feat(eventrecorder): replace event output schema

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## main / (unreleased)
 
+* [CHANGE] eventrecorder: The output data format now uses the new `events/v2` schema. This is a breaking change: alert labels, alert annotations, group labels, silence annotations, and muted-alert labels are JSON maps, and protobuf consumers must use the new schema.
+
 ## 0.34.0 / 2026-08-16
 
 * [CHANGE] notify: The `reason` label on `alertmanager_notifications_failed_total` now distinguishes `authError` (HTTP 401/403) and `rateLimited` (HTTP 429) from the generic `clientError`. Dashboards/alerts matching `reason="clientError"` for these codes must be updated. #5332

app/app.go

@@ -39,7 +39,6 @@ import (
 	"github.com/prometheus/alertmanager/config"
 	"github.com/prometheus/alertmanager/dispatch"
 	"github.com/prometheus/alertmanager/eventrecorder"
-	"github.com/prometheus/alertmanager/eventrecorder/eventrecorderpb"
 	"github.com/prometheus/alertmanager/httpserver"
 	"github.com/prometheus/alertmanager/marker"
 	"github.com/prometheus/alertmanager/nflog"
@@ -265,23 +264,12 @@ func (a *App) setup() error {
 	a.onStop("event recorder", eventRec.Close)
 
 	recordCtx := eventrecorder.WithEventRecording(context.Background())
-	eventRec.RecordEvent(recordCtx, func() *eventrecorderpb.EventData {
-		return &eventrecorderpb.EventData{
-			EventType: &eventrecorderpb.EventData_AlertmanagerStartupEvent{
-				AlertmanagerStartupEvent: &eventrecorderpb.AlertmanagerStartupEvent{
-					Version:      version.Version,
-					BuildContext: version.BuildContext(),
-				},
-			},
-		}
+	eventRec.RecordEvent(recordCtx, func() eventrecorder.EventData {
+		return eventrecorder.NewAlertmanagerStartupEvent(version.Version, version.BuildContext())
 	})
 	a.onStop("shutdown event", func() error {
-		eventRec.RecordEvent(recordCtx, func() *eventrecorderpb.EventData {
-			return &eventrecorderpb.EventData{
-				EventType: &eventrecorderpb.EventData_AlertmanagerShutdownEvent{
-					AlertmanagerShutdownEvent: &eventrecorderpb.AlertmanagerShutdownEvent{},
-				},
-			}
+		eventRec.RecordEvent(recordCtx, func() eventrecorder.EventData {
+			return eventrecorder.NewAlertmanagerShutdownEvent()
 		})
 		return nil
 	})

buf.yaml

@@ -3,11 +3,11 @@ version: v2
 modules:
   - path: cluster/clusterpb
     name: prometheus/alertmanager/cluster
-  - path: eventrecorder/eventrecorderpb
-    name: prometheus/alertmanager/eventrecorder
   - path: nflog/nflogpb
     name: prometheus/alertmanager/nflog
   - path: proto/api
     name: prometheus/alertmanager/api
+  - path: proto/eventrecorder
+    name: prometheus/alertmanager/eventrecorder
   - path: silence/silencepb
     name: prometheus/alertmanager/silence

dispatch/dispatch.go

@@ -34,7 +34,6 @@ import (
 
 	"github.com/prometheus/alertmanager/alert"
 	"github.com/prometheus/alertmanager/eventrecorder"
-	"github.com/prometheus/alertmanager/eventrecorder/eventrecorderpb"
 	"github.com/prometheus/alertmanager/marker"
 	"github.com/prometheus/alertmanager/notify"
 	"github.com/prometheus/alertmanager/pkg/labels"
@@ -890,7 +889,7 @@ func (ag *aggrGroup) insert(ctx context.Context, alert *alert.Alert) bool {
 		span.RecordError(err)
 		ag.logger.Error(message, "err", err)
 	} else {
-		ag.recorder.RecordEvent(ctx, func() *eventrecorderpb.EventData {
+		ag.recorder.RecordEvent(ctx, func() eventrecorder.EventData {
 			return notify.NewAlertGroupedEvent(ag.alertGroupInfo(), alert)
 		})
 		// The alert set changed; the alert is already visible via ag.alerts.
@@ -965,21 +964,17 @@ func (ag *aggrGroup) recordResolvedEvents(resolved types.AlertSlice) {
 	if len(resolved) == 0 {
 		return
 	}
-	groupInfo := ag.alertGroupInfo()
 	for _, a := range resolved {
-		ag.recorder.RecordEvent(ag.ctx, func() *eventrecorderpb.EventData {
-			return notify.NewAlertResolvedEvent(groupInfo, a)
+		ag.recorder.RecordEvent(ag.ctx, func() eventrecorder.EventData {
+			return notify.NewAlertResolvedEvent(ag.alertGroupInfo(), a)
 		})
 	}
 }
 
-func (ag *aggrGroup) alertGroupInfo() *eventrecorderpb.AlertGroupInfo {
-	return &eventrecorderpb.AlertGroupInfo{
-		GroupKey:     ag.GroupKey(),
-		GroupLabels:  eventrecorder.LabelSetAsProto(ag.labels),
-		GroupId:      notify.Key(ag.GroupKey()).Hash(),
-		ReceiverName: ag.opts.Receiver,
-	}
+func (ag *aggrGroup) alertGroupInfo() eventrecorder.AlertGroup {
+	return eventrecorder.NewAlertGroup(
+		ag.GroupKey(), ag.labels, notify.Key(ag.GroupKey()).Hash(), ag.opts.Receiver, nil, "",
+	)
 }
 
 type nilLimits struct{}

docs/configuration.md

@@ -2175,6 +2175,12 @@ stdout_outputs:
   [ - <stdout_output> ... ]
 ```
 
+Every output uses the schema in `proto/eventrecorder/events/v2/events.proto`.
+Alert labels, alert annotations, group labels, silence annotations, and
+muted-alert labels are encoded as maps. Protobuf consumers must use the Go
+package `github.com/prometheus/alertmanager/eventrecorder/events/v2` or bindings
+generated from that schema.
+
 #### `<file_output>`
 
 Writes each event as a single JSON line to a file.  The file is reopened
@@ -2234,7 +2240,10 @@ url: <secret>
 
 For example, [Cloudflare Pipelines streams](https://developers.cloudflare.com/pipelines/streams/writing-to-streams/)
 accept JSON arrays through their HTTP ingestion endpoints and can be configured
-as a batched webhook output:
+as a batched webhook output. Because the event timestamp field is named
+`@timestamp`, quote it when referencing it from the pipeline SQL. A complete
+fan-out example is available under
+[`doc/examples/cloudflare-pipelines`](https://github.com/prometheus/alertmanager/blob/main/doc/examples/cloudflare-pipelines/README.md).
 
 ```yaml
 event_recorder:
@@ -2277,7 +2286,7 @@ topic: <string>
 # On-the-wire encoding for each record value: "json" (protojson) or
 # "protobuf" (binary proto).  JSON is the default for symmetry with the
 # file and webhook outputs; consumers that already use the
-# eventrecorder.proto schema may prefer protobuf for compactness.
+# selected event recorder protobuf schema may prefer protobuf for compactness.
 [ format: <"json" | "protobuf"> | default = "json" ]
 
 # Producer acknowledgement level.  "leader" matches the franz-go default