diff --git a/src/plugins/data/common/search/aggs/agg_type.ts b/src/plugins/data/common/search/aggs/agg_type.ts
index 7931ce1f59577..4583be17478e3 100644
--- a/src/plugins/data/common/search/aggs/agg_type.ts
+++ b/src/plugins/data/common/search/aggs/agg_type.ts
@@ -10,7 +10,7 @@ import { constant, noop, identity } from 'lodash';
 import { i18n } from '@kbn/i18n';
 
 import { ISearchSource } from 'src/plugins/data/public';
-import { SerializedFieldFormat } from 'src/plugins/expressions/common';
+import { DatatableColumnType, SerializedFieldFormat } from 'src/plugins/expressions/common';
 import type { RequestAdapter } from 'src/plugins/inspector/common';
 
 import { initParams } from './agg_params';
@@ -33,6 +33,7 @@ export interface AggTypeConfig<
   ordered?: any;
   hasNoDsl?: boolean;
   params?: Array<Partial<TParam>>;
+  valueType?: DatatableColumnType;
   getRequestAggs?: ((aggConfig: TAggConfig) => TAggConfig[]) | (() => TAggConfig[] | void);
   getResponseAggs?: ((aggConfig: TAggConfig) => TAggConfig[]) | (() => TAggConfig[] | void);
   customLabels?: boolean;
@@ -91,6 +92,11 @@ export class AggType<
    * @type {string}
    */
   title: string;
+  /**
+   * The type the values produced by this agg will have in the final data table.
+   * If not specified, the type of the field is used.
+   */
+  valueType?: DatatableColumnType;
   /**
    * a function that will be called when this aggType is assigned to
    * an aggConfig, and that aggConfig is being rendered (in a form, chart, etc.).
@@ -222,6 +228,7 @@ export class AggType<
     this.dslName = config.dslName || config.name;
     this.expressionName = config.expressionName;
     this.title = config.title;
+    this.valueType = config.valueType;
     this.makeLabel = config.makeLabel || constant(this.name);
     this.ordered = config.ordered;
     this.hasNoDsl = !!config.hasNoDsl;
diff --git a/src/plugins/data/common/search/aggs/metrics/cardinality.ts b/src/plugins/data/common/search/aggs/metrics/cardinality.ts
index 38dd5893eb8ad..5a18924902fc3 100644
--- a/src/plugins/data/common/search/aggs/metrics/cardinality.ts
+++ b/src/plugins/data/common/search/aggs/metrics/cardinality.ts
@@ -24,6 +24,7 @@ export interface AggParamsCardinality extends BaseAggParams {
 export const getCardinalityMetricAgg = () =>
   new MetricAggType({
     name: METRIC_TYPES.CARDINALITY,
+    valueType: 'number',
     expressionName: aggCardinalityFnName,
     title: uniqueCountTitle,
     makeLabel(aggConfig: IMetricAggConfig) {
diff --git a/src/plugins/data/common/search/tabify/response_writer.test.ts b/src/plugins/data/common/search/tabify/response_writer.test.ts
index 6cec6d431ab70..603ccc0f493c7 100644
--- a/src/plugins/data/common/search/tabify/response_writer.test.ts
+++ b/src/plugins/data/common/search/tabify/response_writer.test.ts
@@ -7,7 +7,7 @@
  */
 
 import { TabbedAggResponseWriter } from './response_writer';
-import { AggConfigs, BUCKET_TYPES } from '../aggs';
+import { AggConfigs, BUCKET_TYPES, METRIC_TYPES } from '../aggs';
 import { mockAggTypesRegistry } from '../aggs/test_helpers';
 import { TabbedResponseWriterOptions } from './types';
 
@@ -23,7 +23,12 @@ describe('TabbedAggResponseWriter class', () => {
         field: 'geo.src',
       },
     },
-    { type: 'count' },
+    {
+      type: METRIC_TYPES.CARDINALITY,
+      params: {
+        field: 'machine.os.raw',
+      },
+    },
   ];
 
   const twoSplitsAggConfig = [
@@ -39,7 +44,12 @@ describe('TabbedAggResponseWriter class', () => {
         field: 'machine.os.raw',
       },
     },
-    { type: 'count' },
+    {
+      type: METRIC_TYPES.CARDINALITY,
+      params: {
+        field: 'machine.os.raw',
+      },
+    },
   ];
 
   const createResponseWritter = (aggs: any[] = [], opts?: Partial<TabbedResponseWriterOptions>) => {
@@ -174,19 +184,23 @@ describe('TabbedAggResponseWriter class', () => {
         });
 
         expect(response.columns[1]).toHaveProperty('id', 'col-1-2');
-        expect(response.columns[1]).toHaveProperty('name', 'Count');
+        expect(response.columns[1]).toHaveProperty('name', 'Unique count of machine.os.raw');
         expect(response.columns[1]).toHaveProperty('meta', {
           index: 'logstash-*',
+          field: 'machine.os.raw',
           params: {
             id: 'number',
           },
           source: 'esaggs',
           sourceParams: {
+            appliedTimeRange: undefined,
             enabled: true,
             id: '2',
             indexPatternId: '1234',
-            params: {},
-            type: 'count',
+            params: {
+              field: 'machine.os.raw',
+            },
+            type: 'cardinality',
           },
           type: 'number',
         });
@@ -231,19 +245,23 @@ describe('TabbedAggResponseWriter class', () => {
         });
 
         expect(response.columns[1]).toHaveProperty('id', 'col-1-2');
-        expect(response.columns[1]).toHaveProperty('name', 'Count');
+        expect(response.columns[1]).toHaveProperty('name', 'Unique count of machine.os.raw');
         expect(response.columns[1]).toHaveProperty('meta', {
           index: 'logstash-*',
+          field: 'machine.os.raw',
           params: {
             id: 'number',
           },
           source: 'esaggs',
           sourceParams: {
+            appliedTimeRange: undefined,
             enabled: true,
             id: '2',
             indexPatternId: '1234',
-            params: {},
-            type: 'count',
+            params: {
+              field: 'machine.os.raw',
+            },
+            type: 'cardinality',
           },
           type: 'number',
         });
diff --git a/src/plugins/data/common/search/tabify/response_writer.ts b/src/plugins/data/common/search/tabify/response_writer.ts
index 1c312e5cd2200..a0ba07598e53a 100644
--- a/src/plugins/data/common/search/tabify/response_writer.ts
+++ b/src/plugins/data/common/search/tabify/response_writer.ts
@@ -73,7 +73,8 @@ export class TabbedAggResponseWriter {
           id: column.id,
           name: column.name,
           meta: {
-            type: column.aggConfig.params.field?.type || 'number',
+            type:
+              column.aggConfig.type.valueType || column.aggConfig.params.field?.type || 'number',
             field: column.aggConfig.params.field?.name,
             index: column.aggConfig.getIndexPattern()?.title,
             params: column.aggConfig.toSerializedFieldFormat(),
diff --git a/src/plugins/data/public/public.api.md b/src/plugins/data/public/public.api.md
index 03ae893ab526d..782f6f45eadc7 100644
--- a/src/plugins/data/public/public.api.md
+++ b/src/plugins/data/public/public.api.md
@@ -24,6 +24,7 @@ import * as CSS from 'csstype';
 import { Datatable as Datatable_2 } from 'src/plugins/expressions';
 import { Datatable as Datatable_3 } from 'src/plugins/expressions/common';
 import { DatatableColumn as DatatableColumn_2 } from 'src/plugins/expressions';
+import { DatatableColumnType } from 'src/plugins/expressions/common';
 import { DetailedPeerCertificate } from 'tls';
 import { Ensure } from '@kbn/utility-types';
 import { EnvironmentMode } from '@kbn/config';
diff --git a/src/plugins/data/server/server.api.md b/src/plugins/data/server/server.api.md
index 3951bb0c7ed75..d579663eeca43 100644
--- a/src/plugins/data/server/server.api.md
+++ b/src/plugins/data/server/server.api.md
@@ -18,6 +18,7 @@ import { CoreStart as CoreStart_2 } from 'src/core/server';
 import { Datatable } from 'src/plugins/expressions';
 import { Datatable as Datatable_2 } from 'src/plugins/expressions/common';
 import { DatatableColumn } from 'src/plugins/expressions';
+import { DatatableColumnType } from 'src/plugins/expressions/common';
 import { Duration } from 'moment';
 import { ElasticsearchClient } from 'src/core/server';
 import { ElasticsearchClient as ElasticsearchClient_2 } from 'kibana/server';