feat: add explicit OpenAI fallback mode with clean TypeScript propagation

src/config/chatAPI-config.ts

@@ -15,7 +15,8 @@ export const guidelines = {
   UNRELATED_QUESTION: `If the question is not related to the context, say this phrase EXACTLY '${ERROR_MESSAGES.NO_ANSWER}'`,
   LINKING: `DO NOT explicity mention the existence of the context provided, however, references can and should be made to the links provided in the context e.g '[0]'.`,
   FOLLOW_UP_QUESTIONS: 'If you have an answer, generate four relevant follow up questions, do not include introductory text about follow-up questions. Each question must be in this format: `--{{ what problems did segwit solve }}--` in a new line.',
-  USED_SOURCES: `Lastly, list all sources relevant in generating the answer in a list in this format '__sources__: [LINK_INDICES_HERE]'`
+  USED_SOURCES: `Lastly, list all sources relevant in generating the answer in a list in this format '__sources__: [LINK_INDICES_HERE]'`,
+  FALLBACK_INSTRUCTION: `You are an AI assistant providing helpful answers to user queries. Answer the user's question directly and concisely without using any external context or search results. You must rely on your own internal knowledge to generate the response.`,
 };
 
 export const CONTEXT_WINDOW_MESSAGES = 6

src/pages/api/server.ts

@@ -50,11 +50,11 @@ export default async function handler(req: Request) {
     const requesturl = req.url;
     const reqBody = await req.json();
 
-    let esResults: any[] | null;
+    let esResults: any[] | null = null;
     let userQuery;
 
     const inputs = reqBody?.inputs;
-    const { query, author }: { query: string; author: string } = inputs;
+    const { query, author, fallback }: { query: string; author: string; fallback?: boolean } = inputs;
 
     if (!query) {
       return new Response(
@@ -66,20 +66,22 @@ export default async function handler(req: Request) {
     const chatHistory = reqBody?.chatHistory ?? ([] as ChatHistory[]);
 
     try {
-      const fetchUrl = getNewUrl(requesturl, "/search");
+      if (!fallback) {
+        const fetchUrl = getNewUrl(requesturl, "/search");
 
-      const gptKeywords = await GPTKeywordExtractor([...chatHistory]);
+        const gptKeywords = await GPTKeywordExtractor([...chatHistory]);
 
-      esResults = await internalFetch({url: fetchUrl, query, author, keywords: gptKeywords});
+        esResults = await internalFetch({ url: fetchUrl, query, author, keywords: gptKeywords });
 
-      // FOR logging purposes
-      const loggedResultsURLs = esResults?.map(result => result?._source.url)
-      console.log(`query: ${query}\n gptKeywords: ${gptKeywords} \n results: ${loggedResultsURLs}`)
+        // FOR logging purposes
+        const loggedResultsURLs = esResults?.map(result => result?._source.url)
+        console.log(`query: ${query}\n gptKeywords: ${gptKeywords} \n results: ${loggedResultsURLs}`)
 
-      if (!esResults || !esResults.length) {
-        const error = createReadableStream(ERROR_MESSAGES.NO_ANSWER);
-        console.log(error);
-        return new Response(error);
+        if (!esResults || !esResults.length) {
+          const error = createReadableStream(ERROR_MESSAGES.NO_ANSWER);
+          console.log(error);
+          return new Response(error);
+        }
       }
     } catch (error) {
       console.log(error);
@@ -90,7 +92,7 @@ export default async function handler(req: Request) {
     }
 
     try {
-      const result = await processInput(esResults, query, chatHistory);
+      const result = await processInput(esResults ?? undefined, query, chatHistory, fallback);
       return new Response(result);
     } catch (error: any) {
       const errMessage = error?.message

src/service/chat/history.ts

@@ -3,14 +3,20 @@ import { separateLinksFromApiMessage } from "@/utils/links";
 import { CONTEXT_WINDOW_MESSAGES, guidelines } from "@/config/chatAPI-config";
 import { ChatHistory } from "@/types";
 
-const buildSystemMessage = (question: string, context: string) => {
+const buildSystemMessage = (question: string, context: string, fallback?: boolean) => {
   const {
     BASE_INSTRUCTION,
     NO_ANSWER,
     UNRELATED_QUESTION,
     FOLLOW_UP_QUESTIONS,
     LINKING,
+    FALLBACK_INSTRUCTION,
   } = guidelines;
+
+  if (fallback) {
+    return `${FALLBACK_INSTRUCTION}`;
+  }
+
   return `${BASE_INSTRUCTION}\n${NO_ANSWER}\n${UNRELATED_QUESTION}\n${context}\n${LINKING}\n${FOLLOW_UP_QUESTIONS}`;
 };
 
@@ -19,13 +25,15 @@ export const buildChatMessages = ({
   context,
   oldContext,
   messages,
+  fallback,
 }: {
   question: string;
   context: string;
   oldContext?: string;
   messages: ChatHistory[];
+  fallback?: boolean;
 }) => {
-  const systemMessage = buildSystemMessage(question, context);
+  const systemMessage = buildSystemMessage(question, context, fallback);
   return [
     {
       role: "system",