diff --git a/hub/internal/service/connection_manager/agent_test.go b/hub/internal/service/connection_manager/agent_test.go
index dca76c7..5e68497 100644
--- a/hub/internal/service/connection_manager/agent_test.go
+++ b/hub/internal/service/connection_manager/agent_test.go
@@ -2,6 +2,7 @@ package connection_manager
 
 import (
 	"context"
+	"errors"
 	"io"
 	"sync"
 	"testing"
@@ -18,6 +19,10 @@ type streamMock struct {
 	sendCh  chan *pb.ServerCommandRequest
 	closeCh chan struct{}
 	ctx     context.Context
+	mu      sync.Mutex
+	sendErr error
+	recvErr error
+	closeOnce sync.Once
 }
 
 func (f *streamMock) Context() context.Context {
@@ -25,11 +30,23 @@ func (f *streamMock) Context() context.Context {
 }
 
 func (f *streamMock) Send(request *pb.ServerCommandRequest) error {
+	f.mu.Lock()
+	err := f.sendErr
+	f.mu.Unlock()
+	if err != nil {
+		return err
+	}
 	f.sendCh <- request
 	return nil
 }
 
 func (f *streamMock) Recv() (*pb.AgentEvent, error) {
+	f.mu.Lock()
+	recvErr := f.recvErr
+	f.mu.Unlock()
+	if recvErr != nil {
+		return nil, recvErr
+	}
 	select {
 	case msg, ok := <-f.recvCh:
 		if !ok {
@@ -44,101 +61,153 @@ func (f *streamMock) Recv() (*pb.AgentEvent, error) {
 func (f *streamMock) Close() error {
 	select {
 	case f.closeCh <- struct{}{}:
-		close(f.recvCh)
 	default:
 	}
+	f.closeOnce.Do(func() {
+		close(f.recvCh)
+	})
 	return nil
 }
 
 type heartBeatMock struct {
+	mu       sync.Mutex
 	countUse int
 	doneCh   chan struct{}
+	err      error
 }
 
 func (h *heartBeatMock) CreateHeartbeat(ctx context.Context, heartbeat domainHub.CreateHeartbeatModel) error {
+	h.mu.Lock()
 	h.countUse += 1
+	err := h.err
+	h.mu.Unlock()
 	select {
 	case h.doneCh <- struct{}{}:
 	default:
 	}
-	return nil
+	return err
 }
 
 type statusMock struct {
+	mu     sync.Mutex
 	online bool
 	doneCh chan struct{}
 }
 
 func (s *statusMock) Offline() {
+	s.mu.Lock()
 	s.online = false
+	s.mu.Unlock()
 }
 
 func (s *statusMock) Online() {
+	s.mu.Lock()
 	s.online = true
+	s.mu.Unlock()
 	select {
 	case s.doneCh <- struct{}{}:
 	default:
 	}
 }
 
-func TestAgentConnection_Heartbeat(t *testing.T) {
-	// Создаем вся поля для Agent Connection
-	// Нужно как то вынести в отдельную функцию
-	sendStream := make(chan *pb.ServerCommandRequest, 1)
-	recvStream := make(chan *pb.AgentEvent)
+func (s *statusMock) IsOnline() bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.online
+}
+
+type agentTestHarness struct {
+	ctx       context.Context
+	cancel    context.CancelFunc
+	stream    *streamMock
+	heartbeat *heartBeatMock
+	status    *statusMock
+	agent     *AgentConnection
+	recvCh    chan *pb.AgentEvent
+	sendCh    chan *pb.ServerCommandRequest
+}
+
+func newAgentTestHarness(t *testing.T, heartbeatTimeoutMS int) *agentTestHarness {
+	t.Helper()
+	sendStream := make(chan *pb.ServerCommandRequest, 4)
+	recvStream := make(chan *pb.AgentEvent, 4)
 	ctx, cancel := context.WithCancel(context.Background())
 
-	stream := streamMock{recvCh: recvStream, sendCh: sendStream, ctx: ctx, closeCh: make(chan struct{}, 1)}
-	heartbeat := heartBeatMock{doneCh: make(chan struct{}, 1)}
-	status := statusMock{doneCh: make(chan struct{}, 1)}
+	stream := &streamMock{recvCh: recvStream, sendCh: sendStream, ctx: ctx, closeCh: make(chan struct{}, 1)}
+	heartbeat := &heartBeatMock{doneCh: make(chan struct{}, 2)}
+	status := &statusMock{doneCh: make(chan struct{}, 2)}
 
-	agent := newAgentConnection("123", &stream, &heartbeat, &status, 5000, zerolog.New(nil))
-	go agent.Listen()
+	agent := newAgentConnection("123", stream, heartbeat, status, heartbeatTimeoutMS, zerolog.New(nil))
 
-	recvStream <- &pb.AgentEvent{AgentId: "agent-1", Event: &pb.AgentEvent_Heartbeat{
+	t.Cleanup(func() {
+		cancel()
+	})
+
+	return &agentTestHarness{
+		ctx: ctx, cancel: cancel, stream: stream, heartbeat: heartbeat, status: status,
+		agent: agent, recvCh: recvStream, sendCh: sendStream,
+	}
+}
+
+func waitFor(t *testing.T, ch <-chan struct{}, timeout time.Duration, message string) {
+	t.Helper()
+	select {
+	case <-ch:
+	case <-time.After(timeout):
+		t.Fatal(message)
+	}
+}
+
+func waitForClose(t *testing.T, closeCh <-chan struct{}, timeout time.Duration) {
+	t.Helper()
+	select {
+	case <-closeCh:
+	case <-time.After(timeout):
+		t.Fatal("timeout waiting for close")
+	}
+}
+
+func commandResponseEvent(requestID, output string) *pb.AgentEvent {
+	return &pb.AgentEvent{
+		AgentId: "agent-1",
+		Event: &pb.AgentEvent_CommandResponse{
+			CommandResponse: &pb.CommandResponse{
+				RequestId: requestID,
+				Success:   true,
+				Output:    output,
+			},
+		},
+	}
+}
+
+func TestAgentConnection_Heartbeat(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	go h.agent.Listen()
+
+	h.recvCh <- &pb.AgentEvent{AgentId: "agent-1", Event: &pb.AgentEvent_Heartbeat{
 		Heartbeat: &pb.Heartbeat{
 			Timestamp: time.Now().Unix(),
 			Metrics:   &pb.SystemMetrics{CpuUsage: 0.5, MemoryUsage: 0.3, DiskUsage: 0.7},
 		}}}
 
-	select {
-	case <-heartbeat.doneCh:
-	case <-time.After(500 * time.Millisecond):
-		t.Fatal("timeout waiting for heartbeat")
-	}
+	waitFor(t, h.heartbeat.doneCh, 500*time.Millisecond, "timeout waiting for heartbeat")
+	waitFor(t, h.status.doneCh, 500*time.Millisecond, "timeout waiting for status online")
 
-	select {
-	case <-status.doneCh:
-	case <-time.After(500 * time.Millisecond):
-		t.Fatal("timeout waiting for status online")
-	}
+	h.heartbeat.mu.Lock()
+	count := h.heartbeat.countUse
+	h.heartbeat.mu.Unlock()
 
-	assert.Equal(t, heartbeat.countUse, 1)
-	assert.Equal(t, status.online, true)
+	assert.Equal(t, count, 1)
+	assert.Equal(t, h.status.IsOnline(), true)
 
-	cancel()
-
-	select {
-	case <-stream.closeCh:
-	case <-time.After(500 * time.Millisecond):
-		t.Fatal("timeout waiting for close")
-	}
-
-	assert.Equal(t, status.online, false)
+	h.cancel()
+	waitForClose(t, h.stream.closeCh, 500*time.Millisecond)
+	assert.Equal(t, h.status.IsOnline(), false)
 }
 
 func TestAgentConnection_Execute(t *testing.T) {
-	sendStream := make(chan *pb.ServerCommandRequest, 1)
-	recvStream := make(chan *pb.AgentEvent)
-	ctx, cancel := context.WithCancel(context.Background())
-	t.Cleanup(cancel)
-
-	stream := streamMock{recvCh: recvStream, sendCh: sendStream, ctx: ctx}
-	heartbeat := heartBeatMock{doneCh: make(chan struct{}, 1)}
-	status := statusMock{doneCh: make(chan struct{}, 1)}
-
-	agent := newAgentConnection("123", &stream, &heartbeat, &status, 5000, zerolog.New(nil))
-	go agent.Listen()
+	h := newAgentTestHarness(t, 5000)
+	go h.agent.Listen()
 
 	// Данные для проверки
 	requestID := make(chan domainHub.AgentResponse)
@@ -146,7 +215,7 @@ func TestAgentConnection_Execute(t *testing.T) {
 	name := "test name"
 
 	go func() {
-		response, _ := agent.Execute(ctx, domainHub.AgentRequest{
+		response, _ := h.agent.Execute(h.ctx, domainHub.AgentRequest{
 			Name:    name,
 			Args:    nil,
 			TimeOut: 0,
@@ -155,10 +224,10 @@ func TestAgentConnection_Execute(t *testing.T) {
 		requestID <- response
 	}()
 
-	request := <-sendStream
+	request := <-h.sendCh
 	assert.Equal(t, name, request.Name)
 
-	recvStream <- &pb.AgentEvent{AgentId: "agent-1", Event: &pb.AgentEvent_CommandResponse{
+	h.recvCh <- &pb.AgentEvent{AgentId: "agent-1", Event: &pb.AgentEvent_CommandResponse{
 		CommandResponse: &pb.CommandResponse{
 			RequestId: request.RequestId,
 			Success:   true,
@@ -174,29 +243,19 @@ func TestAgentConnection_Execute(t *testing.T) {
 	}
 }
 
-// Написать тест когда heartbeat не приходит и все закрывается
 func TestAgentConnection_HeartbeatTimeout(t *testing.T) {
-	sendStream := make(chan *pb.ServerCommandRequest, 1)
-	recvStream := make(chan *pb.AgentEvent)
-	ctx, cancel := context.WithCancel(context.Background())
-	t.Cleanup(cancel)
-
-	stream := streamMock{recvCh: recvStream, sendCh: sendStream, ctx: ctx, closeCh: make(chan struct{}, 1)}
-	heartbeat := heartBeatMock{doneCh: make(chan struct{}, 1)}
-	status := statusMock{doneCh: make(chan struct{}, 1)}
+	h := newAgentTestHarness(t, 200)
 	var wg sync.WaitGroup
 
-	agent := newAgentConnection("123", &stream, &heartbeat, &status, 200, zerolog.New(nil))
-
 	wg.Add(2)
 	go func() {
-		err := agent.Listen()
+		err := h.agent.Listen()
 		assert.NilError(t, err)
 		wg.Done()
 	}()
 
 	go func() {
-		_, err := agent.Execute(ctx, domainHub.AgentRequest{
+		_, err := h.agent.Execute(h.ctx, domainHub.AgentRequest{
 			Name:    "test",
 			Args:    nil,
 			TimeOut: 0,
@@ -207,11 +266,168 @@ func TestAgentConnection_HeartbeatTimeout(t *testing.T) {
 
 	wg.Wait()
 
-	select {
-	case <-stream.closeCh:
-	case <-time.After(500 * time.Millisecond):
-		t.Fatal("timeout waiting for close")
-	}
+	waitForClose(t, h.stream.closeCh, 500*time.Millisecond)
 }
 
-//Написать тест при закрытии соединения Execute завершается
+func TestAgentConnection_ConnectionClose(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	var wg sync.WaitGroup
+
+	wg.Add(2)
+	go func() {
+		err := h.agent.Listen()
+		assert.ErrorIs(t, err, context.Canceled)
+		wg.Done()
+	}()
+
+	go func() {
+		_, err := h.agent.Execute(context.Background(), domainHub.AgentRequest{
+			Name:    "test",
+			Args:    nil,
+			TimeOut: 0,
+		})
+		assert.ErrorIs(t, err, ConnectionCloseErr)
+		wg.Done()
+	}()
+
+	h.cancel()
+
+	wg.Wait()
+
+	waitForClose(t, h.stream.closeCh, 500*time.Millisecond)
+}
+
+func TestAgentConnection_ExecuteClose(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	ctxExecute, cancelExecute := context.WithCancel(context.Background())
+	t.Cleanup(cancelExecute)
+
+	executeCh := make(chan struct{})
+	go h.agent.Listen()
+
+	go func() {
+		_, err := h.agent.Execute(ctxExecute, domainHub.AgentRequest{
+			Name:    "test",
+			Args:    nil,
+			TimeOut: 0,
+		})
+
+		assert.ErrorIs(t, err, context.Canceled)
+		executeCh <- struct{}{}
+	}()
+
+	cancelExecute()
+	waitFor(t, executeCh, 500*time.Millisecond, "timeout waiting for execute close")
+}
+
+func TestAgentConnection_ListenEOF(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	h.stream.Close()
+
+	err := h.agent.Listen()
+	assert.NilError(t, err)
+	waitForClose(t, h.stream.closeCh, 500*time.Millisecond)
+}
+
+func TestAgentConnection_ListenRecvError(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+
+	recvErr := errors.New("recv failure")
+	h.stream.mu.Lock()
+	h.stream.recvErr = recvErr
+	h.stream.mu.Unlock()
+
+	err := h.agent.Listen()
+	assert.ErrorIs(t, err, recvErr)
+}
+
+func TestAgentConnection_ExecuteSendError(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	h.stream.mu.Lock()
+	h.stream.sendErr = errors.New("send failure")
+	h.stream.mu.Unlock()
+
+	_, err := h.agent.Execute(h.ctx, domainHub.AgentRequest{Name: "test"})
+	assert.ErrorContains(t, err, "execute command")
+}
+
+func TestAgentConnection_ExecuteContextCanceled(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	_, err := h.agent.Execute(ctx, domainHub.AgentRequest{Name: "test"})
+	assert.ErrorIs(t, err, context.Canceled)
+}
+
+func TestAgentConnection_ExecuteConnectionCanceled(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	h.cancel()
+
+	_, err := h.agent.Execute(context.Background(), domainHub.AgentRequest{Name: "test"})
+	assert.ErrorIs(t, err, ConnectionCloseErr)
+}
+
+func TestAgentConnection_UnknownResponseID(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	go h.agent.Listen()
+
+	h.recvCh <- &pb.AgentEvent{AgentId: "agent-1", Event: &pb.AgentEvent_CommandResponse{
+		CommandResponse: &pb.CommandResponse{
+			RequestId: "unknown",
+			Success:   true,
+			Output:    "ok",
+		}}}
+
+	h.cancel()
+	waitForClose(t, h.stream.closeCh, 500*time.Millisecond)
+}
+
+func TestAgentConnection_HeartbeatErrorDoesNotStop(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	h.heartbeat.mu.Lock()
+	h.heartbeat.err = errors.New("db error")
+	h.heartbeat.mu.Unlock()
+
+	go h.agent.Listen()
+	h.recvCh <- &pb.AgentEvent{AgentId: "agent-1", Event: &pb.AgentEvent_Heartbeat{
+		Heartbeat: &pb.Heartbeat{
+			Timestamp: time.Now().Unix(),
+			Metrics:   &pb.SystemMetrics{CpuUsage: 0.2, MemoryUsage: 0.1, DiskUsage: 0.3},
+		}}}
+
+	waitFor(t, h.heartbeat.doneCh, 500*time.Millisecond, "timeout waiting for heartbeat")
+	h.cancel()
+}
+
+func TestAgentConnection_ConcurrentExecute(t *testing.T) {
+	h := newAgentTestHarness(t, 5000)
+	go h.agent.Listen()
+
+	responses := make(chan domainHub.AgentResponse, 2)
+
+	go func() {
+		resp, _ := h.agent.Execute(h.ctx, domainHub.AgentRequest{Name: "cmd-1"})
+		responses <- resp
+	}()
+	go func() {
+		resp, _ := h.agent.Execute(h.ctx, domainHub.AgentRequest{Name: "cmd-2"})
+		responses <- resp
+	}()
+
+	first := <-h.sendCh
+	second := <-h.sendCh
+
+	// ответы приходят в обратном порядке
+	h.recvCh <- commandResponseEvent(second.RequestId, "second")
+	h.recvCh <- commandResponseEvent(first.RequestId, "first")
+
+	resp1 := <-responses
+	resp2 := <-responses
+
+	assert.Assert(t, resp1.Output == "first" || resp1.Output == "second")
+	assert.Assert(t, resp2.Output == "first" || resp2.Output == "second")
+	assert.Assert(t, resp1.Output != resp2.Output)
+
+	h.cancel()
+}