diff --git a/op-e2e/actions/l2_proposer.go b/op-e2e/actions/l2_proposer.go
new file mode 100644
index 0000000000000..dc91c0cf655a4
--- /dev/null
+++ b/op-e2e/actions/l2_proposer.go
@@ -0,0 +1,78 @@
+package actions
+
+import (
+	"crypto/ecdsa"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/stretchr/testify/require"
+
+	"github.com/ethereum-optimism/optimism/op-node/sources"
+	"github.com/ethereum-optimism/optimism/op-proposer/drivers/l2output"
+)
+
+type ProposerCfg struct {
+	OutputOracleAddr  common.Address
+	ProposerKey       *ecdsa.PrivateKey
+	AllowNonFinalized bool
+}
+
+type L2Proposer struct {
+	log     log.Logger
+	l1      *ethclient.Client
+	driver  *l2output.Driver
+	address common.Address
+	lastTx  common.Hash
+}
+
+func NewL2Proposer(t Testing, log log.Logger, cfg *ProposerCfg, l1 *ethclient.Client, rollupCl *sources.RollupClient) *L2Proposer {
+	chainID, err := l1.ChainID(t.Ctx())
+	require.NoError(t, err)
+	dr, err := l2output.NewDriver(l2output.Config{
+		Log:               log,
+		Name:              "proposer",
+		L1Client:          l1,
+		RollupClient:      rollupCl,
+		AllowNonFinalized: cfg.AllowNonFinalized,
+		L2OOAddr:          cfg.OutputOracleAddr,
+		ChainID:           chainID,
+		PrivKey:           cfg.ProposerKey,
+	})
+	require.NoError(t, err)
+	return &L2Proposer{
+		log:     log,
+		l1:      l1,
+		driver:  dr,
+		address: crypto.PubkeyToAddress(cfg.ProposerKey.PublicKey),
+	}
+}
+
+func (p *L2Proposer) CanPropose(t Testing) bool {
+	start, end, err := p.driver.GetBlockRange(t.Ctx())
+	require.NoError(t, err)
+	return start.Cmp(end) < 0
+}
+
+func (p *L2Proposer) ActMakeProposalTx(t Testing) {
+	start, end, err := p.driver.GetBlockRange(t.Ctx())
+	require.NoError(t, err)
+	if start.Cmp(end) == 0 {
+		t.InvalidAction("nothing to propose, block range starts and ends at %s", start.String())
+	}
+	nonce, err := p.l1.PendingNonceAt(t.Ctx(), p.address)
+	require.NoError(t, err)
+
+	tx, err := p.driver.CraftTx(t.Ctx(), start, end, new(big.Int).SetUint64(nonce))
+	require.NoError(t, err)
+
+	err = p.driver.SendTransaction(t.Ctx(), tx)
+	require.NoError(t, err)
+	p.lastTx = tx.Hash()
+}
+
+func (p *L2Proposer) LastProposalTx() common.Hash {
+	return p.lastTx
+}
diff --git a/op-e2e/actions/l2_proposer_test.go b/op-e2e/actions/l2_proposer_test.go
new file mode 100644
index 0000000000000..ea8698cb8b6e1
--- /dev/null
+++ b/op-e2e/actions/l2_proposer_test.go
@@ -0,0 +1,82 @@
+package actions
+
+import (
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/stretchr/testify/require"
+
+	"github.com/ethereum-optimism/optimism/op-bindings/bindings"
+	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils"
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum-optimism/optimism/op-node/testlog"
+)
+
+func TestProposer(gt *testing.T) {
+	t := NewDefaultTesting(gt)
+	dp := e2eutils.MakeDeployParams(t, defaultRollupTestParams)
+	sd := e2eutils.Setup(t, dp, defaultAlloc)
+	log := testlog.Logger(t, log.LvlDebug)
+	miner, seqEngine, sequencer := setupSequencerTest(t, sd, log)
+
+	rollupSeqCl := sequencer.RollupClient()
+	batcher := NewL2Batcher(log, sd.RollupCfg, &BatcherCfg{
+		MinL1TxSize: 0,
+		MaxL1TxSize: 128_000,
+		BatcherKey:  dp.Secrets.Batcher,
+	}, rollupSeqCl, miner.EthClient(), seqEngine.EthClient())
+
+	proposer := NewL2Proposer(t, log, &ProposerCfg{
+		OutputOracleAddr:  sd.DeploymentsL1.L2OutputOracleProxy,
+		ProposerKey:       dp.Secrets.Proposer,
+		AllowNonFinalized: false,
+	}, miner.EthClient(), sequencer.RollupClient())
+
+	// L1 block
+	miner.ActEmptyBlock(t)
+	// L2 block
+	sequencer.ActL1HeadSignal(t)
+	sequencer.ActL2PipelineFull(t)
+	sequencer.ActBuildToL1Head(t)
+	// submit and include in L1
+	batcher.ActSubmitAll(t)
+	miner.ActL1StartBlock(12)(t)
+	miner.ActL1IncludeTx(dp.Addresses.Batcher)(t)
+	miner.ActL1EndBlock(t)
+	// finalize the first and second L1 blocks, including the batch
+	miner.ActL1SafeNext(t)
+	miner.ActL1SafeNext(t)
+	miner.ActL1FinalizeNext(t)
+	miner.ActL1FinalizeNext(t)
+	// derive and see the L2 chain fully finalize
+	sequencer.ActL2PipelineFull(t)
+	sequencer.ActL1SafeSignal(t)
+	sequencer.ActL1FinalizedSignal(t)
+	require.Equal(t, sequencer.SyncStatus().UnsafeL2, sequencer.SyncStatus().FinalizedL2)
+	// make proposals until there is nothing left to propose
+	for proposer.CanPropose(t) {
+		// and propose it to L1
+		proposer.ActMakeProposalTx(t)
+		// include proposal on L1
+		miner.ActL1StartBlock(12)(t)
+		miner.ActL1IncludeTx(dp.Addresses.Proposer)(t)
+		miner.ActL1EndBlock(t)
+		// Check proposal was successful
+		receipt, err := miner.EthClient().TransactionReceipt(t.Ctx(), proposer.LastProposalTx())
+		require.NoError(t, err)
+		require.Equal(t, types.ReceiptStatusSuccessful, receipt.Status, "proposal failed")
+	}
+
+	// check that L1 stored the expected output root
+	outputOracleContract, err := bindings.NewL2OutputOracle(sd.DeploymentsL1.L2OutputOracleProxy, miner.EthClient())
+	require.NoError(t, err)
+	block := sequencer.SyncStatus().FinalizedL2
+	outputOnL1, err := outputOracleContract.GetL2Output(nil, new(big.Int).SetUint64(block.Number))
+	require.NoError(t, err)
+	require.Less(t, block.Time, outputOnL1.Timestamp.Uint64(), "output is registered with L1 timestamp of proposal tx, past L2 block")
+	outputComputed, err := sequencer.RollupClient().OutputAtBlock(t.Ctx(), block.Number)
+	require.NoError(t, err)
+	require.Equal(t, eth.Bytes32(outputOnL1.OutputRoot), outputComputed.OutputRoot, "output roots must match")
+}
diff --git a/op-e2e/actions/l2_verifier.go b/op-e2e/actions/l2_verifier.go
index de741bf74d404..c7eab809c348e 100644
--- a/op-e2e/actions/l2_verifier.go
+++ b/op-e2e/actions/l2_verifier.go
@@ -26,7 +26,10 @@ import (
 type L2Verifier struct {
 	log log.Logger
 
-	eng derive.Engine
+	eng interface {
+		derive.Engine
+		L2BlockRefByNumber(ctx context.Context, num uint64) (eth.L2BlockRef, error)
+	}
 
 	// L2 rollup
 	derivation *derive.DerivationPipeline
@@ -46,7 +49,8 @@ type L2Verifier struct {
 
 type L2API interface {
 	derive.Engine
-	InfoByRpcNumber(ctx context.Context, num rpc.BlockNumber) (eth.BlockInfo, error)
+	L2BlockRefByNumber(ctx context.Context, num uint64) (eth.L2BlockRef, error)
+	InfoByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, error)
 	// GetProof returns a proof of the account, it may return a nil result without error if the address was not found.
 	GetProof(ctx context.Context, address common.Address, blockTag string) (*eth.AccountResult, error)
 }
@@ -95,6 +99,11 @@ type l2VerifierBackend struct {
 	verifier *L2Verifier
 }
 
+func (s *l2VerifierBackend) BlockRefWithStatus(ctx context.Context, num uint64) (eth.L2BlockRef, *eth.SyncStatus, error) {
+	ref, err := s.verifier.eng.L2BlockRefByNumber(ctx, num)
+	return ref, s.verifier.SyncStatus(), err
+}
+
 func (s *l2VerifierBackend) SyncStatus(ctx context.Context) (*eth.SyncStatus, error) {
 	return s.verifier.SyncStatus(), nil
 }
diff --git a/op-e2e/setup.go b/op-e2e/setup.go
index 3e2aab5d14a69..b982d4927b528 100644
--- a/op-e2e/setup.go
+++ b/op-e2e/setup.go
@@ -11,6 +11,17 @@ import (
 	"testing"
 	"time"
 
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core"
+	geth_eth "github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/rpc"
+	mocknet "github.com/libp2p/go-libp2p/p2p/net/mock"
+	"github.com/stretchr/testify/require"
+
 	bss "github.com/ethereum-optimism/optimism/op-batcher"
 	"github.com/ethereum-optimism/optimism/op-bindings/predeploys"
 	"github.com/ethereum-optimism/optimism/op-chain-ops/genesis"
@@ -24,16 +35,6 @@ import (
 	"github.com/ethereum-optimism/optimism/op-node/testlog"
 	l2os "github.com/ethereum-optimism/optimism/op-proposer"
 	oplog "github.com/ethereum-optimism/optimism/op-service/log"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/ethereum/go-ethereum/core"
-	geth_eth "github.com/ethereum/go-ethereum/eth"
-	"github.com/ethereum/go-ethereum/ethclient"
-	"github.com/ethereum/go-ethereum/log"
-	"github.com/ethereum/go-ethereum/node"
-	"github.com/ethereum/go-ethereum/rpc"
-	mocknet "github.com/libp2p/go-libp2p/p2p/net/mock"
-	"github.com/stretchr/testify/require"
 )
 
 var (
@@ -139,7 +140,8 @@ func DefaultSystemConfig(t *testing.T) SystemConfig {
 			"batcher":   testlog.Logger(t, log.LvlInfo).New("role", "batcher"),
 			"proposer":  testlog.Logger(t, log.LvlCrit).New("role", "proposer"),
 		},
-		P2PTopology: nil, // no P2P connectivity by default
+		P2PTopology:           nil, // no P2P connectivity by default
+		NonFinalizedProposals: false,
 	}
 }
 
@@ -181,6 +183,9 @@ type SystemConfig struct {
 	// A nil map disables P2P completely.
 	// Any node name not in the topology will not have p2p enabled.
 	P2PTopology map[string][]string
+
+	// If the proposer can make proposals for L2 blocks derived from L1 blocks which are not finalized on L1 yet.
+	NonFinalizedProposals bool
 }
 
 type System struct {
@@ -479,13 +484,13 @@ func (cfg SystemConfig) Start() (*System, error) {
 	// L2Output Submitter
 	sys.L2OutputSubmitter, err = l2os.NewL2OutputSubmitter(l2os.Config{
 		L1EthRpc:                  sys.Nodes["l1"].WSEndpoint(),
-		L2EthRpc:                  sys.Nodes["sequencer"].WSEndpoint(),
 		RollupRpc:                 sys.RollupNodes["sequencer"].HTTPEndpoint(),
 		L2OOAddress:               predeploys.DevL2OutputOracleAddr.String(),
 		PollInterval:              50 * time.Millisecond,
 		NumConfirmations:          1,
 		ResubmissionTimeout:       3 * time.Second,
 		SafeAbortNonceTooLowCount: 3,
+		AllowNonFinalized:         cfg.NonFinalizedProposals,
 		LogConfig: oplog.CLIConfig{
 			Level:  "info",
 			Format: "text",
diff --git a/op-e2e/system_test.go b/op-e2e/system_test.go
index 38b99b57ca572..acbbe288a4015 100644
--- a/op-e2e/system_test.go
+++ b/op-e2e/system_test.go
@@ -8,14 +8,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/ethereum-optimism/optimism/op-bindings/bindings"
-	"github.com/ethereum-optimism/optimism/op-bindings/predeploys"
-	"github.com/ethereum-optimism/optimism/op-node/client"
-	"github.com/ethereum-optimism/optimism/op-node/eth"
-	"github.com/ethereum-optimism/optimism/op-node/rollup/derive"
-	"github.com/ethereum-optimism/optimism/op-node/sources"
-	"github.com/ethereum-optimism/optimism/op-node/testlog"
-	"github.com/ethereum-optimism/optimism/op-node/withdrawals"
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/accounts/keystore"
@@ -27,6 +19,15 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/libp2p/go-libp2p-core/peer"
 	"github.com/stretchr/testify/require"
+
+	"github.com/ethereum-optimism/optimism/op-bindings/bindings"
+	"github.com/ethereum-optimism/optimism/op-bindings/predeploys"
+	"github.com/ethereum-optimism/optimism/op-node/client"
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum-optimism/optimism/op-node/rollup/derive"
+	"github.com/ethereum-optimism/optimism/op-node/sources"
+	"github.com/ethereum-optimism/optimism/op-node/testlog"
+	"github.com/ethereum-optimism/optimism/op-node/withdrawals"
 )
 
 // Init testing to enable test flags
@@ -49,6 +50,7 @@ func TestL2OutputSubmitter(t *testing.T) {
 	}
 
 	cfg := DefaultSystemConfig(t)
+	cfg.NonFinalizedProposals = true // speed up the time till we see output proposals
 
 	sys, err := cfg.Start()
 	require.Nil(t, err, "Error starting up system")
@@ -99,11 +101,9 @@ func TestL2OutputSubmitter(t *testing.T) {
 			// finalized.
 			ctx, cancel := context.WithTimeout(context.Background(), time.Second)
 			defer cancel()
-			l2Output, err := rollupClient.OutputAtBlock(ctx, l2ooBlockNumber)
+			l2Output, err := rollupClient.OutputAtBlock(ctx, l2ooBlockNumber.Uint64())
 			require.Nil(t, err)
-			require.Len(t, l2Output, 2)
-
-			require.Equal(t, l2Output[1][:], committedL2Output.OutputRoot[:])
+			require.Equal(t, l2Output.OutputRoot[:], committedL2Output.OutputRoot[:])
 			break
 		}
 
diff --git a/op-node/eth/output.go b/op-node/eth/output.go
new file mode 100644
index 0000000000000..9594775d48415
--- /dev/null
+++ b/op-node/eth/output.go
@@ -0,0 +1,14 @@
+package eth
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+)
+
+type OutputResponse struct {
+	Version               Bytes32     `json:"version"`
+	OutputRoot            Bytes32     `json:"outputRoot"`
+	BlockRef              L2BlockRef  `json:"blockRef"`
+	WithdrawalStorageRoot common.Hash `json:"withdrawalStorageRoot"`
+	StateRoot             common.Hash `json:"stateRoot"`
+	Status                *SyncStatus `json:"syncStatus"`
+}
diff --git a/op-node/node/api.go b/op-node/node/api.go
index e5a4b14c5ec45..b8dd7de6e329f 100644
--- a/op-node/node/api.go
+++ b/op-node/node/api.go
@@ -4,24 +4,26 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/log"
+
 	"github.com/ethereum-optimism/optimism/op-bindings/predeploys"
 	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
 	"github.com/ethereum-optimism/optimism/op-node/version"
-	"github.com/ethereum/go-ethereum"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/log"
-	"github.com/ethereum/go-ethereum/rpc"
 )
 
 type l2EthClient interface {
-	InfoByRpcNumber(ctx context.Context, num rpc.BlockNumber) (eth.BlockInfo, error)
+	InfoByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, error)
 	// GetProof returns a proof of the account, it may return a nil result without error if the address was not found.
 	GetProof(ctx context.Context, address common.Address, blockTag string) (*eth.AccountResult, error)
 }
 
 type driverClient interface {
 	SyncStatus(ctx context.Context) (*eth.SyncStatus, error)
+	BlockRefWithStatus(ctx context.Context, num uint64) (eth.L2BlockRef, *eth.SyncStatus, error)
 	ResetDerivationPipeline(context.Context) error
 }
 
@@ -66,38 +68,47 @@ func NewNodeAPI(config *rollup.Config, l2Client l2EthClient, dr driverClient, lo
 	}
 }
 
-func (n *nodeAPI) OutputAtBlock(ctx context.Context, number rpc.BlockNumber) ([]eth.Bytes32, error) {
+func (n *nodeAPI) OutputAtBlock(ctx context.Context, number hexutil.Uint64) (*eth.OutputResponse, error) {
 	recordDur := n.m.RecordRPCServerRequest("optimism_outputAtBlock")
 	defer recordDur()
-	// TODO: rpc.BlockNumber doesn't support the "safe" tag. Need a new type
 
-	head, err := n.client.InfoByRpcNumber(ctx, number)
+	ref, status, err := n.dr.BlockRefWithStatus(ctx, uint64(number))
 	if err != nil {
-		n.log.Error("failed to get block", "err", err)
-		return nil, err
+		return nil, fmt.Errorf("failed to get L2 block ref with sync status: %w", err)
+	}
+
+	head, err := n.client.InfoByHash(ctx, ref.Hash)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get L2 block by hash %s: %w", ref, err)
 	}
 	if head == nil {
 		return nil, ethereum.NotFound
 	}
 
-	proof, err := n.client.GetProof(ctx, predeploys.L2ToL1MessagePasserAddr, toBlockNumArg(number))
+	proof, err := n.client.GetProof(ctx, predeploys.L2ToL1MessagePasserAddr, ref.Hash.String())
 	if err != nil {
-		n.log.Error("failed to get contract proof", "err", err)
-		return nil, err
+		return nil, fmt.Errorf("failed to get contract proof at block %s: %w", ref, err)
 	}
 	if proof == nil {
-		return nil, ethereum.NotFound
+		return nil, fmt.Errorf("proof %w", ethereum.NotFound)
 	}
 	// make sure that the proof (including storage hash) that we retrieved is correct by verifying it against the state-root
 	if err := proof.Verify(head.Root()); err != nil {
 		n.log.Error("invalid withdrawal root detected in block", "stateRoot", head.Root(), "blocknum", number, "msg", err)
-		return nil, fmt.Errorf("invalid withdrawal root hash")
+		return nil, fmt.Errorf("invalid withdrawal root hash, state root was %s: %w", head.Root(), err)
 	}
 
 	var l2OutputRootVersion eth.Bytes32 // it's zero for now
 	l2OutputRoot := rollup.ComputeL2OutputRoot(l2OutputRootVersion, head.Hash(), head.Root(), proof.StorageHash)
 
-	return []eth.Bytes32{l2OutputRootVersion, l2OutputRoot}, nil
+	return &eth.OutputResponse{
+		Version:               l2OutputRootVersion,
+		OutputRoot:            l2OutputRoot,
+		BlockRef:              ref,
+		WithdrawalStorageRoot: proof.StorageHash,
+		StateRoot:             head.Root(),
+		Status:                status,
+	}, nil
 }
 
 func (n *nodeAPI) SyncStatus(ctx context.Context) (*eth.SyncStatus, error) {
@@ -117,9 +128,3 @@ func (n *nodeAPI) Version(ctx context.Context) (string, error) {
 	defer recordDur()
 	return version.Version + "-" + version.Meta, nil
 }
-
-func toBlockNumArg(number rpc.BlockNumber) string {
-	// never returns an error
-	out, _ := number.MarshalText()
-	return string(out)
-}
diff --git a/op-node/node/server_test.go b/op-node/node/server_test.go
index 83b9206551875..a1f42a972c906 100644
--- a/op-node/node/server_test.go
+++ b/op-node/node/server_test.go
@@ -6,9 +6,15 @@ import (
 	"math/rand"
 	"testing"
 
-	rpcclient "github.com/ethereum-optimism/optimism/op-node/client"
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+
+	rpcclient "github.com/ethereum-optimism/optimism/op-node/client"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
 
 	"github.com/ethereum-optimism/optimism/op-bindings/predeploys"
 	"github.com/ethereum-optimism/optimism/op-node/eth"
@@ -17,9 +23,6 @@ import (
 	"github.com/ethereum-optimism/optimism/op-node/testlog"
 	"github.com/ethereum-optimism/optimism/op-node/testutils"
 	"github.com/ethereum-optimism/optimism/op-node/version"
-	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/log"
-	"github.com/ethereum/go-ethereum/rpc"
 )
 
 func TestOutputAtBlock(t *testing.T) {
@@ -92,24 +95,40 @@ func TestOutputAtBlock(t *testing.T) {
 		InfoBaseFee:     header.BaseFee,
 		InfoReceiptRoot: header.ReceiptHash,
 	}
-	l2Client.ExpectInfoByRpcNumber(rpc.LatestBlockNumber, info, nil)
-	l2Client.ExpectGetProof(predeploys.L2ToL1MessagePasserAddr, "latest", &result, nil)
+	ref := eth.L2BlockRef{
+		Hash:           header.Hash(),
+		Number:         header.Number.Uint64(),
+		ParentHash:     header.ParentHash,
+		Time:           header.Time,
+		L1Origin:       eth.BlockID{},
+		SequenceNumber: 0,
+	}
+	l2Client.ExpectInfoByHash(common.HexToHash("0x8512bee03061475e4b069171f7b406097184f16b22c3f5c97c0abfc49591c524"), info, nil)
+	l2Client.ExpectGetProof(predeploys.L2ToL1MessagePasserAddr, "0x8512bee03061475e4b069171f7b406097184f16b22c3f5c97c0abfc49591c524", &result, nil)
 
 	drClient := &mockDriverClient{}
+	status := randomSyncStatus(rand.New(rand.NewSource(123)))
+	drClient.ExpectBlockRefWithStatus(0xdcdc89, ref, status, nil)
 
 	server, err := newRPCServer(context.Background(), rpcCfg, rollupCfg, l2Client, drClient, log, "0.0", metrics.NewMetrics(""))
-	assert.NoError(t, err)
-	assert.NoError(t, server.Start())
+	require.NoError(t, err)
+	require.NoError(t, server.Start())
 	defer server.Stop()
 
 	client, err := rpcclient.DialRPCClientWithBackoff(context.Background(), log, "http://"+server.Addr().String())
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
-	var out []eth.Bytes32
-	err = client.CallContext(context.Background(), &out, "optimism_outputAtBlock", "latest")
-	assert.NoError(t, err)
-	assert.Len(t, out, 2)
+	var out *eth.OutputResponse
+	err = client.CallContext(context.Background(), &out, "optimism_outputAtBlock", "0xdcdc89")
+	require.NoError(t, err)
+
+	require.Equal(t, "0x0000000000000000000000000000000000000000000000000000000000000000", out.Version.String())
+	require.Equal(t, "0xc861dbdc5bf1d8bbbc0bca7cd876ab6a70748c50b2054a46e8f30e99002170ab", out.OutputRoot.String())
+	require.Equal(t, "0xb46d4bcb0e471e1b8506031a1f34ebc6f200253cbaba56246dd2320e8e2c8f13", out.StateRoot.String())
+	require.Equal(t, "0xc1917a80cb25ccc50d0d1921525a44fb619b4601194ca726ae32312f08a799f8", out.WithdrawalStorageRoot.String())
+	require.Equal(t, *status, *out.Status)
 	l2Client.Mock.AssertExpectations(t)
+	drClient.Mock.AssertExpectations(t)
 }
 
 func TestVersion(t *testing.T) {
@@ -137,19 +156,26 @@ func TestVersion(t *testing.T) {
 	assert.Equal(t, version.Version+"-"+version.Meta, out)
 }
 
+func randomSyncStatus(rng *rand.Rand) *eth.SyncStatus {
+	return &eth.SyncStatus{
+		CurrentL1:          testutils.RandomBlockRef(rng),
+		CurrentL1Finalized: testutils.RandomBlockRef(rng),
+		HeadL1:             testutils.RandomBlockRef(rng),
+		SafeL1:             testutils.RandomBlockRef(rng),
+		FinalizedL1:        testutils.RandomBlockRef(rng),
+		UnsafeL2:           testutils.RandomL2BlockRef(rng),
+		SafeL2:             testutils.RandomL2BlockRef(rng),
+		FinalizedL2:        testutils.RandomL2BlockRef(rng),
+	}
+}
+
 func TestSyncStatus(t *testing.T) {
 	log := testlog.Logger(t, log.LvlError)
 	l2Client := &testutils.MockL2Client{}
 	drClient := &mockDriverClient{}
 	rng := rand.New(rand.NewSource(1234))
-	status := eth.SyncStatus{
-		CurrentL1:   testutils.RandomBlockRef(rng),
-		HeadL1:      testutils.RandomBlockRef(rng),
-		UnsafeL2:    testutils.RandomL2BlockRef(rng),
-		SafeL2:      testutils.RandomL2BlockRef(rng),
-		FinalizedL2: testutils.RandomL2BlockRef(rng),
-	}
-	drClient.On("SyncStatus").Return(&status)
+	status := randomSyncStatus(rng)
+	drClient.On("SyncStatus").Return(status)
 
 	rpcCfg := &RPCConfig{
 		ListenAddr: "localhost",
@@ -169,13 +195,22 @@ func TestSyncStatus(t *testing.T) {
 	var out *eth.SyncStatus
 	err = client.CallContext(context.Background(), &out, "optimism_syncStatus")
 	assert.NoError(t, err)
-	assert.Equal(t, &status, out)
+	assert.Equal(t, status, out)
 }
 
 type mockDriverClient struct {
 	mock.Mock
 }
 
+func (c *mockDriverClient) ExpectBlockRefWithStatus(num uint64, ref eth.L2BlockRef, status *eth.SyncStatus, err error) {
+	c.Mock.On("BlockRefWithStatus", num).Return(ref, status, &err)
+}
+
+func (c *mockDriverClient) BlockRefWithStatus(ctx context.Context, num uint64) (eth.L2BlockRef, *eth.SyncStatus, error) {
+	m := c.Mock.MethodCalled("BlockRefWithStatus", num)
+	return m[0].(eth.L2BlockRef), m[1].(*eth.SyncStatus), *m[2].(*error)
+}
+
 func (c *mockDriverClient) SyncStatus(ctx context.Context) (*eth.SyncStatus, error) {
 	return c.Mock.MethodCalled("SyncStatus").Get(0).(*eth.SyncStatus), nil
 }
diff --git a/op-node/sources/eth_client.go b/op-node/sources/eth_client.go
index 26b8fb235bae2..f70d8c5fb0f66 100644
--- a/op-node/sources/eth_client.go
+++ b/op-node/sources/eth_client.go
@@ -5,15 +5,15 @@ import (
 	"fmt"
 	"io"
 
-	"github.com/ethereum-optimism/optimism/op-node/client"
-	"github.com/ethereum-optimism/optimism/op-node/eth"
-	"github.com/ethereum-optimism/optimism/op-node/sources/caching"
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
-	"github.com/ethereum/go-ethereum/rpc"
+
+	"github.com/ethereum-optimism/optimism/op-node/client"
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum-optimism/optimism/op-node/sources/caching"
 )
 
 type EthClientConfig struct {
@@ -193,11 +193,6 @@ func (s *EthClient) InfoByLabel(ctx context.Context, label eth.BlockLabel) (eth.
 	return s.headerCall(ctx, "eth_getBlockByNumber", string(label))
 }
 
-func (s *EthClient) InfoByRpcNumber(ctx context.Context, num rpc.BlockNumber) (eth.BlockInfo, error) {
-	// can't hit the cache when querying the head due to reorgs / changes.
-	return s.headerCall(ctx, "eth_getBlockByNumber", num)
-}
-
 func (s *EthClient) InfoAndTxsByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, types.Transactions, error) {
 	if header, ok := s.headersCache.Get(hash); ok {
 		if txs, ok := s.transactionsCache.Get(hash); ok {
diff --git a/op-node/sources/rollupclient.go b/op-node/sources/rollupclient.go
index 577c69dcadc61..0747974e54dee 100644
--- a/op-node/sources/rollupclient.go
+++ b/op-node/sources/rollupclient.go
@@ -2,12 +2,12 @@ package sources
 
 import (
 	"context"
-	"math/big"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
 
 	"github.com/ethereum-optimism/optimism/op-node/client"
 	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
-	"github.com/ethereum/go-ethereum/common/hexutil"
 )
 
 type RollupClient struct {
@@ -18,9 +18,9 @@ func NewRollupClient(rpc client.RPC) *RollupClient {
 	return &RollupClient{rpc}
 }
 
-func (r *RollupClient) OutputAtBlock(ctx context.Context, blockNum *big.Int) ([]eth.Bytes32, error) {
-	var output []eth.Bytes32
-	err := r.rpc.CallContext(ctx, &output, "optimism_outputAtBlock", hexutil.EncodeBig(blockNum))
+func (r *RollupClient) OutputAtBlock(ctx context.Context, blockNum uint64) (*eth.OutputResponse, error) {
+	var output *eth.OutputResponse
+	err := r.rpc.CallContext(ctx, &output, "optimism_outputAtBlock", hexutil.Uint64(blockNum))
 	return output, err
 }
 
diff --git a/op-node/testutils/mock_eth_client.go b/op-node/testutils/mock_eth_client.go
index 2c377c4871336..9cd39b013ec0e 100644
--- a/op-node/testutils/mock_eth_client.go
+++ b/op-node/testutils/mock_eth_client.go
@@ -5,10 +5,10 @@ import (
 
 	"github.com/stretchr/testify/mock"
 
-	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/rpc"
+
+	"github.com/ethereum-optimism/optimism/op-node/eth"
 )
 
 type MockEthClient struct {
@@ -42,15 +42,6 @@ func (m *MockEthClient) ExpectInfoByLabel(label eth.BlockLabel, info eth.BlockIn
 	m.Mock.On("InfoByLabel", label).Once().Return(&info, &err)
 }
 
-func (m *MockEthClient) InfoByRpcNumber(ctx context.Context, num rpc.BlockNumber) (eth.BlockInfo, error) {
-	out := m.Mock.MethodCalled("InfoByRpcNumber", num)
-	return *out[0].(*eth.BlockInfo), *out[1].(*error)
-}
-
-func (m *MockEthClient) ExpectInfoByRpcNumber(num rpc.BlockNumber, info eth.BlockInfo, err error) {
-	m.Mock.On("InfoByRpcNumber", num).Once().Return(&info, &err)
-}
-
 func (m *MockEthClient) InfoAndTxsByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, types.Transactions, error) {
 	out := m.Mock.MethodCalled("InfoAndTxsByHash", hash)
 	return out[0].(eth.BlockInfo), out[1].(types.Transactions), *out[2].(*error)
diff --git a/op-proposer/config.go b/op-proposer/config.go
index 95b25ec99621d..f407b8ee5af58 100644
--- a/op-proposer/config.go
+++ b/op-proposer/config.go
@@ -18,9 +18,6 @@ type Config struct {
 	// L1EthRpc is the HTTP provider URL for L1.
 	L1EthRpc string
 
-	// L2EthRpc is the HTTP provider URL for L2.
-	L2EthRpc string
-
 	// RollupRpc is the HTTP provider URL for the rollup node.
 	RollupRpc string
 
@@ -60,6 +57,10 @@ type Config struct {
 
 	/* Optional Params */
 
+	// AllowNonFinalized can be set to true to propose outputs
+	// for L2 blocks derived from non-finalized L1 data.
+	AllowNonFinalized bool
+
 	LogConfig oplog.CLIConfig
 
 	MetricsConfig opmetrics.CLIConfig
@@ -88,7 +89,6 @@ func NewConfig(ctx *cli.Context) Config {
 	return Config{
 		/* Required Flags */
 		L1EthRpc:                  ctx.GlobalString(flags.L1EthRpcFlag.Name),
-		L2EthRpc:                  ctx.GlobalString(flags.L2EthRpcFlag.Name),
 		RollupRpc:                 ctx.GlobalString(flags.RollupRpcFlag.Name),
 		L2OOAddress:               ctx.GlobalString(flags.L2OOAddressFlag.Name),
 		PollInterval:              ctx.GlobalDuration(flags.PollIntervalFlag.Name),
@@ -98,6 +98,7 @@ func NewConfig(ctx *cli.Context) Config {
 		Mnemonic:                  ctx.GlobalString(flags.MnemonicFlag.Name),
 		L2OutputHDPath:            ctx.GlobalString(flags.L2OutputHDPathFlag.Name),
 		PrivateKey:                ctx.GlobalString(flags.PrivateKeyFlag.Name),
+		AllowNonFinalized:         ctx.GlobalBool(flags.AllowNonFinalizedFlag.Name),
 		RPCConfig:                 oprpc.ReadCLIConfig(ctx),
 		LogConfig:                 oplog.ReadCLIConfig(ctx),
 		MetricsConfig:             opmetrics.ReadCLIConfig(ctx),
diff --git a/op-proposer/drivers/l2output/driver.go b/op-proposer/drivers/l2output/driver.go
index bdca9592e66fc..7282397a9468a 100644
--- a/op-proposer/drivers/l2output/driver.go
+++ b/op-proposer/drivers/l2output/driver.go
@@ -9,8 +9,6 @@ import (
 
 	"github.com/ethereum-optimism/optimism/op-node/sources"
 
-	"github.com/ethereum-optimism/optimism/op-bindings/bindings"
-	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum/go-ethereum/accounts/abi"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
@@ -18,20 +16,37 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/log"
+
+	"github.com/ethereum-optimism/optimism/op-bindings/bindings"
+	"github.com/ethereum-optimism/optimism/op-node/eth"
 )
 
 var bigOne = big.NewInt(1)
 var supportedL2OutputVersion = eth.Bytes32{}
 
 type Config struct {
-	Log          log.Logger
-	Name         string
-	L1Client     *ethclient.Client
-	L2Client     *ethclient.Client
+	Log  log.Logger
+	Name string
+
+	// L1Client is used to submit transactions to
+	L1Client *ethclient.Client
+	// RollupClient is used to retrieve output roots from
 	RollupClient *sources.RollupClient
-	L2OOAddr     common.Address
-	ChainID      *big.Int
-	PrivKey      *ecdsa.PrivateKey
+
+	// AllowNonFinalized enables the proposal of safe, but non-finalized L2 blocks.
+	// The L1 block-hash embedded in the proposal TX is checked and should ensure the proposal
+	// is never valid on an alternative L1 chain that would produce different L2 data.
+	// This option is not necessary when higher proposal latency is acceptable and L1 is healthy.
+	AllowNonFinalized bool
+
+	// L2OOAddr is the L1 contract address of the L2 Output Oracle.
+	L2OOAddr common.Address
+
+	// ChainID is the L1 chain ID used for proposal transaction signing
+	ChainID *big.Int
+
+	// Privkey used for proposal transaction signing
+	PrivKey *ecdsa.PrivateKey
 }
 
 type Driver struct {
@@ -43,9 +58,7 @@ type Driver struct {
 }
 
 func NewDriver(cfg Config) (*Driver, error) {
-	l2ooContract, err := bindings.NewL2OutputOracle(
-		cfg.L2OOAddr, cfg.L1Client,
-	)
+	l2ooContract, err := bindings.NewL2OutputOracle(cfg.L2OOAddr, cfg.L1Client)
 	if err != nil {
 		return nil, err
 	}
@@ -62,7 +75,7 @@ func NewDriver(cfg Config) (*Driver, error) {
 	)
 
 	walletAddr := crypto.PubkeyToAddress(cfg.PrivKey.PublicKey)
-	log.Info("Configured driver", "wallet", walletAddr, "l2-output-contract", cfg.L2OOAddr)
+	cfg.Log.Info("Configured driver", "wallet", walletAddr, "l2-output-contract", cfg.L2OOAddr)
 
 	return &Driver{
 		cfg:             cfg,
@@ -86,9 +99,7 @@ func (d *Driver) WalletAddr() common.Address {
 // GetBlockRange returns the start and end L2 block heights that need to be
 // processed. Note that the end value is *exclusive*, therefore if the returned
 // values are identical nothing needs to be processed.
-func (d *Driver) GetBlockRange(
-	ctx context.Context) (*big.Int, *big.Int, error) {
-
+func (d *Driver) GetBlockRange(ctx context.Context) (*big.Int, *big.Int, error) {
 	name := d.cfg.Name
 
 	callOpts := &bind.CallOpts{
@@ -115,12 +126,12 @@ func (d *Driver) GetBlockRange(
 		d.l.Error(name+" unable to get sync status", "err", err)
 		return nil, nil, err
 	}
-	latestHeader, err := d.cfg.L2Client.HeaderByNumber(ctx, new(big.Int).SetUint64(status.SafeL2.Number))
-	if err != nil {
-		d.l.Error(name+" unable to retrieve latest header", "err", err)
-		return nil, nil, err
+	var currentBlockNumber *big.Int
+	if d.cfg.AllowNonFinalized {
+		currentBlockNumber = new(big.Int).SetUint64(status.SafeL2.Number)
+	} else {
+		currentBlockNumber = new(big.Int).SetUint64(status.FinalizedL2.Number)
 	}
-	currentBlockNumber := big.NewInt(latestHeader.Number.Int64())
 
 	// If we do not have the new L2 Block number
 	if currentBlockNumber.Cmp(nextBlockNumber) < 0 {
@@ -144,46 +155,36 @@ func (d *Driver) GetBlockRange(
 // using the given nonce.
 //
 // NOTE: This method SHOULD NOT publish the resulting transaction.
-func (d *Driver) CraftTx(
-	ctx context.Context,
-	start, end, nonce *big.Int,
-) (*types.Transaction, error) {
-
+func (d *Driver) CraftTx(ctx context.Context, start, end, nonce *big.Int) (*types.Transaction, error) {
 	name := d.cfg.Name
 
-	d.l.Info(name+" crafting checkpoint tx", "start", start, "end", end,
-		"nonce", nonce)
+	d.l.Info(name+" crafting checkpoint tx", "start", start, "end", end, "nonce", nonce)
 
-	// Fetch the final block in the range, as this is the only L2 output we need
-	// to submit.
-	nextCheckpointBlock := new(big.Int).Sub(end, bigOne)
+	// Fetch the final block in the range, as this is the only L2 output we need to submit.
+	nextCheckpointBlock := new(big.Int).Sub(end, bigOne).Uint64()
 
-	l2OutputRoot, err := d.outputRootAtBlock(ctx, nextCheckpointBlock)
+	output, err := d.cfg.RollupClient.OutputAtBlock(ctx, nextCheckpointBlock)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to fetch output at block %d: %w", nextCheckpointBlock, err)
 	}
-
-	numElements := new(big.Int).Sub(start, end).Uint64()
-	d.l.Info(name+" checkpoint constructed", "start", start, "end", end,
-		"nonce", nonce, "blocks_committed", numElements, "checkpoint_block", nextCheckpointBlock)
-
-	l1Header, err := d.cfg.L1Client.HeaderByNumber(ctx, nil)
-	if err != nil {
-		return nil, fmt.Errorf("error resolving checkpoint block: %w", err)
+	if output.Version != supportedL2OutputVersion {
+		return nil, fmt.Errorf("unsupported l2 output version: %s", output.Version)
 	}
-
-	l2Header, err := d.cfg.L2Client.HeaderByNumber(ctx, nextCheckpointBlock)
-	if err != nil {
-		return nil, fmt.Errorf("error resolving checkpoint block: %w", err)
+	if output.BlockRef.Number != nextCheckpointBlock { // sanity check, e.g. in case of bad RPC caching
+		return nil, fmt.Errorf("invalid blockNumber: next blockNumber is %v, blockNumber of block is %v", nextCheckpointBlock, output.BlockRef.Number)
 	}
 
-	if l2Header.Number.Cmp(nextCheckpointBlock) != 0 {
-		return nil, fmt.Errorf("invalid blockNumber: next blockNumber is %v, blockNumber of block is %v", nextCheckpointBlock, l2Header.Number)
+	// Always propose if it's part of the Finalized L2 chain. Or if allowed, if it's part of the safe L2 chain.
+	if !(output.BlockRef.Number <= output.Status.FinalizedL2.Number || (d.cfg.AllowNonFinalized && output.BlockRef.Number <= output.Status.SafeL2.Number)) {
+		d.l.Debug("not proposing yet, L2 block is not ready for proposal",
+			"l2_proposal", output.BlockRef,
+			"l2_safe", output.Status.SafeL2,
+			"l2_finalized", output.Status.FinalizedL2,
+			"allow_non_finalized", d.cfg.AllowNonFinalized)
+		return nil, fmt.Errorf("output for L2 block %s is still unsafe", output.BlockRef)
 	}
 
-	opts, err := bind.NewKeyedTransactorWithChainID(
-		d.cfg.PrivKey, d.cfg.ChainID,
-	)
+	opts, err := bind.NewKeyedTransactorWithChainID(d.cfg.PrivKey, d.cfg.ChainID)
 	if err != nil {
 		return nil, err
 	}
@@ -191,18 +192,41 @@ func (d *Driver) CraftTx(
 	opts.Nonce = nonce
 	opts.NoSend = true
 
-	return d.l2ooContract.ProposeL2Output(opts, l2OutputRoot, nextCheckpointBlock, l1Header.Hash(), l1Header.Number)
+	// Note: the CurrentL1 is up to (and incl.) what the safe chain and finalized chain have been derived from,
+	// and should be a quite recent L1 block (depends on L1 conf distance applied to rollup node).
+
+	tx, err := d.l2ooContract.ProposeL2Output(
+		opts,
+		output.OutputRoot,
+		new(big.Int).SetUint64(output.BlockRef.Number),
+		output.Status.CurrentL1.Hash,
+		new(big.Int).SetUint64(output.Status.CurrentL1.Number))
+	if err != nil {
+		return nil, err
+	}
+
+	numElements := new(big.Int).Sub(start, end).Uint64()
+	d.l.Info(name+" proposal constructed",
+		"start", start, "end", end,
+		"nonce", nonce, "blocks_committed", numElements,
+		"tx_hash", tx.Hash(),
+		"output_version", output.Version,
+		"output_root", output.OutputRoot,
+		"output_block", output.BlockRef,
+		"output_withdrawals_root", output.WithdrawalStorageRoot,
+		"output_state_root", output.StateRoot,
+		"current_l1", output.Status.CurrentL1,
+		"safe_l2", output.Status.SafeL2,
+		"finalized_l2", output.Status.FinalizedL2,
+	)
+	return tx, nil
 }
 
 // UpdateGasPrice signs an otherwise identical txn to the one provided but with
 // updated gas prices sampled from the existing network conditions.
 //
-// NOTE: Thie method SHOULD NOT publish the resulting transaction.
-func (d *Driver) UpdateGasPrice(
-	ctx context.Context,
-	tx *types.Transaction,
-) (*types.Transaction, error) {
-
+// NOTE: This method SHOULD NOT publish the resulting transaction.
+func (d *Driver) UpdateGasPrice(ctx context.Context, tx *types.Transaction) (*types.Transaction, error) {
 	opts, err := bind.NewKeyedTransactorWithChainID(
 		d.cfg.PrivKey, d.cfg.ChainID,
 	)
@@ -216,26 +240,8 @@ func (d *Driver) UpdateGasPrice(
 	return d.rawL2ooContract.RawTransact(opts, tx.Data())
 }
 
-// SendTransaction injects a signed transaction into the pending pool for
-// execution.
-func (d *Driver) SendTransaction(
-	ctx context.Context,
-	tx *types.Transaction,
-) error {
-
+// SendTransaction injects a signed transaction into the pending pool for execution.
+func (d *Driver) SendTransaction(ctx context.Context, tx *types.Transaction) error {
+	d.l.Info(d.cfg.Name+" sending transaction", "tx", tx.Hash())
 	return d.cfg.L1Client.SendTransaction(ctx, tx)
 }
-
-func (d *Driver) outputRootAtBlock(ctx context.Context, blockNum *big.Int) (eth.Bytes32, error) {
-	output, err := d.cfg.RollupClient.OutputAtBlock(ctx, blockNum)
-	if err != nil {
-		return eth.Bytes32{}, err
-	}
-	if len(output) != 2 {
-		return eth.Bytes32{}, fmt.Errorf("invalid outputAtBlock response")
-	}
-	if version := output[0]; version != supportedL2OutputVersion {
-		return eth.Bytes32{}, fmt.Errorf("unsupported l2 output version")
-	}
-	return output[1], nil
-}
diff --git a/op-proposer/flags/flags.go b/op-proposer/flags/flags.go
index 4550c14b42a8d..09bccc4ef7a77 100644
--- a/op-proposer/flags/flags.go
+++ b/op-proposer/flags/flags.go
@@ -21,12 +21,6 @@ var (
 		Required: true,
 		EnvVar:   opservice.PrefixEnvVar(envVarPrefix, "L1_ETH_RPC"),
 	}
-	L2EthRpcFlag = cli.StringFlag{
-		Name:     "l2-eth-rpc",
-		Usage:    "HTTP provider URL for L2",
-		Required: true,
-		EnvVar:   opservice.PrefixEnvVar(envVarPrefix, "L2_ETH_RPC"),
-	}
 	RollupRpcFlag = cli.StringFlag{
 		Name:     "rollup-rpc",
 		Usage:    "HTTP provider URL for the rollup node",
@@ -68,6 +62,9 @@ var (
 		Required: true,
 		EnvVar:   opservice.PrefixEnvVar(envVarPrefix, "RESUBMISSION_TIMEOUT"),
 	}
+
+	/* Optional flags */
+
 	MnemonicFlag = cli.StringFlag{
 		Name: "mnemonic",
 		Usage: "The mnemonic used to derive the wallets for either the " +
@@ -85,11 +82,15 @@ var (
 		Usage:  "The private key to use with the l2output wallet. Must not be used with mnemonic.",
 		EnvVar: opservice.PrefixEnvVar(envVarPrefix, "PRIVATE_KEY"),
 	}
+	AllowNonFinalizedFlag = cli.BoolFlag{
+		Name:   "allow-non-finalized",
+		Usage:  "Allow the proposer to submit proposals for L2 blocks derived from non-finalized L1 blocks.",
+		EnvVar: opservice.PrefixEnvVar(envVarPrefix, "ALLOW_NON_FINALIZED"),
+	}
 )
 
 var requiredFlags = []cli.Flag{
 	L1EthRpcFlag,
-	L2EthRpcFlag,
 	RollupRpcFlag,
 	L2OOAddressFlag,
 	PollIntervalFlag,
@@ -102,6 +103,7 @@ var optionalFlags = []cli.Flag{
 	MnemonicFlag,
 	L2OutputHDPathFlag,
 	PrivateKeyFlag,
+	AllowNonFinalizedFlag,
 }
 
 func init() {
diff --git a/op-proposer/l2_output_submitter.go b/op-proposer/l2_output_submitter.go
index a5655a3a1b007..4ecbe71ca2a8f 100644
--- a/op-proposer/l2_output_submitter.go
+++ b/op-proposer/l2_output_submitter.go
@@ -12,14 +12,6 @@ import (
 	"syscall"
 	"time"
 
-	"github.com/ethereum-optimism/optimism/op-node/client"
-	"github.com/ethereum-optimism/optimism/op-node/sources"
-	"github.com/ethereum-optimism/optimism/op-proposer/drivers/l2output"
-	"github.com/ethereum-optimism/optimism/op-proposer/txmgr"
-	oplog "github.com/ethereum-optimism/optimism/op-service/log"
-	opmetrics "github.com/ethereum-optimism/optimism/op-service/metrics"
-	oppprof "github.com/ethereum-optimism/optimism/op-service/pprof"
-	oprpc "github.com/ethereum-optimism/optimism/op-service/rpc"
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
@@ -28,6 +20,15 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 	hdwallet "github.com/miguelmota/go-ethereum-hdwallet"
 	"github.com/urfave/cli"
+
+	"github.com/ethereum-optimism/optimism/op-node/client"
+	"github.com/ethereum-optimism/optimism/op-node/sources"
+	"github.com/ethereum-optimism/optimism/op-proposer/drivers/l2output"
+	"github.com/ethereum-optimism/optimism/op-proposer/txmgr"
+	oplog "github.com/ethereum-optimism/optimism/op-service/log"
+	opmetrics "github.com/ethereum-optimism/optimism/op-service/metrics"
+	oppprof "github.com/ethereum-optimism/optimism/op-service/pprof"
+	oprpc "github.com/ethereum-optimism/optimism/op-service/rpc"
 )
 
 const (
@@ -172,11 +173,6 @@ func NewL2OutputSubmitter(
 		return nil, err
 	}
 
-	l2Client, err := dialEthClientWithTimeout(ctx, cfg.L2EthRpc)
-	if err != nil {
-		return nil, err
-	}
-
 	rollupClient, err := dialRollupClientWithTimeout(ctx, cfg.RollupRpc)
 	if err != nil {
 		return nil, err
@@ -197,14 +193,14 @@ func NewL2OutputSubmitter(
 	}
 
 	l2OutputDriver, err := l2output.NewDriver(l2output.Config{
-		Log:          l,
-		Name:         "L2Output Submitter",
-		L1Client:     l1Client,
-		L2Client:     l2Client,
-		RollupClient: rollupClient,
-		L2OOAddr:     l2ooAddress,
-		ChainID:      chainID,
-		PrivKey:      l2OutputPrivKey,
+		Log:               l,
+		Name:              "L2Output Submitter",
+		L1Client:          l1Client,
+		RollupClient:      rollupClient,
+		AllowNonFinalized: cfg.AllowNonFinalized,
+		L2OOAddr:          l2ooAddress,
+		ChainID:           chainID,
+		PrivKey:           l2OutputPrivKey,
 	})
 	if err != nil {
 		return nil, err
diff --git a/ops-bedrock/docker-compose.yml b/ops-bedrock/docker-compose.yml
index 80335f9340a46..967bdc5a7f365 100644
--- a/ops-bedrock/docker-compose.yml
+++ b/ops-bedrock/docker-compose.yml
@@ -89,7 +89,6 @@ services:
       - "7302:7300"
     environment:
       OP_PROPOSER_L1_ETH_RPC: http://l1:8545
-      OP_PROPOSER_L2_ETH_RPC: http://l2:8545
       OP_PROPOSER_ROLLUP_RPC: http://op-node:8545
       OP_PROPOSER_POLL_INTERVAL: 1s
       OP_PROPOSER_NUM_CONFIRMATIONS: 1
@@ -101,6 +100,7 @@ services:
       OP_PROPOSER_L2OO_ADDRESS: "${L2OO_ADDRESS}"
       OP_PROPOSER_PPROF_ENABLED: "true"
       OP_PROPOSER_METRICS_ENABLED: "true"
+      OP_PROPOSER_ALLOW_NON_FINALIZED: "true"
 
   op-batcher:
     depends_on: