diff --git a/tensorflow/core/framework/summary.proto b/tensorflow/core/framework/summary.proto
index 532e4fcd87b..b6e4aaf6331 100644
--- a/tensorflow/core/framework/summary.proto
+++ b/tensorflow/core/framework/summary.proto
@@ -53,8 +53,32 @@ message SummaryMetadata {
 
   // Longform readable description of the summary sequence. Markdown supported.
   string summary_description = 3;
+
+  // Class of data stored in this time series. Required for compatibility with
+  // TensorBoard's generic data facilities (`DataProvider`, et al.). This value
+  // imposes constraints on the dtype and shape of the corresponding tensor
+  // values. See `DataClass` docs for details.
+  DataClass data_class = 4;
 };
 
+enum DataClass {
+  // Unknown data class, used (implicitly) for legacy data. Will not be
+  // processed by data ingestion pipelines.
+  DATA_CLASS_UNKNOWN = 0;
+  // Scalar time series. Each `Value` for the corresponding tag must have
+  // `tensor` set to a rank-0 tensor of floating-point dtype, which will be
+  // converted to float64.
+  DATA_CLASS_SCALAR = 1;
+  // Tensor time series. Each `Value` for the corresponding tag must have
+  // `tensor` set. The tensor value is arbitrary, but should be small to
+  // accommodate direct storage in database backends: an upper bound of a few
+  // kilobytes is a reasonable rule of thumb.
+  DATA_CLASS_TENSOR = 2;
+  // Blob sequence time series. Each `Value` for the corresponding tag must
+  // have `tensor` set to a rank-1 tensor of bytestring dtype.
+  DATA_CLASS_BLOB_SEQUENCE = 3;
+}
+
 // A Summary is a set of named values to be displayed by the
 // visualizer.
 //
diff --git a/tensorflow/tools/api/golden/v1/tensorflow.-summary-metadata.pbtxt b/tensorflow/tools/api/golden/v1/tensorflow.-summary-metadata.pbtxt
index c02575b9626..dd655b1a75d 100644
--- a/tensorflow/tools/api/golden/v1/tensorflow.-summary-metadata.pbtxt
+++ b/tensorflow/tools/api/golden/v1/tensorflow.-summary-metadata.pbtxt
@@ -21,6 +21,13 @@ tf_proto {
       label: LABEL_OPTIONAL
       type: TYPE_STRING
     }
+    field {
+      name: "data_class"
+      number: 4
+      label: LABEL_OPTIONAL
+      type: TYPE_ENUM
+      type_name: ".tensorflow.DataClass"
+    }
     nested_type {
       name: "PluginData"
       field {