diff --git a/apidom/packages/apidom-ls/src/parser-factory.ts b/apidom/packages/apidom-ls/src/parser-factory.ts
index 842e772943..2abee3fe09 100644
--- a/apidom/packages/apidom-ls/src/parser-factory.ts
+++ b/apidom/packages/apidom-ls/src/parser-factory.ts
@@ -10,15 +10,8 @@ import * as openapi3_1Adapter_Yaml from 'apidom-parser-adapter-openapi-yaml-3-1'
 // @ts-ignore
 import * as asyncapi2_0Adapter_Yaml from 'apidom-parser-adapter-asyncapi-yaml-2-0';
 
-// @ts-ignore
-import { ParseResultElement } from 'apidom';
-
 import { TextDocument } from 'vscode-languageserver-textdocument';
 
-export interface Parser {
-  parse(source: string, options: ParserOptions): PromiseLike<ParseResultElement>;
-}
-
 export interface ParserOptions {
   sourceMap?: boolean;
   specObj?: string;
@@ -58,7 +51,7 @@ export function isJsonDoc(document: TextDocument | string): boolean {
   return jsonStart != null && JSON_ENDS[jsonStart[0]].test(text);
 }
 
-export function getParser(document: TextDocument): Parser {
+export function getParser(document: TextDocument): ApiDOMParser {
   const async = isAsyncDoc(document);
   const json = isJsonDoc(document);
   if (async && json) {
diff --git a/apidom/packages/apidom-ls/test/openapi-json.ts b/apidom/packages/apidom-ls/test/openapi-json.ts
index de6ba6bcd0..a0c8a49ddf 100644
--- a/apidom/packages/apidom-ls/test/openapi-json.ts
+++ b/apidom/packages/apidom-ls/test/openapi-json.ts
@@ -230,8 +230,13 @@ describe('apidom-ls', function () {
     // parser.use(asyncapi2_0Adapter);
     // eslint-disable-next-line @typescript-eslint/no-unused-vars
     const parseResult = await parser.parse(value, { sourceMap: true });
-    addMetadataMapping(parseResult.api);
 
-    assert.deepEqual(parseResult.api.meta.get('metadataMap').toValue(), metadataMap);
+    if (parseResult.api !== undefined) {
+      addMetadataMapping(parseResult.api);
+
+      assert.deepEqual(parseResult.api.meta.get('metadataMap').toValue(), metadataMap);
+    } else {
+      assert.fail('parserResult.api should return OpenApi Element');
+    }
   });
 });
diff --git a/apidom/packages/apidom-parser/src/parser.ts b/apidom/packages/apidom-parser/src/parser.ts
index e0d4954c07..b7511311e6 100644
--- a/apidom/packages/apidom-parser/src/parser.ts
+++ b/apidom/packages/apidom-parser/src/parser.ts
@@ -3,12 +3,12 @@ import { head } from 'ramda';
 import { isArray, isFunction, isString, isUndefined } from 'ramda-adjunct';
 import { ParseResultElement, Namespace } from 'apidom';
 
-interface ParserOptions {
+interface ParserOptions extends Record<string, any> {
   mediaType?: string;
 }
 
 type Detect = (source: string) => boolean;
-type Parse = (source: string, options: ParserOptions) => ParseResultElement;
+type Parse = (source: string, options: ParserOptions) => Promise<ParseResultElement>;
 
 interface ApiDOMParserAdapter {
   detect?: Detect;
@@ -17,7 +17,13 @@ interface ApiDOMParserAdapter {
   namespace: Namespace;
 }
 
-const ApiDOMParser = stampit().init(function ApiDOMParser() {
+interface ApiDOMParser {
+  use(adapter: ApiDOMParserAdapter): ApiDOMParser;
+  findNamespace(source: string, options?: ParserOptions): Namespace;
+  parse(source: string, options?: ParserOptions): Promise<ParseResultElement>;
+}
+
+const ApiDOMParser: stampit.Stamp<ApiDOMParser> = stampit().init(function ApiDOMParser() {
   const adapters: ApiDOMParserAdapter[] = [];
 
   const detectAdapterCandidates = (source: string) => {
@@ -45,7 +51,7 @@ const ApiDOMParser = stampit().init(function ApiDOMParser() {
     return this;
   };
 
-  this.namespace = function namespace(source: string, options: ParserOptions = {}) {
+  this.findNamespace = function findNamespace(source: string, options: ParserOptions = {}) {
     const adapter = findAdapter(source, options.mediaType);
 
     return adapter?.namespace;
diff --git a/experiments/apidom-playground/src/features/app/file-importer/components/FileImporter.jsx b/experiments/apidom-playground/src/features/app/file-importer/components/FileImporter.jsx
index 4d41a50fa5..ba4362e352 100644
--- a/experiments/apidom-playground/src/features/app/file-importer/components/FileImporter.jsx
+++ b/experiments/apidom-playground/src/features/app/file-importer/components/FileImporter.jsx
@@ -7,7 +7,7 @@ import SpeedDialAction from '@material-ui/lab/SpeedDialAction';
 import DescriptionIcon from '@material-ui/icons/Description';
 import AttachFileIcon from '@material-ui/icons/AttachFile';
 import ImportExportIcon from '@material-ui/icons/ImportExport';
-import { setSource } from 'features/app/slice';
+import { setSource, setBaseURI } from 'features/app/slice';
 import UrlImportDialog from 'features/app/file-importer/url-import-dialog/components/UrlImportDialog';
 
 const useStyles = makeStyles((theme) => ({
@@ -46,6 +46,7 @@ const FileImporter = () => {
     const reader = new FileReader();
     const onloadend = (onloadendEvent) => {
       const source = onloadendEvent.target.result;
+      dispatch(setBaseURI(window.location.href));
       dispatch(setSource(source));
     };
 
diff --git a/experiments/apidom-playground/src/features/app/left-pane/editor-controls/components/EditorControls.jsx b/experiments/apidom-playground/src/features/app/left-pane/editor-controls/components/EditorControls.jsx
index dc087aa5fa..483d04c46d 100644
--- a/experiments/apidom-playground/src/features/app/left-pane/editor-controls/components/EditorControls.jsx
+++ b/experiments/apidom-playground/src/features/app/left-pane/editor-controls/components/EditorControls.jsx
@@ -63,7 +63,7 @@ const EditorControls = () => {
     dispatch(parseSource({ source, mediaType }));
   };
   const handleApiDOMResolve = () => {
-    dispatch(resolveApiDOM({ apiDOM, mediaType, baseURI }));
+    dispatch(resolveApiDOM({ source, apiDOM, mediaType, baseURI }));
   };
 
   return (
diff --git a/experiments/apidom-playground/src/features/app/slice.js b/experiments/apidom-playground/src/features/app/slice.js
index eee672c86d..f805bfa382 100644
--- a/experiments/apidom-playground/src/features/app/slice.js
+++ b/experiments/apidom-playground/src/features/app/slice.js
@@ -67,7 +67,7 @@ export const importURL = createAsyncThunk('importURLStatus', async (url) => {
 });
 
 export const parseSource = createAsyncThunk('parseSourceStatus', async ({ source, mediaType }) => {
-  const namespace = parser.namespace(source, { sourceMap: true, mediaType });
+  const namespace = parser.findNamespace(source, { sourceMap: true, mediaType });
   const parseResult = await parser.parse(source, { sourceMap: true, mediaType });
   const refract = dehydrate(parseResult, namespace);
 
@@ -76,8 +76,8 @@ export const parseSource = createAsyncThunk('parseSourceStatus', async ({ source
 
 export const resolveApiDOM = createAsyncThunk(
   'resolveApiDOMStatus',
-  async ({ apiDOM, mediaType, baseURI }) => {
-    const namespace = parser.namespace('', { mediaType });
+  async ({ source, apiDOM, mediaType, baseURI }) => {
+    const namespace = parser.findNamespace(source, { mediaType });
     const parseResult = from(apiDOM, namespace);
 
     return resolveApiDOMReferences(parseResult, { parse: { mediaType }, resolve: { baseURI } });