diff --git a/cmd/telemetry-gateway/internal/events/BUILD.bazel b/cmd/telemetry-gateway/internal/events/BUILD.bazel
index b9da5e6ada4..df0af3981ba 100644
--- a/cmd/telemetry-gateway/internal/events/BUILD.bazel
+++ b/cmd/telemetry-gateway/internal/events/BUILD.bazel
@@ -38,5 +38,6 @@ go_test(
         "@com_github_stretchr_testify//assert",
         "@com_github_stretchr_testify//require",
         "@org_golang_google_protobuf//types/known/structpb",
+        "@org_golang_google_protobuf//types/known/timestamppb",
     ],
 )
diff --git a/cmd/telemetry-gateway/internal/events/attributes.go b/cmd/telemetry-gateway/internal/events/attributes.go
index 04498293386..2a1233f8eca 100644
--- a/cmd/telemetry-gateway/internal/events/attributes.go
+++ b/cmd/telemetry-gateway/internal/events/attributes.go
@@ -10,10 +10,11 @@ import (
 // extractPubSubAttributes extracts attributes from the event for use in the
 // published pub/sub message as attributes. This makes it easiser to build
 // routing of events in our data pipelines.
-func extractPubSubAttributes(event *telemetrygatewayv1.Event) map[string]string {
+func extractPubSubAttributes(publisherSource string, event *telemetrygatewayv1.Event) map[string]string {
 	attributes := map[string]string{
-		"event.feature": event.Feature,
-		"event.action":  event.Action,
+		"publisher.source": publisherSource,
+		"event.feature":    event.Feature,
+		"event.action":     event.Action,
 		"event.hasPrivateMetadata": strconv.FormatBool(
 			event.GetParameters().GetPrivateMetadata() != nil),
 	}
diff --git a/cmd/telemetry-gateway/internal/events/attributes_test.go b/cmd/telemetry-gateway/internal/events/attributes_test.go
index 42df8c4e029..d4ca1e3b285 100644
--- a/cmd/telemetry-gateway/internal/events/attributes_test.go
+++ b/cmd/telemetry-gateway/internal/events/attributes_test.go
@@ -25,6 +25,7 @@ func TestExtractPubSubAttributes(t *testing.T) {
 			expect: autogold.Expect(map[string]string{
 				"event.action": "chat", "event.feature": "cody.feature",
 				"event.hasPrivateMetadata": "false",
+				"publisher.source":         "licensed_instance",
 			}),
 		},
 		{
@@ -41,6 +42,7 @@ func TestExtractPubSubAttributes(t *testing.T) {
 			expect: autogold.Expect(map[string]string{
 				"event.action": "chat", "event.feature": "cody.feature",
 				"event.hasPrivateMetadata": "true",
+				"publisher.source":         "licensed_instance",
 			}),
 		},
 		{
@@ -63,6 +65,7 @@ func TestExtractPubSubAttributes(t *testing.T) {
 				"event.action": "chat", "event.feature": "cody.feature",
 				"event.hasPrivateMetadata":               "true",
 				"event.recordsPrivateMetadataTranscript": "true",
+				"publisher.source":                       "licensed_instance",
 			}),
 		},
 		{
@@ -80,11 +83,12 @@ func TestExtractPubSubAttributes(t *testing.T) {
 			expect: autogold.Expect(map[string]string{
 				"event.action": "chat", "event.feature": "cody.feature",
 				"event.hasPrivateMetadata": "false",
+				"publisher.source":         "licensed_instance",
 			}),
 		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
-			tc.expect.Equal(t, extractPubSubAttributes(tc.event))
+			tc.expect.Equal(t, extractPubSubAttributes("licensed_instance", tc.event))
 		})
 	}
 }
diff --git a/cmd/telemetry-gateway/internal/events/events.go b/cmd/telemetry-gateway/internal/events/events.go
index 0fe3d601220..37d681d6276 100644
--- a/cmd/telemetry-gateway/internal/events/events.go
+++ b/cmd/telemetry-gateway/internal/events/events.go
@@ -21,6 +21,7 @@ import (
 
 type Publisher struct {
 	logger log.Logger
+	source string
 
 	topic pubsub.TopicPublisher
 	opts  PublishStreamOptions
@@ -50,14 +51,39 @@ func NewPublisherForStream(
 	if opts.ConcurrencyLimit <= 0 {
 		opts.ConcurrencyLimit = 250
 	}
+
+	var source string
+	switch identifier := metadata.GetIdentifier(); identifier.GetIdentifier().(type) {
+	case *telemetrygatewayv1.Identifier_LicensedInstance:
+		source = "licensed_instance"
+	case *telemetrygatewayv1.Identifier_UnlicensedInstance:
+		source = "unlicensed_instance"
+	case *telemetrygatewayv1.Identifier_ManagedService:
+		// Is a trusted client, so use the service ID directly as the source
+		source = identifier.GetManagedService().ServiceId
+	default:
+		source = "unknown"
+	}
+
 	return &Publisher{
-		logger:       logger,
+		logger:       logger.With(log.String("source", source)),
+		source:       source,
 		topic:        eventsTopic,
 		opts:         opts,
 		metadataJSON: metadataJSON,
 	}, nil
 }
 
+// GetSourceName returns a name inferred from metadata provided to
+// NewPublisherForStream, for use as a metric label. It is safe to call on a nil
+// publisher.
+func (p *Publisher) GetSourceName() string {
+	if p == nil {
+		return "invalid"
+	}
+	return p.source
+}
+
 type PublishEventResult struct {
 	// EventID is the ID of the event that was published.
 	EventID string
@@ -74,6 +100,21 @@ func (p *Publisher) Publish(ctx context.Context, events []*telemetrygatewayv1.Ev
 		event := event // capture range variable :(
 
 		doPublish := func(event *telemetrygatewayv1.Event) error {
+			// Ensure the most important fields are in place
+			if event.Id == "" {
+				return errors.New("event ID is required")
+			}
+			if event.Feature == "" {
+				return errors.New("event feature is required")
+			}
+			if event.Action == "" {
+				return errors.New("event action is required")
+			}
+			if event.Timestamp == nil {
+				return errors.New("event timestamp is required")
+			}
+
+			// Render JSON format for publishing
 			eventJSON, err := protojson.Marshal(event)
 			if err != nil {
 				return errors.Wrap(err, "marshalling event")
@@ -120,7 +161,7 @@ func (p *Publisher) Publish(ctx context.Context, events []*telemetrygatewayv1.Ev
 			// Publish a single message in each callback to manage concurrency
 			// ourselves, and attach attributes for ease of routing the pub/sub
 			// message.
-			if err := p.topic.PublishMessage(ctx, payload, extractPubSubAttributes(event)); err != nil {
+			if err := p.topic.PublishMessage(ctx, payload, extractPubSubAttributes(p.source, event)); err != nil {
 				// Try to record the cancel cause as the primary error in case
 				// one is recorded.
 				if cancelCause := context.Cause(ctx); cancelCause != nil {
diff --git a/cmd/telemetry-gateway/internal/events/events_test.go b/cmd/telemetry-gateway/internal/events/events_test.go
index 777b9a36d25..ce05a7a1917 100644
--- a/cmd/telemetry-gateway/internal/events/events_test.go
+++ b/cmd/telemetry-gateway/internal/events/events_test.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"google.golang.org/protobuf/types/known/timestamppb"
 
 	"github.com/sourcegraph/log/logtest"
 
@@ -35,18 +36,28 @@ func TestPublish(t *testing.T) {
 	publisher, err := events.NewPublisherForStream(
 		logtest.Scoped(t),
 		memTopic,
-		&telemetrygatewayv1.RecordEventsRequestMetadata{},
+		&telemetrygatewayv1.RecordEventsRequestMetadata{
+			Identifier: &telemetrygatewayv1.Identifier{
+				Identifier: &telemetrygatewayv1.Identifier_LicensedInstance{
+					LicensedInstance: &telemetrygatewayv1.Identifier_LicensedInstanceIdentifier{},
+				},
+			},
+		},
 		events.PublishStreamOptions{
 			ConcurrencyLimit: concurrency,
 		})
 	require.NoError(t, err)
 
+	// Check the evaluated source
+	assert.Equal(t, "licensed_instance", publisher.GetSourceName())
+
 	events := make([]*telemetrygatewayv1.Event, concurrency)
 	for i := range events {
 		events[i] = &telemetrygatewayv1.Event{
-			Id:      strconv.Itoa(i),
-			Feature: t.Name(),
-			Action:  strconv.Itoa(i),
+			Id:        strconv.Itoa(i),
+			Feature:   t.Name(),
+			Action:    strconv.Itoa(i),
+			Timestamp: timestamppb.Now(),
 		}
 	}
 
@@ -77,9 +88,13 @@ func TestPublish(t *testing.T) {
 		var payload map[string]json.RawMessage
 		require.NoError(t, json.Unmarshal(m.Data, &payload))
 
-		var event telemetrygatewayv1.Event
+		var event struct {
+			Id      string
+			Feature string
+			Action  string
+		}
 		require.NoError(t, json.Unmarshal(payload["event"], &event))
-		publishedEvents[event.GetId()] = true
+		publishedEvents[event.Id] = true
 
 		assert.Equal(t, event.Feature, m.Attributes["event.feature"])
 		assert.Equal(t, event.Action, m.Attributes["event.action"])
diff --git a/cmd/telemetry-gateway/internal/server/BUILD.bazel b/cmd/telemetry-gateway/internal/server/BUILD.bazel
index 96e324dd269..c56688c0135 100644
--- a/cmd/telemetry-gateway/internal/server/BUILD.bazel
+++ b/cmd/telemetry-gateway/internal/server/BUILD.bazel
@@ -13,8 +13,10 @@ go_library(
     visibility = ["//cmd/telemetry-gateway:__subpackages__"],
     deps = [
         "//cmd/telemetry-gateway/internal/events",
+        "//cmd/telemetry-gateway/internal/server/samsm2m",
         "//internal/licensing",
         "//internal/pubsub",
+        "//internal/sams",
         "//internal/telemetrygateway/v1:telemetrygateway",
         "//internal/trace",
         "//lib/errors",
diff --git a/cmd/telemetry-gateway/internal/server/metrics.go b/cmd/telemetry-gateway/internal/server/metrics.go
index 8c5422acbcc..6b7bb189ca3 100644
--- a/cmd/telemetry-gateway/internal/server/metrics.go
+++ b/cmd/telemetry-gateway/internal/server/metrics.go
@@ -44,3 +44,19 @@ func newRecordEventsMetrics() (m recordEventsMetrics, err error) {
 
 	return m, err
 }
+
+type recordEventMetrics struct {
+	// Count of processed events
+	processedEvents metric.Int64Counter
+}
+
+func newRecordEventMetrics() (m recordEventMetrics, err error) {
+	m.processedEvents, err = meter.Int64Counter(
+		"telemetry-gateway.record_event.processed_events",
+		metric.WithDescription("Number of events processed"))
+	if err != nil {
+		return m, err
+	}
+
+	return m, nil
+}
diff --git a/cmd/telemetry-gateway/internal/server/publish_events.go b/cmd/telemetry-gateway/internal/server/publish_events.go
index 7a8a4b4e823..3edcbf339be 100644
--- a/cmd/telemetry-gateway/internal/server/publish_events.go
+++ b/cmd/telemetry-gateway/internal/server/publish_events.go
@@ -36,13 +36,14 @@ func handlePublishEvents(
 
 	// Record the result on the trace and metrics
 	resultAttribute := attribute.String("result", summary.result)
-	tr.SetAttributes(resultAttribute)
+	sourceAttribute := attribute.String("source", publisher.GetSourceName())
+	tr.SetAttributes(resultAttribute, sourceAttribute)
 	payloadMetrics.length.Record(ctx, int64(len(events)),
-		metric.WithAttributes(resultAttribute))
+		metric.WithAttributes(resultAttribute, sourceAttribute))
 	payloadMetrics.processedEvents.Add(ctx, int64(len(summary.succeededEvents)),
-		metric.WithAttributes(attribute.Bool("succeeded", true), resultAttribute))
+		metric.WithAttributes(attribute.Bool("succeeded", true), resultAttribute, sourceAttribute))
 	payloadMetrics.processedEvents.Add(ctx, int64(len(summary.failedEvents)),
-		metric.WithAttributes(attribute.Bool("succeeded", false), resultAttribute))
+		metric.WithAttributes(attribute.Bool("succeeded", false), resultAttribute, sourceAttribute))
 
 	// Generate a log message for convenience
 	summaryFields := []log.Field{
diff --git a/cmd/telemetry-gateway/internal/server/samsm2m/BUILD.bazel b/cmd/telemetry-gateway/internal/server/samsm2m/BUILD.bazel
new file mode 100644
index 00000000000..673a61dbb65
--- /dev/null
+++ b/cmd/telemetry-gateway/internal/server/samsm2m/BUILD.bazel
@@ -0,0 +1,36 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("//dev:go_defs.bzl", "go_test")
+
+go_library(
+    name = "samsm2m",
+    srcs = ["samsm2m.go"],
+    importpath = "github.com/sourcegraph/sourcegraph/cmd/telemetry-gateway/internal/server/samsm2m",
+    visibility = ["//cmd/telemetry-gateway:__subpackages__"],
+    deps = [
+        "//internal/authbearer",
+        "//internal/sams",
+        "//lib/errors",
+        "@com_github_sourcegraph_log//:log",
+        "@io_opentelemetry_go_otel//:otel",
+        "@io_opentelemetry_go_otel//codes",
+        "@io_opentelemetry_go_otel_trace//:trace",
+        "@org_golang_google_grpc//codes",
+        "@org_golang_google_grpc//metadata",
+        "@org_golang_google_grpc//status",
+    ],
+)
+
+go_test(
+    name = "samsm2m_test",
+    srcs = ["samsm2m_test.go"],
+    embed = [":samsm2m"],
+    deps = [
+        "//internal/sams",
+        "//lib/errors",
+        "@com_github_hexops_autogold_v2//:autogold",
+        "@com_github_sourcegraph_log//logtest",
+        "@com_github_stretchr_testify//assert",
+        "@com_github_stretchr_testify//require",
+        "@org_golang_google_grpc//metadata",
+    ],
+)
diff --git a/cmd/telemetry-gateway/internal/server/samsm2m/samsm2m.go b/cmd/telemetry-gateway/internal/server/samsm2m/samsm2m.go
new file mode 100644
index 00000000000..18ed13d4c33
--- /dev/null
+++ b/cmd/telemetry-gateway/internal/server/samsm2m/samsm2m.go
@@ -0,0 +1,86 @@
+package samsm2m
+
+import (
+	"context"
+	"slices"
+	"strings"
+
+	"go.opentelemetry.io/otel"
+	otelcodes "go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+
+	"github.com/sourcegraph/log"
+
+	"github.com/sourcegraph/sourcegraph/internal/authbearer"
+	"github.com/sourcegraph/sourcegraph/internal/sams"
+	"github.com/sourcegraph/sourcegraph/lib/errors"
+)
+
+const requiredSamsScope = "telemetry_gateway::events::write"
+
+var tracer = otel.GetTracerProvider().Tracer("telemetry-gateway/samsm2m")
+
+// CheckWriteEventsScope ensures the request context has a valid SAMS MSM token
+// with requiredSamsScope. It returns a gRPC status error suitable to be returned
+// directly from an RPC implementation.
+//
+// See: go/sams-m2m
+func CheckWriteEventsScope(ctx context.Context, logger log.Logger, samsClient sams.Client) (err error) {
+	var span trace.Span
+	ctx, span = tracer.Start(ctx, "CheckWriteEventsScope")
+	defer func() {
+		if err != nil {
+			span.RecordError(err)
+			span.SetStatus(otelcodes.Error, "check failed")
+		}
+		span.End()
+	}()
+
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return status.Error(codes.Unauthenticated, "no token header")
+	}
+
+	var token string
+	if v := md.Get("authorization"); len(v) == 1 && v[0] != "" {
+		var err error
+		token, err = authbearer.ExtractBearerContents(v[0])
+		if err != nil {
+			return status.Errorf(codes.Unauthenticated, "invalid token header: %v", err)
+		}
+	} else {
+		return status.Error(codes.Unauthenticated, "no token header value")
+	}
+
+	// TODO: as part of go/sams-m2m we need to build out a SDK for SAMS M2M
+	// consumers that has a recommended short-caching mechanism. Avoid doing it
+	// for now until we have a concerted effort.
+	result, err := samsClient.IntrospectToken(ctx, token)
+	if err != nil {
+		logger.Error("samsClient.IntrospectToken failed", log.Error(err))
+		return status.Error(codes.Internal, "unable to validate token")
+	}
+
+	// Active encapsulates whether the token is active, including expiration.
+	if !result.Active {
+		// Record detailed error in span, and return an opaque one
+		span.RecordError(errors.New("inactive scope"))
+		return status.Error(codes.PermissionDenied, "permission denied")
+	}
+
+	// Check for our required scope.
+	gotScopes := strings.Split(result.Scope, " ")
+	if !slices.Contains(gotScopes, requiredSamsScope) {
+		// Record detailed error in span and logs, and return an opaque one
+		err = errors.Newf("got scopes %q, required: %q", gotScopes, requiredSamsScope)
+		span.RecordError(err)
+		logger.Error("attempt to authenticate using SAMS token without required scope",
+			log.Error(err))
+		return status.Error(codes.PermissionDenied, "permission denied")
+	}
+
+	return nil
+}
diff --git a/cmd/telemetry-gateway/internal/server/samsm2m/samsm2m_test.go b/cmd/telemetry-gateway/internal/server/samsm2m/samsm2m_test.go
new file mode 100644
index 00000000000..cc28d487f25
--- /dev/null
+++ b/cmd/telemetry-gateway/internal/server/samsm2m/samsm2m_test.go
@@ -0,0 +1,97 @@
+package samsm2m
+
+import (
+	"context"
+	"testing"
+
+	"github.com/hexops/autogold/v2"
+	"github.com/sourcegraph/log/logtest"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/grpc/metadata"
+
+	"github.com/sourcegraph/sourcegraph/internal/sams"
+	"github.com/sourcegraph/sourcegraph/lib/errors"
+)
+
+type mockSAMSClient struct {
+	result *sams.TokenIntrospection
+	error  error
+}
+
+func (m mockSAMSClient) IntrospectToken(context.Context, string) (*sams.TokenIntrospection, error) {
+	return m.result, m.error
+}
+
+func TestCheckWriteEventsScope(t *testing.T) {
+	for _, tc := range []struct {
+		name       string
+		metadata   map[string]string
+		samsClient sams.Client
+		wantErr    autogold.Value
+	}{
+		{
+			name:       "no metadata",
+			metadata:   nil,
+			samsClient: nil, // will not be used
+			wantErr:    autogold.Expect("rpc error: code = Unauthenticated desc = no token header"),
+		},
+		{
+			name:       "no authorization header",
+			metadata:   map[string]string{"somethingelse": "foobar"},
+			samsClient: nil, // will not be used
+			wantErr:    autogold.Expect("rpc error: code = Unauthenticated desc = no token header value"),
+		},
+		{
+			name:       "malformed authorization header",
+			metadata:   map[string]string{"authorization": "bearer"},
+			samsClient: nil, // will not be used
+			wantErr:    autogold.Expect("rpc error: code = Unauthenticated desc = invalid token header: token type missing in Authorization header"),
+		},
+		{
+			name:       "token ok, introspect failed",
+			metadata:   map[string]string{"authorization": "bearer foobar"},
+			samsClient: mockSAMSClient{error: errors.New("introspection failed")},
+			wantErr:    autogold.Expect("rpc error: code = Internal desc = unable to validate token"),
+		},
+		{
+			name:       "token ok, but inactive",
+			metadata:   map[string]string{"authorization": "bearer foobar"},
+			samsClient: mockSAMSClient{result: &sams.TokenIntrospection{Active: false}},
+			wantErr:    autogold.Expect("rpc error: code = PermissionDenied desc = permission denied"),
+		},
+		{
+			name:       "token ok and active, but invalid scope",
+			metadata:   map[string]string{"authorization": "bearer foobar"},
+			samsClient: mockSAMSClient{result: &sams.TokenIntrospection{Active: true, Scope: "foo bar"}},
+			wantErr:    autogold.Expect("rpc error: code = PermissionDenied desc = permission denied"),
+		},
+		{
+			name:     "token ok and active and valid scope",
+			metadata: map[string]string{"authorization": "bearer foobar"},
+			samsClient: mockSAMSClient{
+				result: &sams.TokenIntrospection{
+					Active: true,
+					Scope:  "foo bar " + requiredSamsScope,
+				},
+			},
+			wantErr: nil, // success
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			ctx := context.Background()
+			if len(tc.metadata) > 0 {
+				// we mock the ctx of an incoming context
+				ctx = metadata.NewIncomingContext(ctx, metadata.New(tc.metadata))
+			}
+
+			err := CheckWriteEventsScope(ctx, logtest.Scoped(t), tc.samsClient)
+			if tc.wantErr == nil {
+				assert.NoError(t, err)
+			} else {
+				require.Error(t, err)
+				tc.wantErr.Equal(t, err.Error())
+			}
+		})
+	}
+}
diff --git a/cmd/telemetry-gateway/internal/server/server.go b/cmd/telemetry-gateway/internal/server/server.go
index 45bec9858a0..17f0d7ab83d 100644
--- a/cmd/telemetry-gateway/internal/server/server.go
+++ b/cmd/telemetry-gateway/internal/server/server.go
@@ -1,6 +1,7 @@
 package server
 
 import (
+	"context"
 	"fmt"
 	"io"
 
@@ -11,12 +12,14 @@ import (
 
 	"github.com/sourcegraph/log"
 
-	"github.com/sourcegraph/sourcegraph/cmd/telemetry-gateway/internal/events"
 	"github.com/sourcegraph/sourcegraph/internal/licensing"
 	"github.com/sourcegraph/sourcegraph/internal/pubsub"
+	"github.com/sourcegraph/sourcegraph/internal/sams"
 	sgtrace "github.com/sourcegraph/sourcegraph/internal/trace"
 	"github.com/sourcegraph/sourcegraph/lib/errors"
 
+	"github.com/sourcegraph/sourcegraph/cmd/telemetry-gateway/internal/events"
+	"github.com/sourcegraph/sourcegraph/cmd/telemetry-gateway/internal/server/samsm2m"
 	telemetrygatewayv1 "github.com/sourcegraph/sourcegraph/internal/telemetrygateway/v1"
 )
 
@@ -25,7 +28,11 @@ type Server struct {
 	eventsTopic pubsub.TopicPublisher
 	publishOpts events.PublishStreamOptions
 
+	// samsClient is used for M2M authn/authz: go/sams-m2m
+	samsClient sams.Client
+
 	recordEventsMetrics recordEventsMetrics
+	recordEventMetrics  recordEventMetrics
 
 	// Fallback unimplemented handler
 	telemetrygatewayv1.UnimplementedTelemeteryGatewayServiceServer
@@ -33,8 +40,17 @@ type Server struct {
 
 var _ telemetrygatewayv1.TelemeteryGatewayServiceServer = (*Server)(nil)
 
-func New(logger log.Logger, eventsTopic pubsub.TopicPublisher, publishOpts events.PublishStreamOptions) (*Server, error) {
-	m, err := newRecordEventsMetrics()
+func New(
+	logger log.Logger,
+	eventsTopic pubsub.TopicPublisher,
+	samsClient sams.Client,
+	publishOpts events.PublishStreamOptions,
+) (*Server, error) {
+	recordEventsRPCMetrics, err := newRecordEventsMetrics()
+	if err != nil {
+		return nil, err
+	}
+	recordEventRPCMetrics, err := newRecordEventMetrics()
 	if err != nil {
 		return nil, err
 	}
@@ -44,13 +60,17 @@ func New(logger log.Logger, eventsTopic pubsub.TopicPublisher, publishOpts event
 		eventsTopic: eventsTopic,
 		publishOpts: publishOpts,
 
-		recordEventsMetrics: m,
+		samsClient: samsClient,
+
+		recordEventsMetrics: recordEventsRPCMetrics,
+		recordEventMetrics:  recordEventRPCMetrics,
 	}, nil
 }
 
 func (s *Server) RecordEvents(stream telemetrygatewayv1.TelemeteryGatewayService_RecordEventsServer) (err error) {
 	var (
-		logger = sgtrace.Logger(stream.Context(), s.logger)
+		logger = sgtrace.Logger(stream.Context(), s.logger).
+			Scoped("RecordEvent")
 		// publisher is initialized once for RecordEventsRequestMetadata.
 		publisher *events.Publisher
 		// count of all processed events, collected at the end of a request
@@ -60,7 +80,10 @@ func (s *Server) RecordEvents(stream telemetrygatewayv1.TelemeteryGatewayService
 	defer func() {
 		s.recordEventsMetrics.totalLength.Record(stream.Context(),
 			totalProcessedEvents,
-			metric.WithAttributes(attribute.Bool("error", err != nil)))
+			metric.WithAttributes(
+				attribute.Bool("error", err != nil),
+				attribute.String("source", publisher.GetSourceName()),
+			))
 	}()
 
 	for {
@@ -82,14 +105,13 @@ func (s *Server) RecordEvents(stream telemetrygatewayv1.TelemeteryGatewayService
 			logger = logger.With(log.String("requestID", metadata.GetRequestId()))
 
 			// Validate self-reported instance identifier
-			switch metadata.GetIdentifier().Identifier.(type) {
+			switch metadata.GetIdentifier().GetIdentifier().(type) {
 			case *telemetrygatewayv1.Identifier_LicensedInstance:
 				identifier := metadata.Identifier.GetLicensedInstance()
 				licenseInfo, _, err := licensing.ParseProductLicenseKey(identifier.GetLicenseKey())
 				if err != nil {
 					return status.Errorf(codes.InvalidArgument, "invalid license_key: %s", err)
 				}
-				// Attach instance ID to all subsequent log messages
 				logger = logger.With(log.String("instanceID", identifier.InstanceId))
 				// Record start of stream + additional diagnostics details
 				// like salesforce info and external URL once
@@ -103,13 +125,29 @@ func (s *Server) RecordEvents(stream telemetrygatewayv1.TelemeteryGatewayService
 				if identifier.InstanceId == "" {
 					return status.Error(codes.InvalidArgument, "instance_id is required for unlicensed instance")
 				}
-				// Attach instance ID to all subsequent log messages
 				logger = logger.With(log.String("instanceID", identifier.InstanceId))
 				// Record start of stream
 				logger.Info("handling events submission stream for unlicensed instance")
 
+			case *telemetrygatewayv1.Identifier_ManagedService:
+				identifier := metadata.Identifier.GetManagedService()
+				if identifier.ServiceId == "" {
+					return status.Error(codes.InvalidArgument, "service_id is required for managed services")
+				}
+				logger = logger.With(
+					log.String("serviceID", identifier.ServiceId),
+					log.Stringp("serviceEnvironment", identifier.ServiceEnvironment))
+
+				// 🚨 SECURITY: Only known clients registered in SAMS can submit events
+				// as a managed service.
+				if err := samsm2m.CheckWriteEventsScope(stream.Context(), logger, s.samsClient); err != nil {
+					return err
+				}
+
+				logger.Info("handling events submission stream for managed service")
+
 			default:
-				logger.Error("unknown identifier type",
+				logger.Error("identifier not supported for this RPC",
 					log.String("type", fmt.Sprintf("%T", metadata.Identifier.Identifier)))
 				return status.Error(codes.Unimplemented, "unsupported identifier type")
 			}
@@ -119,6 +157,7 @@ func (s *Server) RecordEvents(stream telemetrygatewayv1.TelemeteryGatewayService
 			if err != nil {
 				return status.Errorf(codes.Internal, "failed to create publisher: %v", err)
 			}
+			logger = logger.With(log.String("source", publisher.GetSourceName()))
 
 		case *telemetrygatewayv1.RecordEventsRequest_Events:
 			events := msg.GetEvents().GetEvents()
@@ -156,3 +195,78 @@ func (s *Server) RecordEvents(stream telemetrygatewayv1.TelemeteryGatewayService
 	logger.Info("request done")
 	return nil
 }
+
+func (s *Server) RecordEvent(ctx context.Context, req *telemetrygatewayv1.RecordEventRequest) (_ *telemetrygatewayv1.RecordEventResponse, err error) {
+	var (
+		metadata = req.GetMetadata()
+		event    = req.GetEvent()
+	)
+	if event == nil {
+		return nil, status.Error(codes.InvalidArgument, "event is required")
+	}
+
+	logger := sgtrace.Logger(ctx, s.logger).
+		Scoped("RecordEvent").
+		With(
+			log.String("requestID", metadata.GetRequestId()),
+			// Include more liberal amounts of diagnostics because this RPC
+			// currently has a more limited audience
+			log.String("eventID", event.GetId()),
+			log.String("eventFeature", event.GetFeature()),
+			log.String("eventAction", event.GetAction()))
+
+	// We only allow a limited set of identifiers to use this RPC for now, as
+	// Sourcegraph instances should only use RecordEvents.
+	switch metadata.GetIdentifier().GetIdentifier().(type) {
+	case *telemetrygatewayv1.Identifier_ManagedService:
+		identifier := metadata.Identifier.GetManagedService()
+		if identifier.ServiceId == "" {
+			return nil, status.Error(codes.InvalidArgument, "service_id is required for managed services")
+		}
+		logger = logger.With(
+			log.String("serviceID", identifier.ServiceId),
+			log.Stringp("serviceEnvironment", identifier.ServiceEnvironment))
+
+		// 🚨 SECURITY: Only known clients registered in SAMS can submit events
+		// as a managed service.
+		if err := samsm2m.CheckWriteEventsScope(ctx, logger, s.samsClient); err != nil {
+			return nil, err
+		}
+
+	default:
+		logger.Error("identifier not supported for this RPC",
+			log.String("type", fmt.Sprintf("%T", metadata.Identifier.Identifier)))
+		return nil, status.Error(codes.Unimplemented, "unsupported identifier type")
+	}
+
+	// Set up a publisher with the provided metadata
+	publisher, err := events.NewPublisherForStream(s.logger, s.eventsTopic, metadata, s.publishOpts)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "failed to create publisher: %v", err)
+	}
+	logger = logger.With(log.String("source", publisher.GetSourceName()))
+
+	defer func() {
+		s.recordEventMetrics.processedEvents.Add(ctx,
+			1, // RPC only accepts 1 event at a time
+			metric.WithAttributes(
+				attribute.Bool("error", err != nil),
+				attribute.String("source", publisher.GetSourceName())))
+	}()
+
+	// Submit the single event
+	results := publisher.Publish(ctx, []*telemetrygatewayv1.Event{event})
+	if len(results) != 1 {
+		logger.Error("unexpected result when publishing",
+			log.Error(errors.Newf("expected 1 result, got %d", len(results))))
+		return nil, status.Errorf(codes.Internal, "unexpected publishing issue")
+	}
+	if err := results[0].PublishError; err != nil {
+		logger.Error("failed to publish event", log.Error(err))
+		return nil, status.Errorf(codes.Internal, "failed to publish event: %v", err)
+	}
+
+	return &telemetrygatewayv1.RecordEventResponse{
+		// no properties
+	}, nil
+}
diff --git a/cmd/telemetry-gateway/main.go b/cmd/telemetry-gateway/main.go
index ea27d87370b..e64f11844ab 100644
--- a/cmd/telemetry-gateway/main.go
+++ b/cmd/telemetry-gateway/main.go
@@ -6,5 +6,5 @@ import (
 )
 
 func main() {
-	runtime.Start[service.Config](&service.Service{})
+	runtime.Start(&service.Service{})
 }
diff --git a/cmd/telemetry-gateway/service/BUILD.bazel b/cmd/telemetry-gateway/service/BUILD.bazel
index 6cfc20f171e..9550e8cd208 100644
--- a/cmd/telemetry-gateway/service/BUILD.bazel
+++ b/cmd/telemetry-gateway/service/BUILD.bazel
@@ -16,6 +16,7 @@ go_library(
         "//internal/grpc/defaults",
         "//internal/httpserver",
         "//internal/pubsub",
+        "//internal/sams",
         "//internal/telemetrygateway/v1:telemetrygateway",
         "//internal/trace/policy",
         "//internal/version",
@@ -25,5 +26,6 @@ go_library(
         "@com_github_sourcegraph_log//:log",
         "@io_opentelemetry_go_otel//:otel",
         "@io_opentelemetry_go_otel_metric//:metric",
+        "@org_golang_x_oauth2//clientcredentials",
     ],
 )
diff --git a/cmd/telemetry-gateway/service/config.go b/cmd/telemetry-gateway/service/config.go
index eb7c65aec24..58ff53a59a7 100644
--- a/cmd/telemetry-gateway/service/config.go
+++ b/cmd/telemetry-gateway/service/config.go
@@ -14,6 +14,12 @@ type Config struct {
 
 		StreamPublishConcurrency int
 	}
+
+	SAMS struct {
+		ServerURL    string
+		ClientID     string
+		ClientSecret string
+	}
 }
 
 func (c *Config) Load(env *runtime.Env) {
@@ -25,4 +31,11 @@ func (c *Config) Load(env *runtime.Env) {
 		"The topic ID for the Pub/Sub.")
 	c.Events.StreamPublishConcurrency = env.GetInt("TELEMETRY_GATEWAY_EVENTS_STREAM_PUBLISH_CONCURRENCY", "250",
 		"Per-stream concurrent publishing limit.")
+
+	c.SAMS.ServerURL = env.Get("TELEMETRY_GATEWAY_SAMS_SERVER_URL", "https://accounts.sourcegraph.com",
+		"Sourcegraph Accounts Management System URL")
+	c.SAMS.ClientID = env.Get("TELEMETRY_GATEWAY_SAMS_CLIENT_ID", "",
+		"Sourcegraph Accounts Management System client ID")
+	c.SAMS.ClientSecret = env.Get("TELEMETRY_GATEWAY_SAMS_CLIENT_SECRET", "",
+		"Sourcegraph Accounts Management System client secret")
 }
diff --git a/cmd/telemetry-gateway/service/service.go b/cmd/telemetry-gateway/service/service.go
index d47871ccd4b..d149621430f 100644
--- a/cmd/telemetry-gateway/service/service.go
+++ b/cmd/telemetry-gateway/service/service.go
@@ -10,12 +10,14 @@ import (
 	"github.com/sourcegraph/log"
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/metric"
+	"golang.org/x/oauth2/clientcredentials"
 
 	"github.com/sourcegraph/sourcegraph/internal/debugserver"
 	internalgrpc "github.com/sourcegraph/sourcegraph/internal/grpc"
 	"github.com/sourcegraph/sourcegraph/internal/grpc/defaults"
 	"github.com/sourcegraph/sourcegraph/internal/httpserver"
 	"github.com/sourcegraph/sourcegraph/internal/pubsub"
+	"github.com/sourcegraph/sourcegraph/internal/sams"
 	"github.com/sourcegraph/sourcegraph/internal/trace/policy"
 	"github.com/sourcegraph/sourcegraph/internal/version"
 
@@ -61,11 +63,23 @@ func (Service) Initialize(ctx context.Context, logger log.Logger, contract runti
 		return nil, errors.Wrap(err, "create pubsub.published_message_size metric")
 	}
 
+	// Prepare SAMS client, so that we can enforce SAMS-based M2M authz/authn
+	logger.Debug("using SAMS client",
+		log.String("samsServer", config.SAMS.ServerURL),
+		log.String("clientID", config.SAMS.ClientID))
+	samsClient := sams.NewClient(config.SAMS.ServerURL, clientcredentials.Config{
+		ClientID:     config.SAMS.ClientID,
+		ClientSecret: config.SAMS.ClientSecret,
+		TokenURL:     fmt.Sprintf("%s/oauth/token", config.SAMS.ServerURL),
+		Scopes:       []string{"openid", "profile", "email"},
+	})
+
 	// Initialize our gRPC server
 	grpcServer := defaults.NewPublicServer(logger)
 	telemetryGatewayServer, err := server.New(
 		logger,
 		eventsTopic,
+		samsClient,
 		events.PublishStreamOptions{
 			ConcurrencyLimit:     config.Events.StreamPublishConcurrency,
 			MessageSizeHistogram: publishMessageBytes,
@@ -87,6 +101,7 @@ func (Service) Initialize(ctx context.Context, logger log.Logger, contract runti
 		// development!
 		grpcUI := debugserver.NewGRPCWebUIEndpoint("telemetry-gateway", listenAddr)
 		diagnosticsServer.Handle(grpcUI.Path, grpcUI.Handler)
+		logger.Warn("gRPC web UI enabled", log.String("url", fmt.Sprintf("%s%s", listenAddr, grpcUI.Path)))
 	}
 
 	return background.LIFOStopRoutine{
diff --git a/doc/dev/background-information/telemetry/protocol.md b/doc/dev/background-information/telemetry/protocol.md
index 1f752c73724..528e4033c71 100644
--- a/doc/dev/background-information/telemetry/protocol.md
+++ b/doc/dev/background-information/telemetry/protocol.md
@@ -305,7 +305,7 @@ Sourcegraph.com instance and managed services.
 | ----- | ---- | ----- | ----------- |
 | licensed_instance | [Identifier.LicensedInstanceIdentifier](#telemetrygateway-v1-Identifier-LicensedInstanceIdentifier) |  | <p>A licensed Sourcegraph instance.</p> |
 | unlicensed_instance | [Identifier.UnlicensedInstanceIdentifier](#telemetrygateway-v1-Identifier-UnlicensedInstanceIdentifier) |  | <p>An unlicensed Sourcegraph instance.</p> |
-| managed_service | [Identifier.ManagedServiceIdentifier](#telemetrygateway-v1-Identifier-ManagedServiceIdentifier) |  | <p>A service operated and managed by the Sourcegraph team, for example</p><p>a service deployed by https://handbook.sourcegraph.com/departments/engineering/teams/core-services/managed-services/platform/</p> |
+| managed_service | [Identifier.ManagedServiceIdentifier](#telemetrygateway-v1-Identifier-ManagedServiceIdentifier) |  | <p>A service operated and managed by the Sourcegraph team, for example</p><p>a service deployed by MSP: https://handbook.sourcegraph.com/departments/engineering/teams/core-services/managed-services/platform/</p><p>Valid SAMS client credentials are required to publish events under a</p><p>managed service identifier. The required scope is</p><p>'telemetry_gateway::events::publish'. See go/sams-client-credentials and</p><p>go/sams-token-scopes for more information.</p> |
 
 
 
@@ -463,7 +463,7 @@ Sourcegraph.com instance and managed services.
 | Method Name | Request Type | Response Type | Description |
 | ----------- | ------------ | ------------- | ------------|
 | RecordEvents | [RecordEventsRequest](#telemetrygateway-v1-RecordEventsRequest) stream | [RecordEventsResponse](#telemetrygateway-v1-RecordEventsResponse) stream | <p>RecordEvents streams telemetry events in batches to the Telemetry Gateway</p><p>service. Events should only be considered delivered if recording is</p><p>acknowledged in RecordEventsResponse.</p><p>This is the preferred mechanism for exporting large volumes of events in</p><p>bulk.</p><p>🚨 SECURITY: Callers exporting for single-tenant Sourcegraph should check</p><p>the attributes of the Event type to ensure that only the appropriate fields</p><p>are exported, as some fields should only be exported on an allowlist basis.</p> |
-| RecordEvent | [RecordEventRequest](#telemetrygateway-v1-RecordEventRequest) | [RecordEventResponse](#telemetrygateway-v1-RecordEventResponse) | <p>RecordEvent records a single telemetry event to the Telemetry Gateway service.</p><p>If the RPC succeeds, then the event was successfully published.</p><p>This mechanism is intended for low-volume managed services. Higher-volume</p><p>use cases should implement a batching mechanism and use the RecordEvents</p><p>RPC instead.</p><p>🚨 SECURITY: Callers exporting for single-tenant Sourcegraph should check</p><p>the attributes of the Event type to ensure that only the appropriate fields</p><p>are exported, as some fields should only be exported on an allowlist basis.</p> |
+| RecordEvent | [RecordEventRequest](#telemetrygateway-v1-RecordEventRequest) | [RecordEventResponse](#telemetrygateway-v1-RecordEventResponse) | <p>RecordEvent records a single telemetry event to the Telemetry Gateway service.</p><p>If the RPC succeeds, then the event was successfully published.</p><p>This RPC currently ONLY accepts events published by ManagedServiceIdentifier,</p><p>as this mechanism is intended for low-volume managed services. Higher-volume</p><p>use cases should implement a batching mechanism and use the RecordEvents</p><p>RPC instead.</p><p>🚨 SECURITY: Callers exporting for single-tenant Sourcegraph should check</p><p>the attributes of the Event type to ensure that only the appropriate fields</p><p>are exported, as some fields should only be exported on an allowlist basis.</p> |
 
  <!-- end services -->
 
diff --git a/internal/authbearer/authbearer.go b/internal/authbearer/authbearer.go
index f93238c97b6..bb5bd9543d3 100644
--- a/internal/authbearer/authbearer.go
+++ b/internal/authbearer/authbearer.go
@@ -8,19 +8,22 @@ import (
 )
 
 func ExtractBearer(h http.Header) (string, error) {
-	var token string
-
 	if authHeader := h.Get("Authorization"); authHeader != "" {
-		typ := strings.SplitN(authHeader, " ", 2)
-		if len(typ) != 2 {
-			return "", errors.New("token type missing in Authorization header")
-		}
-		if strings.ToLower(typ[0]) != "bearer" {
-			return "", errors.Newf("invalid token type %s", typ[0])
-		}
-
-		token = typ[1]
+		return ExtractBearerContents(authHeader)
 	}
-
-	return token, nil
+	return "", nil
+}
+
+func ExtractBearerContents(s string) (string, error) {
+	if s == "" {
+		return "", errors.New("no token provided in Authorization header")
+	}
+	typ := strings.SplitN(s, " ", 2)
+	if len(typ) != 2 {
+		return "", errors.New("token type missing in Authorization header")
+	}
+	if strings.ToLower(typ[0]) != "bearer" {
+		return "", errors.Newf("invalid token type %s in Authorization header", typ[0])
+	}
+	return typ[1], nil
 }
diff --git a/internal/telemetrygateway/v1/telemetrygateway.pb.go b/internal/telemetrygateway/v1/telemetrygateway.pb.go
index a307b6de0d7..7213fb96c48 100644
--- a/internal/telemetrygateway/v1/telemetrygateway.pb.go
+++ b/internal/telemetrygateway/v1/telemetrygateway.pb.go
@@ -119,7 +119,12 @@ type Identifier_UnlicensedInstance struct {
 
 type Identifier_ManagedService struct {
 	// A service operated and managed by the Sourcegraph team, for example
-	// a service deployed by https://handbook.sourcegraph.com/departments/engineering/teams/core-services/managed-services/platform/
+	// a service deployed by MSP: https://handbook.sourcegraph.com/departments/engineering/teams/core-services/managed-services/platform/
+	//
+	// Valid SAMS client credentials are required to publish events under a
+	// managed service identifier. The required scope is
+	// 'telemetry_gateway::events::publish'. See go/sams-client-credentials and
+	// go/sams-token-scopes for more information.
 	ManagedService *Identifier_ManagedServiceIdentifier `protobuf:"bytes,3,opt,name=managed_service,json=managedService,proto3,oneof"`
 }
 
diff --git a/internal/telemetrygateway/v1/telemetrygateway.proto b/internal/telemetrygateway/v1/telemetrygateway.proto
index c09b1ebf0da..581f64e9e89 100644
--- a/internal/telemetrygateway/v1/telemetrygateway.proto
+++ b/internal/telemetrygateway/v1/telemetrygateway.proto
@@ -31,7 +31,8 @@ service TelemeteryGatewayService {
   // RecordEvent records a single telemetry event to the Telemetry Gateway service.
   // If the RPC succeeds, then the event was successfully published.
   //
-  // This mechanism is intended for low-volume managed services. Higher-volume
+  // This RPC currently ONLY accepts events published by ManagedServiceIdentifier,
+  // as this mechanism is intended for low-volume managed services. Higher-volume
   // use cases should implement a batching mechanism and use the RecordEvents
   // RPC instead.
   //
@@ -71,7 +72,12 @@ message Identifier {
     // An unlicensed Sourcegraph instance.
     UnlicensedInstanceIdentifier unlicensed_instance = 2;
     // A service operated and managed by the Sourcegraph team, for example
-    // a service deployed by https://handbook.sourcegraph.com/departments/engineering/teams/core-services/managed-services/platform/
+    // a service deployed by MSP: https://handbook.sourcegraph.com/departments/engineering/teams/core-services/managed-services/platform/
+    //
+    // Valid SAMS client credentials are required to publish events under a
+    // managed service identifier. The required scope is
+    // 'telemetry_gateway::events::publish'. See go/sams-client-credentials and
+    // go/sams-token-scopes for more information.
     ManagedServiceIdentifier managed_service = 3;
   }
 }
diff --git a/internal/telemetrygateway/v1/telemetrygateway_grpc.pb.go b/internal/telemetrygateway/v1/telemetrygateway_grpc.pb.go
index 5db87f3b2bb..05155265458 100644
--- a/internal/telemetrygateway/v1/telemetrygateway_grpc.pb.go
+++ b/internal/telemetrygateway/v1/telemetrygateway_grpc.pb.go
@@ -49,7 +49,8 @@ type TelemeteryGatewayServiceClient interface {
 	// RecordEvent records a single telemetry event to the Telemetry Gateway service.
 	// If the RPC succeeds, then the event was successfully published.
 	//
-	// This mechanism is intended for low-volume managed services. Higher-volume
+	// This RPC currently ONLY accepts events published by ManagedServiceIdentifier,
+	// as this mechanism is intended for low-volume managed services. Higher-volume
 	// use cases should implement a batching mechanism and use the RecordEvents
 	// RPC instead.
 	//
@@ -125,7 +126,8 @@ type TelemeteryGatewayServiceServer interface {
 	// RecordEvent records a single telemetry event to the Telemetry Gateway service.
 	// If the RPC succeeds, then the event was successfully published.
 	//
-	// This mechanism is intended for low-volume managed services. Higher-volume
+	// This RPC currently ONLY accepts events published by ManagedServiceIdentifier,
+	// as this mechanism is intended for low-volume managed services. Higher-volume
 	// use cases should implement a batching mechanism and use the RecordEvents
 	// RPC instead.
 	//
diff --git a/lib/managedservicesplatform/runtime/env.go b/lib/managedservicesplatform/runtime/env.go
index 24957c7008e..f0b99c6b355 100644
--- a/lib/managedservicesplatform/runtime/env.go
+++ b/lib/managedservicesplatform/runtime/env.go
@@ -75,7 +75,8 @@ func (e *Env) validate() error {
 func (e *Env) Get(name, defaultValue, description string) string {
 	rawValue := e.get(name, defaultValue, description)
 	if rawValue == "" {
-		e.AddError(errors.Errorf("invalid value %q for %s: no value supplied", rawValue, name))
+		e.AddError(errors.Errorf("invalid value %q for %s: no value supplied, description: %s",
+			rawValue, name, description))
 		return ""
 	}
 
diff --git a/sg.config.yaml b/sg.config.yaml
index 124c22dd625..9c9b9986749 100644
--- a/sg.config.yaml
+++ b/sg.config.yaml
@@ -334,6 +334,11 @@ commands:
       TELEMETRY_GATEWAY_EVENTS_PUBSUB_ENABLED: false
       SRC_LOG_LEVEL: info
       GRPC_WEB_UI_ENABLED: true
+      # Set for convenience - use real values in sg.config.overwrite.yaml if you
+      # are interacting with RPCs that enforce SAMS M2M auth. See
+      # https://github.com/sourcegraph/accounts.sourcegraph.com/wiki/Operators-Cheat-Sheet#create-a-new-idp-client
+      TELEMETRY_GATEWAY_SAMS_CLIENT_ID: "foo"
+      TELEMETRY_GATEWAY_SAMS_CLIENT_SECRET: "bar"
     watch:
       - lib
       - internal