LangChain Memory Store

Dhiraj Patra
2 min readJun 24, 2024

--

To add bigger memory space with LangChain, you can leverage the various memory modules that LangChain provides. Here’s a brief guide on how to do it:

1. Use a Larger Memory Backend

LangChain allows you to use different types of memory backends. For larger memory capacity, you can use backends like databases or cloud storage. For instance, using a vector database like Pinecone or FAISS can help manage larger context effectively.

2. Implement a Custom Memory Class

You can implement your own memory class to handle larger context. Here’s an example of how to create a custom memory class:

```python

from langchain.memory import BaseMemory

class CustomMemory(BaseMemory):

def __init__(self):

self.memory = []

def add_to_memory(self, message):

self.memory.append(message)

def get_memory(self):

return self.memory

def clear_memory(self):

self.memory = []

```

3. Configure Memory in LangChain

When setting up the chain, you can specify the memory class you want to use:

```python

from langchain import LLMChain

from langchain.llms import OpenAI

# Create an instance of your custom memory class

custom_memory = CustomMemory()

# Initialize the language model

llm = OpenAI(api_key=’your_openai_api_key’)

# Create the chain with the custom memory

chain = LLMChain(llm=llm, memory=custom_memory)

# Add messages to memory

chain.memory.add_to_memory(“Previous context or message”)

# Retrieve memory

context = chain.memory.get_memory()

```

4. Use External Storage

For even larger memory, consider using external storage solutions like a database (e.g., PostgreSQL, MongoDB) or cloud storage (e.g., AWS S3, Google Cloud Storage). You can extend the memory class to interact with these external storage systems.

Example with SQLite:

```python

import sqlite3

from langchain.memory import BaseMemory

class SQLiteMemory(BaseMemory):

def __init__(self, db_path):

self.conn = sqlite3.connect(db_path)

self.cursor = self.conn.cursor()

self.cursor.execute(‘’’CREATE TABLE IF NOT EXISTS memory (message TEXT)’’’)

def add_to_memory(self, message):

self.cursor.execute(“INSERT INTO memory (message) VALUES (?)”, (message,))

self.conn.commit()

def get_memory(self):

self.cursor.execute(“SELECT message FROM memory”)

return [row[0] for row in self.cursor.fetchall()]

def clear_memory(self):

self.cursor.execute(“DELETE FROM memory”)

self.conn.commit()

self.conn.close()

# Initialize SQLite memory

sqlite_memory = SQLiteMemory(‘memory.db’)

# Create the chain with SQLite memory

chain = LLMChain(llm=llm, memory=sqlite_memory)

```

By using these methods, you can effectively increase the memory capacity for your LangChain application, ensuring it can handle and recall larger contexts across interactions.

--

--

Dhiraj Patra
Dhiraj Patra

Written by Dhiraj Patra

AI Strategy, Generative AI, AI & ML Consulting, Product Development, Startup Advisory, Data Architecture, Data Analytics, Executive Mentorship, Value Creation

No responses yet