diff --git a/package-lock.json b/package-lock.json
index b5b4b0d..5a72069 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "epsillajs",
-  "version": "0.3.5",
+  "version": "0.3.6",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "epsillajs",
-      "version": "0.3.5",
+      "version": "0.3.6",
       "license": "Apache-2",
       "dependencies": {
         "axios": "^1.4.0"
diff --git a/package.json b/package.json
index 0c14df5..0e12931 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "epsillajs",
-  "version": "0.3.5",
+  "version": "0.3.6",
   "description": "A JS library to connect Epsilla vector database",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
diff --git a/src/models.ts b/src/models.ts
index 07b7b2c..af68bac 100644
--- a/src/models.ts
+++ b/src/models.ts
@@ -24,6 +24,7 @@ export interface Index {
   name: string;
   field: string;
   model?: string;
+  dimensions?: number;
 }
 
 export interface SparseVector {
@@ -41,6 +42,12 @@ export interface QueryPayload {
   response?: string[];
   filter?: string;
   withDistance?: boolean;
+  facets?: FacetConfig[];
+}
+
+export interface FacetConfig {
+  group?: string[];
+  aggregate: string[];
 }
 
 export interface QueryConfig {
@@ -52,6 +59,7 @@ export interface QueryConfig {
   response?: string[];
   filter?: string;
   withDistance?: boolean;
+  facets?: FacetConfig[];
 }
 
 export interface DeleteRecordsConfig {
@@ -65,6 +73,7 @@ export interface PreviewConfig {
   filter?: string;
   skip?: number;
   limit?: number;
+  facets?: FacetConfig[];
 }
 
 export interface EpsillaBaseResponse {
diff --git a/src/searchengine.ts b/src/searchengine.ts
index aad1dbe..e51c73f 100644
--- a/src/searchengine.ts
+++ b/src/searchengine.ts
@@ -1,13 +1,13 @@
 // VectorRetriever.ts
+import { VectorDB } from './cloud';
 import {
   QueryPayload,
-  SearchEngineCandidate,
   Reranker,
-  RetrieverConfig,
   RerankerConfig,
+  RetrieverConfig,
+  SearchEngineCandidate
 } from './models';
 import EpsillaDB from './vectordb';
-import { VectorDB } from './cloud';
 
 export class VectorRetriever {
   private dbClient: EpsillaDB | VectorDB;
@@ -29,7 +29,7 @@ export class VectorRetriever {
     queryVector?: any,
     response?: string[],
     limit: number = 2,
-    filter: string = '',
+    filter: string = ''
   ) {
     this.dbClient = dbClient;
     this.table = table;
@@ -52,7 +52,7 @@ export class VectorRetriever {
       response: this.response,
       limit: this.limit,
       filter: this.filter,
-      withDistance: true,
+      withDistance: true
     };
     const response = await this.dbClient.query(this.table, queryPayload);
     if (response instanceof Error) {
@@ -155,7 +155,7 @@ export class RelativeScoreFusionReranker implements Reranker {
         if (aggregatedScores[id]) {
           aggregatedScores[id].score += normalizedScore as number;
         } else {
-          aggregatedScores[id] = { 
+          aggregatedScores[id] = {
             candidate: list.find(candidate => candidate['@id'] === id) as SearchEngineCandidate,
             score: normalizedScore as number
           };
@@ -202,7 +202,7 @@ export class DistributionBasedScoreFusionReranker implements Reranker {
       throw new Error("The length of scaleRanges should be equal to the number of candidates lists.");
     }
 
-    const normalizedLists = candidatesLists.map((list, index) => 
+    const normalizedLists = candidatesLists.map((list, index) =>
       this.normalizeDistances(this.scaleRanges[index], list)
     );