Initial commit

src/agents/imageSearchAgent.ts

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+import {
+  RunnableSequence,
+  RunnableMap,
+  RunnableLambda,
+} from '@langchain/core/runnables';
+import { PromptTemplate } from '@langchain/core/prompts';
+import { OpenAI } from '@langchain/openai';
+import formatChatHistoryAsString from '../utils/formatHistory';
+import { BaseMessage } from '@langchain/core/messages';
+import { StringOutputParser } from '@langchain/core/output_parsers';
+import { searchSearxng } from '../core/searxng';
+
+const llm = new OpenAI({
+  temperature: 0,
+  modelName: 'gpt-3.5-turbo',
+});
+
+const imageSearchChainPrompt = `
+You will be given a conversation below and a follow up question. You need to rephrase the follow-up question so it is a standalone question that can be used by the LLM to search the web for images.
+You need to make sure the rephrased question agrees with the conversation and is relevant to the conversation.
+
+Example:
+1. Follow up question: What is a cat?
+Rephrased: A cat
+
+2. Follow up question: What is a car? How does it works?
+Rephrased: Car working
+
+3. Follow up question: How does an AC work?
+Rephrased: AC working
+
+Conversation:
+{chat_history}
+
+Follow up question: {query}
+Rephrased question:
+`;
+
+type ImageSearchChainInput = {
+  chat_history: BaseMessage[];
+  query: string;
+};
+
+const strParser = new StringOutputParser();
+
+const imageSearchChain = RunnableSequence.from([
+  RunnableMap.from({
+    chat_history: (input: ImageSearchChainInput) => {
+      return formatChatHistoryAsString(input.chat_history);
+    },
+    query: (input: ImageSearchChainInput) => {
+      return input.query;
+    },
+  }),
+  PromptTemplate.fromTemplate(imageSearchChainPrompt),
+  llm,
+  strParser,
+  RunnableLambda.from(async (input: string) => {
+    const res = await searchSearxng(input, {
+      categories: ['images'],
+      engines: ['bing_images', 'google_images'],
+    });
+
+    const images = [];
+
+    res.results.forEach((result) => {
+      if (result.img_src && result.url && result.title) {
+        images.push({
+          img_src: result.img_src,
+          url: result.url,
+          title: result.title,
+        });
+      }
+    });
+
+    return images.slice(0, 10);
+  }),
+]);
+
+export default imageSearchChain;