diff --git a/docs/api/index-patterns.asciidoc b/docs/api/index-patterns.asciidoc
index 79d2f164fb8c3b..b343d80b4fc15c 100644
--- a/docs/api/index-patterns.asciidoc
+++ b/docs/api/index-patterns.asciidoc
@@ -20,6 +20,12 @@ The following index patterns APIs are available:
     ** <<index-patterns-api-default-set, Set default index pattern API>> to set a default index pattern
 * Fields
     ** <<index-patterns-fields-api-update, Update index pattern field>> to change field metadata, such as `count`, `customLabel` and `format`
+* Runtime fields
+    ** <<index-patterns-runtime-field-api-get, Get runtime field API>> to retrieve a runtime field
+    ** <<index-patterns-runtime-field-api-create, Create runtime field API>> to create a runtime field
+    ** <<index-patterns-runtime-field-api-upsert, Upsert runtime field API>> to create or update a runtime field
+    ** <<index-patterns-runtime-field-api-update, Update runtime field API>> to partially update an existing runtime field
+    ** <<index-patterns-runtime-field-api-delete, Delete runtime field API>> to delete a runtime field
 
 include::index-patterns/get.asciidoc[]
 include::index-patterns/create.asciidoc[]
@@ -28,3 +34,9 @@ include::index-patterns/delete.asciidoc[]
 include::index-patterns/default-get.asciidoc[]
 include::index-patterns/default-set.asciidoc[]
 include::index-patterns/update-fields.asciidoc[]
+include::index-patterns/runtime-fields/get.asciidoc[]
+include::index-patterns/runtime-fields/create.asciidoc[]
+include::index-patterns/runtime-fields/upsert.asciidoc[]
+include::index-patterns/runtime-fields/update.asciidoc[]
+include::index-patterns/runtime-fields/delete.asciidoc[]
+
diff --git a/docs/api/index-patterns/create.asciidoc b/docs/api/index-patterns/create.asciidoc
index 771292d6f934d5..521e25931ad49f 100644
--- a/docs/api/index-patterns/create.asciidoc
+++ b/docs/api/index-patterns/create.asciidoc
@@ -84,6 +84,7 @@ $ curl -X POST api/index_patterns/index_pattern
       "typeMeta": {},
       "fieldFormats": {},
       "fieldAttrs": {},
+      "runtimeFieldMap": {}
       "allowNoIndex": "..."
     }
 }
diff --git a/docs/api/index-patterns/get.asciidoc b/docs/api/index-patterns/get.asciidoc
index 3f53bf0726bf14..64588e63f62ae3 100644
--- a/docs/api/index-patterns/get.asciidoc
+++ b/docs/api/index-patterns/get.asciidoc
@@ -58,6 +58,7 @@ The API returns an index pattern object:
         "typeMeta": {},
         "fieldFormats": {},
         "fieldAttrs": {},
+        "runtimeFieldMap" {},
         "allowNoIndex: "..."
     }
 }
diff --git a/docs/api/index-patterns/runtime-fields/create.asciidoc b/docs/api/index-patterns/runtime-fields/create.asciidoc
new file mode 100644
index 00000000000000..b0773c29e5309f
--- /dev/null
+++ b/docs/api/index-patterns/runtime-fields/create.asciidoc
@@ -0,0 +1,61 @@
+[[index-patterns-runtime-field-api-create]]
+=== Create runtime field API
+++++
+<titleabbrev>Create runtime field</titleabbrev>
+++++
+
+experimental[] Create a runtime field
+
+[[index-patterns-runtime-field-create-request]]
+==== Request
+
+`POST <kibana host>:<port>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field`
+
+`POST <kibana host>:<port>/s/<space_id>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field`
+
+[[index-patterns-runtime-field-create-params]]
+==== Path parameters
+
+`space_id`::
+(Optional, string) An identifier for the space. If `space_id` is not provided in the URL, the default space is used.
+
+`index_pattern_id`::
+(Required, string) The ID of the index pattern.
+
+[[index-patterns-runtime-field-create-body]]
+==== Request body
+
+`name`:: (Required, string) The name for a runtime field.
+
+`runtimeField`:: (Required, object) The runtime field definition object.
+
+
+[[index-patterns-runtime-field-create-example]]
+==== Examples
+
+Create a runtime field on an index pattern:
+
+[source,sh]
+--------------------------------------------------
+$ curl -X POST api/index_patterns/index_pattern/<index_pattern_id>/runtime_field
+{
+  "name": "runtimeFoo",
+  "runtimeField": {
+     "type": "long",
+     "script": {
+        "source": "emit(doc["foo"].value)"
+      }
+  }
+}
+--------------------------------------------------
+// KIBANA
+
+The API returns created runtime field object and update index pattern object:
+
+[source,sh]
+--------------------------------------------------
+{
+    "index_pattern": {...},
+    "field": {...}
+}
+--------------------------------------------------
diff --git a/docs/api/index-patterns/runtime-fields/delete.asciidoc b/docs/api/index-patterns/runtime-fields/delete.asciidoc
new file mode 100644
index 00000000000000..840789fe1ec23f
--- /dev/null
+++ b/docs/api/index-patterns/runtime-fields/delete.asciidoc
@@ -0,0 +1,37 @@
+[[index-patterns-runtime-field-api-delete]]
+=== Delete runtime field API
+++++
+<titleabbrev>Delete runtime field</titleabbrev>
+++++
+
+experimental[] Delete a runtime field from an index pattern.
+
+[[index-patterns-runtime-field-api-delete-request]]
+==== Request
+
+`DELETE <kibana host>:<port>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field/<name>`
+
+`DELETE <kibana host>:<port>/s/<space_id>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field/<name>`
+
+[[index-patterns-runtime-field-api-delete-path-params]]
+==== Path parameters
+
+`space_id`::
+(Optional, string) An identifier for the space. If `space_id` is not provided in the URL, the default space is used.
+
+`index_pattern_id`::
+(Required, string) The ID of the index pattern your want to delete a runtime field from.
+
+`name`::
+(Required, string) The name of the runtime field you want to delete.
+
+
+==== Example
+
+Delete a runtime field from an index pattern:
+
+[source,sh]
+--------------------------------------------------
+$ curl -X DELETE api/index_patterns/index_pattern/<my-pattern>/runtime_field/<runtime-field-name>
+--------------------------------------------------
+// KIBANA
diff --git a/docs/api/index-patterns/runtime-fields/get.asciidoc b/docs/api/index-patterns/runtime-fields/get.asciidoc
new file mode 100644
index 00000000000000..42bd209c708bc3
--- /dev/null
+++ b/docs/api/index-patterns/runtime-fields/get.asciidoc
@@ -0,0 +1,52 @@
+[[index-patterns-runtime-field-api-get]]
+=== Get runtime field API
+++++
+<titleabbrev>Get runtime field</titleabbrev>
+++++
+
+experimental[] Get a runtime field
+
+[[index-patterns-runtime-field-get-request]]
+==== Request
+
+`GET <kibana host>:<port>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field/<name>`
+
+`GET <kibana host>:<port>/s/<space_id>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field/<name>`
+
+[[index-patterns-runtime-field-get-params]]
+==== Path parameters
+
+`space_id`::
+(Optional, string) An identifier for the space. If `space_id` is not provided in the URL, the default space is used.
+
+`index_pattern_id`::
+(Required, string) The ID of the index pattern.
+
+`name`::
+(Required, string) The name of the runtime field you want to retrieve.
+
+
+[[index-patterns-runtime-field-get-example]]
+==== Example
+
+Retrieve a runtime field named `foo` of index pattern with the `my-pattern` ID:
+
+[source,sh]
+--------------------------------------------------
+$ curl -X GET api/index_patterns/index_pattern/my-pattern/runtime_field/foo
+--------------------------------------------------
+// KIBANA
+
+The API returns a runtime `field` object, and a `runtimeField` definition object:
+
+[source,sh]
+--------------------------------------------------
+{
+    "field": {
+        ...
+    },
+    "runtimeField": {
+        ...
+    }
+}
+--------------------------------------------------
diff --git a/docs/api/index-patterns/runtime-fields/update.asciidoc b/docs/api/index-patterns/runtime-fields/update.asciidoc
new file mode 100644
index 00000000000000..f34460896f7bc9
--- /dev/null
+++ b/docs/api/index-patterns/runtime-fields/update.asciidoc
@@ -0,0 +1,66 @@
+[[index-patterns-runtime-field-api-update]]
+=== Update runtime field API
+++++
+<titleabbrev>Update runtime field</titleabbrev>
+++++
+
+experimental[] Update an existing runtime field
+
+[[index-patterns-runtime-field-update-request]]
+==== Request
+
+`POST <kibana host>:<port>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field/<name>`
+
+`POST <kibana host>:<port>/s/<space_id>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field/<name>`
+
+[[index-patterns-runtime-field-update-params]]
+==== Path parameters
+
+`space_id`::
+(Optional, string) An identifier for the space. If `space_id` is not provided in the URL, the default space is used.
+
+`index_pattern_id`::
+(Required, string) The ID of the index pattern.
+
+`name`::
+(Required, string) The name of the runtime field you want to update.
+
+[[index-patterns-runtime-field-update-body]]
+==== Request body
+
+`runtimeField`:: (Required, object) The runtime field definition object.
+
+You can update following fields:
+
+* `type`
+* `script`
+
+
+
+[[index-patterns-runtime-field-update-example]]
+==== Examples
+
+Update an existing runtime field on an index pattern:
+
+[source,sh]
+--------------------------------------------------
+$ curl -X POST api/index_patterns/index_pattern/<index_pattern_id>/runtime_field/<runtime_field_name>
+{
+  "runtimeField": {
+     "script": {
+        "source": "emit(doc["bar"].value)"
+      }
+  }
+}
+--------------------------------------------------
+// KIBANA
+
+The API returns updated runtime field object and updated index pattern object:
+
+[source,sh]
+--------------------------------------------------
+{
+    "index_pattern": {...},
+    "field": {...}
+}
+--------------------------------------------------
diff --git a/docs/api/index-patterns/runtime-fields/upsert.asciidoc b/docs/api/index-patterns/runtime-fields/upsert.asciidoc
new file mode 100644
index 00000000000000..1b436db19c62e4
--- /dev/null
+++ b/docs/api/index-patterns/runtime-fields/upsert.asciidoc
@@ -0,0 +1,61 @@
+[[index-patterns-runtime-field-api-upsert]]
+=== Upsert runtime field API
+++++
+<titleabbrev>Upsert runtime field</titleabbrev>
+++++
+
+experimental[] Create or update an existing runtime field
+
+[[index-patterns-runtime-field-upsert-request]]
+==== Request
+
+`PUT <kibana host>:<port>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field`
+
+`PUT <kibana host>:<port>/s/<space_id>/api/index_patterns/index_pattern/<index_pattern_id>/runtime_field`
+
+[[index-patterns-runtime-field-upsert-params]]
+==== Path parameters
+
+`space_id`::
+(Optional, string) An identifier for the space. If `space_id` is not provided in the URL, the default space is used.
+
+`index_pattern_id`::
+(Required, string) The ID of the index pattern.
+
+[[index-patterns-runtime-field-upsert-body]]
+==== Request body
+
+`name`:: (Required, string) The name for a new runtime field or a name of an existing runtime field.
+
+`runtimeField`:: (Required, object) The runtime field definition object.
+
+
+[[index-patterns-runtime-field-upsert-example]]
+==== Examples
+
+Create or update an existing runtime field on an index pattern:
+
+[source,sh]
+--------------------------------------------------
+$ curl -X PUT api/index_patterns/index_pattern/<index_pattern_id>/runtime_field
+{
+  "name": "runtimeFoo",
+  "runtimeField": {
+     "type": "long",
+     "script": {
+        "source": "emit(doc["foo"].value)"
+      }
+  }
+}
+--------------------------------------------------
+// KIBANA
+
+The API returns created or updated runtime field object and updated index pattern object:
+
+[source,sh]
+--------------------------------------------------
+{
+    "index_pattern": {...},
+    "field": {...}
+}
+--------------------------------------------------
diff --git a/docs/api/index-patterns/update.asciidoc b/docs/api/index-patterns/update.asciidoc
index 8ed0ff89fb928c..2d5fe882d448df 100644
--- a/docs/api/index-patterns/update.asciidoc
+++ b/docs/api/index-patterns/update.asciidoc
@@ -93,7 +93,8 @@ $ curl -X POST api/saved_objects/index-pattern/my-pattern
     "fieldFormats": {},
     "type": "...",
     "typeMeta": {},
-    "fields": {}
+    "fields": {},
+    "runtimeFieldMap": {}
   }
 }
 --------------------------------------------------
diff --git a/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.getruntimefield.md b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.getruntimefield.md
new file mode 100644
index 00000000000000..c0aca53255b8fd
--- /dev/null
+++ b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.getruntimefield.md
@@ -0,0 +1,24 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-plugins-data-public](./kibana-plugin-plugins-data-public.md) &gt; [IndexPattern](./kibana-plugin-plugins-data-public.indexpattern.md) &gt; [getRuntimeField](./kibana-plugin-plugins-data-public.indexpattern.getruntimefield.md)
+
+## IndexPattern.getRuntimeField() method
+
+Returns runtime field if exists
+
+<b>Signature:</b>
+
+```typescript
+getRuntimeField(name: string): RuntimeField | null;
+```
+
+## Parameters
+
+|  Parameter | Type | Description |
+|  --- | --- | --- |
+|  name | <code>string</code> |  |
+
+<b>Returns:</b>
+
+`RuntimeField | null`
+
diff --git a/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.hasruntimefield.md b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.hasruntimefield.md
new file mode 100644
index 00000000000000..96dbe13a7f1978
--- /dev/null
+++ b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.hasruntimefield.md
@@ -0,0 +1,24 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-plugins-data-public](./kibana-plugin-plugins-data-public.md) &gt; [IndexPattern](./kibana-plugin-plugins-data-public.indexpattern.md) &gt; [hasRuntimeField](./kibana-plugin-plugins-data-public.indexpattern.hasruntimefield.md)
+
+## IndexPattern.hasRuntimeField() method
+
+Checks if runtime field exists
+
+<b>Signature:</b>
+
+```typescript
+hasRuntimeField(name: string): boolean;
+```
+
+## Parameters
+
+|  Parameter | Type | Description |
+|  --- | --- | --- |
+|  name | <code>string</code> |  |
+
+<b>Returns:</b>
+
+`boolean`
+
diff --git a/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.md b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.md
index 53d173d39f50d0..51ca42fdce70a7 100644
--- a/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.md
+++ b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.md
@@ -54,13 +54,16 @@ export declare class IndexPattern implements IIndexPattern
 |  [getFormatterForField(field)](./kibana-plugin-plugins-data-public.indexpattern.getformatterforfield.md) |  | Provide a field, get its formatter |
 |  [getFormatterForFieldNoDefault(fieldname)](./kibana-plugin-plugins-data-public.indexpattern.getformatterforfieldnodefault.md) |  | Get formatter for a given field name. Return undefined if none exists |
 |  [getNonScriptedFields()](./kibana-plugin-plugins-data-public.indexpattern.getnonscriptedfields.md) |  |  |
+|  [getRuntimeField(name)](./kibana-plugin-plugins-data-public.indexpattern.getruntimefield.md) |  | Returns runtime field if exists |
 |  [getScriptedFields()](./kibana-plugin-plugins-data-public.indexpattern.getscriptedfields.md) |  |  |
 |  [getSourceFiltering()](./kibana-plugin-plugins-data-public.indexpattern.getsourcefiltering.md) |  | Get the source filtering configuration for that index. |
 |  [getTimeField()](./kibana-plugin-plugins-data-public.indexpattern.gettimefield.md) |  |  |
+|  [hasRuntimeField(name)](./kibana-plugin-plugins-data-public.indexpattern.hasruntimefield.md) |  | Checks if runtime field exists |
 |  [isTimeBased()](./kibana-plugin-plugins-data-public.indexpattern.istimebased.md) |  |  |
 |  [isTimeNanosBased()](./kibana-plugin-plugins-data-public.indexpattern.istimenanosbased.md) |  |  |
-|  [removeRuntimeField(name)](./kibana-plugin-plugins-data-public.indexpattern.removeruntimefield.md) |  | Remove a runtime field - removed from mapped field or removed unmapped field as appropriate |
+|  [removeRuntimeField(name)](./kibana-plugin-plugins-data-public.indexpattern.removeruntimefield.md) |  | Remove a runtime field - removed from mapped field or removed unmapped field as appropriate. Doesn't clear associated field attributes. |
 |  [removeScriptedField(fieldName)](./kibana-plugin-plugins-data-public.indexpattern.removescriptedfield.md) |  | Remove scripted field from field list |
+|  [replaceAllRuntimeFields(newFields)](./kibana-plugin-plugins-data-public.indexpattern.replaceallruntimefields.md) |  | Replaces all existing runtime fields with new fields |
 |  [setFieldAttrs(fieldName, attrName, value)](./kibana-plugin-plugins-data-public.indexpattern.setfieldattrs.md) |  |  |
 |  [setFieldCount(fieldName, count)](./kibana-plugin-plugins-data-public.indexpattern.setfieldcount.md) |  |  |
 |  [setFieldCustomLabel(fieldName, customLabel)](./kibana-plugin-plugins-data-public.indexpattern.setfieldcustomlabel.md) |  |  |
diff --git a/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.removeruntimefield.md b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.removeruntimefield.md
index 7a5228fece782e..f2774924fc73c1 100644
--- a/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.removeruntimefield.md
+++ b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.removeruntimefield.md
@@ -4,7 +4,7 @@
 
 ## IndexPattern.removeRuntimeField() method
 
-Remove a runtime field - removed from mapped field or removed unmapped field as appropriate
+Remove a runtime field - removed from mapped field or removed unmapped field as appropriate. Doesn't clear associated field attributes.
 
 <b>Signature:</b>
 
@@ -16,7 +16,7 @@ removeRuntimeField(name: string): void;
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  name | <code>string</code> |  |
+|  name | <code>string</code> | Field name to remove |
 
 <b>Returns:</b>
 
diff --git a/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.replaceallruntimefields.md b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.replaceallruntimefields.md
new file mode 100644
index 00000000000000..076b2b38cf474a
--- /dev/null
+++ b/docs/development/plugins/data/public/kibana-plugin-plugins-data-public.indexpattern.replaceallruntimefields.md
@@ -0,0 +1,24 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-plugins-data-public](./kibana-plugin-plugins-data-public.md) &gt; [IndexPattern](./kibana-plugin-plugins-data-public.indexpattern.md) &gt; [replaceAllRuntimeFields](./kibana-plugin-plugins-data-public.indexpattern.replaceallruntimefields.md)
+
+## IndexPattern.replaceAllRuntimeFields() method
+
+Replaces all existing runtime fields with new fields
+
+<b>Signature:</b>
+
+```typescript
+replaceAllRuntimeFields(newFields: Record<string, RuntimeField>): void;
+```
+
+## Parameters
+
+|  Parameter | Type | Description |
+|  --- | --- | --- |
+|  newFields | <code>Record&lt;string, RuntimeField&gt;</code> |  |
+
+<b>Returns:</b>
+
+`void`
+
diff --git a/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.getruntimefield.md b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.getruntimefield.md
new file mode 100644
index 00000000000000..d5dc8f966316b0
--- /dev/null
+++ b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.getruntimefield.md
@@ -0,0 +1,24 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-plugins-data-server](./kibana-plugin-plugins-data-server.md) &gt; [IndexPattern](./kibana-plugin-plugins-data-server.indexpattern.md) &gt; [getRuntimeField](./kibana-plugin-plugins-data-server.indexpattern.getruntimefield.md)
+
+## IndexPattern.getRuntimeField() method
+
+Returns runtime field if exists
+
+<b>Signature:</b>
+
+```typescript
+getRuntimeField(name: string): RuntimeField | null;
+```
+
+## Parameters
+
+|  Parameter | Type | Description |
+|  --- | --- | --- |
+|  name | <code>string</code> |  |
+
+<b>Returns:</b>
+
+`RuntimeField | null`
+
diff --git a/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.hasruntimefield.md b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.hasruntimefield.md
new file mode 100644
index 00000000000000..5000d5e645cbb9
--- /dev/null
+++ b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.hasruntimefield.md
@@ -0,0 +1,24 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-plugins-data-server](./kibana-plugin-plugins-data-server.md) &gt; [IndexPattern](./kibana-plugin-plugins-data-server.indexpattern.md) &gt; [hasRuntimeField](./kibana-plugin-plugins-data-server.indexpattern.hasruntimefield.md)
+
+## IndexPattern.hasRuntimeField() method
+
+Checks if runtime field exists
+
+<b>Signature:</b>
+
+```typescript
+hasRuntimeField(name: string): boolean;
+```
+
+## Parameters
+
+|  Parameter | Type | Description |
+|  --- | --- | --- |
+|  name | <code>string</code> |  |
+
+<b>Returns:</b>
+
+`boolean`
+
diff --git a/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.md b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.md
index 97d1cd91152623..27b8a31a2582ba 100644
--- a/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.md
+++ b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.md
@@ -54,13 +54,16 @@ export declare class IndexPattern implements IIndexPattern
 |  [getFormatterForField(field)](./kibana-plugin-plugins-data-server.indexpattern.getformatterforfield.md) |  | Provide a field, get its formatter |
 |  [getFormatterForFieldNoDefault(fieldname)](./kibana-plugin-plugins-data-server.indexpattern.getformatterforfieldnodefault.md) |  | Get formatter for a given field name. Return undefined if none exists |
 |  [getNonScriptedFields()](./kibana-plugin-plugins-data-server.indexpattern.getnonscriptedfields.md) |  |  |
+|  [getRuntimeField(name)](./kibana-plugin-plugins-data-server.indexpattern.getruntimefield.md) |  | Returns runtime field if exists |
 |  [getScriptedFields()](./kibana-plugin-plugins-data-server.indexpattern.getscriptedfields.md) |  |  |
 |  [getSourceFiltering()](./kibana-plugin-plugins-data-server.indexpattern.getsourcefiltering.md) |  | Get the source filtering configuration for that index. |
 |  [getTimeField()](./kibana-plugin-plugins-data-server.indexpattern.gettimefield.md) |  |  |
+|  [hasRuntimeField(name)](./kibana-plugin-plugins-data-server.indexpattern.hasruntimefield.md) |  | Checks if runtime field exists |
 |  [isTimeBased()](./kibana-plugin-plugins-data-server.indexpattern.istimebased.md) |  |  |
 |  [isTimeNanosBased()](./kibana-plugin-plugins-data-server.indexpattern.istimenanosbased.md) |  |  |
-|  [removeRuntimeField(name)](./kibana-plugin-plugins-data-server.indexpattern.removeruntimefield.md) |  | Remove a runtime field - removed from mapped field or removed unmapped field as appropriate |
+|  [removeRuntimeField(name)](./kibana-plugin-plugins-data-server.indexpattern.removeruntimefield.md) |  | Remove a runtime field - removed from mapped field or removed unmapped field as appropriate. Doesn't clear associated field attributes. |
 |  [removeScriptedField(fieldName)](./kibana-plugin-plugins-data-server.indexpattern.removescriptedfield.md) |  | Remove scripted field from field list |
+|  [replaceAllRuntimeFields(newFields)](./kibana-plugin-plugins-data-server.indexpattern.replaceallruntimefields.md) |  | Replaces all existing runtime fields with new fields |
 |  [setFieldAttrs(fieldName, attrName, value)](./kibana-plugin-plugins-data-server.indexpattern.setfieldattrs.md) |  |  |
 |  [setFieldCount(fieldName, count)](./kibana-plugin-plugins-data-server.indexpattern.setfieldcount.md) |  |  |
 |  [setFieldCustomLabel(fieldName, customLabel)](./kibana-plugin-plugins-data-server.indexpattern.setfieldcustomlabel.md) |  |  |
diff --git a/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.removeruntimefield.md b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.removeruntimefield.md
index da8e7e40a7fac2..ef32b80ba8502e 100644
--- a/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.removeruntimefield.md
+++ b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.removeruntimefield.md
@@ -4,7 +4,7 @@
 
 ## IndexPattern.removeRuntimeField() method
 
-Remove a runtime field - removed from mapped field or removed unmapped field as appropriate
+Remove a runtime field - removed from mapped field or removed unmapped field as appropriate. Doesn't clear associated field attributes.
 
 <b>Signature:</b>
 
@@ -16,7 +16,7 @@ removeRuntimeField(name: string): void;
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  name | <code>string</code> |  |
+|  name | <code>string</code> | Field name to remove |
 
 <b>Returns:</b>
 
diff --git a/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.replaceallruntimefields.md b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.replaceallruntimefields.md
new file mode 100644
index 00000000000000..35df871763f8a1
--- /dev/null
+++ b/docs/development/plugins/data/server/kibana-plugin-plugins-data-server.indexpattern.replaceallruntimefields.md
@@ -0,0 +1,24 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-plugins-data-server](./kibana-plugin-plugins-data-server.md) &gt; [IndexPattern](./kibana-plugin-plugins-data-server.indexpattern.md) &gt; [replaceAllRuntimeFields](./kibana-plugin-plugins-data-server.indexpattern.replaceallruntimefields.md)
+
+## IndexPattern.replaceAllRuntimeFields() method
+
+Replaces all existing runtime fields with new fields
+
+<b>Signature:</b>
+
+```typescript
+replaceAllRuntimeFields(newFields: Record<string, RuntimeField>): void;
+```
+
+## Parameters
+
+|  Parameter | Type | Description |
+|  --- | --- | --- |
+|  newFields | <code>Record&lt;string, RuntimeField&gt;</code> |  |
+
+<b>Returns:</b>
+
+`void`
+
diff --git a/src/plugins/data/common/index_patterns/index_patterns/index_pattern.ts b/src/plugins/data/common/index_patterns/index_patterns/index_pattern.ts
index c897cdbce2309a..0c3a9901f8c8ca 100644
--- a/src/plugins/data/common/index_patterns/index_patterns/index_pattern.ts
+++ b/src/plugins/data/common/index_patterns/index_patterns/index_pattern.ts
@@ -364,7 +364,6 @@ export class IndexPattern implements IIndexPattern {
    * @param name Field name
    * @param runtimeField Runtime field definition
    */
-
   addRuntimeField(name: string, runtimeField: RuntimeField) {
     const existingField = this.getFieldByName(name);
     if (existingField) {
@@ -384,11 +383,41 @@ export class IndexPattern implements IIndexPattern {
   }
 
   /**
-   * Remove a runtime field - removed from mapped field or removed unmapped
-   * field as appropriate
-   * @param name Field name
+   * Checks if runtime field exists
+   * @param name
+   */
+  hasRuntimeField(name: string): boolean {
+    return !!this.runtimeFieldMap[name];
+  }
+
+  /**
+   * Returns runtime field if exists
+   * @param name
+   */
+  getRuntimeField(name: string): RuntimeField | null {
+    return this.runtimeFieldMap[name] ?? null;
+  }
+
+  /**
+   * Replaces all existing runtime fields with new fields
+   * @param newFields
    */
+  replaceAllRuntimeFields(newFields: Record<string, RuntimeField>) {
+    const oldRuntimeFieldNames = Object.keys(this.runtimeFieldMap);
+    oldRuntimeFieldNames.forEach((name) => {
+      this.removeRuntimeField(name);
+    });
 
+    Object.entries(newFields).forEach(([name, field]) => {
+      this.addRuntimeField(name, field);
+    });
+  }
+
+  /**
+   * Remove a runtime field - removed from mapped field or removed unmapped
+   * field as appropriate. Doesn't clear associated field attributes.
+   * @param name - Field name to remove
+   */
   removeRuntimeField(name: string) {
     const existingField = this.getFieldByName(name);
     if (existingField) {
@@ -396,9 +425,6 @@ export class IndexPattern implements IIndexPattern {
         // mapped field, remove runtimeField def
         existingField.runtimeField = undefined;
       } else {
-        // runtimeField only
-        this.setFieldCustomLabel(name, null);
-        this.deleteFieldFormat(name);
         this.fields.remove(existingField);
       }
     }
diff --git a/src/plugins/data/public/public.api.md b/src/plugins/data/public/public.api.md
index 5ef499840fa6de..67534577d99fcf 100644
--- a/src/plugins/data/public/public.api.md
+++ b/src/plugins/data/public/public.api.md
@@ -1413,6 +1413,7 @@ export class IndexPattern implements IIndexPattern {
         typeMeta?: string | undefined;
         type?: string | undefined;
     };
+    getRuntimeField(name: string): RuntimeField | null;
     // @deprecated (undocumented)
     getScriptedFields(): IndexPatternField[];
     getSourceFiltering(): {
@@ -1420,6 +1421,7 @@ export class IndexPattern implements IIndexPattern {
     };
     // (undocumented)
     getTimeField(): IndexPatternField | undefined;
+    hasRuntimeField(name: string): boolean;
     // (undocumented)
     id?: string;
     // @deprecated (undocumented)
@@ -1433,6 +1435,7 @@ export class IndexPattern implements IIndexPattern {
     removeRuntimeField(name: string): void;
     // @deprecated
     removeScriptedField(fieldName: string): void;
+    replaceAllRuntimeFields(newFields: Record<string, RuntimeField>): void;
     resetOriginalSavedObjectBody: () => void;
     // (undocumented)
     protected setFieldAttrs<K extends keyof FieldAttrSet>(fieldName: string, attrName: K, value: FieldAttrSet[K]): void;
diff --git a/src/plugins/data/server/index_patterns/routes.ts b/src/plugins/data/server/index_patterns/routes.ts
index 9bff590b54f1c1..d2d8cb82cf646e 100644
--- a/src/plugins/data/server/index_patterns/routes.ts
+++ b/src/plugins/data/server/index_patterns/routes.ts
@@ -21,6 +21,11 @@ import { registerDeleteScriptedFieldRoute } from './routes/scripted_fields/delet
 import { registerUpdateScriptedFieldRoute } from './routes/scripted_fields/update_scripted_field';
 import type { DataPluginStart, DataPluginStartDependencies } from '../plugin';
 import { registerManageDefaultIndexPatternRoutes } from './routes/default_index_pattern';
+import { registerCreateRuntimeFieldRoute } from './routes/runtime_fields/create_runtime_field';
+import { registerGetRuntimeFieldRoute } from './routes/runtime_fields/get_runtime_field';
+import { registerDeleteRuntimeFieldRoute } from './routes/runtime_fields/delete_runtime_field';
+import { registerPutRuntimeFieldRoute } from './routes/runtime_fields/put_runtime_field';
+import { registerUpdateRuntimeFieldRoute } from './routes/runtime_fields/update_runtime_field';
 
 export function registerRoutes(
   http: HttpServiceSetup,
@@ -55,6 +60,13 @@ export function registerRoutes(
   registerDeleteScriptedFieldRoute(router, getStartServices);
   registerUpdateScriptedFieldRoute(router, getStartServices);
 
+  // Runtime Fields API
+  registerCreateRuntimeFieldRoute(router, getStartServices);
+  registerGetRuntimeFieldRoute(router, getStartServices);
+  registerDeleteRuntimeFieldRoute(router, getStartServices);
+  registerPutRuntimeFieldRoute(router, getStartServices);
+  registerUpdateRuntimeFieldRoute(router, getStartServices);
+
   router.get(
     {
       path: '/api/index_patterns/_fields_for_wildcard',
diff --git a/src/plugins/data/server/index_patterns/routes/create_index_pattern.ts b/src/plugins/data/server/index_patterns/routes/create_index_pattern.ts
index d0767334626229..7049903f84e8c2 100644
--- a/src/plugins/data/server/index_patterns/routes/create_index_pattern.ts
+++ b/src/plugins/data/server/index_patterns/routes/create_index_pattern.ts
@@ -9,7 +9,11 @@
 import { schema } from '@kbn/config-schema';
 import { IndexPatternSpec } from 'src/plugins/data/common';
 import { handleErrors } from './util/handle_errors';
-import { fieldSpecSchema, serializedFieldFormatSchema } from './util/schemas';
+import {
+  fieldSpecSchema,
+  runtimeFieldSpecSchema,
+  serializedFieldFormatSchema,
+} from './util/schemas';
 import { IRouter, StartServicesAccessor } from '../../../../../core/server';
 import type { DataPluginStart, DataPluginStartDependencies } from '../../plugin';
 
@@ -39,6 +43,7 @@ const indexPatternSpecSchema = schema.object({
     )
   ),
   allowNoIndex: schema.maybe(schema.boolean()),
+  runtimeFieldMap: schema.maybe(schema.recordOf(schema.string(), runtimeFieldSpecSchema)),
 });
 
 export const registerCreateIndexPatternRoute = (
@@ -66,6 +71,7 @@ export const registerCreateIndexPatternRoute = (
           elasticsearchClient
         );
         const body = req.body;
+
         const indexPattern = await indexPatternsService.createAndSave(
           body.index_pattern as IndexPatternSpec,
           body.override,
diff --git a/src/plugins/data/server/index_patterns/routes/runtime_fields/create_runtime_field.ts b/src/plugins/data/server/index_patterns/routes/runtime_fields/create_runtime_field.ts
new file mode 100644
index 00000000000000..faf6d87b6d10bf
--- /dev/null
+++ b/src/plugins/data/server/index_patterns/routes/runtime_fields/create_runtime_field.ts
@@ -0,0 +1,74 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { schema } from '@kbn/config-schema';
+import { handleErrors } from '../util/handle_errors';
+import { runtimeFieldSpecSchema } from '../util/schemas';
+import { IRouter, StartServicesAccessor } from '../../../../../../core/server';
+import type { DataPluginStart, DataPluginStartDependencies } from '../../../plugin';
+
+export const registerCreateRuntimeFieldRoute = (
+  router: IRouter,
+  getStartServices: StartServicesAccessor<DataPluginStartDependencies, DataPluginStart>
+) => {
+  router.post(
+    {
+      path: '/api/index_patterns/index_pattern/{id}/runtime_field',
+      validate: {
+        params: schema.object({
+          id: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+        }),
+        body: schema.object({
+          name: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+          runtimeField: runtimeFieldSpecSchema,
+        }),
+      },
+    },
+
+    handleErrors(async (ctx, req, res) => {
+      const savedObjectsClient = ctx.core.savedObjects.client;
+      const elasticsearchClient = ctx.core.elasticsearch.client.asCurrentUser;
+      const [, , { indexPatterns }] = await getStartServices();
+      const indexPatternsService = await indexPatterns.indexPatternsServiceFactory(
+        savedObjectsClient,
+        elasticsearchClient
+      );
+      const id = req.params.id;
+      const { name, runtimeField } = req.body;
+
+      const indexPattern = await indexPatternsService.get(id);
+
+      if (indexPattern.fields.getByName(name)) {
+        throw new Error(`Field [name = ${name}] already exists.`);
+      }
+
+      indexPattern.addRuntimeField(name, runtimeField);
+
+      const addedField = indexPattern.fields.getByName(name);
+      if (!addedField) throw new Error(`Could not create a field [name = ${name}].`);
+
+      await indexPatternsService.updateSavedObject(indexPattern);
+
+      const savedField = indexPattern.fields.getByName(name);
+      if (!savedField) throw new Error(`Could not create a field [name = ${name}].`);
+
+      return res.ok({
+        body: {
+          field: savedField.toSpec(),
+          index_pattern: indexPattern.toSpec(),
+        },
+      });
+    })
+  );
+};
diff --git a/src/plugins/data/server/index_patterns/routes/runtime_fields/delete_runtime_field.ts b/src/plugins/data/server/index_patterns/routes/runtime_fields/delete_runtime_field.ts
new file mode 100644
index 00000000000000..58b8529d7cf5af
--- /dev/null
+++ b/src/plugins/data/server/index_patterns/routes/runtime_fields/delete_runtime_field.ts
@@ -0,0 +1,64 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { schema } from '@kbn/config-schema';
+import { ErrorIndexPatternFieldNotFound } from '../../error';
+import { handleErrors } from '../util/handle_errors';
+import { IRouter, StartServicesAccessor } from '../../../../../../core/server';
+import type { DataPluginStart, DataPluginStartDependencies } from '../../../plugin';
+
+export const registerDeleteRuntimeFieldRoute = (
+  router: IRouter,
+  getStartServices: StartServicesAccessor<DataPluginStartDependencies, DataPluginStart>
+) => {
+  router.delete(
+    {
+      path: '/api/index_patterns/index_pattern/{id}/runtime_field/{name}',
+      validate: {
+        params: schema.object({
+          id: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+          name: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+        }),
+      },
+    },
+    handleErrors(async (ctx, req, res) => {
+      const savedObjectsClient = ctx.core.savedObjects.client;
+      const elasticsearchClient = ctx.core.elasticsearch.client.asCurrentUser;
+      const [, , { indexPatterns }] = await getStartServices();
+      const indexPatternsService = await indexPatterns.indexPatternsServiceFactory(
+        savedObjectsClient,
+        elasticsearchClient
+      );
+      const id = req.params.id;
+      const name = req.params.name;
+
+      const indexPattern = await indexPatternsService.get(id);
+      const field = indexPattern.fields.getByName(name);
+
+      if (!field) {
+        throw new ErrorIndexPatternFieldNotFound(id, name);
+      }
+
+      if (!field.runtimeField) {
+        throw new Error('Only runtime fields can be deleted.');
+      }
+
+      indexPattern.removeRuntimeField(name);
+
+      await indexPatternsService.updateSavedObject(indexPattern);
+
+      return res.ok();
+    })
+  );
+};
diff --git a/src/plugins/data/server/index_patterns/routes/runtime_fields/get_runtime_field.ts b/src/plugins/data/server/index_patterns/routes/runtime_fields/get_runtime_field.ts
new file mode 100644
index 00000000000000..6bc2bf396c0b44
--- /dev/null
+++ b/src/plugins/data/server/index_patterns/routes/runtime_fields/get_runtime_field.ts
@@ -0,0 +1,67 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { schema } from '@kbn/config-schema';
+import { ErrorIndexPatternFieldNotFound } from '../../error';
+import { handleErrors } from '../util/handle_errors';
+import { IRouter, StartServicesAccessor } from '../../../../../../core/server';
+import type { DataPluginStart, DataPluginStartDependencies } from '../../../plugin';
+
+export const registerGetRuntimeFieldRoute = (
+  router: IRouter,
+  getStartServices: StartServicesAccessor<DataPluginStartDependencies, DataPluginStart>
+) => {
+  router.get(
+    {
+      path: '/api/index_patterns/index_pattern/{id}/runtime_field/{name}',
+      validate: {
+        params: schema.object({
+          id: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+          name: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+        }),
+      },
+    },
+
+    handleErrors(async (ctx, req, res) => {
+      const savedObjectsClient = ctx.core.savedObjects.client;
+      const elasticsearchClient = ctx.core.elasticsearch.client.asCurrentUser;
+      const [, , { indexPatterns }] = await getStartServices();
+      const indexPatternsService = await indexPatterns.indexPatternsServiceFactory(
+        savedObjectsClient,
+        elasticsearchClient
+      );
+      const id = req.params.id;
+      const name = req.params.name;
+
+      const indexPattern = await indexPatternsService.get(id);
+
+      const field = indexPattern.fields.getByName(name);
+
+      if (!field) {
+        throw new ErrorIndexPatternFieldNotFound(id, name);
+      }
+
+      if (!field.runtimeField) {
+        throw new Error('Only runtime fields can be retrieved.');
+      }
+
+      return res.ok({
+        body: {
+          field: field.toSpec(),
+          runtimeField: indexPattern.getRuntimeField(name),
+        },
+      });
+    })
+  );
+};
diff --git a/src/plugins/data/server/index_patterns/routes/runtime_fields/put_runtime_field.ts b/src/plugins/data/server/index_patterns/routes/runtime_fields/put_runtime_field.ts
new file mode 100644
index 00000000000000..a5e92fa5a36ecb
--- /dev/null
+++ b/src/plugins/data/server/index_patterns/routes/runtime_fields/put_runtime_field.ts
@@ -0,0 +1,76 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { schema } from '@kbn/config-schema';
+import { handleErrors } from '../util/handle_errors';
+import { runtimeFieldSpecSchema } from '../util/schemas';
+import { IRouter, StartServicesAccessor } from '../../../../../../core/server';
+import type { DataPluginStart, DataPluginStartDependencies } from '../../../plugin';
+
+export const registerPutRuntimeFieldRoute = (
+  router: IRouter,
+  getStartServices: StartServicesAccessor<DataPluginStartDependencies, DataPluginStart>
+) => {
+  router.put(
+    {
+      path: '/api/index_patterns/index_pattern/{id}/runtime_field',
+      validate: {
+        params: schema.object({
+          id: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+        }),
+        body: schema.object({
+          name: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+          runtimeField: runtimeFieldSpecSchema,
+        }),
+      },
+    },
+    handleErrors(async (ctx, req, res) => {
+      const savedObjectsClient = ctx.core.savedObjects.client;
+      const elasticsearchClient = ctx.core.elasticsearch.client.asCurrentUser;
+      const [, , { indexPatterns }] = await getStartServices();
+      const indexPatternsService = await indexPatterns.indexPatternsServiceFactory(
+        savedObjectsClient,
+        elasticsearchClient
+      );
+      const id = req.params.id;
+      const { name, runtimeField } = req.body;
+
+      const indexPattern = await indexPatternsService.get(id);
+
+      const oldFieldObject = indexPattern.fields.getByName(name);
+
+      if (oldFieldObject && !oldFieldObject.runtimeField) {
+        throw new Error('Only runtime fields can be updated');
+      }
+
+      if (oldFieldObject) {
+        indexPattern.removeRuntimeField(name);
+      }
+
+      indexPattern.addRuntimeField(name, runtimeField);
+
+      await indexPatternsService.updateSavedObject(indexPattern);
+
+      const fieldObject = indexPattern.fields.getByName(name);
+      if (!fieldObject) throw new Error(`Could not create a field [name = ${name}].`);
+
+      return res.ok({
+        body: {
+          field: fieldObject.toSpec(),
+          index_pattern: indexPattern.toSpec(),
+        },
+      });
+    })
+  );
+};
diff --git a/src/plugins/data/server/index_patterns/routes/runtime_fields/update_runtime_field.ts b/src/plugins/data/server/index_patterns/routes/runtime_fields/update_runtime_field.ts
new file mode 100644
index 00000000000000..3f3aae46c43882
--- /dev/null
+++ b/src/plugins/data/server/index_patterns/routes/runtime_fields/update_runtime_field.ts
@@ -0,0 +1,84 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { schema } from '@kbn/config-schema';
+import { RuntimeField } from 'src/plugins/data/common';
+import { ErrorIndexPatternFieldNotFound } from '../../error';
+import { handleErrors } from '../util/handle_errors';
+import { runtimeFieldSpec, runtimeFieldSpecTypeSchema } from '../util/schemas';
+import { IRouter, StartServicesAccessor } from '../../../../../../core/server';
+import type { DataPluginStart, DataPluginStartDependencies } from '../../../plugin';
+
+export const registerUpdateRuntimeFieldRoute = (
+  router: IRouter,
+  getStartServices: StartServicesAccessor<DataPluginStartDependencies, DataPluginStart>
+) => {
+  router.post(
+    {
+      path: '/api/index_patterns/index_pattern/{id}/runtime_field/{name}',
+      validate: {
+        params: schema.object({
+          id: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+          name: schema.string({
+            minLength: 1,
+            maxLength: 1_000,
+          }),
+        }),
+        body: schema.object({
+          name: schema.never(),
+          runtimeField: schema.object({
+            ...runtimeFieldSpec,
+            // We need to overwrite the below fields on top of `runtimeFieldSpec`,
+            // because some fields would be optional
+            type: schema.maybe(runtimeFieldSpecTypeSchema),
+          }),
+        }),
+      },
+    },
+    handleErrors(async (ctx, req, res) => {
+      const savedObjectsClient = ctx.core.savedObjects.client;
+      const elasticsearchClient = ctx.core.elasticsearch.client.asCurrentUser;
+      const [, , { indexPatterns }] = await getStartServices();
+      const indexPatternsService = await indexPatterns.indexPatternsServiceFactory(
+        savedObjectsClient,
+        elasticsearchClient
+      );
+      const id = req.params.id;
+      const name = req.params.name;
+      const runtimeField = req.body.runtimeField as Partial<RuntimeField>;
+
+      const indexPattern = await indexPatternsService.get(id);
+      const existingRuntimeField = indexPattern.getRuntimeField(name);
+
+      if (!existingRuntimeField) {
+        throw new ErrorIndexPatternFieldNotFound(id, name);
+      }
+
+      indexPattern.removeRuntimeField(name);
+      indexPattern.addRuntimeField(name, {
+        ...existingRuntimeField,
+        ...runtimeField,
+      });
+
+      await indexPatternsService.updateSavedObject(indexPattern);
+
+      const fieldObject = indexPattern.fields.getByName(name);
+      if (!fieldObject) throw new Error(`Could not create a field [name = ${name}].`);
+
+      return res.ok({
+        body: {
+          field: fieldObject.toSpec(),
+          index_pattern: indexPattern.toSpec(),
+        },
+      });
+    })
+  );
+};
diff --git a/src/plugins/data/server/index_patterns/routes/update_index_pattern.ts b/src/plugins/data/server/index_patterns/routes/update_index_pattern.ts
index c1509b9b848bef..1c88550c154c56 100644
--- a/src/plugins/data/server/index_patterns/routes/update_index_pattern.ts
+++ b/src/plugins/data/server/index_patterns/routes/update_index_pattern.ts
@@ -8,7 +8,11 @@
 
 import { schema } from '@kbn/config-schema';
 import { handleErrors } from './util/handle_errors';
-import { fieldSpecSchema, serializedFieldFormatSchema } from './util/schemas';
+import {
+  fieldSpecSchema,
+  runtimeFieldSpecSchema,
+  serializedFieldFormatSchema,
+} from './util/schemas';
 import { IRouter, StartServicesAccessor } from '../../../../../core/server';
 import type { DataPluginStart, DataPluginStartDependencies } from '../../plugin';
 
@@ -28,6 +32,7 @@ const indexPatternUpdateSchema = schema.object({
   fieldFormats: schema.maybe(schema.recordOf(schema.string(), serializedFieldFormatSchema)),
   fields: schema.maybe(schema.recordOf(schema.string(), fieldSpecSchema)),
   allowNoIndex: schema.maybe(schema.boolean()),
+  runtimeFieldMap: schema.maybe(schema.recordOf(schema.string(), runtimeFieldSpecSchema)),
 });
 
 export const registerUpdateIndexPatternRoute = (
@@ -78,6 +83,7 @@ export const registerUpdateIndexPatternRoute = (
             type,
             typeMeta,
             fields,
+            runtimeFieldMap,
           },
         } = req.body;
 
@@ -131,6 +137,11 @@ export const registerUpdateIndexPatternRoute = (
           );
         }
 
+        if (runtimeFieldMap !== undefined) {
+          changeCount++;
+          indexPattern.replaceAllRuntimeFields(runtimeFieldMap);
+        }
+
         if (changeCount < 1) {
           throw new Error('Index pattern change set is empty.');
         }
diff --git a/src/plugins/data/server/index_patterns/routes/util/schemas.ts b/src/plugins/data/server/index_patterns/routes/util/schemas.ts
index d916423c4fc69c..79ee1ffa1ab970 100644
--- a/src/plugins/data/server/index_patterns/routes/util/schemas.ts
+++ b/src/plugins/data/server/index_patterns/routes/util/schemas.ts
@@ -6,7 +6,8 @@
  * Side Public License, v 1.
  */
 
-import { schema } from '@kbn/config-schema';
+import { schema, Type } from '@kbn/config-schema';
+import { RUNTIME_FIELD_TYPES, RuntimeType } from '../../../../common';
 
 export const serializedFieldFormatSchema = schema.object({
   id: schema.maybe(schema.string()),
@@ -52,4 +53,24 @@ export const fieldSpecSchemaFields = {
   shortDotsEnable: schema.maybe(schema.boolean()),
 };
 
-export const fieldSpecSchema = schema.object(fieldSpecSchemaFields);
+export const fieldSpecSchema = schema.object(fieldSpecSchemaFields, {
+  // Allow and ignore unknowns to make fields transient.
+  // Because `fields` have a bunch of calculated fields
+  // this allows to retrieve an index pattern and then to re-create by using the retrieved payload
+  unknowns: 'ignore',
+});
+
+export const runtimeFieldSpecTypeSchema = schema.oneOf(
+  RUNTIME_FIELD_TYPES.map((runtimeFieldType) => schema.literal(runtimeFieldType)) as [
+    Type<RuntimeType>
+  ]
+);
+export const runtimeFieldSpec = {
+  type: runtimeFieldSpecTypeSchema,
+  script: schema.maybe(
+    schema.object({
+      source: schema.string(),
+    })
+  ),
+};
+export const runtimeFieldSpecSchema = schema.object(runtimeFieldSpec);
diff --git a/src/plugins/data/server/server.api.md b/src/plugins/data/server/server.api.md
index ff265ccf533015..783bd8d2fcd0e1 100644
--- a/src/plugins/data/server/server.api.md
+++ b/src/plugins/data/server/server.api.md
@@ -816,6 +816,7 @@ export class IndexPattern implements IIndexPattern {
         typeMeta?: string | undefined;
         type?: string | undefined;
     };
+    getRuntimeField(name: string): RuntimeField | null;
     // @deprecated (undocumented)
     getScriptedFields(): IndexPatternField[];
     getSourceFiltering(): {
@@ -823,6 +824,7 @@ export class IndexPattern implements IIndexPattern {
     };
     // (undocumented)
     getTimeField(): IndexPatternField | undefined;
+    hasRuntimeField(name: string): boolean;
     // (undocumented)
     id?: string;
     // @deprecated (undocumented)
@@ -836,6 +838,7 @@ export class IndexPattern implements IIndexPattern {
     removeRuntimeField(name: string): void;
     // @deprecated
     removeScriptedField(fieldName: string): void;
+    replaceAllRuntimeFields(newFields: Record<string, RuntimeField>): void;
     resetOriginalSavedObjectBody: () => void;
     // (undocumented)
     protected setFieldAttrs<K extends keyof FieldAttrSet>(fieldName: string, attrName: K, value: FieldAttrSet[K]): void;
diff --git a/test/api_integration/apis/index_patterns/fields_api/update_fields/main.ts b/test/api_integration/apis/index_patterns/fields_api/update_fields/main.ts
index 3bec22de48ee66..16861f3c28051e 100644
--- a/test/api_integration/apis/index_patterns/fields_api/update_fields/main.ts
+++ b/test/api_integration/apis/index_patterns/fields_api/update_fields/main.ts
@@ -22,6 +22,7 @@ export default function ({ getService }: FtrProviderContext) {
 
       indexPattern = (
         await supertest.post('/api/index_patterns/index_pattern').send({
+          override: true,
           index_pattern: {
             title: basicIndex,
           },
diff --git a/test/api_integration/apis/index_patterns/index.js b/test/api_integration/apis/index_patterns/index.js
index 9c1e1bba0ab9a5..656b4e506fa23d 100644
--- a/test/api_integration/apis/index_patterns/index.js
+++ b/test/api_integration/apis/index_patterns/index.js
@@ -15,5 +15,7 @@ export default function ({ loadTestFile }) {
     loadTestFile(require.resolve('./scripted_fields_crud'));
     loadTestFile(require.resolve('./fields_api'));
     loadTestFile(require.resolve('./default_index_pattern'));
+    loadTestFile(require.resolve('./runtime_fields_crud'));
+    loadTestFile(require.resolve('./integration'));
   });
 }
diff --git a/test/api_integration/apis/index_patterns/index_pattern_crud/create_index_pattern/main.ts b/test/api_integration/apis/index_patterns/index_pattern_crud/create_index_pattern/main.ts
index 31c3f13a6e05fb..500a642f60850e 100644
--- a/test/api_integration/apis/index_patterns/index_pattern_crud/create_index_pattern/main.ts
+++ b/test/api_integration/apis/index_patterns/index_pattern_crud/create_index_pattern/main.ts
@@ -117,7 +117,7 @@ export default function ({ getService }: FtrProviderContext) {
         expect(response.body.index_pattern.fields.bar.type).to.be('boolean');
       });
 
-      it('Can add scripted fields, other fields created from es index', async () => {
+      it('can add scripted fields, other fields created from es index', async () => {
         const title = `basic_index*`;
         const response = await supertest.post('/api/index_patterns/index_pattern').send({
           override: true,
@@ -159,6 +159,32 @@ export default function ({ getService }: FtrProviderContext) {
         expect(response.body.index_pattern.fields.bar.esTypes[0]).to.be('test-type');
         expect(response.body.index_pattern.fields.bar.scripted).to.be(true);
       });
+
+      it('can add runtime fields', async () => {
+        const title = `basic_index*`;
+        const response = await supertest.post('/api/index_patterns/index_pattern').send({
+          override: true,
+          index_pattern: {
+            title,
+            runtimeFieldMap: {
+              runtimeFoo: {
+                type: 'keyword',
+                script: {
+                  source: 'emit(doc["foo"].value)',
+                },
+              },
+            },
+          },
+        });
+
+        expect(response.status).to.be(200);
+        expect(response.body.index_pattern.title).to.be(title);
+
+        expect(response.body.index_pattern.runtimeFieldMap.runtimeFoo.type).to.be('keyword');
+        expect(response.body.index_pattern.runtimeFieldMap.runtimeFoo.script.source).to.be(
+          'emit(doc["foo"].value)'
+        );
+      });
     });
 
     it('can specify optional typeMeta attribute when creating an index pattern', async () => {
diff --git a/test/api_integration/apis/index_patterns/index_pattern_crud/create_index_pattern/validation.ts b/test/api_integration/apis/index_patterns/index_pattern_crud/create_index_pattern/validation.ts
index 2f62ea231b7229..598001644eedbe 100644
--- a/test/api_integration/apis/index_patterns/index_pattern_crud/create_index_pattern/validation.ts
+++ b/test/api_integration/apis/index_patterns/index_pattern_crud/create_index_pattern/validation.ts
@@ -64,5 +64,25 @@ export default function ({ getService }: FtrProviderContext) {
         '[request body.refresh_fields]: expected value of type [boolean] but got [number]'
       );
     });
+
+    it('returns an error when unknown runtime field type', async () => {
+      const title = `basic_index*`;
+      const response = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+          runtimeFieldMap: {
+            runtimeFoo: {
+              type: 'wrong-type',
+              script: {
+                source: 'emit(doc["foo"].value)',
+              },
+            },
+          },
+        },
+      });
+
+      expect(response.status).to.be(400);
+    });
   });
 }
diff --git a/test/api_integration/apis/index_patterns/index_pattern_crud/update_index_pattern/main.ts b/test/api_integration/apis/index_patterns/index_pattern_crud/update_index_pattern/main.ts
index cd34724e6cda35..7532278d7eb128 100644
--- a/test/api_integration/apis/index_patterns/index_pattern_crud/update_index_pattern/main.ts
+++ b/test/api_integration/apis/index_patterns/index_pattern_crud/update_index_pattern/main.ts
@@ -284,5 +284,53 @@ export default function ({ getService }: FtrProviderContext) {
       expect(response3.body.index_pattern.intervalName).to.be('intervalName2');
       expect(response3.body.index_pattern.typeMeta.baz).to.be('qux');
     });
+
+    it('can update runtime fields', async () => {
+      const title = `basic_index*`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+          runtimeFieldMap: {
+            runtimeFoo: {
+              type: 'keyword',
+              script: {
+                source: 'emit(doc["foo"].value)',
+              },
+            },
+          },
+        },
+      });
+
+      expect(response1.status).to.be(200);
+      expect(response1.body.index_pattern.title).to.be(title);
+
+      expect(response1.body.index_pattern.runtimeFieldMap.runtimeFoo.type).to.be('keyword');
+      expect(response1.body.index_pattern.runtimeFieldMap.runtimeFoo.script.source).to.be(
+        'emit(doc["foo"].value)'
+      );
+
+      const id = response1.body.index_pattern.id;
+      const response2 = await supertest.post('/api/index_patterns/index_pattern/' + id).send({
+        index_pattern: {
+          runtimeFieldMap: {
+            runtimeBar: {
+              type: 'keyword',
+              script: {
+                source: 'emit(doc["foo"].value)',
+              },
+            },
+          },
+        },
+      });
+
+      expect(response2.body.index_pattern.runtimeFieldMap.runtimeBar.type).to.be('keyword');
+      expect(response2.body.index_pattern.runtimeFieldMap.runtimeFoo).to.be(undefined);
+
+      const response3 = await supertest.get('/api/index_patterns/index_pattern/' + id);
+
+      expect(response3.body.index_pattern.runtimeFieldMap.runtimeBar.type).to.be('keyword');
+      expect(response3.body.index_pattern.runtimeFieldMap.runtimeFoo).to.be(undefined);
+    });
   });
 }
diff --git a/test/api_integration/apis/index_patterns/integration/index.ts b/test/api_integration/apis/index_patterns/integration/index.ts
new file mode 100644
index 00000000000000..6fd5f644ae8949
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/integration/index.ts
@@ -0,0 +1,18 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { FtrProviderContext } from '../../../ftr_provider_context';
+
+/**
+ * Test usage of different index patterns APIs in combination
+ */
+export default function ({ loadTestFile }: FtrProviderContext) {
+  describe('integration', () => {
+    loadTestFile(require.resolve('./integration'));
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/integration/integration.ts b/test/api_integration/apis/index_patterns/integration/integration.ts
new file mode 100644
index 00000000000000..22f07553733235
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/integration/integration.ts
@@ -0,0 +1,119 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import _ from 'lodash';
+import { FtrProviderContext } from '../../../ftr_provider_context';
+
+/**
+ * Test usage of different index patterns APIs in combination
+ */
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+  const esArchiver = getService('esArchiver');
+
+  describe('integration', () => {
+    before(async () => {
+      await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
+    });
+
+    after(async () => {
+      await esArchiver.unload(
+        'test/api_integration/fixtures/es_archiver/index_patterns/basic_index'
+      );
+    });
+
+    it('create an index pattern, add a runtime field, add a field formatter, then re-create the same index pattern', async () => {
+      const title = `basic_index*`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+        },
+      });
+      const id = response1.body.index_pattern.id;
+      const response2 = await supertest
+        .post(`/api/index_patterns/index_pattern/${id}/runtime_field`)
+        .send({
+          name: 'runtimeBar',
+          runtimeField: {
+            type: 'long',
+            script: {
+              source: "emit(doc['field_name'].value)",
+            },
+          },
+        });
+
+      expect(response2.status).to.be(200);
+
+      const response3 = await supertest
+        .post(`/api/index_patterns/index_pattern/${response1.body.index_pattern.id}/fields`)
+        .send({
+          fields: {
+            runtimeBar: {
+              count: 123,
+              customLabel: 'test',
+            },
+          },
+        });
+
+      expect(response3.status).to.be(200);
+
+      const response4 = await supertest
+        .post(`/api/index_patterns/index_pattern/${response1.body.index_pattern.id}/fields`)
+        .send({
+          fields: {
+            runtimeBar: {
+              format: {
+                id: 'duration',
+                params: { inputFormat: 'milliseconds', outputFormat: 'humanizePrecise' },
+              },
+            },
+          },
+        });
+
+      expect(response4.status).to.be(200);
+
+      const response5 = await supertest.get(
+        '/api/index_patterns/index_pattern/' + response1.body.index_pattern.id
+      );
+
+      expect(response5.status).to.be(200);
+
+      const resultIndexPattern = response5.body.index_pattern;
+
+      const runtimeField = resultIndexPattern.fields.runtimeBar;
+      expect(runtimeField.name).to.be('runtimeBar');
+      expect(runtimeField.runtimeField.type).to.be('long');
+      expect(runtimeField.runtimeField.script.source).to.be("emit(doc['field_name'].value)");
+      expect(runtimeField.scripted).to.be(false);
+
+      expect(resultIndexPattern.fieldFormats.runtimeBar.id).to.be('duration');
+      expect(resultIndexPattern.fieldFormats.runtimeBar.params.inputFormat).to.be('milliseconds');
+      expect(resultIndexPattern.fieldFormats.runtimeBar.params.outputFormat).to.be(
+        'humanizePrecise'
+      );
+
+      expect(resultIndexPattern.fieldAttrs.runtimeBar.count).to.be(123);
+      expect(resultIndexPattern.fieldAttrs.runtimeBar.customLabel).to.be('test');
+
+      // check that retrieved object is transient and a clone can be created
+      const response6 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: resultIndexPattern,
+      });
+
+      expect(response6.status).to.be(200);
+      const recreatedIndexPattern = response6.body.index_pattern;
+
+      expect(_.omit(recreatedIndexPattern, 'version')).to.eql(
+        _.omit(resultIndexPattern, 'version')
+      );
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/create_runtime_field/errors.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/create_runtime_field/errors.ts
new file mode 100644
index 00000000000000..8ce9e3b36b5c8d
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/create_runtime_field/errors.ts
@@ -0,0 +1,35 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+
+  describe('errors', () => {
+    it('returns an error field object is not provided', async () => {
+      const title = `foo-${Date.now()}-${Math.random()}*`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        index_pattern: {
+          title,
+        },
+      });
+      const id = response1.body.index_pattern.id;
+      const response2 = await supertest
+        .post(`/api/index_patterns/index_pattern/${id}/runtime_field`)
+        .send({});
+
+      expect(response2.status).to.be(400);
+      expect(response2.body.statusCode).to.be(400);
+      expect(response2.body.message).to.be(
+        '[request body.name]: expected value of type [string] but got [undefined]'
+      );
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/create_runtime_field/index.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/create_runtime_field/index.ts
new file mode 100644
index 00000000000000..2cb90ca087f497
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/create_runtime_field/index.ts
@@ -0,0 +1,16 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ loadTestFile }: FtrProviderContext) {
+  describe('create_runtime_field', () => {
+    loadTestFile(require.resolve('./errors'));
+    loadTestFile(require.resolve('./main'));
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/create_runtime_field/main.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/create_runtime_field/main.ts
new file mode 100644
index 00000000000000..e262b9d838e97a
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/create_runtime_field/main.ts
@@ -0,0 +1,95 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+  const esArchiver = getService('esArchiver');
+
+  describe('main', () => {
+    before(async () => {
+      await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
+    });
+
+    after(async () => {
+      await esArchiver.unload(
+        'test/api_integration/fixtures/es_archiver/index_patterns/basic_index'
+      );
+    });
+
+    it('can create a new runtime field', async () => {
+      const title = `basic_index*`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+        },
+      });
+      const id = response1.body.index_pattern.id;
+      const response2 = await supertest
+        .post(`/api/index_patterns/index_pattern/${id}/runtime_field`)
+        .send({
+          name: 'runtimeBar',
+          runtimeField: {
+            type: 'long',
+            script: {
+              source: "emit(doc['field_name'].value)",
+            },
+          },
+        });
+
+      expect(response2.status).to.be(200);
+      expect(response2.body.field.name).to.be('runtimeBar');
+      expect(response2.body.field.runtimeField.type).to.be('long');
+      expect(response2.body.field.runtimeField.script.source).to.be(
+        "emit(doc['field_name'].value)"
+      );
+      expect(response2.body.field.scripted).to.be(false);
+    });
+
+    it('newly created runtime field is available in the index_pattern object', async () => {
+      const title = `basic_index`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+        },
+      });
+
+      await supertest
+        .post(`/api/index_patterns/index_pattern/${response1.body.index_pattern.id}/runtime_field`)
+        .send({
+          name: 'runtimeBar',
+          runtimeField: {
+            type: 'long',
+            script: {
+              source: "emit(doc['field_name'].value)",
+            },
+          },
+        });
+
+      const response2 = await supertest.get(
+        '/api/index_patterns/index_pattern/' + response1.body.index_pattern.id
+      );
+
+      expect(response2.status).to.be(200);
+
+      const field = response2.body.index_pattern.fields.runtimeBar;
+
+      expect(field.name).to.be('runtimeBar');
+      expect(field.runtimeField.type).to.be('long');
+      expect(field.runtimeField.script.source).to.be("emit(doc['field_name'].value)");
+      expect(field.scripted).to.be(false);
+      await supertest.delete(
+        '/api/index_patterns/index_pattern/' + response1.body.index_pattern.id
+      );
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/delete_runtime_field/errors.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/delete_runtime_field/errors.ts
new file mode 100644
index 00000000000000..b41a630889ff8a
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/delete_runtime_field/errors.ts
@@ -0,0 +1,81 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const esArchiver = getService('esArchiver');
+  const supertest = getService('supertest');
+
+  describe('errors', () => {
+    const basicIndex = 'b*sic_index';
+    let indexPattern: any;
+
+    before(async () => {
+      await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
+
+      indexPattern = (
+        await supertest.post('/api/index_patterns/index_pattern').send({
+          index_pattern: {
+            title: basicIndex,
+          },
+        })
+      ).body.index_pattern;
+    });
+
+    after(async () => {
+      await esArchiver.unload(
+        'test/api_integration/fixtures/es_archiver/index_patterns/basic_index'
+      );
+
+      if (indexPattern) {
+        await supertest.delete('/api/index_patterns/index_pattern/' + indexPattern.id);
+      }
+    });
+
+    it('returns 404 error on non-existing index_pattern', async () => {
+      const id = `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx-${Date.now()}`;
+      const response = await supertest.delete(
+        `/api/index_patterns/index_pattern/${id}/runtime_field/foo`
+      );
+
+      expect(response.status).to.be(404);
+    });
+
+    it('returns 404 error on non-existing runtime field', async () => {
+      const response1 = await supertest.delete(
+        `/api/index_patterns/index_pattern/${indexPattern.id}/runtime_field/test`
+      );
+
+      expect(response1.status).to.be(404);
+    });
+
+    it('returns error when attempting to delete a field which is not a runtime field', async () => {
+      const response2 = await supertest.delete(
+        `/api/index_patterns/index_pattern/${indexPattern.id}/runtime_field/foo`
+      );
+
+      expect(response2.status).to.be(400);
+      expect(response2.body.statusCode).to.be(400);
+      expect(response2.body.message).to.be('Only runtime fields can be deleted.');
+    });
+
+    it('returns error when ID is too long', async () => {
+      const id = `xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx`;
+      const response = await supertest.delete(
+        `/api/index_patterns/index_pattern/${id}/runtime_field/foo`
+      );
+
+      expect(response.status).to.be(400);
+      expect(response.body.message).to.be(
+        '[request params.id]: value has length [1759] but it must have a maximum length of [1000].'
+      );
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/delete_runtime_field/index.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/delete_runtime_field/index.ts
new file mode 100644
index 00000000000000..a14201e750ddaf
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/delete_runtime_field/index.ts
@@ -0,0 +1,16 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ loadTestFile }: FtrProviderContext) {
+  describe('delete_runtime_field', () => {
+    loadTestFile(require.resolve('./errors'));
+    loadTestFile(require.resolve('./main'));
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/delete_runtime_field/main.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/delete_runtime_field/main.ts
new file mode 100644
index 00000000000000..3c74aa336e440c
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/delete_runtime_field/main.ts
@@ -0,0 +1,66 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+  const esArchiver = getService('esArchiver');
+
+  describe('main', () => {
+    before(async () => {
+      await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
+    });
+
+    after(async () => {
+      await esArchiver.unload(
+        'test/api_integration/fixtures/es_archiver/index_patterns/basic_index'
+      );
+    });
+
+    it('can delete a runtime field', async () => {
+      const title = `basic_index*`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+          runtimeFieldMap: {
+            runtimeBar: {
+              type: 'long',
+              script: {
+                source: "emit(doc['field_name'].value)",
+              },
+            },
+          },
+        },
+      });
+
+      const response2 = await supertest.get(
+        '/api/index_patterns/index_pattern/' + response1.body.index_pattern.id
+      );
+
+      expect(typeof response2.body.index_pattern.fields.runtimeBar).to.be('object');
+
+      const response3 = await supertest.delete(
+        `/api/index_patterns/index_pattern/${response1.body.index_pattern.id}/runtime_field/runtimeBar`
+      );
+
+      expect(response3.status).to.be(200);
+
+      const response4 = await supertest.get(
+        '/api/index_patterns/index_pattern/' + response1.body.index_pattern.id
+      );
+
+      expect(typeof response4.body.index_pattern.fields.runtimeBar).to.be('undefined');
+      await supertest.delete(
+        '/api/index_patterns/index_pattern/' + response1.body.index_pattern.id
+      );
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/get_runtime_field/errors.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/get_runtime_field/errors.ts
new file mode 100644
index 00000000000000..3608089e4641a2
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/get_runtime_field/errors.ts
@@ -0,0 +1,81 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const esArchiver = getService('esArchiver');
+  const supertest = getService('supertest');
+
+  describe('errors', () => {
+    const basicIndex = '*asic_index';
+    let indexPattern: any;
+
+    before(async () => {
+      await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
+
+      indexPattern = (
+        await supertest.post('/api/index_patterns/index_pattern').send({
+          index_pattern: {
+            title: basicIndex,
+          },
+        })
+      ).body.index_pattern;
+    });
+
+    after(async () => {
+      await esArchiver.unload(
+        'test/api_integration/fixtures/es_archiver/index_patterns/basic_index'
+      );
+
+      if (indexPattern) {
+        await supertest.delete('/api/index_patterns/index_pattern/' + indexPattern.id);
+      }
+    });
+
+    it('returns 404 error on non-existing index_pattern', async () => {
+      const id = `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx-${Date.now()}`;
+      const response = await supertest.get(
+        `/api/index_patterns/index_pattern/${id}/runtime_field/foo`
+      );
+
+      expect(response.status).to.be(404);
+    });
+
+    it('returns 404 error on non-existing runtime field', async () => {
+      const response1 = await supertest.get(
+        `/api/index_patterns/index_pattern/${indexPattern.id}/runtime_field/sf`
+      );
+
+      expect(response1.status).to.be(404);
+    });
+
+    it('returns error when ID is too long', async () => {
+      const id = `xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx`;
+      const response = await supertest.get(
+        `/api/index_patterns/index_pattern/${id}/runtime_field/foo`
+      );
+
+      expect(response.status).to.be(400);
+      expect(response.body.message).to.be(
+        '[request params.id]: value has length [1759] but it must have a maximum length of [1000].'
+      );
+    });
+
+    it('returns error when attempting to fetch a field which is not a runtime field', async () => {
+      const response2 = await supertest.get(
+        `/api/index_patterns/index_pattern/${indexPattern.id}/runtime_field/foo`
+      );
+
+      expect(response2.status).to.be(400);
+      expect(response2.body.statusCode).to.be(400);
+      expect(response2.body.message).to.be('Only runtime fields can be retrieved.');
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/get_runtime_field/index.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/get_runtime_field/index.ts
new file mode 100644
index 00000000000000..2e48ba64841eeb
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/get_runtime_field/index.ts
@@ -0,0 +1,16 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ loadTestFile }: FtrProviderContext) {
+  describe('get_runtime_field', () => {
+    loadTestFile(require.resolve('./errors'));
+    loadTestFile(require.resolve('./main'));
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/get_runtime_field/main.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/get_runtime_field/main.ts
new file mode 100644
index 00000000000000..fa0283d69d8e3b
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/get_runtime_field/main.ts
@@ -0,0 +1,71 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+  const esArchiver = getService('esArchiver');
+
+  describe('main', () => {
+    before(async () => {
+      await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
+    });
+
+    after(async () => {
+      await esArchiver.unload(
+        'test/api_integration/fixtures/es_archiver/index_patterns/basic_index'
+      );
+    });
+
+    it('can fetch a runtime field', async () => {
+      const title = `basic_index*`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+          runtimeFieldMap: {
+            runtimeFoo: {
+              type: 'keyword',
+              script: {
+                source: "emit(doc['field_name'].value)",
+              },
+            },
+            runtimeBar: {
+              type: 'keyword',
+              script: {
+                source: "emit(doc['field_name'].value)",
+              },
+            },
+          },
+        },
+      });
+
+      expect(response1.status).to.be(200);
+
+      const response2 = await supertest.get(
+        '/api/index_patterns/index_pattern/' +
+          response1.body.index_pattern.id +
+          '/runtime_field/runtimeFoo'
+      );
+
+      expect(response2.status).to.be(200);
+      expect(typeof response2.body.field).to.be('object');
+      expect(response2.body.field.name).to.be('runtimeFoo');
+      expect(response2.body.field.type).to.be('string');
+      expect(response2.body.field.scripted).to.be(false);
+      expect(response2.body.field.runtimeField.script.source).to.be(
+        "emit(doc['field_name'].value)"
+      );
+      await supertest.delete(
+        '/api/index_patterns/index_pattern/' + response1.body.index_pattern.id
+      );
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/index.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/index.ts
new file mode 100644
index 00000000000000..7a727a3e867550
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/index.ts
@@ -0,0 +1,19 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { FtrProviderContext } from '../../../ftr_provider_context';
+
+export default function ({ loadTestFile }: FtrProviderContext) {
+  describe('runtime_fields_crud', () => {
+    loadTestFile(require.resolve('./create_runtime_field'));
+    loadTestFile(require.resolve('./get_runtime_field'));
+    loadTestFile(require.resolve('./delete_runtime_field'));
+    loadTestFile(require.resolve('./put_runtime_field'));
+    loadTestFile(require.resolve('./update_runtime_field'));
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/put_runtime_field/errors.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/put_runtime_field/errors.ts
new file mode 100644
index 00000000000000..9faca08238033e
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/put_runtime_field/errors.ts
@@ -0,0 +1,69 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+  const esArchiver = getService('esArchiver');
+
+  describe('errors', () => {
+    before(async () => {
+      await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
+    });
+
+    after(async () => {
+      await esArchiver.unload(
+        'test/api_integration/fixtures/es_archiver/index_patterns/basic_index'
+      );
+    });
+
+    it('returns 404 error on non-existing index_pattern', async () => {
+      const id = `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx-${Date.now()}`;
+      const response = await supertest
+        .put(`/api/index_patterns/index_pattern/${id}/runtime_field`)
+        .send({
+          name: 'runtimeBar',
+          runtimeField: {
+            type: 'long',
+            script: {
+              source: "emit(doc['field_name'].value)",
+            },
+          },
+        });
+
+      expect(response.status).to.be(404);
+    });
+
+    it('returns error on non-runtime field update attempt', async () => {
+      const title = `basic_index`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+        },
+      });
+
+      const response2 = await supertest
+        .put(`/api/index_patterns/index_pattern/${response1.body.index_pattern.id}/runtime_field`)
+        .send({
+          name: 'bar',
+          runtimeField: {
+            type: 'long',
+            script: {
+              source: "emit(doc['field_name'].value)",
+            },
+          },
+        });
+
+      expect(response2.status).to.be(400);
+      expect(response2.body.message).to.be('Only runtime fields can be updated');
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/put_runtime_field/index.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/put_runtime_field/index.ts
new file mode 100644
index 00000000000000..724f18e57f3efd
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/put_runtime_field/index.ts
@@ -0,0 +1,16 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ loadTestFile }: FtrProviderContext) {
+  describe('put_runtime_field', () => {
+    loadTestFile(require.resolve('./errors'));
+    loadTestFile(require.resolve('./main'));
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/put_runtime_field/main.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/put_runtime_field/main.ts
new file mode 100644
index 00000000000000..92d8c6fd6d3c25
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/put_runtime_field/main.ts
@@ -0,0 +1,122 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+  const esArchiver = getService('esArchiver');
+
+  describe('main', () => {
+    before(async () => {
+      await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
+    });
+
+    after(async () => {
+      await esArchiver.unload(
+        'test/api_integration/fixtures/es_archiver/index_patterns/basic_index'
+      );
+    });
+
+    it('can overwrite an existing field', async () => {
+      const title = `basic_index`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+          runtimeFieldMap: {
+            runtimeFoo: {
+              type: 'keyword',
+              script: {
+                source: "doc['field_name'].value",
+              },
+            },
+            runtimeBar: {
+              type: 'keyword',
+              script: {
+                source: "doc['field_name'].value",
+              },
+            },
+          },
+        },
+      });
+
+      const response2 = await supertest
+        .put(`/api/index_patterns/index_pattern/${response1.body.index_pattern.id}/runtime_field`)
+        .send({
+          name: 'runtimeFoo',
+          runtimeField: {
+            type: 'long',
+            script: {
+              source: "doc['field_name'].value",
+            },
+          },
+        });
+
+      expect(response2.status).to.be(200);
+
+      const response3 = await supertest.get(
+        '/api/index_patterns/index_pattern/' +
+          response1.body.index_pattern.id +
+          '/runtime_field/runtimeFoo'
+      );
+
+      expect(response3.status).to.be(200);
+      expect(response3.body.field.type).to.be('number');
+
+      const response4 = await supertest.get(
+        '/api/index_patterns/index_pattern/' +
+          response1.body.index_pattern.id +
+          '/runtime_field/runtimeBar'
+      );
+
+      expect(response4.status).to.be(200);
+      expect(response4.body.field.type).to.be('string');
+    });
+
+    it('can add a new runtime field', async () => {
+      const title = `basic_index`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+          runtimeFieldMap: {
+            runtimeFoo: {
+              type: 'keyword',
+              script: {
+                source: "doc['field_name'].value",
+              },
+            },
+          },
+        },
+      });
+
+      await supertest
+        .put(`/api/index_patterns/index_pattern/${response1.body.index_pattern.id}/runtime_field`)
+        .send({
+          name: 'runtimeBar',
+          runtimeField: {
+            type: 'long',
+            script: {
+              source: "doc['field_name'].value",
+            },
+          },
+        });
+
+      const response2 = await supertest.get(
+        '/api/index_patterns/index_pattern/' +
+          response1.body.index_pattern.id +
+          '/runtime_field/runtimeBar'
+      );
+
+      expect(response2.status).to.be(200);
+      expect(typeof response2.body.field.runtimeField).to.be('object');
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/update_runtime_field/errors.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/update_runtime_field/errors.ts
new file mode 100644
index 00000000000000..3980821c0fd096
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/update_runtime_field/errors.ts
@@ -0,0 +1,51 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+
+  describe('errors', () => {
+    it('returns 404 error on non-existing index_pattern', async () => {
+      const id = `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx-${Date.now()}`;
+      const response = await supertest
+        .post(`/api/index_patterns/index_pattern/${id}/runtime_field/foo`)
+        .send({
+          runtimeField: {
+            script: {
+              source: "doc['something_new'].value",
+            },
+          },
+        });
+
+      expect(response.status).to.be(404);
+    });
+
+    it('returns error when field name is specified', async () => {
+      const id = `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx-${Date.now()}`;
+      const response = await supertest
+        .post(`/api/index_patterns/index_pattern/${id}/runtime_field/foo`)
+        .send({
+          name: 'foo',
+          runtimeField: {
+            script: {
+              source: "doc['something_new'].value",
+            },
+          },
+        });
+
+      expect(response.status).to.be(400);
+      expect(response.body.statusCode).to.be(400);
+      expect(response.body.message).to.be(
+        "[request body.name]: a value wasn't expected to be present"
+      );
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/update_runtime_field/index.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/update_runtime_field/index.ts
new file mode 100644
index 00000000000000..f5d556ca9994ab
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/update_runtime_field/index.ts
@@ -0,0 +1,16 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ loadTestFile }: FtrProviderContext) {
+  describe('update_runtime_field', () => {
+    loadTestFile(require.resolve('./errors'));
+    loadTestFile(require.resolve('./main'));
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/runtime_fields_crud/update_runtime_field/main.ts b/test/api_integration/apis/index_patterns/runtime_fields_crud/update_runtime_field/main.ts
new file mode 100644
index 00000000000000..6b924570a0e45b
--- /dev/null
+++ b/test/api_integration/apis/index_patterns/runtime_fields_crud/update_runtime_field/main.ts
@@ -0,0 +1,76 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+  const esArchiver = getService('esArchiver');
+
+  describe('main', () => {
+    before(async () => {
+      await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
+    });
+
+    after(async () => {
+      await esArchiver.unload(
+        'test/api_integration/fixtures/es_archiver/index_patterns/basic_index'
+      );
+    });
+
+    it('can update an existing field', async () => {
+      const title = `basic_index`;
+      const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
+        index_pattern: {
+          title,
+          runtimeFieldMap: {
+            runtimeFoo: {
+              type: 'keyword',
+              script: {
+                source: "doc['field_name'].value",
+              },
+            },
+            runtimeBar: {
+              type: 'keyword',
+              script: {
+                source: "doc['field_name'].value",
+              },
+            },
+          },
+        },
+      });
+
+      const response2 = await supertest
+        .post(
+          `/api/index_patterns/index_pattern/${response1.body.index_pattern.id}/runtime_field/runtimeFoo`
+        )
+        .send({
+          runtimeField: {
+            script: {
+              source: "doc['something_new'].value",
+            },
+          },
+        });
+
+      expect(response2.status).to.be(200);
+
+      const response3 = await supertest.get(
+        '/api/index_patterns/index_pattern/' +
+          response1.body.index_pattern.id +
+          '/runtime_field/runtimeFoo'
+      );
+
+      expect(response3.status).to.be(200);
+      expect(response3.body.field.type).to.be('string');
+      expect(response3.body.field.runtimeField.type).to.be('keyword');
+      expect(response3.body.field.runtimeField.script.source).to.be("doc['something_new'].value");
+    });
+  });
+}
diff --git a/test/api_integration/apis/index_patterns/scripted_fields_crud/create_scripted_field/main.ts b/test/api_integration/apis/index_patterns/scripted_fields_crud/create_scripted_field/main.ts
index 1210e7247f72dd..663deae1d34769 100644
--- a/test/api_integration/apis/index_patterns/scripted_fields_crud/create_scripted_field/main.ts
+++ b/test/api_integration/apis/index_patterns/scripted_fields_crud/create_scripted_field/main.ts
@@ -54,6 +54,7 @@ export default function ({ getService }: FtrProviderContext) {
     it('newly created scripted field is materialized in the index_pattern object', async () => {
       const title = `basic_index`;
       const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
         index_pattern: {
           title,
         },
diff --git a/test/api_integration/apis/index_patterns/scripted_fields_crud/delete_scripted_field/main.ts b/test/api_integration/apis/index_patterns/scripted_fields_crud/delete_scripted_field/main.ts
index 466af26f6e1272..b9ce3e84d53904 100644
--- a/test/api_integration/apis/index_patterns/scripted_fields_crud/delete_scripted_field/main.ts
+++ b/test/api_integration/apis/index_patterns/scripted_fields_crud/delete_scripted_field/main.ts
@@ -27,6 +27,7 @@ export default function ({ getService }: FtrProviderContext) {
     it('can remove a scripted field', async () => {
       const title = `basic_index`;
       const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
         index_pattern: {
           title,
           fields: {
diff --git a/test/api_integration/apis/index_patterns/scripted_fields_crud/get_scripted_field/main.ts b/test/api_integration/apis/index_patterns/scripted_fields_crud/get_scripted_field/main.ts
index 64d909480260e5..c38c3a01708a74 100644
--- a/test/api_integration/apis/index_patterns/scripted_fields_crud/get_scripted_field/main.ts
+++ b/test/api_integration/apis/index_patterns/scripted_fields_crud/get_scripted_field/main.ts
@@ -27,6 +27,7 @@ export default function ({ getService }: FtrProviderContext) {
     it('can fetch a scripted field', async () => {
       const title = `basic_index`;
       const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
         index_pattern: {
           title,
           fields: {
diff --git a/test/api_integration/apis/index_patterns/scripted_fields_crud/put_scripted_field/main.ts b/test/api_integration/apis/index_patterns/scripted_fields_crud/put_scripted_field/main.ts
index 96f5924e7c132f..16b19583068187 100644
--- a/test/api_integration/apis/index_patterns/scripted_fields_crud/put_scripted_field/main.ts
+++ b/test/api_integration/apis/index_patterns/scripted_fields_crud/put_scripted_field/main.ts
@@ -27,6 +27,7 @@ export default function ({ getService }: FtrProviderContext) {
     it('can overwrite an existing field', async () => {
       const title = `basic_index`;
       const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
         index_pattern: {
           title,
           fields: {
diff --git a/test/api_integration/apis/index_patterns/scripted_fields_crud/update_scripted_field/main.ts b/test/api_integration/apis/index_patterns/scripted_fields_crud/update_scripted_field/main.ts
index 055b3fe9abe04d..4ffc98e0660bca 100644
--- a/test/api_integration/apis/index_patterns/scripted_fields_crud/update_scripted_field/main.ts
+++ b/test/api_integration/apis/index_patterns/scripted_fields_crud/update_scripted_field/main.ts
@@ -27,6 +27,7 @@ export default function ({ getService }: FtrProviderContext) {
     it('can update an existing field', async () => {
       const title = `basic_index`;
       const response1 = await supertest.post('/api/index_patterns/index_pattern').send({
+        override: true,
         index_pattern: {
           title,
           fields: {