diff --git a/alerts/alerts.go b/alerts/alerts.go
index f11004dbe..6b009360d 100644
--- a/alerts/alerts.go
+++ b/alerts/alerts.go
@@ -66,17 +66,27 @@ type (
 	}
 
 	AlertsOpts struct {
-		Offset int
-		Limit  int
+		Offset   int
+		Limit    int
+		Severity Severity
 	}
 
 	AlertsResponse struct {
 		Alerts  []Alert `json:"alerts"`
 		HasMore bool    `json:"hasMore"`
-		Total   int     `json:"total"`
+		Totals  struct {
+			Info     int `json:"info"`
+			Warning  int `json:"warning"`
+			Error    int `json:"error"`
+			Critical int `json:"critical"`
+		} `json:"totals"`
 	}
 )
 
+func (ar AlertsResponse) Total() int {
+	return ar.Totals.Info + ar.Totals.Warning + ar.Totals.Error + ar.Totals.Critical
+}
+
 // String implements the fmt.Stringer interface.
 func (s Severity) String() string {
 	switch s {
@@ -93,15 +103,8 @@ func (s Severity) String() string {
 	}
 }
 
-// MarshalJSON implements the json.Marshaler interface.
-func (s Severity) MarshalJSON() ([]byte, error) {
-	return []byte(fmt.Sprintf(`%q`, s.String())), nil
-}
-
-// UnmarshalJSON implements the json.Unmarshaler interface.
-func (s *Severity) UnmarshalJSON(b []byte) error {
-	status := strings.Trim(string(b), `"`)
-	switch status {
+func (s *Severity) LoadString(str string) error {
+	switch str {
 	case severityInfoStr:
 		*s = SeverityInfo
 	case severityWarningStr:
@@ -111,11 +114,21 @@ func (s *Severity) UnmarshalJSON(b []byte) error {
 	case severityCriticalStr:
 		*s = SeverityCritical
 	default:
-		return fmt.Errorf("unrecognized severity: %v", status)
+		return fmt.Errorf("unrecognized severity: %v", str)
 	}
 	return nil
 }
 
+// MarshalJSON implements the json.Marshaler interface.
+func (s Severity) MarshalJSON() ([]byte, error) {
+	return []byte(fmt.Sprintf(`%q`, s.String())), nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (s *Severity) UnmarshalJSON(b []byte) error {
+	return s.LoadString(strings.Trim(string(b), `"`))
+}
+
 // RegisterAlert implements the Alerter interface.
 func (m *Manager) RegisterAlert(ctx context.Context, alert Alert) error {
 	if alert.ID == (types.Hash256{}) {
@@ -176,9 +189,7 @@ func (m *Manager) Alerts(_ context.Context, opts AlertsOpts) (AlertsResponse, er
 	defer m.mu.Unlock()
 
 	offset, limit := opts.Offset, opts.Limit
-	resp := AlertsResponse{
-		Total: len(m.alerts),
-	}
+	resp := AlertsResponse{}
 
 	if offset >= len(m.alerts) {
 		return resp, nil
@@ -188,6 +199,18 @@ func (m *Manager) Alerts(_ context.Context, opts AlertsOpts) (AlertsResponse, er
 
 	alerts := make([]Alert, 0, len(m.alerts))
 	for _, a := range m.alerts {
+		if a.Severity == SeverityInfo {
+			resp.Totals.Info++
+		} else if a.Severity == SeverityWarning {
+			resp.Totals.Warning++
+		} else if a.Severity == SeverityError {
+			resp.Totals.Error++
+		} else if a.Severity == SeverityCritical {
+			resp.Totals.Critical++
+		}
+		if opts.Severity != 0 && a.Severity != opts.Severity {
+			continue // filter by severity
+		}
 		alerts = append(alerts, a)
 	}
 	sort.Slice(alerts, func(i, j int) bool {
diff --git a/api/object.go b/api/object.go
index 35df9b636..cef672a97 100644
--- a/api/object.go
+++ b/api/object.go
@@ -54,7 +54,7 @@ type (
 	Object struct {
 		Metadata ObjectUserMetadata `json:"metadata,omitempty"`
 		ObjectMetadata
-		*object.Object `json:"omitempty"`
+		*object.Object
 	}
 
 	// ObjectMetadata contains various metadata about an object.
diff --git a/bus/bus.go b/bus/bus.go
index 402694062..fbda894d7 100644
--- a/bus/bus.go
+++ b/bus/bus.go
@@ -1741,6 +1741,7 @@ func (b *bus) handleGETAlerts(jc jape.Context) {
 		return
 	}
 	offset, limit := 0, -1
+	var severity alerts.Severity
 	if jc.DecodeForm("offset", &offset) != nil {
 		return
 	} else if jc.DecodeForm("limit", &limit) != nil {
@@ -1748,8 +1749,14 @@ func (b *bus) handleGETAlerts(jc jape.Context) {
 	} else if offset < 0 {
 		jc.Error(errors.New("offset must be non-negative"), http.StatusBadRequest)
 		return
+	} else if jc.DecodeForm("severity", &severity) != nil {
+		return
 	}
-	ar, err := b.alertMgr.Alerts(jc.Request.Context(), alerts.AlertsOpts{Offset: offset, Limit: limit})
+	ar, err := b.alertMgr.Alerts(jc.Request.Context(), alerts.AlertsOpts{
+		Offset:   offset,
+		Limit:    limit,
+		Severity: severity,
+	})
 	if jc.Check("failed to fetch alerts", err) != nil {
 		return
 	}
diff --git a/bus/client/alerts.go b/bus/client/alerts.go
index 7eceaeaed..28c3b9a84 100644
--- a/bus/client/alerts.go
+++ b/bus/client/alerts.go
@@ -16,6 +16,9 @@ func (c *Client) Alerts(ctx context.Context, opts alerts.AlertsOpts) (resp alert
 	if opts.Limit != 0 {
 		values.Set("limit", fmt.Sprint(opts.Limit))
 	}
+	if opts.Severity != 0 {
+		values.Set("severity", opts.Severity.String())
+	}
 	err = c.c.WithContext(ctx).GET("/alerts?"+values.Encode(), &resp)
 	return
 }
diff --git a/internal/test/e2e/cluster_test.go b/internal/test/e2e/cluster_test.go
index 18d12fa48..5e9f440db 100644
--- a/internal/test/e2e/cluster_test.go
+++ b/internal/test/e2e/cluster_test.go
@@ -1974,6 +1974,44 @@ func TestAlerts(t *testing.T) {
 	if len(foundAlerts) != 1 || foundAlerts[0].ID != alert2.ID {
 		t.Fatal("wrong alert")
 	}
+
+	// register more alerts
+	for severity := alerts.SeverityInfo; severity <= alerts.SeverityCritical; severity++ {
+		for j := 0; j < 3*int(severity); j++ {
+			tt.OK(b.RegisterAlert(context.Background(), alerts.Alert{
+				ID:       frand.Entropy256(),
+				Severity: severity,
+				Message:  "test",
+				Data: map[string]interface{}{
+					"origin": "test",
+				},
+				Timestamp: time.Now(),
+			}))
+		}
+	}
+	for severity := alerts.SeverityInfo; severity <= alerts.SeverityCritical; severity++ {
+		ar, err = b.Alerts(context.Background(), alerts.AlertsOpts{Severity: severity})
+		tt.OK(err)
+		if ar.Total() != 32 {
+			t.Fatal("expected 32 alerts", ar.Total())
+		} else if ar.Totals.Info != 3 {
+			t.Fatal("expected 3 info alerts", ar.Totals.Info)
+		} else if ar.Totals.Warning != 6 {
+			t.Fatal("expected 6 warning alerts", ar.Totals.Warning)
+		} else if ar.Totals.Error != 9 {
+			t.Fatal("expected 9 error alerts", ar.Totals.Error)
+		} else if ar.Totals.Critical != 14 {
+			t.Fatal("expected 14 critical alerts", ar.Totals.Critical)
+		} else if severity == alerts.SeverityInfo && len(ar.Alerts) != ar.Totals.Info {
+			t.Fatalf("expected %v info alerts, got %v", ar.Totals.Info, len(ar.Alerts))
+		} else if severity == alerts.SeverityWarning && len(ar.Alerts) != ar.Totals.Warning {
+			t.Fatalf("expected %v warning alerts, got %v", ar.Totals.Warning, len(ar.Alerts))
+		} else if severity == alerts.SeverityError && len(ar.Alerts) != ar.Totals.Error {
+			t.Fatalf("expected %v error alerts, got %v", ar.Totals.Error, len(ar.Alerts))
+		} else if severity == alerts.SeverityCritical && len(ar.Alerts) != ar.Totals.Critical {
+			t.Fatalf("expected %v critical alerts, got %v", ar.Totals.Critical, len(ar.Alerts))
+		}
+	}
 }
 
 func TestMultipartUploads(t *testing.T) {
diff --git a/object/object.go b/object/object.go
index 2331f6251..965ebce2a 100644
--- a/object/object.go
+++ b/object/object.go
@@ -114,9 +114,12 @@ func GenerateEncryptionKey() EncryptionKey {
 }
 
 // An Object is a unit of data that has been stored on a host.
+// NOTE: Object is embedded in the API's Object type, so all fields should be
+// tagged omitempty to make sure responses where no object is returned remain
+// clean.
 type Object struct {
-	Key   EncryptionKey `json:"key"`
-	Slabs []SlabSlice   `json:"slabs"`
+	Key   EncryptionKey `json:"key,omitempty"`
+	Slabs []SlabSlice   `json:"slabs,omitempty"`
 }
 
 // NewObject returns a new Object with a random key.