diff --git a/gen/go/metrics/v1/metrics.pb.go b/gen/go/metrics/v1/metrics.pb.go
index 5c786dc98..a5fa21eba 100644
--- a/gen/go/metrics/v1/metrics.pb.go
+++ b/gen/go/metrics/v1/metrics.pb.go
@@ -22,74 +22,47 @@ var _ = math.Inf
 // proto package needs to be updated.
 const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
 
-// Type of the metric. It describes how the data is reported.
-//
-// A gauge is an instantaneous measurement of a value.
-//
-// A counter/cumulative measurement is a value accumulated over a time
-// interval. In a time series, cumulative measurements should have the same
-// start time, increasing values, until an event resets the cumulative value
-// to zero and sets a new start time for the subsequent points.
+// Type is the type of values a metric has.
 type MetricDescriptor_Type int32
 
 const (
-	// Do not use this default value.
-	MetricDescriptor_UNSPECIFIED MetricDescriptor_Type = 0
-	// Integer gauge. The value can go both up and down over time.
-	// Corresponding values are stored in Int64DataPoint.
-	MetricDescriptor_GAUGE_INT64 MetricDescriptor_Type = 1
-	// Floating point gauge. The value can go both up and down over time.
-	// Corresponding values are stored in DoubleDataPoint.
-	MetricDescriptor_GAUGE_DOUBLE MetricDescriptor_Type = 2
-	// Histogram gauge measurement.
-	// Used in scenarios like a snapshot of time that current items in a queue
-	// have spent there.
-	// Corresponding values are stored in HistogramDataPoint. The count and sum of the
-	// histogram can go both up and down over time. Recorded values are always >= 0.
-	MetricDescriptor_GAUGE_HISTOGRAM MetricDescriptor_Type = 3
-	// Integer counter measurement. The value cannot decrease; if value is reset then
-	// start_time_unix_nano should also be reset.
-	// Corresponding values are stored in Int64DataPoint.
-	MetricDescriptor_COUNTER_INT64 MetricDescriptor_Type = 4
-	// Floating point counter measurement. The value cannot decrease, if
-	// resets then the start_time_unix_nano should also be reset.
-	// Recorded values are always >= 0.
-	// Corresponding values are stored in DoubleDataPoint.
-	MetricDescriptor_COUNTER_DOUBLE MetricDescriptor_Type = 5
-	// Histogram cumulative measurement.
-	// Corresponding values are stored in HistogramDataPoint. The count and sum of the
-	// histogram cannot decrease; if values are reset then start_time_unix_nano
-	// should also be reset to the new start timestamp.
-	MetricDescriptor_CUMULATIVE_HISTOGRAM MetricDescriptor_Type = 6
+	// INVALID_TYPE is the default Type, it MUST not be used.
+	MetricDescriptor_INVALID_TYPE MetricDescriptor_Type = 0
+	// INT64 values are represents as signed 64-bit integers.
+	//
+	// A Metric of this Type MUST store its values as Int64DataPoint.
+	MetricDescriptor_INT64 MetricDescriptor_Type = 1
+	// DOUBLE values are represents as double-precision floating-point
+	// numbers.
+	//
+	// A Metric of this Type MUST store its values as DoubleDataPoint.
+	MetricDescriptor_DOUBLE MetricDescriptor_Type = 2
+	// Histogram measurement.
+	// Corresponding values are stored in HistogramDataPoint.
+	MetricDescriptor_HISTOGRAM MetricDescriptor_Type = 3
 	// Summary value. Some frameworks implemented Histograms as a summary of observations
 	// (usually things like request durations and response sizes). While it
 	// also provides a total count of observations and a sum of all observed
 	// values, it calculates configurable percentiles over a sliding time
 	// window.
 	// Corresponding values are stored in SummaryDataPoint.
-	MetricDescriptor_SUMMARY MetricDescriptor_Type = 7
+	MetricDescriptor_SUMMARY MetricDescriptor_Type = 4
 )
 
 var MetricDescriptor_Type_name = map[int32]string{
-	0: "UNSPECIFIED",
-	1: "GAUGE_INT64",
-	2: "GAUGE_DOUBLE",
-	3: "GAUGE_HISTOGRAM",
-	4: "COUNTER_INT64",
-	5: "COUNTER_DOUBLE",
-	6: "CUMULATIVE_HISTOGRAM",
-	7: "SUMMARY",
+	0: "INVALID_TYPE",
+	1: "INT64",
+	2: "DOUBLE",
+	3: "HISTOGRAM",
+	4: "SUMMARY",
 }
 
 var MetricDescriptor_Type_value = map[string]int32{
-	"UNSPECIFIED":          0,
-	"GAUGE_INT64":          1,
-	"GAUGE_DOUBLE":         2,
-	"GAUGE_HISTOGRAM":      3,
-	"COUNTER_INT64":        4,
-	"COUNTER_DOUBLE":       5,
-	"CUMULATIVE_HISTOGRAM": 6,
-	"SUMMARY":              7,
+	"INVALID_TYPE": 0,
+	"INT64":        1,
+	"DOUBLE":       2,
+	"HISTOGRAM":    3,
+	"SUMMARY":      4,
 }
 
 func (x MetricDescriptor_Type) String() string {
@@ -100,6 +73,101 @@ func (MetricDescriptor_Type) EnumDescriptor() ([]byte, []int) {
 	return fileDescriptor_3c3112f9fa006917, []int{3, 0}
 }
 
+// Temporality is the temporal quality values of a metric have. It
+// describes how those values relate to the time interval over which they
+// are reported.
+type MetricDescriptor_Temporality int32
+
+const (
+	// INVALID_TEMPORALITY is the default Temporality, it MUST not be
+	// used.
+	MetricDescriptor_INVALID_TEMPORALITY MetricDescriptor_Temporality = 0
+	// INSTANTANEOUS is a metric whose values are measured at a particular
+	// instant. The values are not aggregated over any time interval and are
+	// unique per timestamp. As such, these metrics are not expected to have
+	// an associated start time.
+	MetricDescriptor_INSTANTANEOUS MetricDescriptor_Temporality = 1
+	// DELTA is a metric whose values are the aggregation of measurements
+	// made over a time interval. Successive metrics contain aggregation of
+	// values from continuous and non-overlapping intervals.
+	//
+	// The values for a DELTA metric are based only on the time interval
+	// associated with one measurement cycle. There is no dependency on
+	// previous measurements like is the case for CUMULATIVE metrics.
+	//
+	// For example, consider a system measuring the number of requests that
+	// it receives and reports the sum of these requests every second as a
+	// DELTA metric:
+	//
+	//   1. The system starts receiving at time=t_0.
+	//   2. A request is received, the system measures 1 request.
+	//   3. A request is received, the system measures 1 request.
+	//   4. A request is received, the system measures 1 request.
+	//   5. The 1 second collection cycle ends. A metric is exported for the
+	//      number of requests received over the interval of time t_0 to
+	//      t_0+1 with a value of 3.
+	//   6. A request is received, the system measures 1 request.
+	//   7. A request is received, the system measures 1 request.
+	//   8. The 1 second collection cycle ends. A metric is exported for the
+	//      number of requests received over the interval of time t_0+1 to
+	//      t_0+2 with a value of 2.
+	MetricDescriptor_DELTA MetricDescriptor_Temporality = 2
+	// CUMULATIVE is a metric whose values are the aggregation of
+	// successively made measurements from a fixed start time until the last
+	// reported measurement. This means that current values of a CUMULATIVE
+	// metric depend on all previous measurements since the start time.
+	// Because of this, the sender is required to retain this state in some
+	// form. If this state is lost or invalidated, the CUMULATIVE metric
+	// values MUST be reset and a new fixed start time following the last
+	// reported measurement time sent MUST be used.
+	//
+	// For example, consider a system measuring the number of requests that
+	// it receives and reports the sum of these requests every second as a
+	// CUMULATIVE metric:
+	//
+	//   1. The system starts receiving at time=t_0.
+	//   2. A request is received, the system measures 1 request.
+	//   3. A request is received, the system measures 1 request.
+	//   4. A request is received, the system measures 1 request.
+	//   5. The 1 second collection cycle ends. A metric is exported for the
+	//      number of requests received over the interval of time t_0 to
+	//      t_0+1 with a value of 3.
+	//   6. A request is received, the system measures 1 request.
+	//   7. A request is received, the system measures 1 request.
+	//   8. The 1 second collection cycle ends. A metric is exported for the
+	//      number of requests received over the interval of time t_0 to
+	//      t_0+2 with a value of 5.
+	//   9. The system experiences a fault and loses state.
+	//   10. The system recovers and resumes receiving at time=t_1.
+	//   11. A request is received, the system measures 1 request.
+	//   12. The 1 second collection cycle ends. A metric is exported for the
+	//      number of requests received over the interval of time t_1 to
+	//      t_0+1 with a value of 1.
+	MetricDescriptor_CUMULATIVE MetricDescriptor_Temporality = 3
+)
+
+var MetricDescriptor_Temporality_name = map[int32]string{
+	0: "INVALID_TEMPORALITY",
+	1: "INSTANTANEOUS",
+	2: "DELTA",
+	3: "CUMULATIVE",
+}
+
+var MetricDescriptor_Temporality_value = map[string]int32{
+	"INVALID_TEMPORALITY": 0,
+	"INSTANTANEOUS":       1,
+	"DELTA":               2,
+	"CUMULATIVE":          3,
+}
+
+func (x MetricDescriptor_Temporality) String() string {
+	return proto.EnumName(MetricDescriptor_Temporality_name, int32(x))
+}
+
+func (MetricDescriptor_Temporality) EnumDescriptor() ([]byte, []int) {
+	return fileDescriptor_3c3112f9fa006917, []int{3, 1}
+}
+
 // A collection of InstrumentationLibraryMetrics from a Resource.
 type ResourceMetrics struct {
 	// The resource for the metrics in this message.
@@ -334,8 +402,14 @@ type MetricDescriptor struct {
 	Description string `protobuf:"bytes,2,opt,name=description,proto3" json:"description,omitempty"`
 	// unit in which the metric value is reported. Follows the format
 	// described by http://unitsofmeasure.org/ucum.html.
-	Unit                 string                `protobuf:"bytes,3,opt,name=unit,proto3" json:"unit,omitempty"`
-	Type                 MetricDescriptor_Type `protobuf:"varint,4,opt,name=type,proto3,enum=opentelemetry.proto.metrics.v1.MetricDescriptor_Type" json:"type,omitempty"`
+	Unit string `protobuf:"bytes,3,opt,name=unit,proto3" json:"unit,omitempty"`
+	// type is the type of values this metric has.
+	Type MetricDescriptor_Type `protobuf:"varint,4,opt,name=type,proto3,enum=opentelemetry.proto.metrics.v1.MetricDescriptor_Type" json:"type,omitempty"`
+	// temporality is the Temporality of values this metric has.
+	Temporality MetricDescriptor_Temporality `protobuf:"varint,5,opt,name=temporality,proto3,enum=opentelemetry.proto.metrics.v1.MetricDescriptor_Temporality" json:"temporality,omitempty"`
+	// The set of labels associated with the metric descriptor. Labels in this list apply to
+	// all data points.
+	Labels               []*v11.StringKeyValue `protobuf:"bytes,6,rep,name=labels,proto3" json:"labels,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}              `json:"-"`
 	XXX_unrecognized     []byte                `json:"-"`
 	XXX_sizecache        int32                 `json:"-"`
@@ -391,7 +465,21 @@ func (m *MetricDescriptor) GetType() MetricDescriptor_Type {
 	if m != nil {
 		return m.Type
 	}
-	return MetricDescriptor_UNSPECIFIED
+	return MetricDescriptor_INVALID_TYPE
+}
+
+func (m *MetricDescriptor) GetTemporality() MetricDescriptor_Temporality {
+	if m != nil {
+		return m.Temporality
+	}
+	return MetricDescriptor_INVALID_TEMPORALITY
+}
+
+func (m *MetricDescriptor) GetLabels() []*v11.StringKeyValue {
+	if m != nil {
+		return m.Labels
+	}
+	return nil
 }
 
 // Int64DataPoint is a single data point in a timeseries that describes the time-varying
@@ -953,6 +1041,7 @@ func (m *SummaryDataPoint_ValueAtPercentile) GetValue() float64 {
 
 func init() {
 	proto.RegisterEnum("opentelemetry.proto.metrics.v1.MetricDescriptor_Type", MetricDescriptor_Type_name, MetricDescriptor_Type_value)
+	proto.RegisterEnum("opentelemetry.proto.metrics.v1.MetricDescriptor_Temporality", MetricDescriptor_Temporality_name, MetricDescriptor_Temporality_value)
 	proto.RegisterType((*ResourceMetrics)(nil), "opentelemetry.proto.metrics.v1.ResourceMetrics")
 	proto.RegisterType((*InstrumentationLibraryMetrics)(nil), "opentelemetry.proto.metrics.v1.InstrumentationLibraryMetrics")
 	proto.RegisterType((*Metric)(nil), "opentelemetry.proto.metrics.v1.Metric")
@@ -971,65 +1060,68 @@ func init() {
 }
 
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-	0x07, 0x19, 0x79, 0xf0, 0xe1, 0x5f, 0x01, 0x00, 0x00, 0xff, 0xff, 0xce, 0x2a, 0x11, 0x96, 0xb4,
-	0x0b, 0x00, 0x00,
+	// 994 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xdc, 0x57, 0xdd, 0x6e, 0xe3, 0x44,
+	0x14, 0x5e, 0xc7, 0x69, 0xda, 0x9e, 0x74, 0x5b, 0x67, 0xba, 0xb0, 0x51, 0xa5, 0x5d, 0x42, 0x84,
+	0xa0, 0x20, 0xea, 0xd0, 0x52, 0x2a, 0x21, 0x81, 0x20, 0x21, 0x11, 0x6b, 0x6d, 0xfe, 0x34, 0x71,
+	0x2a, 0x75, 0xa5, 0x5d, 0xe3, 0x24, 0x43, 0x3a, 0xc2, 0x1e, 0x5b, 0xf6, 0xb8, 0x6a, 0x1e, 0x80,
+	0x37, 0x40, 0x82, 0x07, 0x82, 0x07, 0xe0, 0x0d, 0x78, 0x00, 0x6e, 0x10, 0x2f, 0x80, 0x3c, 0xb6,
+	0x63, 0x27, 0x4d, 0x1b, 0x0a, 0x37, 0xb0, 0x77, 0xc7, 0xe7, 0xe7, 0x3b, 0xdf, 0xf9, 0x99, 0xcc,
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+	0x5a, 0x28, 0xd3, 0xb1, 0x5f, 0xbb, 0x3a, 0x4e, 0x44, 0x55, 0x18, 0xd0, 0xd3, 0x05, 0xef, 0x48,
+	0xa9, 0x26, 0x2e, 0x57, 0xc7, 0x07, 0x1f, 0xac, 0x42, 0x1b, 0x3b, 0xb6, 0xed, 0xb0, 0x10, 0x2c,
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+	0xc8, 0xbf, 0xfa, 0x9b, 0x04, 0x7b, 0x38, 0x56, 0x75, 0xa2, 0x94, 0xa8, 0x05, 0x5b, 0x89, 0x57,
+	0x59, 0xaa, 0x48, 0x87, 0xc5, 0x93, 0xf7, 0xd5, 0x55, 0x14, 0xe7, 0x50, 0x57, 0xc7, 0x6a, 0x82,
+	0x81, 0xe7, 0xa1, 0xe8, 0x7b, 0x09, 0xde, 0xa2, 0xcc, 0xe7, 0x5e, 0x60, 0x13, 0xc6, 0x4d, 0x4e,
+	0x1d, 0x66, 0x58, 0x74, 0xe4, 0x99, 0xde, 0xcc, 0x88, 0xab, 0x2b, 0xe7, 0x2a, 0xf2, 0x61, 0xf1,
+	0xe4, 0x73, 0xf5, 0xee, 0x0e, 0xa8, 0xda, 0x22, 0x4c, 0x3b, 0x42, 0x89, 0xf9, 0xe2, 0x27, 0xf4,
+	0x2e, 0x73, 0xf5, 0x57, 0x09, 0x9e, 0xdc, 0x09, 0x80, 0x18, 0x3c, 0xbe, 0x85, 0x68, 0x5c, 0xff,
+	0x27, 0x2b, 0x09, 0xc6, 0x8d, 0xbf, 0x95, 0x1f, 0x7e, 0x73, 0x35, 0x31, 0xf4, 0x25, 0x6c, 0x2e,
+	0x36, 0xe0, 0xdd, 0x75, 0x0d, 0x88, 0x98, 0xe2, 0x24, 0xac, 0xfa, 0xbb, 0x0c, 0x85, 0x48, 0x87,
+	0x5e, 0x42, 0x29, 0xd2, 0x1a, 0x13, 0xe2, 0x8f, 0x3d, 0xea, 0x72, 0xc7, 0x8b, 0x69, 0x7f, 0xf4,
+	0xf7, 0x60, 0x9b, 0xf3, 0x38, 0xac, 0xd8, 0x4b, 0x1a, 0xf4, 0x02, 0x4a, 0x94, 0xf1, 0xb3, 0x53,
+	0x63, 0x62, 0x72, 0xd3, 0x70, 0x1d, 0xca, 0x78, 0xc2, 0x5a, 0x5d, 0x3f, 0x36, 0x7e, 0x76, 0xda,
+	0x34, 0xb9, 0xd9, 0x0f, 0xc3, 0xf0, 0x1e, 0x5d, 0xf8, 0xf6, 0xd1, 0x4b, 0x40, 0x13, 0x27, 0x18,
+	0x59, 0x64, 0x01, 0x5c, 0x16, 0xe0, 0xb5, 0x75, 0xe0, 0x4d, 0x11, 0x99, 0xa2, 0x2b, 0x93, 0x45,
+	0x85, 0x8f, 0xbe, 0x85, 0x37, 0x2e, 0xa9, 0xcf, 0x9d, 0xa9, 0x67, 0xda, 0x0b, 0x19, 0xf2, 0x22,
+	0xc3, 0xc9, 0xba, 0x0c, 0xcf, 0x92, 0xe0, 0x34, 0xc9, 0xfe, 0xe5, 0x0d, 0x9d, 0x8f, 0xbe, 0x81,
+	0x7d, 0x3f, 0xb0, 0xed, 0x70, 0xaf, 0xb3, 0x59, 0x36, 0x44, 0x96, 0xb5, 0x33, 0x18, 0x44, 0xa1,
+	0x69, 0x8e, 0x92, 0xbf, 0xa4, 0xf1, 0xab, 0x7f, 0xc8, 0xa0, 0x2c, 0xcf, 0x0a, 0x21, 0xc8, 0x33,
+	0xd3, 0x8e, 0x8e, 0xe8, 0x36, 0x16, 0x32, 0xaa, 0x40, 0x31, 0xd9, 0x02, 0xea, 0xb0, 0x72, 0x4e,
+	0x98, 0xb2, 0xaa, 0x30, 0x2a, 0x60, 0x94, 0x97, 0xe5, 0x28, 0x2a, 0x94, 0x91, 0x06, 0x79, 0x3e,
+	0x73, 0x49, 0x39, 0x5f, 0x91, 0x0e, 0x77, 0x6f, 0x59, 0xf6, 0x3b, 0xb6, 0x46, 0xd5, 0x67, 0x2e,
+	0xc1, 0x02, 0x02, 0xbd, 0x82, 0x22, 0x27, 0xb6, 0xeb, 0x78, 0xa6, 0x45, 0xf9, 0xac, 0xbc, 0x21,
+	0x10, 0x3f, 0xbb, 0x3f, 0x62, 0x8a, 0x81, 0xb3, 0x80, 0xa8, 0x05, 0x05, 0xcb, 0x1c, 0x11, 0xcb,
+	0x2f, 0x17, 0x44, 0x7b, 0x8f, 0xd6, 0x9c, 0xcc, 0x01, 0xf7, 0x28, 0x9b, 0x3e, 0x27, 0xb3, 0x73,
+	0xd3, 0x0a, 0x08, 0x8e, 0x83, 0xab, 0xcf, 0x21, 0x1f, 0x92, 0x46, 0x0a, 0xec, 0x68, 0xdd, 0xf3,
+	0x7a, 0x5b, 0x6b, 0x1a, 0xfa, 0x45, 0xbf, 0xa5, 0x3c, 0x40, 0xdb, 0xb0, 0xa1, 0x75, 0xf5, 0xb3,
+	0x53, 0x45, 0x42, 0x00, 0x85, 0x66, 0x6f, 0xd8, 0x68, 0xb7, 0x94, 0x1c, 0x7a, 0x08, 0xdb, 0xcf,
+	0xb4, 0x81, 0xde, 0xfb, 0x1a, 0xd7, 0x3b, 0x8a, 0x8c, 0x8a, 0xb0, 0x39, 0x18, 0x76, 0x3a, 0x75,
+	0x7c, 0xa1, 0xe4, 0xab, 0x3a, 0x14, 0x33, 0x7c, 0xd1, 0x63, 0xd8, 0x9f, 0x63, 0xb6, 0x3a, 0xfd,
+	0x1e, 0xae, 0xb7, 0x35, 0xfd, 0x42, 0x79, 0x80, 0x4a, 0xf0, 0x50, 0xeb, 0x0e, 0xf4, 0x7a, 0x57,
+	0xaf, 0x77, 0x5b, 0xbd, 0xe1, 0x40, 0x91, 0xc2, 0x6c, 0xcd, 0x56, 0x5b, 0xaf, 0x2b, 0x39, 0xb4,
+	0x0b, 0xf0, 0xd5, 0xb0, 0x33, 0x6c, 0xd7, 0x75, 0xed, 0xbc, 0xa5, 0xc8, 0xd5, 0x9f, 0x25, 0xd8,
+	0x5d, 0x3c, 0x40, 0x99, 0xe2, 0xa5, 0x7f, 0x51, 0x3c, 0xaa, 0xc1, 0x23, 0x9f, 0x9b, 0x1e, 0x37,
+	0x38, 0xb5, 0x89, 0x11, 0x30, 0x7a, 0x6d, 0x30, 0x93, 0x39, 0x62, 0x5b, 0x0a, 0xb8, 0x24, 0x6c,
+	0x3a, 0xb5, 0xc9, 0x90, 0xd1, 0xeb, 0xae, 0xc9, 0x1c, 0xf4, 0x0e, 0xec, 0x2e, 0xb9, 0xca, 0xc2,
+	0x75, 0x87, 0x67, 0xbd, 0x1e, 0xc1, 0xc6, 0x55, 0x98, 0x47, 0xac, 0x91, 0x8c, 0xa3, 0x8f, 0xea,
+	0x2f, 0x12, 0xec, 0x2d, 0x1d, 0xd5, 0xff, 0x53, 0x1d, 0x52, 0x52, 0xc7, 0x9f, 0x79, 0x40, 0x37,
+	0x7f, 0x10, 0xfe, 0xfb, 0xa5, 0x8c, 0x9d, 0x80, 0x71, 0x51, 0x4a, 0x1e, 0x47, 0x1f, 0x48, 0x01,
+	0xd9, 0x0f, 0x6c, 0x71, 0x36, 0x25, 0x1c, 0x8a, 0x68, 0x00, 0x9b, 0xa3, 0x60, 0xfc, 0x1d, 0xe1,
+	0xc9, 0xb1, 0xfa, 0xf4, 0xfe, 0xbf, 0x8d, 0x6a, 0x43, 0x20, 0xe0, 0x04, 0x09, 0xbd, 0x07, 0x7b,
+	0xe4, 0xda, 0xb5, 0xe8, 0x98, 0x72, 0x63, 0xe4, 0x04, 0x6c, 0xe2, 0x97, 0x37, 0x2b, 0xf2, 0xa1,
+	0x84, 0x77, 0x13, 0x75, 0x43, 0x68, 0x0f, 0x7e, 0xca, 0x41, 0x21, 0x0a, 0x4e, 0x09, 0x4b, 0x59,
+	0xc2, 0xaf, 0x60, 0x8b, 0x5c, 0x13, 0xdb, 0xb5, 0x4c, 0x4f, 0x74, 0xa4, 0x78, 0xd2, 0xf8, 0xc7,
+	0xfc, 0xd4, 0x56, 0x8c, 0x84, 0xe7, 0x98, 0x07, 0x3f, 0x4a, 0xb0, 0x95, 0xa8, 0xd3, 0xf1, 0x4b,
+	0x99, 0xf1, 0xaf, 0xe8, 0x77, 0x6e, 0x45, 0xbf, 0x7b, 0x50, 0x34, 0x39, 0x37, 0xc7, 0x97, 0xe1,
+	0x95, 0x9f, 0xdc, 0x64, 0xf7, 0x5c, 0x89, 0x2c, 0x42, 0xf5, 0x07, 0x19, 0x94, 0xe5, 0x0b, 0xe2,
+	0x35, 0xd9, 0x39, 0x07, 0x4a, 0x2e, 0xf1, 0xc6, 0x84, 0x71, 0x6a, 0x11, 0x43, 0x74, 0x39, 0xd9,
+	0xbe, 0xc6, 0x7d, 0xef, 0x4c, 0x55, 0x54, 0x56, 0xe7, 0xfd, 0x39, 0x20, 0x56, 0x52, 0x70, 0x61,
+	0xf4, 0x0f, 0x34, 0x28, 0xdd, 0x70, 0x43, 0x4f, 0x01, 0x52, 0xc7, 0x78, 0xe4, 0x19, 0x4d, 0xba,
+	0x0d, 0xb9, 0xcc, 0x36, 0x34, 0x38, 0xbc, 0x4d, 0x9d, 0x35, 0x24, 0x1b, 0x3b, 0xf1, 0xf3, 0xb2,
+	0x1f, 0x1a, 0xfa, 0xd2, 0x8b, 0x2f, 0xa6, 0x94, 0x5f, 0x06, 0xa3, 0x70, 0x30, 0xb5, 0x30, 0xf4,
+	0x28, 0x7d, 0xa6, 0x2f, 0x20, 0x1d, 0x45, 0x8f, 0xf6, 0x29, 0x61, 0xb5, 0x69, 0xf6, 0x5f, 0xc3,
+	0xa8, 0x20, 0x0c, 0x1f, 0xff, 0x15, 0x00, 0x00, 0xff, 0xff, 0xe2, 0x78, 0x81, 0x13, 0x5e, 0x0c,
+	0x00, 0x00,
 }
diff --git a/opentelemetry/proto/metrics/v1/metrics.proto b/opentelemetry/proto/metrics/v1/metrics.proto
index 6c160c7fa..46e56de6e 100644
--- a/opentelemetry/proto/metrics/v1/metrics.proto
+++ b/opentelemetry/proto/metrics/v1/metrics.proto
@@ -118,49 +118,25 @@ message MetricDescriptor {
   // described by http://unitsofmeasure.org/ucum.html.
   string unit = 3;
 
-  // Type of the metric. It describes how the data is reported.
-  //
-  // A gauge is an instantaneous measurement of a value.
-  //
-  // A counter/cumulative measurement is a value accumulated over a time
-  // interval. In a time series, cumulative measurements should have the same
-  // start time, increasing values, until an event resets the cumulative value
-  // to zero and sets a new start time for the subsequent points.
+  // Type is the type of values a metric has.
   enum Type {
-    // Do not use this default value.
-    UNSPECIFIED = 0;
-
-    // Integer gauge. The value can go both up and down over time.
-    // Corresponding values are stored in Int64DataPoint.
-    GAUGE_INT64 = 1;
-
-    // Floating point gauge. The value can go both up and down over time.
-    // Corresponding values are stored in DoubleDataPoint.
-    GAUGE_DOUBLE = 2;
-
-    // Histogram gauge measurement.
-    // Used in scenarios like a snapshot of time that current items in a queue
-    // have spent there.
-    // Corresponding values are stored in HistogramDataPoint. The count and sum of the
-    // histogram can go both up and down over time. Recorded values are always >= 0.
-    GAUGE_HISTOGRAM = 3;
-
-    // Integer counter measurement. The value cannot decrease; if value is reset then
-    // start_time_unix_nano should also be reset.
-    // Corresponding values are stored in Int64DataPoint.
-    COUNTER_INT64 = 4;
-
-    // Floating point counter measurement. The value cannot decrease, if
-    // resets then the start_time_unix_nano should also be reset.
-    // Recorded values are always >= 0.
-    // Corresponding values are stored in DoubleDataPoint.
-    COUNTER_DOUBLE = 5;
-
-    // Histogram cumulative measurement.
-    // Corresponding values are stored in HistogramDataPoint. The count and sum of the
-    // histogram cannot decrease; if values are reset then start_time_unix_nano
-    // should also be reset to the new start timestamp.
-    CUMULATIVE_HISTOGRAM = 6;
+    // INVALID_TYPE is the default Type, it MUST not be used.
+    INVALID_TYPE = 0;
+
+    // INT64 values are represents as signed 64-bit integers.
+    //
+    // A Metric of this Type MUST store its values as Int64DataPoint.
+    INT64 = 1;
+
+    // DOUBLE values are represents as double-precision floating-point
+    // numbers.
+    //
+    // A Metric of this Type MUST store its values as DoubleDataPoint.
+    DOUBLE = 2;
+
+    // Histogram measurement.
+    // Corresponding values are stored in HistogramDataPoint.
+    HISTOGRAM = 3;
 
     // Summary value. Some frameworks implemented Histograms as a summary of observations
     // (usually things like request durations and response sizes). While it
@@ -168,9 +144,92 @@ message MetricDescriptor {
     // values, it calculates configurable percentiles over a sliding time
     // window.
     // Corresponding values are stored in SummaryDataPoint.
-    SUMMARY = 7;
+    SUMMARY = 4;
   }
+
+  // type is the type of values this metric has.
   Type type = 4;
+
+  // Temporality is the temporal quality values of a metric have. It
+  // describes how those values relate to the time interval over which they
+  // are reported.
+  enum Temporality {
+    // INVALID_TEMPORALITY is the default Temporality, it MUST not be
+    // used.
+    INVALID_TEMPORALITY = 0;
+
+    // INSTANTANEOUS is a metric whose values are measured at a particular
+    // instant. The values are not aggregated over any time interval and are
+    // unique per timestamp. As such, these metrics are not expected to have
+    // an associated start time.
+    INSTANTANEOUS = 1;
+
+    // DELTA is a metric whose values are the aggregation of measurements
+    // made over a time interval. Successive metrics contain aggregation of
+    // values from continuous and non-overlapping intervals.
+    //
+    // The values for a DELTA metric are based only on the time interval
+    // associated with one measurement cycle. There is no dependency on
+    // previous measurements like is the case for CUMULATIVE metrics.
+    //
+    // For example, consider a system measuring the number of requests that
+    // it receives and reports the sum of these requests every second as a
+    // DELTA metric:
+    //
+    //   1. The system starts receiving at time=t_0.
+    //   2. A request is received, the system measures 1 request.
+    //   3. A request is received, the system measures 1 request.
+    //   4. A request is received, the system measures 1 request.
+    //   5. The 1 second collection cycle ends. A metric is exported for the
+    //      number of requests received over the interval of time t_0 to
+    //      t_0+1 with a value of 3.
+    //   6. A request is received, the system measures 1 request.
+    //   7. A request is received, the system measures 1 request.
+    //   8. The 1 second collection cycle ends. A metric is exported for the
+    //      number of requests received over the interval of time t_0+1 to
+    //      t_0+2 with a value of 2.
+    DELTA = 2;
+
+    // CUMULATIVE is a metric whose values are the aggregation of
+    // successively made measurements from a fixed start time until the last
+    // reported measurement. This means that current values of a CUMULATIVE
+    // metric depend on all previous measurements since the start time.
+    // Because of this, the sender is required to retain this state in some
+    // form. If this state is lost or invalidated, the CUMULATIVE metric
+    // values MUST be reset and a new fixed start time following the last
+    // reported measurement time sent MUST be used.
+    //
+    // For example, consider a system measuring the number of requests that
+    // it receives and reports the sum of these requests every second as a
+    // CUMULATIVE metric:
+    //
+    //   1. The system starts receiving at time=t_0.
+    //   2. A request is received, the system measures 1 request.
+    //   3. A request is received, the system measures 1 request.
+    //   4. A request is received, the system measures 1 request.
+    //   5. The 1 second collection cycle ends. A metric is exported for the
+    //      number of requests received over the interval of time t_0 to
+    //      t_0+1 with a value of 3.
+    //   6. A request is received, the system measures 1 request.
+    //   7. A request is received, the system measures 1 request.
+    //   8. The 1 second collection cycle ends. A metric is exported for the
+    //      number of requests received over the interval of time t_0 to
+    //      t_0+2 with a value of 5.
+    //   9. The system experiences a fault and loses state.
+    //   10. The system recovers and resumes receiving at time=t_1.
+    //   11. A request is received, the system measures 1 request.
+    //   12. The 1 second collection cycle ends. A metric is exported for the
+    //      number of requests received over the interval of time t_1 to
+    //      t_0+1 with a value of 1.
+    CUMULATIVE = 3;
+  }
+
+  // temporality is the Temporality of values this metric has.
+  Temporality temporality = 5;
+
+  // The set of labels associated with the metric descriptor. Labels in this list apply to
+  // all data points.
+  repeated opentelemetry.proto.common.v1.StringKeyValue labels = 6;
 }
 
 // Int64DataPoint is a single data point in a timeseries that describes the time-varying