diff --git a/pkg/node/worker.go b/pkg/node/worker.go
index b371cbe..50ddf0d 100644
--- a/pkg/node/worker.go
+++ b/pkg/node/worker.go
@@ -2,7 +2,6 @@ package node
 
 import (
 	"encoding/base64"
-	"fmt"
 	"path"
 	"time"
 
@@ -127,7 +126,7 @@ func (worker *Worker) HandleMessage(conn *PeerConnection, msg *Message) {
 func (worker *Worker) handlePing(msg *Message) (*Message, error) {
 	var ping PingPayload
 	if err := msg.ParsePayload(&ping); err != nil {
-		return nil, fmt.Errorf("invalid ping payload: %w", err)
+		return nil, &ProtocolError{Code: ErrCodeInvalidMessage, Message: "invalid ping payload: " + err.Error()}
 	}
 
 	pong := PongPayload{
@@ -142,7 +141,7 @@ func (worker *Worker) handlePing(msg *Message) (*Message, error) {
 func (worker *Worker) handleGetStats(msg *Message) (*Message, error) {
 	identity := worker.node.GetIdentity()
 	if identity == nil {
-		return nil, fmt.Errorf("node identity not initialized")
+		return nil, &ProtocolError{Code: ErrCodeUnauthorized, Message: "node identity not initialized"}
 	}
 
 	stats := StatsPayload{
@@ -205,17 +204,17 @@ func convertMinerStats(miner MinerInstance, rawStats interface{}) MinerStatsItem
 // response, err := worker.handleStartMiner(message)
 func (worker *Worker) handleStartMiner(msg *Message) (*Message, error) {
 	if worker.minerManager == nil {
-		return nil, fmt.Errorf("miner manager not configured")
+		return nil, &ProtocolError{Code: ErrCodeOperationFailed, Message: "miner manager not configured"}
 	}
 
 	var payload StartMinerPayload
 	if err := msg.ParsePayload(&payload); err != nil {
-		return nil, fmt.Errorf("invalid start miner payload: %w", err)
+		return nil, &ProtocolError{Code: ErrCodeInvalidMessage, Message: "invalid start miner payload: " + err.Error()}
 	}
 
 	// Validate miner type is provided
 	if payload.MinerType == "" {
-		return nil, fmt.Errorf("miner type is required")
+		return nil, &ProtocolError{Code: ErrCodeInvalidMessage, Message: "miner type is required"}
 	}
 
 	// Get the config from the profile or use the override
@@ -225,11 +224,11 @@ func (worker *Worker) handleStartMiner(msg *Message) (*Message, error) {
 	} else if worker.profileManager != nil {
 		profile, err := worker.profileManager.GetProfile(payload.ProfileID)
 		if err != nil {
-			return nil, fmt.Errorf("profile not found: %s", payload.ProfileID)
+			return nil, &ProtocolError{Code: ErrCodeNotFound, Message: "profile not found: " + payload.ProfileID}
 		}
 		config = profile
 	} else {
-		return nil, fmt.Errorf("no config provided and no profile manager configured")
+		return nil, &ProtocolError{Code: ErrCodeOperationFailed, Message: "no config provided and no profile manager configured"}
 	}
 
 	// Start the miner
@@ -252,12 +251,12 @@ func (worker *Worker) handleStartMiner(msg *Message) (*Message, error) {
 // response, err := worker.handleStopMiner(message)
 func (worker *Worker) handleStopMiner(msg *Message) (*Message, error) {
 	if worker.minerManager == nil {
-		return nil, fmt.Errorf("miner manager not configured")
+		return nil, &ProtocolError{Code: ErrCodeOperationFailed, Message: "miner manager not configured"}
 	}
 
 	var payload StopMinerPayload
 	if err := msg.ParsePayload(&payload); err != nil {
-		return nil, fmt.Errorf("invalid stop miner payload: %w", err)
+		return nil, &ProtocolError{Code: ErrCodeInvalidMessage, Message: "invalid stop miner payload: " + err.Error()}
 	}
 
 	err := worker.minerManager.StopMiner(payload.MinerName)
@@ -275,12 +274,12 @@ func (worker *Worker) handleStopMiner(msg *Message) (*Message, error) {
 // response, err := worker.handleGetLogs(message)
 func (worker *Worker) handleGetLogs(msg *Message) (*Message, error) {
 	if worker.minerManager == nil {
-		return nil, fmt.Errorf("miner manager not configured")
+		return nil, &ProtocolError{Code: ErrCodeOperationFailed, Message: "miner manager not configured"}
 	}
 
 	var payload GetLogsPayload
 	if err := msg.ParsePayload(&payload); err != nil {
-		return nil, fmt.Errorf("invalid get logs payload: %w", err)
+		return nil, &ProtocolError{Code: ErrCodeInvalidMessage, Message: "invalid get logs payload: " + err.Error()}
 	}
 
 	// Validate and limit the Lines parameter to prevent resource exhaustion
@@ -291,7 +290,7 @@ func (worker *Worker) handleGetLogs(msg *Message) (*Message, error) {
 
 	miner, err := worker.minerManager.GetMiner(payload.MinerName)
 	if err != nil {
-		return nil, fmt.Errorf("miner not found: %s", payload.MinerName)
+		return nil, &ProtocolError{Code: ErrCodeNotFound, Message: "miner not found: " + payload.MinerName}
 	}
 
 	lines := miner.GetConsoleHistory(payload.Lines)
@@ -309,7 +308,7 @@ func (worker *Worker) handleGetLogs(msg *Message) (*Message, error) {
 func (worker *Worker) handleDeploy(conn *PeerConnection, msg *Message) (*Message, error) {
 	var payload DeployPayload
 	if err := msg.ParsePayload(&payload); err != nil {
-		return nil, fmt.Errorf("invalid deploy payload: %w", err)
+		return nil, &ProtocolError{Code: ErrCodeInvalidMessage, Message: "invalid deploy payload: " + err.Error()}
 	}
 
 	// Reconstruct Bundle object from payload
@@ -329,19 +328,19 @@ func (worker *Worker) handleDeploy(conn *PeerConnection, msg *Message) (*Message
 	switch bundle.Type {
 	case BundleProfile:
 		if worker.profileManager == nil {
-			return nil, fmt.Errorf("profile manager not configured")
+			return nil, &ProtocolError{Code: ErrCodeOperationFailed, Message: "profile manager not configured"}
 		}
 
 		// Decrypt and extract profile data
 		profileData, err := ExtractProfileBundle(bundle, password)
 		if err != nil {
-			return nil, fmt.Errorf("failed to extract profile bundle: %w", err)
+			return nil, &ProtocolError{Code: ErrCodeOperationFailed, Message: "failed to extract profile bundle: " + err.Error()}
 		}
 
 		// Unmarshal into interface{} to pass to ProfileManager
 		var profile interface{}
 		if err := UnmarshalJSON(profileData, &profile); err != nil {
-			return nil, fmt.Errorf("invalid profile data JSON: %w", err)
+			return nil, &ProtocolError{Code: ErrCodeInvalidMessage, Message: "invalid profile data JSON: " + err.Error()}
 		}
 
 		if err := worker.profileManager.SaveProfile(profile); err != nil {
@@ -374,7 +373,7 @@ func (worker *Worker) handleDeploy(conn *PeerConnection, msg *Message) (*Message
 		// Extract miner bundle
 		minerPath, profileData, err := ExtractMinerBundle(bundle, password, installDir)
 		if err != nil {
-			return nil, fmt.Errorf("failed to extract miner bundle: %w", err)
+			return nil, &ProtocolError{Code: ErrCodeOperationFailed, Message: "failed to extract miner bundle: " + err.Error()}
 		}
 
 		// If the bundle contained a profile config, save it
@@ -404,7 +403,7 @@ func (worker *Worker) handleDeploy(conn *PeerConnection, msg *Message) (*Message
 		return msg.Reply(MsgDeployAck, ack)
 
 	default:
-		return nil, fmt.Errorf("unknown bundle type: %s", payload.BundleType)
+		return nil, &ProtocolError{Code: ErrCodeInvalidMessage, Message: "unknown bundle type: " + payload.BundleType}
 	}
 }