# Momento

> [Momento Cache](https://docs.momentohq.com/) is the world's first truly serverless caching service, offering instant elasticity, scale-to-zero
> capability, and blazing-fast performance.
>
> [Momento Vector Index](https://docs.momentohq.com/vector-index) stands out as the most productive, easiest-to-use, fully serverless vector index.
>
> For both services, simply grab the SDK, obtain an API key, input a few lines into your code, and you're set to go. Together, they provide a comprehensive solution for your LLM data needs.

This page covers how to use the [Momento](https://gomomento.com) ecosystem within LangChain.

## Installation and Setup

- Sign up for a free account [here](https://console.momentohq.com) to get an API key
- Install the Momento Python SDK with `pip install momento`

## Cache

Use Momento as a serverless, distributed, low-latency cache for LLM prompts and responses. The standard cache is the primary use case for Momento users in any environment.

To integrate Momento Cache into your application:

```python
from langchain.cache import MomentoCache
```

Then, set it up with the following code:

```python
from datetime import timedelta
from momento import CacheClient, Configurations, CredentialProvider
from langchain.globals import set_llm_cache

# Instantiate the Momento client
cache_client = CacheClient(
    Configurations.Laptop.v1(),
    CredentialProvider.from_environment_variable("MOMENTO_API_KEY"),
    default_ttl=timedelta(days=1))

# Choose a Momento cache name of your choice
cache_name = "langchain"

# Instantiate the LLM cache
set_llm_cache(MomentoCache(cache_client, cache_name))
```

## Memory

Momento can be used as a distributed memory store for LLMs.

### Chat Message History Memory

See [this notebook](/docs/integrations/memory/momento_chat_message_history) for a walkthrough of how to use Momento as a memory store for chat message history.

## Vector Store

Momento Vector Index (MVI) can be used as a vector store.

See [this notebook](/docs/integrations/vectorstores/momento_vector_index) for a walkthrough of how to use MVI as a vector store.
