feat: add Momento as a standard cache and chat history provider (lang…

…chain-ai#1416)

* chore: add .node-version to gitignore

Because I'm Using nodenv with multiple node versions installed, we use
the node local to specify the version to use in a particular repo.

* feat: add @gomomento/sdk as a dev, peer, optional dependency

* feat: add Momento as a standard caching provider

* feat: add Momento as a chat message history store

* chore: add momento to entrypoints

* docs: add examples and docs for Momento

* chore: make fields readonly

We make appropriate fields readonly.

* refactor: use factory method standard naming fromX

* refactor: extract `ensureCacheExists` to utility module

Previously both the Momento cache module and Momento chat history
modules had a `ensureCacheExists` function, which were identical. This
commit extracts the function to a single place in a utility module.

* Docs fixes

---------

Co-authored-by: jacoblee93 <[email protected]>

.gitignore

@@ -27,3 +27,4 @@ Chinook_Sqlite.sql
 *.swp
 *.swo
 
+.node-version

docs/docs/modules/memory/examples/momento.mdx

@@ -0,0 +1,28 @@
+---
+hide_table_of_contents: true
+---
+
+import CodeBlock from "@theme/CodeBlock";
+
+# Momento-Backed Chat Memory
+
+For distributed, serverless persistence across chat sessions, you can swap in a [Momento](https://gomomento.com/)-backed chat message history.
+Because a Momento cache is instantly available and requires zero infrastructure maintenance, it's a great way to get started with chat history whether building locally or in production.
+
+## Setup
+
+You will need to install the [Momento Client Library](https://github.com/momentohq/client-sdk-javascript) in your project:
+
+```bash npm2yarn
+npm install @gomomento/sdk
+```
+
+You will also need an API key from [Momento](https://gomomento.com/). You can sign up for a free account [here](https://console.gomomento.com/).
+
+## Usage
+
+To distinguish one chat history session from another, we need a unique `sessionId`. You may also provide an optional `sessionTtl` to make sessions expire after a given number of seconds.
+
+import MomentoExample from "@examples/memory/momento.ts";
+
+<CodeBlock language="typescript">{MomentoExample}</CodeBlock>

docs/docs/modules/models/llms/additional_functionality.mdx

@@ -45,6 +45,20 @@ import { OpenAI } from "langchain/llms/openai";
 const model = new OpenAI({ cache: true });
 ```
 
+### Caching with Momento
+
+LangChain also provides a Momento-based cache. [Momento](https://gomomento.com) is a distributed, serverless cache that requires zero setup or infrastructure maintenance. To use it, you'll need to install the `@gomomento/sdk` package:
+
+```bash npm2yarn
+npm install @gomomento/sdk
+```
+
+Next you'll need to sign up and create an API key. Once you've done that, pass a `cache` option when you instantiate the LLM like this:
+
+import MomentoCacheExample from "@examples/cache/momento.ts";
+
+<CodeBlock language="typescript">{MomentoCacheExample}</CodeBlock>
+
 ### Caching with Redis
 
 LangChain also provides a Redis-based cache. This is useful if you want to share the cache across multiple processes or servers. To use it, you'll need to install the `redis` package:

examples/.env.example

@@ -32,3 +32,4 @@ TIGRIS_CLIENT_ID=ADD_YOURS_HERE
 TIGRIS_CLIENT_SECRET=ADD_YOURS_HERE
 NOTION_INTEGRATION_TOKEN=ADD_YOURS_HERE
 FIGMA_ACCESS_TOKEN=ADD_YOURS_HERE
+MOMENTO_AUTH_TOKEN=ADD_YOURS_HERE

examples/package.json

@@ -24,6 +24,7 @@
   "dependencies": {
     "@clickhouse/client": "^0.0.14",
     "@getmetal/metal-sdk": "^4.0.0",
+    "@gomomento/sdk": "^1.23.0",
     "@opensearch-project/opensearch": "^2.2.0",
     "@pinecone-database/pinecone": "^0.0.14",
     "@prisma/client": "^4.11.0",

examples/src/cache/momento.ts

@@ -0,0 +1,22 @@
+import { OpenAI } from "langchain/llms/openai";
+import { MomentoCache } from "langchain/cache/momento";
+import {
+  CacheClient,
+  Configurations,
+  CredentialProvider,
+} from "@gomomento/sdk";
+
+// See https://github.com/momentohq/client-sdk-javascript for connection options
+const client = new CacheClient({
+  configuration: Configurations.Laptop.v1(),
+  credentialProvider: CredentialProvider.fromEnvironmentVariable({
+    environmentVariableName: "MOMENTO_AUTH_TOKEN",
+  }),
+  defaultTtlSeconds: 60 * 60 * 24,
+});
+const cache = await MomentoCache.fromProps({
+  client,
+  cacheName: "langchain",
+});
+
+const model = new OpenAI({ cache });

examples/src/memory/momento.ts

@@ -0,0 +1,65 @@
+import {
+  CacheClient,
+  Configurations,
+  CredentialProvider,
+} from "@gomomento/sdk";
+import { BufferMemory } from "langchain/memory";
+import { ChatOpenAI } from "langchain/chat_models/openai";
+import { ConversationChain } from "langchain/chains";
+import { MomentoChatMessageHistory } from "langchain/stores/message/momento";
+
+// See https://github.com/momentohq/client-sdk-javascript for connection options
+const client = new CacheClient({
+  configuration: Configurations.Laptop.v1(),
+  credentialProvider: CredentialProvider.fromEnvironmentVariable({
+    environmentVariableName: "MOMENTO_AUTH_TOKEN",
+  }),
+  defaultTtlSeconds: 60 * 60 * 24,
+});
+
+// Create a unique session ID
+const sessionId = new Date().toISOString();
+const cacheName = "langchain";
+
+const memory = new BufferMemory({
+  chatHistory: await MomentoChatMessageHistory.fromProps({
+    client,
+    cacheName,
+    sessionId,
+    sessionTtl: 300,
+  }),
+});
+console.log(
+  `cacheName=${cacheName} and sessionId=${sessionId} . This will be used to store the chat history. You can inspect the values at your Momento console at https://console.gomomento.com.`
+);
+
+const model = new ChatOpenAI({
+  modelName: "gpt-3.5-turbo",
+  temperature: 0,
+});
+
+const chain = new ConversationChain({ llm: model, memory });
+
+const res1 = await chain.call({ input: "Hi! I'm Jim." });
+console.log({ res1 });
+/*
+{
+  res1: {
+    text: "Hello Jim! It's nice to meet you. My name is AI. How may I assist you today?"
+  }
+}
+*/
+
+const res2 = await chain.call({ input: "What did I just say my name was?" });
+console.log({ res2 });
+
+/*
+{
+  res1: {
+    text: "You said your name was Jim."
+  }
+}
+*/
+
+// See the chat history in the Momento
+console.log(await memory.chatHistory.getMessages());

langchain/.gitignore

@@ -301,6 +301,9 @@ retrievers/self_query.d.ts
 cache.cjs
 cache.js
 cache.d.ts
+cache/momento.cjs
+cache/momento.js
+cache/momento.d.ts
 cache/redis.cjs
 cache/redis.js
 cache/redis.d.ts
@@ -313,6 +316,9 @@ stores/file/node.d.ts
 stores/message/dynamodb.cjs
 stores/message/dynamodb.js
 stores/message/dynamodb.d.ts
+stores/message/momento.cjs
+stores/message/momento.js
+stores/message/momento.d.ts
 stores/message/redis.cjs
 stores/message/redis.js
 stores/message/redis.d.ts

langchain/package.json

@@ -313,6 +313,9 @@
     "cache.cjs",
     "cache.js",
     "cache.d.ts",
+    "cache/momento.cjs",
+    "cache/momento.js",
+    "cache/momento.d.ts",
     "cache/redis.cjs",
     "cache/redis.js",
     "cache/redis.d.ts",
@@ -325,6 +328,9 @@
     "stores/message/dynamodb.cjs",
     "stores/message/dynamodb.js",
     "stores/message/dynamodb.d.ts",
+    "stores/message/momento.cjs",
+    "stores/message/momento.js",
+    "stores/message/momento.d.ts",
     "stores/message/redis.cjs",
     "stores/message/redis.js",
     "stores/message/redis.d.ts",
@@ -379,6 +385,7 @@
     "@clickhouse/client": "^0.0.14",
     "@faker-js/faker": "^7.6.0",
     "@getmetal/metal-sdk": "^4.0.0",
+    "@gomomento/sdk": "^1.23.0",
     "@huggingface/inference": "^1.5.1",
     "@jest/globals": "^29.5.0",
     "@opensearch-project/opensearch": "^2.2.0",
@@ -449,6 +456,7 @@
     "@aws-sdk/client-sagemaker-runtime": "^3.310.0",
     "@clickhouse/client": "^0.0.14",
     "@getmetal/metal-sdk": "*",
+    "@gomomento/sdk": "^1.23.0",
     "@huggingface/inference": "^1.5.1",
     "@opensearch-project/opensearch": "*",
     "@pinecone-database/pinecone": "*",
@@ -504,6 +512,9 @@
     "@getmetal/metal-sdk": {
       "optional": true
     },
+    "@gomomento/sdk": {
+      "optional": true
+    },
     "@huggingface/inference": {
       "optional": true
     },
@@ -1168,6 +1179,11 @@
       "import": "./cache.js",
       "require": "./cache.cjs"
     },
+    "./cache/momento": {
+      "types": "./cache/momento.d.ts",
+      "import": "./cache/momento.js",
+      "require": "./cache/momento.cjs"
+    },
     "./cache/redis": {
       "types": "./cache/redis.d.ts",
       "import": "./cache/redis.js",
@@ -1188,6 +1204,11 @@
       "import": "./stores/message/dynamodb.js",
       "require": "./stores/message/dynamodb.cjs"
     },
+    "./stores/message/momento": {
+      "types": "./stores/message/momento.d.ts",
+      "import": "./stores/message/momento.js",
+      "require": "./stores/message/momento.cjs"
+    },
     "./stores/message/redis": {
       "types": "./stores/message/redis.d.ts",
       "import": "./stores/message/redis.js",

langchain/scripts/create-entrypoints.js

@@ -130,11 +130,13 @@ const entrypoints = {
   "retrievers/self_query": "retrievers/self_query/index",
   // cache
   cache: "cache/index",
+  "cache/momento": "cache/momento",
   "cache/redis": "cache/redis",
   // stores
   "stores/file/in_memory": "stores/file/in_memory",
   "stores/file/node": "stores/file/node",
   "stores/message/dynamodb": "stores/message/dynamodb",
+  "stores/message/momento": "stores/message/momento",
   "stores/message/redis": "stores/message/redis",
   "stores/message/upstash_redis": "stores/message/upstash_redis",
   // experimental
@@ -220,9 +222,11 @@ const requiresOptionalDependency = [
   "output_parsers/expression",
   "chains/query_constructor",
   "chains/query_constructor/ir",
+  "cache/momento",
   "cache/redis",
   "stores/file/node",
   "stores/message/dynamodb",
+  "stores/message/momento",
   "stores/message/redis",
   "stores/message/upstash_redis",
 ];