diff --git a/packages/kbn-monaco/src/xjson/grammar.test.ts b/packages/kbn-monaco/src/xjson/grammar.test.ts
new file mode 100644
index 0000000000000..29d338cd71b0c
--- /dev/null
+++ b/packages/kbn-monaco/src/xjson/grammar.test.ts
@@ -0,0 +1,189 @@
+/*
+ * 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 { createParser } from './grammar';
+
+describe('createParser', () => {
+  let parser: ReturnType<typeof createParser>;
+
+  beforeEach(() => {
+    parser = createParser();
+  });
+
+  test('should create a xjson grammar parser', () => {
+    expect(createParser()).toBeInstanceOf(Function);
+  });
+
+  test('should return no annotations in case of valid json', () => {
+    expect(
+      parser(`
+        {"menu": {
+          "id": "file",
+          "value": "File",
+          "quotes": "'\\"",
+          "popup": {
+            "actions": [
+              "new",
+              "open",
+              "close"
+            ],
+            "menuitem": [
+              {"value": "New"},
+              {"value": "Open"},
+              {"value": "Close"}
+            ]
+          }
+        }}
+      `)
+    ).toMatchInlineSnapshot(`
+      Object {
+        "annotations": Array [],
+      }
+    `);
+  });
+
+  test('should support triple quotes', () => {
+    expect(
+      parser(`
+        {"menu": {
+          "id": """
+          file
+          """,
+          "value": "File"
+        }}
+      `)
+    ).toMatchInlineSnapshot(`
+      Object {
+        "annotations": Array [],
+      }
+    `);
+  });
+
+  test('triple quotes should be correctly closed', () => {
+    expect(
+      parser(`
+        {"menu": {
+          "id": """"
+          file
+          "",
+          "value": "File"
+        }}
+      `)
+    ).toMatchInlineSnapshot(`
+      Object {
+        "annotations": Array [
+          Object {
+            "at": 36,
+            "text": "Expected ',' instead of '\\"'",
+            "type": "error",
+          },
+        ],
+      }
+    `);
+  });
+
+  test('an escaped quote can be appended to the end of triple quotes', () => {
+    expect(
+      parser(`
+        {"menu": {
+          "id": """
+          file
+          \\"""",
+          "value": "File"
+        }}
+      `)
+    ).toMatchInlineSnapshot(`
+      Object {
+        "annotations": Array [],
+      }
+    `);
+  });
+
+  test('text values should be wrapper into quotes', () => {
+    expect(
+      parser(`
+        {"menu": {
+          "id": id,
+          "value": "File"
+        }}
+      `)
+    ).toMatchInlineSnapshot(`
+      Object {
+        "annotations": Array [
+          Object {
+            "at": 36,
+            "text": "Unexpected 'i'",
+            "type": "error",
+          },
+        ],
+      }
+    `);
+  });
+
+  test('check for close quotes', () => {
+    expect(
+      parser(`
+        {"menu": {
+          "id": "id,
+          "value": "File"
+        }}
+      `)
+    ).toMatchInlineSnapshot(`
+      Object {
+        "annotations": Array [
+          Object {
+            "at": 52,
+            "text": "Expected ',' instead of 'v'",
+            "type": "error",
+          },
+        ],
+      }
+    `);
+  });
+  test('no duplicate keys', () => {
+    expect(
+      parser(`
+        {"menu": {
+          "id": "id",
+          "id": "File"
+        }}
+      `)
+    ).toMatchInlineSnapshot(`
+      Object {
+        "annotations": Array [
+          Object {
+            "at": 53,
+            "text": "Duplicate key \\"id\\"",
+            "type": "warning",
+          },
+        ],
+      }
+    `);
+  });
+
+  test('all curly quotes should be closed', () => {
+    expect(
+      parser(`
+        {"menu": {
+          "id": "id",
+          "name": "File"
+       }
+      `)
+    ).toMatchInlineSnapshot(`
+      Object {
+        "annotations": Array [
+          Object {
+            "at": 82,
+            "text": "Expected ',' instead of ''",
+            "type": "error",
+          },
+        ],
+      }
+    `);
+  });
+});
diff --git a/packages/kbn-monaco/src/xjson/grammar.ts b/packages/kbn-monaco/src/xjson/grammar.ts
index 32c958e66d594..5d26e92f005ba 100644
--- a/packages/kbn-monaco/src/xjson/grammar.ts
+++ b/packages/kbn-monaco/src/xjson/grammar.ts
@@ -57,10 +57,6 @@ export const createParser = () => {
         text: m,
       });
     },
-    reset = function (newAt: number) {
-      ch = text.charAt(newAt);
-      at = newAt + 1;
-    },
     next = function (c?: string) {
       return (
         c && c !== ch && error("Expected '" + c + "' instead of '" + ch + "'"),
@@ -69,15 +65,6 @@ export const createParser = () => {
         ch
       );
     },
-    nextUpTo = function (upTo: any, errorMessage: string) {
-      let currentAt = at,
-        i = text.indexOf(upTo, currentAt);
-      if (i < 0) {
-        error(errorMessage || "Expected '" + upTo + "'");
-      }
-      reset(i + upTo.length);
-      return text.substring(currentAt, i);
-    },
     peek = function (c: string) {
       return text.substr(at, c.length) === c; // nocommit - double check
     },
@@ -96,37 +83,50 @@ export const createParser = () => {
           (string += ch), next();
       return (number = +string), isNaN(number) ? (error('Bad number'), void 0) : number;
     },
+    stringLiteral = function () {
+      let quotes = '"""';
+      let end = text.indexOf('\\"' + quotes, at + quotes.length);
+
+      if (end >= 0) {
+        quotes = '\\"' + quotes;
+      } else {
+        end = text.indexOf(quotes, at + quotes.length);
+      }
+
+      if (end >= 0) {
+        for (let l = end - at + quotes.length; l > 0; l--) {
+          next();
+        }
+      }
+
+      return next();
+    },
     string = function () {
       let hex: any,
         i: any,
         uffff: any,
         string = '';
+
       if ('"' === ch) {
-        if (peek('""')) {
-          // literal
-          next('"');
-          next('"');
-          return nextUpTo('"""', 'failed to find closing \'"""\'');
-        } else {
-          for (; next(); ) {
-            if ('"' === ch) return next(), string;
-            if ('\\' === ch)
-              if ((next(), 'u' === ch)) {
-                for (
-                  uffff = 0, i = 0;
-                  4 > i && ((hex = parseInt(next(), 16)), isFinite(hex));
-                  i += 1
-                )
-                  uffff = 16 * uffff + hex;
-                string += String.fromCharCode(uffff);
-              } else {
-                if ('string' != typeof escapee[ch]) break;
-                string += escapee[ch];
-              }
-            else string += ch;
-          }
+        for (; next(); ) {
+          if ('"' === ch) return next(), string;
+          if ('\\' === ch)
+            if ((next(), 'u' === ch)) {
+              for (
+                uffff = 0, i = 0;
+                4 > i && ((hex = parseInt(next(), 16)), isFinite(hex));
+                i += 1
+              )
+                uffff = 16 * uffff + hex;
+              string += String.fromCharCode(uffff);
+            } else {
+              if ('string' != typeof escapee[ch]) break;
+              string += escapee[ch];
+            }
+          else string += ch;
         }
       }
+
       error('Bad string');
     },
     white = function () {
@@ -165,9 +165,9 @@ export const createParser = () => {
             ((key = string()),
             white(),
             next(':'),
-            Object.hasOwnProperty.call(object, key) &&
+            Object.hasOwnProperty.call(object, key!) &&
               warning('Duplicate key "' + key + '"', latchKeyStart),
-            (object[key] = value()),
+            (object[key!] = value()),
             white(),
             '}' === ch)
           )
@@ -179,6 +179,9 @@ export const createParser = () => {
     };
   return (
     (value = function () {
+      if (peek('"""')) {
+        return stringLiteral();
+      }
       switch ((white(), ch)) {
         case '{':
           return object();
diff --git a/packages/kbn-monaco/src/xjson/lexer_rules/xjson.ts b/packages/kbn-monaco/src/xjson/lexer_rules/xjson.ts
index 2c8186ac7fa4f..f2ab22f8c97df 100644
--- a/packages/kbn-monaco/src/xjson/lexer_rules/xjson.ts
+++ b/packages/kbn-monaco/src/xjson/lexer_rules/xjson.ts
@@ -103,6 +103,7 @@ export const lexerRules: monaco.languages.IMonarchLanguage = {
 
     string_literal: [
       [/"""/, { token: 'punctuation.end_triple_quote', next: '@pop' }],
+      [/\\""""/, { token: 'punctuation.end_triple_quote', next: '@pop' }],
       [/./, { token: 'multi_string' }],
     ],
   },
diff --git a/src/plugins/data/common/search/aggs/param_types/json.test.ts b/src/plugins/data/common/search/aggs/param_types/json.test.ts
index 1b3af5b92c26b..8e71cf4657e1f 100644
--- a/src/plugins/data/common/search/aggs/param_types/json.test.ts
+++ b/src/plugins/data/common/search/aggs/param_types/json.test.ts
@@ -67,10 +67,34 @@ describe('JSON', function () {
       aggParam.write(aggConfig, output);
       expect(aggConfig.params).toHaveProperty(paramName);
 
-      expect(output.params).toEqual({
-        existing: 'true',
-        new_param: 'should exist in output',
-      });
+      expect(output.params).toMatchInlineSnapshot(`
+        Object {
+          "existing": "true",
+          "new_param": "should exist in output",
+        }
+      `);
+    });
+
+    it('should append param when valid JSON with triple quotes', () => {
+      const aggParam = initAggParam();
+      const jsonData = `{
+      "a": """
+        multiline string - line 1
+      """
+      }`;
+
+      aggConfig.params[paramName] = jsonData;
+
+      aggParam.write(aggConfig, output);
+      expect(aggConfig.params).toHaveProperty(paramName);
+
+      expect(output.params).toMatchInlineSnapshot(`
+        Object {
+          "a": "
+                multiline string - line 1
+              ",
+        }
+      `);
     });
 
     it('should not overwrite existing params', () => {
diff --git a/src/plugins/data/common/search/aggs/param_types/json.ts b/src/plugins/data/common/search/aggs/param_types/json.ts
index 1678b6586ce80..f499286140af1 100644
--- a/src/plugins/data/common/search/aggs/param_types/json.ts
+++ b/src/plugins/data/common/search/aggs/param_types/json.ts
@@ -11,6 +11,17 @@ import _ from 'lodash';
 import { IAggConfig } from '../agg_config';
 import { BaseParamType } from './base';
 
+function collapseLiteralStrings(xjson: string) {
+  const tripleQuotes = '"""';
+  const splitData = xjson.split(tripleQuotes);
+
+  for (let idx = 1; idx < splitData.length - 1; idx += 2) {
+    splitData[idx] = JSON.stringify(splitData[idx]);
+  }
+
+  return splitData.join('');
+}
+
 export class JsonParamType extends BaseParamType {
   constructor(config: Record<string, any>) {
     super(config);
@@ -26,9 +37,8 @@ export class JsonParamType extends BaseParamType {
           return;
         }
 
-        // handle invalid Json input
         try {
-          paramJson = JSON.parse(param);
+          paramJson = JSON.parse(collapseLiteralStrings(param));
         } catch (err) {
           return;
         }
diff --git a/src/plugins/vis_default_editor/kibana.json b/src/plugins/vis_default_editor/kibana.json
index efed1eab1e494..253edc74f87b4 100644
--- a/src/plugins/vis_default_editor/kibana.json
+++ b/src/plugins/vis_default_editor/kibana.json
@@ -3,7 +3,7 @@
   "version": "kibana",
   "ui": true,
   "optionalPlugins": ["visualize"],
-  "requiredBundles": ["kibanaUtils", "kibanaReact", "data", "fieldFormats", "discover"],
+  "requiredBundles": ["kibanaUtils", "kibanaReact", "data", "fieldFormats", "discover", "esUiShared"],
   "owner": {
     "name": "Vis Editors",
     "githubTeam": "kibana-vis-editors"
diff --git a/src/plugins/vis_default_editor/public/components/controls/raw_json.tsx b/src/plugins/vis_default_editor/public/components/controls/raw_json.tsx
index af6096be87f59..6e5ae78e54dc1 100644
--- a/src/plugins/vis_default_editor/public/components/controls/raw_json.tsx
+++ b/src/plugins/vis_default_editor/public/components/controls/raw_json.tsx
@@ -12,6 +12,7 @@ import { EuiFormRow, EuiIconTip, EuiScreenReaderOnly } from '@elastic/eui';
 import { i18n } from '@kbn/i18n';
 import { XJsonLang } from '@kbn/monaco';
 import { CodeEditor } from '../../../../kibana_react/public';
+import { XJson } from '../../../../es_ui_shared/public';
 
 import { AggParamEditorProps } from '../agg_param_props';
 
@@ -58,7 +59,7 @@ function RawJsonParamEditor({
       let isJsonValid = true;
       try {
         if (newValue) {
-          JSON.parse(newValue);
+          JSON.parse(XJson.collapseLiteralStrings(newValue));
         }
       } catch (e) {
         isJsonValid = false;