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Zep Cloud Retriever

Zep is a long-term memory service for AI Assistant apps. With Zep, you can provide AI assistants with the ability to recall past conversations, no matter how distant, while also reducing hallucinations, latency, and cost.

This example shows how to use the Zep Retriever in a retrieval chain to retrieve documents from Zep Open Source memory store.

Installation​

Sign up for Zep Cloud and create a project.

Follow the Zep Cloud Typescript SDK Installation Guide to install and get started with Zep.

You'll need your Zep Cloud Project API Key to use the ZepCloudRetriever. See the Zep Cloud docs for more information.

Setup​

tip

See this section for general instructions on installing integration packages.

npm i @getzep/zep-cloud @langchain/community @langchain/core

Usage​

import { ZepCloudRetriever } from "@langchain/community/retrievers/zep_cloud";
import { randomUUID } from "crypto";
import { ZepClient } from "@getzep/zep-cloud";
import { Message } from "@getzep/zep-cloud/api";

function sleep(ms: number) {
  // eslint-disable-next-line no-promise-executor-return
  return new Promise((resolve) => setTimeout(resolve, ms));
}

const zepConfig = {
  // Your Zep Cloud Project API key https://help.getzep.com/projects
  apiKey: "<Zep Api Key>",
  sessionId: `session_${randomUUID()}`,
};

console.log(`Zep Config: ${JSON.stringify(zepConfig)}`);

// Generate chat messages about traveling to France
const chatMessages = [
  {
    role: "AI",
    message: "Bonjour! How can I assist you with your travel plans today?",
  },
  { role: "User", message: "I'm planning a trip to France." },
  {
    role: "AI",
    message: "That sounds exciting! What cities are you planning to visit?",
  },
  { role: "User", message: "I'm thinking of visiting Paris and Nice." },
  {
    role: "AI",
    message: "Great choices! Are you interested in any specific activities?",
  },
  { role: "User", message: "I would love to visit some vineyards." },
  {
    role: "AI",
    message:
      "France has some of the best vineyards in the world. I can help you find some.",
  },
  { role: "User", message: "That would be great!" },
  { role: "AI", message: "Do you prefer red or white wine?" },
  { role: "User", message: "I prefer red wine." },
  {
    role: "AI",
    message:
      "Perfect! I'll find some vineyards that are known for their red wines.",
  },
  { role: "User", message: "Thank you, that would be very helpful." },
  {
    role: "AI",
    message:
      "You're welcome! I'll also look up some French wine etiquette for you.",
  },
  {
    role: "User",
    message: "That sounds great. I can't wait to start my trip!",
  },
  {
    role: "AI",
    message:
      "I'm sure you'll have a fantastic time. Do you have any other questions about your trip?",
  },
  { role: "User", message: "Not at the moment, thank you for your help!" },
];

const zepClient = new ZepClient({
  apiKey: zepConfig.apiKey,
});

// Add chat messages to memory
for (const chatMessage of chatMessages) {
  let m: Message;
  if (chatMessage.role === "AI") {
    m = { role: "ai", roleType: "assistant", content: chatMessage.message };
  } else {
    m = { role: "human", roleType: "user", content: chatMessage.message };
  }

  await zepClient.memory.add(zepConfig.sessionId, { messages: [m] });
}

// Wait for messages to be summarized, enriched, embedded and indexed.
await sleep(10000);

// Simple similarity search
const query = "Can I drive red cars in France?";
const retriever = new ZepCloudRetriever({ ...zepConfig, topK: 3 });
const docs = await retriever.invoke(query);
console.log("Simple similarity search");
console.log(JSON.stringify(docs, null, 2));

// mmr reranking search
const mmrRetriever = new ZepCloudRetriever({
  ...zepConfig,
  topK: 3,
  searchType: "mmr",
  mmrLambda: 0.5,
});
const mmrDocs = await mmrRetriever.invoke(query);
console.log("MMR reranking search");
console.log(JSON.stringify(mmrDocs, null, 2));

// summary search with mmr reranking
const mmrSummaryRetriever = new ZepCloudRetriever({
  ...zepConfig,
  topK: 3,
  searchScope: "summary",
  searchType: "mmr",
  mmrLambda: 0.5,
});
const mmrSummaryDocs = await mmrSummaryRetriever.invoke(query);
console.log("Summary search with MMR reranking");
console.log(JSON.stringify(mmrSummaryDocs, null, 2));

// Filtered search
const filteredRetriever = new ZepCloudRetriever({
  ...zepConfig,
  topK: 3,
  filter: {
    where: { jsonpath: '$[*] ? (@.foo == "bar")' },
  },
});
const filteredDocs = await filteredRetriever.invoke(query);
console.log("Filtered search");
console.log(JSON.stringify(filteredDocs, null, 2));

API Reference:

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