diff --git a/embed/host.go b/embed/host.go
index 5f202b6..5914776 100644
--- a/embed/host.go
+++ b/embed/host.go
@@ -34,7 +34,7 @@ type Host struct {
 	// runtime-owned copy that no caller can race with; callers must still
 	// treat their own reference as frozen once they hand the Host off.
 	// See cloneResource in this package.
-	Resource map[string]string
+	Resource map[string]any
 
 	// Environment is the simulated datagen.Environment that generators draw
 	// their host identities (host.name / os.type) from (PIPE-1036). Nil means
@@ -56,11 +56,11 @@ type Host struct {
 // worker goroutines reading the per-session resource attributes race
 // neither with each other nor with a caller that retains a reference
 // and later mutates its own copy.
-func cloneResource(m map[string]string) map[string]string {
+func cloneResource(m map[string]any) map[string]any {
 	if m == nil {
 		return nil
 	}
-	out := make(map[string]string, len(m))
+	out := make(map[string]any, len(m))
 	for k, v := range m {
 		out[k] = v
 	}
diff --git a/embed/new.go b/embed/new.go
index db76cc2..996f63a 100644
--- a/embed/new.go
+++ b/embed/new.go
@@ -35,7 +35,7 @@ type runner struct {
 
 	mu       sync.Mutex
 	rt       *runtime.Runtime
-	resource map[string]string // cloned from host.Resource at Start
+	resource map[string]any // cloned from host.Resource at Start
 	started  bool
 }
 
diff --git a/embed/record.go b/embed/record.go
index 7271035..ee86e5e 100644
--- a/embed/record.go
+++ b/embed/record.go
@@ -38,7 +38,7 @@ type LogRecordMetadata struct {
 	Timestamp  time.Time
 	Severity   string
 	Attributes map[string]any
-	Resource   map[string]string
+	Resource   map[string]any
 }
 
 // MetricType represents the type of a metric data point.
@@ -101,7 +101,7 @@ type MetricPoint struct {
 type MetricPointMetadata struct {
 	Timestamp  time.Time
 	Attributes map[string]string
-	Resource   map[string]string
+	Resource   map[string]any
 }
 
 // SpanKind represents the kind of a trace span.
@@ -156,5 +156,5 @@ type Span struct {
 // arrays).
 type SpanMetadata struct {
 	Attributes map[string]any
-	Resource   map[string]string
+	Resource   map[string]any
 }
diff --git a/embed/record_test.go b/embed/record_test.go
index 4c40561..8d1b4bd 100644
--- a/embed/record_test.go
+++ b/embed/record_test.go
@@ -28,7 +28,7 @@ func TestLogRecordMetadataCarriesResourceAndAttributes(t *testing.T) {
 		Message: "GET / 200",
 		Metadata: embed.LogRecordMetadata{
 			Severity: "INFO",
-			Resource: map[string]string{
+			Resource: map[string]any{
 				"host.name":        "web-01",
 				"telemetry.source": "apache",
 				"apache.format":    "common",
diff --git a/generator/fix/fix_test.go b/generator/fix/fix_test.go
index a89d6ae..6429283 100644
--- a/generator/fix/fix_test.go
+++ b/generator/fix/fix_test.go
@@ -19,7 +19,7 @@ import (
 type captureConsumer struct {
 	mu        sync.Mutex
 	got       [][]byte
-	resources []map[string]string
+	resources []map[string]any
 }
 
 func (c *captureConsumer) ConsumeLogs(_ context.Context, records []embed.LogRecord) error {
@@ -42,7 +42,7 @@ func (c *captureConsumer) Snapshot() [][]byte {
 	return out
 }
 
-func (c *captureConsumer) ResourceAt(i int) map[string]string {
+func (c *captureConsumer) ResourceAt(i int) map[string]any {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	if i < 0 || i >= len(c.resources) {
diff --git a/generator/hostmetrics/cpu.go b/generator/hostmetrics/cpu.go
index ac0fc7b..18ee38c 100644
--- a/generator/hostmetrics/cpu.go
+++ b/generator/hostmetrics/cpu.go
@@ -11,7 +11,7 @@ type cpuScraper struct{}
 
 func (s *cpuScraper) Name() string { return "cpu" }
 
-func (s *cpuScraper) Scrape(r *rand.Rand, hostname string, resource map[string]string) []output.MetricRecord {
+func (s *cpuScraper) Scrape(r *rand.Rand, hostname string, resource map[string]any) []output.MetricRecord {
 	now := time.Now()
 	numCPUs := r.Intn(16) + 1 // #nosec G404
 
diff --git a/generator/hostmetrics/disk.go b/generator/hostmetrics/disk.go
index e00216d..c95e384 100644
--- a/generator/hostmetrics/disk.go
+++ b/generator/hostmetrics/disk.go
@@ -11,7 +11,7 @@ type diskScraper struct{}
 
 func (s *diskScraper) Name() string { return "disk" }
 
-func (s *diskScraper) Scrape(r *rand.Rand, _ string, resource map[string]string) []output.MetricRecord {
+func (s *diskScraper) Scrape(r *rand.Rand, _ string, resource map[string]any) []output.MetricRecord {
 	now := time.Now()
 	devices := []string{"sda", "sdb", "nvme0n1"}
 	device := devices[r.Intn(len(devices))] // #nosec G404
diff --git a/generator/hostmetrics/filesystem.go b/generator/hostmetrics/filesystem.go
index b439030..9f4b5f6 100644
--- a/generator/hostmetrics/filesystem.go
+++ b/generator/hostmetrics/filesystem.go
@@ -11,7 +11,7 @@ type filesystemScraper struct{}
 
 func (s *filesystemScraper) Name() string { return "filesystem" }
 
-func (s *filesystemScraper) Scrape(r *rand.Rand, _ string, resource map[string]string) []output.MetricRecord {
+func (s *filesystemScraper) Scrape(r *rand.Rand, _ string, resource map[string]any) []output.MetricRecord {
 	now := time.Now()
 
 	type mount struct {
diff --git a/generator/hostmetrics/hostmetrics_test.go b/generator/hostmetrics/hostmetrics_test.go
index b0ca4a3..8109541 100644
--- a/generator/hostmetrics/hostmetrics_test.go
+++ b/generator/hostmetrics/hostmetrics_test.go
@@ -200,7 +200,7 @@ func TestSeedDeterminism(t *testing.T) {
 // Test individual scrapers produce non-empty records.
 func TestScrapers(t *testing.T) {
 	r := rand.New(rand.NewSource(42)) // #nosec G404
-	resource := map[string]string{"host.name": "test", "os.type": "linux"}
+	resource := map[string]any{"host.name": "test", "os.type": "linux"}
 
 	scrapers := allScrapers()
 	for _, s := range scrapers {
diff --git a/generator/hostmetrics/load.go b/generator/hostmetrics/load.go
index e58ae1e..8e56067 100644
--- a/generator/hostmetrics/load.go
+++ b/generator/hostmetrics/load.go
@@ -11,7 +11,7 @@ type loadScraper struct{}
 
 func (s *loadScraper) Name() string { return "load" }
 
-func (s *loadScraper) Scrape(r *rand.Rand, _ string, resource map[string]string) []output.MetricRecord {
+func (s *loadScraper) Scrape(r *rand.Rand, _ string, resource map[string]any) []output.MetricRecord {
 	now := time.Now()
 
 	// Load averages: 1m > 5m > 15m (typical pattern)
diff --git a/generator/hostmetrics/memory.go b/generator/hostmetrics/memory.go
index b737c72..082ea93 100644
--- a/generator/hostmetrics/memory.go
+++ b/generator/hostmetrics/memory.go
@@ -11,7 +11,7 @@ type memoryScraper struct{}
 
 func (s *memoryScraper) Name() string { return "memory" }
 
-func (s *memoryScraper) Scrape(r *rand.Rand, _ string, resource map[string]string) []output.MetricRecord {
+func (s *memoryScraper) Scrape(r *rand.Rand, _ string, resource map[string]any) []output.MetricRecord {
 	now := time.Now()
 	totalGB := []int64{4, 8, 16, 32, 64}
 	total := totalGB[r.Intn(len(totalGB))] * 1024 * 1024 * 1024 // #nosec G404
diff --git a/generator/hostmetrics/network.go b/generator/hostmetrics/network.go
index 75ea1a5..1207876 100644
--- a/generator/hostmetrics/network.go
+++ b/generator/hostmetrics/network.go
@@ -11,7 +11,7 @@ type networkScraper struct{}
 
 func (s *networkScraper) Name() string { return "network" }
 
-func (s *networkScraper) Scrape(r *rand.Rand, _ string, resource map[string]string) []output.MetricRecord {
+func (s *networkScraper) Scrape(r *rand.Rand, _ string, resource map[string]any) []output.MetricRecord {
 	now := time.Now()
 	ifaces := []string{"eth0", "eth1", "lo", "ens192", "bond0"}
 	iface := ifaces[r.Intn(len(ifaces))] // #nosec G404
diff --git a/generator/hostmetrics/paging.go b/generator/hostmetrics/paging.go
index 2ed9bda..9cd9756 100644
--- a/generator/hostmetrics/paging.go
+++ b/generator/hostmetrics/paging.go
@@ -11,7 +11,7 @@ type pagingScraper struct{}
 
 func (s *pagingScraper) Name() string { return "paging" }
 
-func (s *pagingScraper) Scrape(r *rand.Rand, _ string, resource map[string]string) []output.MetricRecord {
+func (s *pagingScraper) Scrape(r *rand.Rand, _ string, resource map[string]any) []output.MetricRecord {
 	now := time.Now()
 
 	swapTotal := int64(r.Intn(8)+1) * 1024 * 1024 * 1024 // 1-8 GB #nosec G404
diff --git a/generator/hostmetrics/processes.go b/generator/hostmetrics/processes.go
index 9ed4ba0..760c159 100644
--- a/generator/hostmetrics/processes.go
+++ b/generator/hostmetrics/processes.go
@@ -11,7 +11,7 @@ type processesScraper struct{}
 
 func (s *processesScraper) Name() string { return "processes" }
 
-func (s *processesScraper) Scrape(r *rand.Rand, _ string, resource map[string]string) []output.MetricRecord {
+func (s *processesScraper) Scrape(r *rand.Rand, _ string, resource map[string]any) []output.MetricRecord {
 	now := time.Now()
 
 	running := int64(r.Intn(20)) + 1    // #nosec G404
diff --git a/generator/hostmetrics/scraper.go b/generator/hostmetrics/scraper.go
index d5de7b5..c16182a 100644
--- a/generator/hostmetrics/scraper.go
+++ b/generator/hostmetrics/scraper.go
@@ -11,5 +11,5 @@ type Scraper interface {
 	// Name returns the scraper name.
 	Name() string
 	// Scrape generates metric records for the current scrape cycle.
-	Scrape(r *rand.Rand, hostname string, resource map[string]string) []output.MetricRecord
+	Scrape(r *rand.Rand, hostname string, resource map[string]any) []output.MetricRecord
 }
diff --git a/generator/resource/resource.go b/generator/resource/resource.go
index e42ba89..438fece 100644
--- a/generator/resource/resource.go
+++ b/generator/resource/resource.go
@@ -50,7 +50,7 @@ func Hostname() string {
 //
 //	resource.Default("apache", "apache.format", "common")
 //	// → {"host.name": "<host>", "telemetry.source": "apache", "apache.format": "common"}
-func Default(source string, extras ...string) map[string]string {
+func Default(source string, extras ...string) map[string]any {
 	return WithHost(Hostname(), source, extras...)
 }
 
@@ -58,8 +58,8 @@ func Default(source string, extras ...string) map[string]string {
 // for generators whose hostname comes from a resolved datagen SystemIdentity
 // (PIPE-1036) rather than the process's os.Hostname(). extras follow the same
 // key/value convention as Default.
-func WithHost(hostname, source string, extras ...string) map[string]string {
-	r := map[string]string{
+func WithHost(hostname, source string, extras ...string) map[string]any {
+	r := map[string]any{
 		"host.name":        hostname,
 		"telemetry.source": source,
 	}
@@ -78,14 +78,14 @@ func WithHost(hostname, source string, extras ...string) map[string]string {
 // The model is: Static + Dynamic (per record) = Record. Static carries the
 // fields that never change for the worker; Record merges in the few that do.
 type StaticResources struct {
-	attrs map[string]string
+	attrs map[string]any
 }
 
 // NewStaticResources builds a StaticResources from a base attribute set. The
 // map is copied, so a caller that retains and later mutates attrs does not
 // affect the constructed value.
-func NewStaticResources(attrs map[string]string) *StaticResources {
-	cp := make(map[string]string, len(attrs))
+func NewStaticResources(attrs map[string]any) *StaticResources {
+	cp := make(map[string]any, len(attrs))
 	for k, v := range attrs {
 		cp[k] = v
 	}
@@ -102,11 +102,11 @@ func NewStaticResources(attrs map[string]string) *StaticResources {
 // corrupts every other record and races concurrent workers. When dynamic pairs
 // are supplied, Record returns a fresh merged map that is safe to mutate and
 // leaves the static set untouched.
-func (s *StaticResources) Record(dynamicKV ...string) map[string]string {
+func (s *StaticResources) Record(dynamicKV ...string) map[string]any {
 	if len(dynamicKV) < 2 {
 		return s.attrs
 	}
-	out := make(map[string]string, len(s.attrs)+len(dynamicKV)/2)
+	out := make(map[string]any, len(s.attrs)+len(dynamicKV)/2)
 	for k, v := range s.attrs {
 		out[k] = v
 	}
diff --git a/generator/resource/resource_static_test.go b/generator/resource/resource_static_test.go
index a19bf2d..92adfe4 100644
--- a/generator/resource/resource_static_test.go
+++ b/generator/resource/resource_static_test.go
@@ -5,10 +5,10 @@ import (
 	"testing"
 )
 
-func mapPtr(m map[string]string) uintptr { return reflect.ValueOf(m).Pointer() }
+func mapPtr(m map[string]any) uintptr { return reflect.ValueOf(m).Pointer() }
 
 func TestStaticResourcesConstructorCopies(t *testing.T) {
-	base := map[string]string{"host.name": "thor-web-01", "telemetry.source": "apache"}
+	base := map[string]any{"host.name": "thor-web-01", "telemetry.source": "apache"}
 	s := NewStaticResources(base)
 
 	// Mutating the input after construction must not leak into the static set.
@@ -25,7 +25,7 @@ func TestStaticResourcesConstructorCopies(t *testing.T) {
 }
 
 func TestStaticResourcesRecordNoDynamicIsSharedAndReadOnly(t *testing.T) {
-	s := NewStaticResources(map[string]string{"host.name": "thor-web-01", "telemetry.source": "apache"})
+	s := NewStaticResources(map[string]any{"host.name": "thor-web-01", "telemetry.source": "apache"})
 
 	a := s.Record()
 	b := s.Record()
@@ -40,7 +40,7 @@ func TestStaticResourcesRecordNoDynamicIsSharedAndReadOnly(t *testing.T) {
 }
 
 func TestStaticResourcesRecordWithDynamicMergesWithoutMutatingStatic(t *testing.T) {
-	s := NewStaticResources(map[string]string{"host.name": "thor-web-01", "telemetry.source": "wel"})
+	s := NewStaticResources(map[string]any{"host.name": "thor-web-01", "telemetry.source": "wel"})
 
 	rec := s.Record("wel.channel", "Security", "wel.role", "dc")
 
@@ -59,7 +59,7 @@ func TestStaticResourcesRecordWithDynamicMergesWithoutMutatingStatic(t *testing.
 }
 
 func TestStaticResourcesRecordOddArgsIgnoresTrailing(t *testing.T) {
-	s := NewStaticResources(map[string]string{"telemetry.source": "json"})
+	s := NewStaticResources(map[string]any{"telemetry.source": "json"})
 
 	// A single unpaired arg is treated as "no complete dynamic pair": shared static.
 	if mapPtr(s.Record("dangling")) != mapPtr(s.Record()) {
diff --git a/generator/traces/traces.go b/generator/traces/traces.go
index ed64582..c9957df 100644
--- a/generator/traces/traces.go
+++ b/generator/traces/traces.go
@@ -340,7 +340,7 @@ func (g *Generator) startTrace(r *mathrand.Rand) {
 	}
 }
 
-func (g *Generator) buildChildSpan(r *mathrand.Rand, kind childKind, traceID, parentID string, earliestStart time.Time, res map[string]string) embed.Span {
+func (g *Generator) buildChildSpan(r *mathrand.Rand, kind childKind, traceID, parentID string, earliestStart time.Time, res map[string]any) embed.Span {
 	spanID := generateSpanID()
 	startOffset := time.Duration(r.Intn(50)) * time.Millisecond // #nosec G404
 	start := earliestStart.Add(startOffset)
@@ -447,8 +447,8 @@ func (g *Generator) emitSpan(sp embed.Span) {
 
 // cloneResource returns a defensive copy so per-span mutations (e.g. a
 // future host-base merge in the runner) can't bleed across spans.
-func cloneResource(src map[string]string) map[string]string {
-	out := make(map[string]string, len(src))
+func cloneResource(src map[string]any) map[string]any {
+	out := make(map[string]any, len(src))
 	for k, v := range src {
 		out[k] = v
 	}
diff --git a/output/otlp_grpc/metrics_traces.go b/output/otlp_grpc/metrics_traces.go
index 53b94e7..272383b 100644
--- a/output/otlp_grpc/metrics_traces.go
+++ b/output/otlp_grpc/metrics_traces.go
@@ -195,6 +195,13 @@ func toAnyValueSimple(v any) *commonpb.AnyValue {
 		return &commonpb.AnyValue{Value: &commonpb.AnyValue_DoubleValue{DoubleValue: x}}
 	case bool:
 		return &commonpb.AnyValue{Value: &commonpb.AnyValue_BoolValue{BoolValue: x}}
+	case []string:
+		// Homogeneous string array (e.g. host.ip / host.mac) → OTLP ArrayValue.
+		values := make([]*commonpb.AnyValue, 0, len(x))
+		for _, s := range x {
+			values = append(values, &commonpb.AnyValue{Value: &commonpb.AnyValue_StringValue{StringValue: s}})
+		}
+		return &commonpb.AnyValue{Value: &commonpb.AnyValue_ArrayValue{ArrayValue: &commonpb.ArrayValue{Values: values}}}
 	default:
 		return &commonpb.AnyValue{Value: &commonpb.AnyValue_StringValue{StringValue: fmt.Sprintf("%v", x)}}
 	}
@@ -224,18 +231,13 @@ func hexByte(c byte) byte {
 }
 
 // buildMetricRequest builds an OTLP ExportMetricsServiceRequest from prepared metrics.
-func buildMetricRequest(metrics []*metricspb.Metric, resource map[string]string) *metricspb.ResourceMetrics {
+func buildMetricRequest(metrics []*metricspb.Metric, resource map[string]any) *metricspb.ResourceMetrics {
 	resourceAttrs := make([]*commonpb.KeyValue, 0, len(resource)+1)
 	resourceAttrs = append(resourceAttrs, &commonpb.KeyValue{
 		Key:   "service.name",
 		Value: &commonpb.AnyValue{Value: &commonpb.AnyValue_StringValue{StringValue: "blitz"}},
 	})
-	for k, v := range resource {
-		resourceAttrs = append(resourceAttrs, &commonpb.KeyValue{
-			Key:   k,
-			Value: &commonpb.AnyValue{Value: &commonpb.AnyValue_StringValue{StringValue: v}},
-		})
-	}
+	resourceAttrs = append(resourceAttrs, anyMapToKeyValues(resource)...)
 
 	return &metricspb.ResourceMetrics{
 		Resource: &resourcepb.Resource{
diff --git a/output/otlp_grpc/resource_array_test.go b/output/otlp_grpc/resource_array_test.go
new file mode 100644
index 0000000..7858c8e
--- /dev/null
+++ b/output/otlp_grpc/resource_array_test.go
@@ -0,0 +1,45 @@
+package otlpgrpc
+
+import (
+	"testing"
+
+	commonpb "go.opentelemetry.io/proto/otlp/common/v1"
+)
+
+// A []string resource attribute (e.g. host.ip / host.mac) must serialize to an
+// OTLP ArrayValue of StringValues, not a stringified slice (PIPE-1253).
+func TestBuildMetricRequest_ArrayResourceAttribute(t *testing.T) {
+	rm := buildMetricRequest(nil, map[string]any{
+		"host.ip": []string{"10.0.0.1", "10.0.0.2"},
+	})
+
+	var hostIP *commonpb.AnyValue
+	for _, kv := range rm.Resource.Attributes {
+		if kv.Key == "host.ip" {
+			hostIP = kv.Value
+		}
+	}
+	if hostIP == nil {
+		t.Fatal("host.ip resource attribute not found")
+	}
+
+	arr, ok := hostIP.Value.(*commonpb.AnyValue_ArrayValue)
+	if !ok {
+		t.Fatalf("host.ip should serialize as an ArrayValue, got %T", hostIP.Value)
+	}
+	if len(arr.ArrayValue.Values) != 2 {
+		t.Fatalf("host.ip array should have 2 elements, got %d", len(arr.ArrayValue.Values))
+	}
+
+	got := make([]string, 0, 2)
+	for _, v := range arr.ArrayValue.Values {
+		sv, ok := v.Value.(*commonpb.AnyValue_StringValue)
+		if !ok {
+			t.Fatalf("array element should be a StringValue, got %T", v.Value)
+		}
+		got = append(got, sv.StringValue)
+	}
+	if got[0] != "10.0.0.1" || got[1] != "10.0.0.2" {
+		t.Errorf("array elements = %v, want [10.0.0.1 10.0.0.2]", got)
+	}
+}