diff --git a/src/app/api/test/reranker/route.ts b/src/app/api/test/reranker/route.ts
index f05cc674..054a3f51 100644
--- a/src/app/api/test/reranker/route.ts
+++ b/src/app/api/test/reranker/route.ts
@@ -76,7 +76,7 @@ export const POST = defineHandler({
   body
 }) => {
   const { query, config, llmConfig, top_k } = body;
-  const llm = llmConfig ? await buildLLM(llmConfig) : undefined;
+  const llm = llmConfig ? buildLLM(llmConfig) : undefined;
   const serviceContext = serviceContextFromDefaults({
     llm: llm
   })
diff --git a/src/app/api/v1/indexes/[name]/retrieve/route.ts b/src/app/api/v1/indexes/[name]/retrieve/route.ts
index 8b771bd8..d4eabc4c 100644
--- a/src/app/api/v1/indexes/[name]/retrieve/route.ts
+++ b/src/app/api/v1/indexes/[name]/retrieve/route.ts
@@ -36,7 +36,7 @@ export const POST = defineHandler({
 
   const flow = await getFlow(baseRegistry);
   const serviceContext = serviceContextFromDefaults({
-    llm: await buildLLM(llmConfig),
+    llm: buildLLM(llmConfig),
     embedModel: await buildEmbedding(index.config.embedding),
   });
 
diff --git a/src/core/services/llamaindex/chating.ts b/src/core/services/llamaindex/chating.ts
index 9d4cb6b6..621e5ac9 100644
--- a/src/core/services/llamaindex/chating.ts
+++ b/src/core/services/llamaindex/chating.ts
@@ -135,7 +135,7 @@ export class LlamaindexChatService extends AppChatService {
     });
 
     // Service context.
-    const llm = await buildLLM(llmConfig!, trace);
+    const llm = buildLLM(llmConfig!, trace);
     const promptHelper = new PromptHelper(llm.metadata.contextWindow);
     const embedModel = await buildEmbedding(this.index.config.embedding);
     const serviceContext = serviceContextFromDefaults({
diff --git a/src/core/services/llamaindex/indexing.ts b/src/core/services/llamaindex/indexing.ts
index 2ebb1037..481172eb 100644
--- a/src/core/services/llamaindex/indexing.ts
+++ b/src/core/services/llamaindex/indexing.ts
@@ -47,7 +47,7 @@ export class LlamaindexIndexProvider extends DocumentIndexProvider {
     });
 
     // Select and config the llm for indexing (metadata extractor).
-    const llm = await buildLLM(index.config.llm);
+    const llm = buildLLM(index.config.llm);
     llm.metadata.model = index.config.llm.options?.model!;
 
     // Select and config the embedding (important and immutable)
diff --git a/src/lib/llamaindex/builders/indices.ts b/src/lib/llamaindex/builders/indices.ts
index 87de1710..d1ec2f22 100644
--- a/src/lib/llamaindex/builders/indices.ts
+++ b/src/lib/llamaindex/builders/indices.ts
@@ -24,7 +24,7 @@ export async function createVectorStoreIndex (id: number) {
       dimensions: DEFAULT_TIDB_VECTOR_DIMENSIONS,
     }),
     serviceContext: serviceContextFromDefaults({
-      llm: await buildLLM(index.config.llm),
+      llm: buildLLM(index.config.llm),
       embedModel: await buildEmbedding(index.config.embedding),
     }),
   });
diff --git a/src/lib/llamaindex/builders/llm.ts b/src/lib/llamaindex/builders/llm.ts
index 3c7ac4fb..d88cfeb8 100644
--- a/src/lib/llamaindex/builders/llm.ts
+++ b/src/lib/llamaindex/builders/llm.ts
@@ -4,7 +4,7 @@ import {LangfuseTraceClient} from "langfuse";
 import {OpenAI, Ollama} from "llamaindex";
 import {Bitdeer} from "@/lib/llamaindex/llm/bitdeer";
 
-export async function buildLLM ({ provider, options}: LLMConfig, trace?: LangfuseTraceClient) {
+export function buildLLM ({ provider, options}: LLMConfig, trace?: LangfuseTraceClient) {
   let baseLLM;
   switch (provider) {
     case LLMProvider.OPENAI:
diff --git a/src/lib/llamaindex/builders/metadata-filter.ts b/src/lib/llamaindex/builders/metadata-filter.ts
index 63e3e6a8..f766e13e 100644
--- a/src/lib/llamaindex/builders/metadata-filter.ts
+++ b/src/lib/llamaindex/builders/metadata-filter.ts
@@ -1,17 +1,22 @@
+import {buildLLM} from "@/lib/llamaindex/builders/llm";
 import {MetadataFilterConfig} from "@/lib/llamaindex/config/metadata-filter";
 import {
   MetadataPostFilter
 } from "@/lib/llamaindex/postprocessors/postfilters/MetadataPostFilter";
 import {ServiceContext} from 'llamaindex';
 
-export function buildMetadataFilter (serviceContext: ServiceContext, { provider, options }: MetadataFilterConfig) {
-    switch (provider) {
+export function buildMetadataFilter (serviceContext: ServiceContext, config: MetadataFilterConfig) {
+    switch (config.provider) {
       case 'default':
+        let llm = serviceContext.llm;
+        if (config.options?.llm) {
+          llm = buildLLM(config.options.llm);
+        }
         return new MetadataPostFilter({
-          ...options,
-          serviceContext,
+          llm,
+
         });
       default:
-        throw new Error(`Unknown metadata filter provider: ${provider}`)
+        throw new Error(`Unknown metadata filter provider: ${config.provider}`)
     }
 }
diff --git a/src/lib/llamaindex/config/metadata-filter.ts b/src/lib/llamaindex/config/metadata-filter.ts
index 3312270b..743f38ab 100644
--- a/src/lib/llamaindex/config/metadata-filter.ts
+++ b/src/lib/llamaindex/config/metadata-filter.ts
@@ -1,3 +1,4 @@
+import {LLMConfigSchema} from "@/lib/llamaindex/config/llm";
 import {z} from "zod";
 
 export const metadataFilterSchema = z.object({
@@ -25,6 +26,7 @@ export enum MetadataFilterProvider {
 }
 
 export const DefaultMetadataFilterOptions = z.object({
+  llm: LLMConfigSchema.optional(),
   metadata_fields: z.array(metadataFieldSchema).optional(),
   filters: z.array(metadataFilterSchema).optional()
 });
diff --git a/src/lib/llamaindex/postprocessors/postfilters/MetadataPostFilter.ts b/src/lib/llamaindex/postprocessors/postfilters/MetadataPostFilter.ts
index 23c296b4..a938e6ca 100644
--- a/src/lib/llamaindex/postprocessors/postfilters/MetadataPostFilter.ts
+++ b/src/lib/llamaindex/postprocessors/postfilters/MetadataPostFilter.ts
@@ -1,5 +1,6 @@
 import {MetadataField, MetadataFieldFilter} from "@/lib/llamaindex/config/metadata-filter";
 import {BaseNodePostprocessor, NodeWithScore, ServiceContext, serviceContextFromDefaults} from "llamaindex";
+import {BaseLLM} from "llamaindex/llm/base";
 import {DateTime} from "luxon";
 
 export const defaultMetadataFilterChoicePrompt = ({metadataFields, query}: {
@@ -48,41 +49,49 @@ export type MetadataFilterChoicePrompt = typeof defaultMetadataFilterChoicePromp
 export type MetadataPostFilterOptions = Partial<MetadataPostFilter>;
 
 export class MetadataPostFilter implements BaseNodePostprocessor {
-  serviceContext: ServiceContext = serviceContextFromDefaults();
-  metadataFilterChoicePrompt: MetadataFilterChoicePrompt = defaultMetadataFilterChoicePrompt;
-
+  serviceContext: ServiceContext;
+  /**
+   * The llm model used for filters generating.
+   */
+  llm: BaseLLM;
+  /**
+   * The prompt for metadata filter choice.
+   */
+  metadataFilterChoicePrompt: MetadataFilterChoicePrompt;
   /**
    * The definition of metadata fields.
    */
-  metadata_fields: MetadataField[] = [];
+  metadata_fields: MetadataField[];
   /**
    * Provide the filters to apply to the search.
    */
-  filters: MetadataFieldFilter[] | null = null;
+  filters: MetadataFieldFilter[] | null;
 
   constructor(init?: MetadataPostFilterOptions) {
-    Object.assign(this, init);
+    this.serviceContext = init?.serviceContext ?? serviceContextFromDefaults();
+    this.llm = init?.llm ?? this.serviceContext.llm;
+    this.metadata_fields = init?.metadata_fields ?? [];
+    this.filters = init?.filters ?? null;
+    this.metadataFilterChoicePrompt = init?.metadataFilterChoicePrompt || defaultMetadataFilterChoicePrompt;
   }
 
   async postprocessNodes(nodes: NodeWithScore[], query: string): Promise<NodeWithScore[]> {
     let filters;
     if (this.filters) {
       filters = this.filters;
-      console.info('Apply provided filters:', filters);
+      console.info('[Metadata Filter] Provided filters: ', filters);
     } else {
       const start = DateTime.now();
       filters = await this.generateFilters(query);
-      const end = DateTime.now();
-      console.info('Generate filters took:', end.diff(start).as('seconds'), 's');
-      console.info('Apply generated filters:', filters);
+      const duration = DateTime.now().diff(start).as('milliseconds')
+      console.info(`[Metadata Filter] Generate filters (took: ${duration} ms): `, filters);
     }
 
-    console.log('Nodes before filter:', nodes.length, 'nodes');
-    let filteredNodes = await this.filterNodes(nodes, filters);
-    console.log('Nodes after filter:', filteredNodes.length, 'nodes');
+    const filteredNodes = await this.filterNodes(nodes, filters);
+    console.log(`[Metadata Filter] Applied provided/generated filter (before: ${nodes.length} nodes, after: ${filteredNodes.length} nodes).`);
 
     if (filteredNodes.length === 0) {
-      console.warn('No nodes left after filtering, fallback to using all nodes.');
+      console.warn('[Metadata Filter] No nodes left after filtering, fallback to using all nodes.');
       return nodes;
     }
 
@@ -91,12 +100,11 @@ export class MetadataPostFilter implements BaseNodePostprocessor {
 
   async generateFilters(query: string): Promise<MetadataFieldFilter[]> {
     try {
-      const llm = this.serviceContext.llm;
       const prompt = this.metadataFilterChoicePrompt({
         metadataFields: this.metadata_fields,
         query
       });
-      const raw = await llm.chat({
+      const raw = await this.llm.chat({
         messages: [
           {
             role: 'system',