diff --git a/pkg/commands/cmd_acp.go b/pkg/commands/cmd_acp.go
index 9e9260ff9..22657dd39 100644
--- a/pkg/commands/cmd_acp.go
+++ b/pkg/commands/cmd_acp.go
@@ -10,57 +10,54 @@ import (
 
 func acpCommand() Definition {
 	return Definition{
-		Prefix:      "acp",
+		Name:        "acp",
 		Description: "Agent Client Protocol capabilities (e.g. acp spawn, status, close)",
-		Category:    "System",
 		Usage:       "/acp <action> [args...]",
-		Handler: func(ctx context.Context, args string, rt Runtime) error {
-			parts := strings.Fields(args)
-			if len(parts) == 0 {
-				return fmt.Errorf("missing acp action (spawn, status, close)")
+		Handler: func(ctx context.Context, req Request, rt *Runtime) error {
+			parts := strings.Fields(req.Text)
+			if len(parts) < 2 {
+				return req.Reply("Usage: /acp <action> [args...]")
 			}
 
-			action := parts[0]
+			action := parts[1]
 			switch action {
 			case "spawn":
-				if len(parts) < 2 {
-					return fmt.Errorf("usage: /acp spawn <harness_id>")
+				if len(parts) < 3 {
+					return req.Reply("usage: /acp spawn <harness_id>")
 				}
-				harness := parts[1]
+				harness := parts[2]
 				session, err := acp.GetManager().Spawn(harness, "session", harness, "", "cli-spawned", []string{})
 				if err != nil {
-					return fmt.Errorf("failed to spawn ACP session: %v", err)
+					return req.Reply(fmt.Sprintf("failed to spawn ACP session: %v", err))
 				}
-				rt.PrintSysMessage(fmt.Sprintf("✓ Spawned ACP harness '%s'. Session Key: %s", harness, session.Key))
+				return req.Reply(fmt.Sprintf("✓ Spawned ACP harness '%s'. Session Key: %s", harness, session.Key))
 
 			case "status":
 				sessions := acp.GetManager().ListSessions()
 				if len(sessions) == 0 {
-					rt.PrintSysMessage("No active ACP sessions.")
-					return nil
+					return req.Reply("No active ACP sessions.")
 				}
 				var b strings.Builder
 				b.WriteString("Active ACP Sessions:\n")
 				for _, s := range sessions {
 					b.WriteString(fmt.Sprintf("- Key: %s | Harness: %s | Status: %s\n", s.Key, s.AgentID, s.Status()))
 				}
-				rt.PrintSysMessage(b.String())
+				return req.Reply(b.String())
 
 			case "close":
-				if len(parts) < 2 {
-					return fmt.Errorf("usage: /acp close <session_key>")
+				if len(parts) < 3 {
+					return req.Reply("usage: /acp close <session_key>")
 				}
-				key := parts[1]
+				key := parts[2]
 				err := acp.GetManager().CloseSession(key)
 				if err != nil {
-					return fmt.Errorf("failed to close session: %v", err)
+					return req.Reply(fmt.Sprintf("failed to close session: %v", err))
 				}
-				rt.PrintSysMessage(fmt.Sprintf("✓ Closed ACP session %s", key))
+				return req.Reply(fmt.Sprintf("✓ Closed ACP session %s", key))
 
 			default:
-				return fmt.Errorf("unknown acp action: %s", action)
+				return req.Reply(fmt.Sprintf("unknown acp action: %s", action))
 			}
-			return nil
 		},
 	}
 }
diff --git a/pkg/commands/cmd_system.go b/pkg/commands/cmd_system.go
index dce896a9e..d92806921 100644
--- a/pkg/commands/cmd_system.go
+++ b/pkg/commands/cmd_system.go
@@ -4,6 +4,8 @@ import (
 	"context"
 	"fmt"
 	"strings"
+
+	"github.com/sipeed/picoclaw/pkg/auth"
 )
 
 func versionCommand() Definition {
diff --git a/pkg/commands/cmd_whatsapp.go b/pkg/commands/cmd_whatsapp.go
index 72096d1f1..7b9b4b51d 100644
--- a/pkg/commands/cmd_whatsapp.go
+++ b/pkg/commands/cmd_whatsapp.go
@@ -13,40 +13,27 @@ func whatsappCommand() Definition {
 	return Definition{
 		Name:        "whatsapp",
 		Description: "WhatsApp management commands",
-		Subcommands: []Definition{
+		SubCommands: []SubCommand{
 			{
 				Name:        "qr",
 				Description: "Get the latest WhatsApp pairing QR code",
-				Handler: func(ctx context.Context, req Request, rt Runtime) ExecuteResult {
+				Handler: func(ctx context.Context, req Request, rt *Runtime) error {
 					ch, ok := rt.GetChannel("whatsapp_native")
 					if !ok {
-						return ExecuteResult{
-							Outcome: OutcomeHandled,
-							Err:     fmt.Errorf("whatsapp_native channel is not enabled"),
-						}
+						return req.Reply("whatsapp_native channel is not enabled")
 					}
 
 					qp, ok := ch.(qrProvider)
 					if !ok {
-						return ExecuteResult{
-							Outcome: OutcomeHandled,
-							Err:     fmt.Errorf("whatsapp_native channel does not support QR retrieval"),
-						}
+						return req.Reply("whatsapp_native channel does not support QR retrieval")
 					}
 
 					qr := qp.GetLastQR()
 					if qr == "" {
-						return ExecuteResult{
-							Outcome: OutcomeHandled,
-							Err:     fmt.Errorf("no QR code available yet. please wait for the channel to initialize"),
-						}
+						return req.Reply("no QR code available yet. please wait for the channel to initialize")
 					}
 
-					// For now, return the QR code string.
-					// Optimization: In the future, we can return an image reference.
-					_ = req.Reply(fmt.Sprintf("Scan this QR code string (or wait for image support): %s", qr))
-
-					return ExecuteResult{Outcome: OutcomeHandled}
+					return req.Reply(fmt.Sprintf("Scan this QR code string (or wait for image support): %s", qr))
 				},
 			},
 		},
diff --git a/pkg/providers/builtin_resolvers.go b/pkg/providers/builtin_resolvers.go
index 7386af7da..cf440069c 100644
--- a/pkg/providers/builtin_resolvers.go
+++ b/pkg/providers/builtin_resolvers.go
@@ -1,7 +1,6 @@
 package providers
 
 import (
-	"strings"
 	"github.com/sipeed/picoclaw/pkg/config"
 )