diff --git a/cairo/adapters/messages.go b/cairo/adapters/messages.go
new file mode 100644
index 0000000..7ee83cb
--- /dev/null
+++ b/cairo/adapters/messages.go
@@ -0,0 +1,128 @@
+package adapters
+
+import (
+	"errors"
+	"fmt"
+	"github.com/NethermindEth/juno/core/felt"
+	"github.com/ethereum/go-ethereum/common"
+
+	"math/big"
+)
+
+type MessageL1ToL2 struct {
+	// The address of the L1 contract sending the message.
+	From common.Address `json:"from_address" validate:"required"`
+	// The address of the L1 contract sending the message.
+	To       felt.Felt `json:"to_address" validate:"required"`
+	Nonce    felt.Felt `json:"nonce" validate:"required"`
+	Selector felt.Felt `json:"entry_point_selector" validate:"required"`
+	// The payload of the message.
+	Payload []felt.Felt `json:"payload" validate:"required"`
+}
+
+func (m *MessageL1ToL2) EncodeTo() ([]*big.Int, error) {
+	var result []*big.Int
+
+	// From
+	result = append(result, new(big.Int).SetBytes(m.From.Bytes()))
+
+	// To
+	if m.To.IsZero() {
+		return nil, errors.New("To field is zero (invalid)")
+	}
+	result = append(result, m.To.BigInt(new(big.Int)))
+
+	// Nonce
+	result = append(result, m.Nonce.BigInt(new(big.Int)))
+
+	// Selector
+	if m.Selector.IsZero() {
+		return nil, errors.New("Selector field is zero (invalid)")
+	}
+	result = append(result, m.Selector.BigInt(new(big.Int)))
+
+	payloadSize := big.NewInt(int64(len(m.Payload)))
+	result = append(result, payloadSize)
+	// Payload
+	for _, p := range m.Payload {
+		if !p.IsZero() {
+			result = append(result, p.BigInt(new(big.Int)))
+		}
+	}
+
+	return result, nil
+}
+
+func (m *MessageL1ToL2) SizeInFelts() int {
+	size := 0
+	size += sizeOfCommonAddress(m.From)
+	size += sizeOfFelt(m.To)
+	size += sizeOfFelt(m.Selector)
+	// for payload length field
+	size += 1
+	for _, p := range m.Payload {
+		size += sizeOfFelt(p)
+	}
+	return size
+}
+
+func sizeOfCommonAddress(addr common.Address) int {
+	return 1
+}
+
+func sizeOfFelt(f felt.Felt) int {
+	return 1
+}
+
+// MessageL2ToL1 L2ToL1Message
+type MessageL2ToL1 struct {
+	From *felt.Felt     `json:"from_address,omitempty"`
+	To   common.Address `json:"to_address"`
+
+	Payload []*felt.Felt `json:"payload"`
+}
+
+func (m *MessageL2ToL1) EncodeTo() ([]*big.Int, error) {
+	var result []*big.Int
+
+	// From
+	if m.From != nil {
+		result = append(result, m.From.BigInt(new(big.Int)))
+	} else {
+		return nil, errors.New("From field is nil")
+	}
+
+	// To
+	result = append(result, new(big.Int).SetBytes(m.To.Bytes()))
+	fmt.Println("To:", new(big.Int).SetBytes(m.To.Bytes()))
+
+	payloadSize := big.NewInt(int64(len(m.Payload)))
+	result = append(result, payloadSize)
+	// Payload
+	for _, p := range m.Payload {
+		if p != nil {
+			result = append(result, p.BigInt(new(big.Int)))
+		}
+	}
+
+	return result, nil
+}
+
+func (m *MessageL2ToL1) SizeInFelts() int {
+	size := 0
+
+	if m.From != nil {
+		size += sizeOfFelt(*m.From)
+	}
+
+	size += sizeOfCommonAddress(m.To)
+
+	// for payload length field
+	size += 1
+
+	for _, p := range m.Payload {
+		size += sizeOfFelt(*p)
+	}
+
+	return size
+}
diff --git a/cairo/cairo.go b/cairo/cairo.go
index 800c8ab..2b939f4 100644
--- a/cairo/cairo.go
+++ b/cairo/cairo.go
@@ -20,6 +20,7 @@ import (
 	"github.com/yu-org/yu/core/types"
 	. "github.com/yu-org/yu/core/types"
 	"github.com/yu-org/yu/utils/log"
+	"itachi/cairo/adapters"
 	"itachi/cairo/config"
 	"itachi/cairo/l1"
 	"itachi/cairo/l1/contract"
@@ -61,7 +62,6 @@ func (c *Cairo) FinalizeBlock(block *Block) {
 	var starkReceipt *rpc.TransactionReceipt
 	txns := block.Txns.ToArray()
 	messagesToL1 := make([]*rpc.MsgToL1, 0)
-	messagesToL2 := make([]*rpc.MsgFromL1, 0)
 	for t := 0; t < len(txns); t++ {
 		txn := txns[t]
 		receipt, _ := c.TxDB.GetReceipt(txn.TxnHash)
@@ -74,6 +74,18 @@ func (c *Cairo) FinalizeBlock(block *Block) {
 			messagesToL1 = append(messagesToL1, starkReceipt.MessagesSent...)
 		}
 	}
+	// Adapt
+	messageL2ToL1 := make([]*adapters.MessageL2ToL1, len(messagesToL1))
+	for idx, msg := range messagesToL1 {
+		messageL2ToL1[idx] = &adapters.MessageL2ToL1{
+			From:    msg.From,
+			To:      msg.To,
+			Payload: msg.Payload,
+		}
+	}
+
+	// todo 	messagesToL2 := make([]*rpc.MsgFromL1, 0)
+	messagesToL2 := make([]*adapters.MessageL1ToL2, 0)
 
 	num := uint64(block.Height)
 	// init StarknetOsOutput by block
@@ -84,7 +96,7 @@ func (c *Cairo) FinalizeBlock(block *Block) {
 		BlockHash:     new(felt.Felt).SetBytes(block.Hash.Bytes()),
 		ConfigHash:    new(felt.Felt).SetUint64(0),
 		KzgDA:         new(felt.Felt).SetUint64(0),
-		MessagesToL1:  messagesToL1,
+		MessagesToL1:  messageL2ToL1,
 		MessagesToL2:  messagesToL2,
 	}
 	// cairoState.UpdateStarknetOsOutput(snOsOutput)
diff --git a/cairo/snos-ouput/codec.go b/cairo/snos-ouput/codec.go
index 6c2e7fc..da7615d 100644
--- a/cairo/snos-ouput/codec.go
+++ b/cairo/snos-ouput/codec.go
@@ -3,7 +3,7 @@ package snos_ouput
 import (
 	"fmt"
 	"github.com/NethermindEth/juno/core/felt"
-	"github.com/NethermindEth/juno/rpc"
+	"itachi/cairo/adapters"
 	"math/big"
 )
 
@@ -23,8 +23,8 @@ type StarknetOsOutput struct {
 	// KZG_DA
 	KzgDA *felt.Felt `json:"kzgDA"`
 
-	MessagesToL1 []*rpc.MsgToL1   `json:"messages_to_l1"`
-	MessagesToL2 []*rpc.MsgFromL1 `json:"messages_to_l2"`
+	MessagesToL1 []*adapters.MessageL2ToL1 `json:"messages_to_l1"`
+	MessagesToL2 []*adapters.MessageL1ToL2 `json:"messages_to_l2"`
 }
 
 type SnosCodec interface {