
+		args := append(toArgList(req), "--l2.head", l2HeadValue, "--l2.agreed-prestate", "0x1234")
+		verifyArgsInvalid(t, "flag l2.head and l2.agreed-prestate must not be specified together", args)
 	})
 
 	t.Run("Valid", func(t *testing.T) {
@@ -210,7 +261,7 @@ func TestL2OutputRoot(t *testing.T) {
 	})
 
 	t.Run("NotRequiredWhenAgreedPrestateProvided", func(t *testing.T) {
-		configForArgs(t, addRequiredArgsExcept("--l2.outputroot", "--l2.agreed-prestate", "0x1234"))
+		configForArgs(t, addRequiredArgsExceptMultiple([]string{"--l2.outputroot", "--l2.head"}, "--l2.agreed-prestate", "0x1234"))
 	})
 
 	t.Run("Valid", func(t *testing.T) {
@@ -225,14 +276,14 @@ func TestL2OutputRoot(t *testing.T) {
 
 func TestL2AgreedPrestate(t *testing.T) {
 	t.Run("NotRequiredWhenL2OutputRootProvided", func(t *testing.T) {
-		configForArgs(t, addRequiredArgsExcept("--l2.outputroot", "--l2.outputroot", "0x1234"))
+		configForArgs(t, addRequiredArgsExceptMultiple([]string{"--l2.outputroot", "--l2.head"}, "--l2.agreed-prestate", "0x1234"))
 	})
 
 	t.Run("Valid", func(t *testing.T) {
 		prestate := "0x1234"
 		prestateBytes := common.FromHex(prestate)
 		expectedOutputRoot := crypto.Keccak256Hash(prestateBytes)
-		cfg := configForArgs(t, addRequiredArgsExcept("--l2.outputroot", "--l2.agreed-prestate", prestate))
+		cfg := configForArgs(t, addRequiredArgsExceptMultiple([]string{"--l2.outputroot", "--l2.head"}, "--l2.agreed-prestate", prestate))
 		require.Equal(t, expectedOutputRoot, cfg.L2OutputRoot)
 		require.Equal(t, prestateBytes, cfg.AgreedPrestate)
 	})
@@ -242,11 +293,11 @@ func TestL2AgreedPrestate(t *testing.T) {
 	})
 
 	t.Run("Invalid", func(t *testing.T) {
-		verifyArgsInvalid(t, config.ErrInvalidAgreedPrestate.Error(), addRequiredArgsExcept("--l2.outputroot", "--l2.agreed-prestate", "something"))
+		verifyArgsInvalid(t, config.ErrInvalidAgreedPrestate.Error(), addRequiredArgsExceptMultiple([]string{"--l2.outputroot", "--l2.head"}, "--l2.agreed-prestate", "something"))
 	})
 
 	t.Run("ZeroLength", func(t *testing.T) {
-		verifyArgsInvalid(t, config.ErrInvalidAgreedPrestate.Error(), addRequiredArgsExcept("--l2.outputroot", "--l2.agreed-prestate", "0x"))
+		verifyArgsInvalid(t, config.ErrInvalidAgreedPrestate.Error(), addRequiredArgsExceptMultiple([]string{"--l2.outputroot", "--l2.head"}, "--l2.agreed-prestate", "0x"))
 	})
 }
 
@@ -345,6 +396,12 @@ func TestL2Experimental(t *testing.T) {
 		cfg := configForArgs(t, addRequiredArgs("--l2.experimental", expected))
 		require.EqualValues(t, []string{expected}, cfg.L2ExperimentalURLs)
 	})
+
+	t.Run("Multiple", func(t *testing.T) {
+		expected := []string{"https://example.com:8545", "https://example.com:9000"}
+		cfg := configForArgs(t, addRequiredArgs("--l2.experimental", strings.Join(expected, ",")))
+		require.EqualValues(t, expected, cfg.L2ExperimentalURLs)
+	})
 }
 
 func TestL2BlockNumber(t *testing.T) {
@@ -431,6 +488,14 @@ func addRequiredArgsExcept(name string, optionalArgs ...string) []string {
 	return append(toArgList(req), optionalArgs...)
 }
 
+func addRequiredArgsExceptMultiple(remove []string, optionalArgs ...string) []string {
+	req := requiredArgs()
+	for _, name := range remove {
+		delete(req, name)
+	}
+	return append(toArgList(req), optionalArgs...)
+}
+
 func replaceRequiredArg(name string, value string) []string {
 	req := requiredArgs()
 	req[name] = value
@@ -451,8 +516,21 @@ func requiredArgs() map[string]string {
 }
 
 func writeValidGenesis(t *testing.T) string {
+	genesis := l2Genesis
+	return writeGenesis(t, genesis)
+}
+
+func writeGenesisFileWithChainID(t *testing.T, chainID uint64) (string, *params.ChainConfig) {
+	genesis := *l2Genesis
+	chainCfg := *genesis.Config
+	chainCfg.ChainID = new(big.Int).SetUint64(chainID)
+	genesis.Config = &chainCfg
+	return writeGenesis(t, &genesis), &chainCfg
+}
+
+func writeGenesis(t *testing.T, genesis *core.Genesis) string {
 	dir := t.TempDir()
-	j, err := json.Marshal(l2Genesis)
+	j, err := json.Marshal(genesis)
 	require.NoError(t, err)
 	genesisFile := dir + "/genesis.json"
 	require.NoError(t, os.WriteFile(genesisFile, j, 0666))
@@ -460,8 +538,18 @@ func writeValidGenesis(t *testing.T) string {
 }
 
 func writeValidRollupConfig(t *testing.T) string {
+	return writeRollupConfig(t, chaincfg.OPSepolia())
+}
+
+func writeRollupConfigWithChainID(t *testing.T, chainID uint64) (string, *rollup.Config) {
+	rollupCfg := *chaincfg.OPSepolia()
+	rollupCfg.L2ChainID = new(big.Int).SetUint64(chainID)
+	return writeRollupConfig(t, &rollupCfg), &rollupCfg
+}
+
+func writeRollupConfig(t *testing.T, rollupCfg *rollup.Config) string {
 	dir := t.TempDir()
-	j, err := json.Marshal(chaincfg.OPSepolia())
+	j, err := json.Marshal(&rollupCfg)
 	require.NoError(t, err)
 	cfgFile := dir + "/rollup.json"
 	require.NoError(t, os.WriteFile(cfgFile, j, 0666))

op-program/host/config/config.go

@@ -25,9 +25,13 @@ import (
 )
 
 var (
+	ErrNoL2Chains            = errors.New("at least one L2 chain must be specified")
 	ErrMissingL2ChainID      = errors.New("missing l2 chain id")
-	ErrMissingRollupConfig   = errors.New("missing rollup config")
 	ErrMissingL2Genesis      = errors.New("missing l2 genesis")
+	ErrNoRollupForGenesis    = errors.New("no rollup config matching l2 genesis")
+	ErrNoGenesisForRollup    = errors.New("no l2 genesis for rollup")
+	ErrDuplicateRollup       = errors.New("duplicate rollup")
+	ErrDuplicateGenesis      = errors.New("duplicate l2 genesis")
 	ErrInvalidL1Head         = errors.New("invalid l1 head")
 	ErrInvalidL2Head         = errors.New("invalid l2 head")
 	ErrInvalidL2OutputRoot   = errors.New("invalid l2 output root")
@@ -97,7 +101,7 @@ func (c *Config) Check() error {
 		return ErrMissingL2ChainID
 	}
 	if len(c.Rollups) == 0 {
-		return ErrMissingRollupConfig
+		return ErrNoL2Chains
 	}
 	for _, rollupCfg := range c.Rollups {
 		if err := rollupCfg.Check(); err != nil {
@@ -119,6 +123,30 @@ func (c *Config) Check() error {
 	if len(c.L2ChainConfigs) == 0 {
 		return ErrMissingL2Genesis
 	}
+	// Make of known rollup chain IDs to whether we have the L2 chain config for it
+	chainIDToHasChainConfig := make(map[uint64]bool, len(c.Rollups))
+	for _, config := range c.Rollups {
+		chainID := config.L2ChainID.Uint64()
+		if _, ok := chainIDToHasChainConfig[chainID]; ok {
+			return fmt.Errorf("%w for chain ID %v", ErrDuplicateRollup, chainID)
+		}
+		chainIDToHasChainConfig[chainID] = false
+	}
+	for _, config := range c.L2ChainConfigs {
+		chainID := config.ChainID.Uint64()
+		if _, ok := chainIDToHasChainConfig[chainID]; !ok {
+			return fmt.Errorf("%w for chain ID %v", ErrNoRollupForGenesis, config.ChainID)
+		}
+		if chainIDToHasChainConfig[chainID] {
+			return fmt.Errorf("%w for chain ID %v", ErrDuplicateGenesis, config.ChainID)
+		}
+		chainIDToHasChainConfig[chainID] = true
+	}
+	for chainID, hasChainConfig := range chainIDToHasChainConfig {
+		if !hasChainConfig {
+			return fmt.Errorf("%w for chain ID %v", ErrNoGenesisForRollup, chainID)
+		}
+	}
 	if (c.L1URL != "") != (len(c.L2URLs) > 0) {
 		return ErrL1AndL2Inconsistent
 	}
@@ -201,9 +229,12 @@ func NewConfigFromCLI(log log.Logger, ctx *cli.Context) (*Config, error) {
 		return nil, err
 	}
 
-	l2Head := common.HexToHash(ctx.String(flags.L2Head.Name))
-	if l2Head == (common.Hash{}) {
-		return nil, ErrInvalidL2Head
+	var l2Head common.Hash
+	if ctx.IsSet(flags.L2Head.Name) {
+		l2Head = common.HexToHash(ctx.String(flags.L2Head.Name))
+		if l2Head == (common.Hash{}) {
+			return nil, ErrInvalidL2Head
+		}
 	}
 	var l2OutputRoot common.Hash
 	var agreedPrestate []byte
@@ -235,11 +266,11 @@ func NewConfigFromCLI(log log.Logger, ctx *cli.Context) (*Config, error) {
 	}
 
 	var err error
-	var rollupCfg *rollup.Config
-	var l2ChainConfig *params.ChainConfig
+	var rollupCfgs []*rollup.Config
+	var l2ChainConfigs []*params.ChainConfig
 	var l2ChainID uint64
-	networkName := ctx.String(flags.Network.Name)
-	if networkName != "" {
+	networkNames := ctx.StringSlice(flags.Network.Name)
+	for _, networkName := range networkNames {
 		var chainID uint64
 		if chainID, err = strconv.ParseUint(networkName, 10, 64); err != nil {
 			ch := chaincfg.ChainByName(networkName)
@@ -249,55 +280,58 @@ func NewConfigFromCLI(log log.Logger, ctx *cli.Context) (*Config, error) {
 			chainID = ch.ChainID
 		}
 
-		l2ChainConfig, err = chainconfig.ChainConfigByChainID(chainID)
+		l2ChainConfig, err := chainconfig.ChainConfigByChainID(chainID)
 		if err != nil {
 			return nil, fmt.Errorf("failed to load chain config for chain %d: %w", chainID, err)
 		}
-		rollupCfg, err = chainconfig.RollupConfigByChainID(chainID)
+		l2ChainConfigs = append(l2ChainConfigs, l2ChainConfig)
+		rollupCfg, err := chainconfig.RollupConfigByChainID(chainID)
 		if err != nil {
 			return nil, fmt.Errorf("failed to load rollup config for chain %d: %w", chainID, err)
 		}
+		rollupCfgs = append(rollupCfgs, rollupCfg)
 		l2ChainID = chainID
-	} else {
-		l2GenesisPath := ctx.String(flags.L2GenesisPath.Name)
-		l2ChainConfig, err = loadChainConfigFromGenesis(l2GenesisPath)
+	}
+
+	genesisPaths := ctx.StringSlice(flags.L2GenesisPath.Name)
+	for _, l2GenesisPath := range genesisPaths {
+		l2ChainConfig, err := loadChainConfigFromGenesis(l2GenesisPath)
 		if err != nil {
 			return nil, fmt.Errorf("invalid genesis: %w", err)
 		}
+		l2ChainConfigs = append(l2ChainConfigs, l2ChainConfig)
+		l2ChainID = l2ChainConfig.ChainID.Uint64()
+	}
 
-		rollupConfigPath := ctx.String(flags.RollupConfig.Name)
-		rollupCfg, err = loadRollupConfig(rollupConfigPath)
+	rollupPaths := ctx.StringSlice(flags.RollupConfig.Name)
+	for _, rollupConfigPath := range rollupPaths {
+		rollupCfg, err := loadRollupConfig(rollupConfigPath)
 		if err != nil {
 			return nil, fmt.Errorf("invalid rollup config: %w", err)
 		}
+		rollupCfgs = append(rollupCfgs, rollupCfg)
 
-		l2ChainID = l2ChainConfig.ChainID.Uint64()
-		if ctx.Bool(flags.L2Custom.Name) {
-			log.Warn("Using custom chain configuration via preimage oracle. This is not compatible with on-chain execution.")
-			l2ChainID = boot.CustomChainIDIndicator
-		}
+	}
+	if ctx.Bool(flags.L2Custom.Name) {
+		log.Warn("Using custom chain configuration via preimage oracle. This is not compatible with on-chain execution.")
+		l2ChainID = boot.CustomChainIDIndicator
+	} else if len(rollupCfgs) > 1 {
+		// L2ChainID is not applicable when multiple L2 sources are used and not using custom configs
+		l2ChainID = 0
 	}
 
 	dbFormat := types.DataFormat(ctx.String(flags.DataFormat.Name))
 	if !slices.Contains(types.SupportedDataFormats, dbFormat) {
 		return nil, fmt.Errorf("invalid %w: %v", ErrInvalidDataFormat, dbFormat)
 	}
-	var l2URLs []string
-	if ctx.IsSet(flags.L2NodeAddr.Name) {
-		l2URLs = append(l2URLs, ctx.String(flags.L2NodeAddr.Name))
-	}
-	var l2ExperimentalURLs []string
-	if ctx.IsSet(flags.L2NodeExperimentalAddr.Name) {
-		l2ExperimentalURLs = append(l2ExperimentalURLs, ctx.String(flags.L2NodeExperimentalAddr.Name))
-	}
 	return &Config{
 		L2ChainID:          l2ChainID,
-		Rollups:            []*rollup.Config{rollupCfg},
+		Rollups:            rollupCfgs,
 		DataDir:            ctx.String(flags.DataDir.Name),
 		DataFormat:         dbFormat,
-		L2URLs:             l2URLs,
-		L2ExperimentalURLs: l2ExperimentalURLs,
-		L2ChainConfigs:     []*params.ChainConfig{l2ChainConfig},
+		L2URLs:             ctx.StringSlice(flags.L2NodeAddr.Name),
+		L2ExperimentalURLs: ctx.StringSlice(flags.L2NodeExperimentalAddr.Name),
+		L2ChainConfigs:     l2ChainConfigs,
 		L2Head:             l2Head,
 		L2OutputRoot:       l2OutputRoot,
 		AgreedPrestate:     agreedPrestate,

op-program/host/config/config_test.go

@@ -58,7 +58,7 @@ func TestRollupConfig(t *testing.T) {
 		config := validConfig()
 		config.Rollups = nil
 		err := config.Check()
-		require.ErrorIs(t, err, ErrMissingRollupConfig)
+		require.ErrorIs(t, err, ErrNoL2Chains)
 	})
 
 	t.Run("Invalid", func(t *testing.T) {
@@ -67,6 +67,12 @@ func TestRollupConfig(t *testing.T) {
 		err := config.Check()
 		require.ErrorIs(t, err, rollup.ErrBlockTimeZero)
 	})
+
+	t.Run("DisallowDuplicates", func(t *testing.T) {
+		cfg := validConfig()
+		cfg.Rollups = append(cfg.Rollups, validRollupConfig)
+		require.ErrorIs(t, cfg.Check(), ErrDuplicateRollup)
+	})
 }
 
 func TestL1HeadRequired(t *testing.T) {
@@ -111,6 +117,26 @@ func TestL2GenesisRequired(t *testing.T) {
 	require.ErrorIs(t, err, ErrMissingL2Genesis)
 }
 
+func TestL2Genesis_ExtraGenesisProvided(t *testing.T) {
+	config := validConfig()
+	config.L2ChainConfigs = append(config.L2ChainConfigs, &params.ChainConfig{ChainID: big.NewInt(422142)})
+	require.ErrorIs(t, config.Check(), ErrNoRollupForGenesis)
+}
+
+func TestL2Genesis_GenesisMissingForChain(t *testing.T) {
+	config := validConfig()
+	secondConfig := *chaincfg.OPSepolia()
+	secondConfig.L2ChainID = big.NewInt(422142)
+	config.Rollups = append(config.Rollups, &secondConfig)
+	require.ErrorIs(t, config.Check(), ErrNoGenesisForRollup)
+}
+
+func TestL2Genesis_Duplicate(t *testing.T) {
+	config := validConfig()
+	config.L2ChainConfigs = append(config.L2ChainConfigs, validL2Genesis)
+	require.ErrorIs(t, config.Check(), ErrDuplicateGenesis)
+}
+
 func TestFetchingArgConsistency(t *testing.T) {
 	t.Run("RequireL2WhenL1Set", func(t *testing.T) {
 		cfg := validConfig()

op-program/host/flags/flags.go

@@ -29,12 +29,12 @@ var (
 		Value:   false,
 		Hidden:  true,
 	}
-	RollupConfig = &cli.StringFlag{
+	RollupConfig = &cli.StringSliceFlag{
 		Name:    "rollup.config",
 		Usage:   "Rollup chain parameters",
 		EnvVars: prefixEnvVars("ROLLUP_CONFIG"),
 	}
-	Network = &cli.StringFlag{
+	Network = &cli.StringSliceFlag{
 		Name:    "network",
 		Usage:   fmt.Sprintf("Predefined network selection. Available networks: %s", strings.Join(chaincfg.AvailableNetworks(), ", ")),
 		EnvVars: prefixEnvVars("NETWORK"),
@@ -50,12 +50,12 @@ var (
 		EnvVars: prefixEnvVars("DATA_FORMAT"),
 		Value:   string(types.DataFormatDirectory),
 	}
-	L2NodeAddr = &cli.StringFlag{
+	L2NodeAddr = &cli.StringSliceFlag{
 		Name:    "l2",
 		Usage:   "Address of L2 JSON-RPC endpoint to use (eth and debug namespace required)",
 		EnvVars: prefixEnvVars("L2_RPC"),
 	}
-	L2NodeExperimentalAddr = &cli.StringFlag{
+	L2NodeExperimentalAddr = &cli.StringSliceFlag{
 		Name:    "l2.experimental",
 		Usage:   "Address of L2 JSON-RPC endpoint to use for experimental features (debug_executionWitness)",
 		EnvVars: prefixEnvVars("L2_RPC_EXPERIMENTAL_RPC"),
@@ -91,7 +91,7 @@ var (
 		Usage:   "Number of the L2 block that the claim is from",
 		EnvVars: prefixEnvVars("L2_BLOCK_NUM"),
 	}
-	L2GenesisPath = &cli.StringFlag{
+	L2GenesisPath = &cli.StringSliceFlag{
 		Name:    "l2.genesis",
 		Usage:   "Path to the op-geth genesis file",
 		EnvVars: prefixEnvVars("L2_GENESIS"),
@@ -138,12 +138,12 @@ var Flags []cli.Flag
 
 var requiredFlags = []cli.Flag{
 	L1Head,
-	L2Head,
 	L2Claim,
 	L2BlockNumber,
 }
 
 var programFlags = []cli.Flag{
+	L2Head,
 	L2OutputRoot,
 	L2AgreedPrestate,
 	L2Custom,
@@ -169,21 +169,7 @@ func init() {
 }
 
 func CheckRequired(ctx *cli.Context) error {
-	rollupConfig := ctx.String(RollupConfig.Name)
-	network := ctx.String(Network.Name)
-	if rollupConfig == "" && network == "" {
-		return fmt.Errorf("flag %s or %s is required", RollupConfig.Name, Network.Name)
-	}
-	if rollupConfig != "" && network != "" {
-		return fmt.Errorf("cannot specify both %s and %s", RollupConfig.Name, Network.Name)
-	}
-	if network == "" && ctx.String(L2GenesisPath.Name) == "" {
-		return fmt.Errorf("flag %s is required for custom networks", L2GenesisPath.Name)
-	}
-	if ctx.String(L2GenesisPath.Name) != "" && network != "" {
-		return fmt.Errorf("cannot specify both %s and %s", L2GenesisPath.Name, Network.Name)
-	}
-	if ctx.Bool(L2Custom.Name) && rollupConfig == "" {
+	if ctx.Bool(L2Custom.Name) && ctx.IsSet(Network.Name) {
 		return fmt.Errorf("flag %s cannot be used with named networks", L2Custom.Name)
 	}
 	for _, flag := range requiredFlags {
@@ -197,5 +183,11 @@ func CheckRequired(ctx *cli.Context) error {
 	if ctx.IsSet(L2OutputRoot.Name) && ctx.IsSet(L2AgreedPrestate.Name) {
 		return fmt.Errorf("flag %s and %s must not be specified together", L2OutputRoot.Name, L2AgreedPrestate.Name)
 	}
+	if ctx.IsSet(L2Head.Name) && ctx.IsSet(L2AgreedPrestate.Name) {
+		return fmt.Errorf("flag %s and %s must not be specified together", L2Head.Name, L2AgreedPrestate.Name)
+	}
+	if !ctx.IsSet(L2Head.Name) && ctx.IsSet(L2OutputRoot.Name) {
+		return fmt.Errorf("flag %s is required when %s is specified", L2Head.Name, L2OutputRoot.Name)
+	}
 	return nil
 }