---
title: Chat Memory Buffer
 | Developer Documentation
---

**NOTE:** This example of memory is deprecated in favor of the newer and more flexible `Memory` class. See the [latest docs](https://docs.llamaindex.ai/en/stable/module_guides/deploying/agents/memory/).

The `ChatMemoryBuffer` is a memory buffer that simply stores the last X messages that fit into a token limit.

%pip install llama-index-core

## Setup

```
from llama_index.core.memory import ChatMemoryBuffer


memory = ChatMemoryBuffer.from_defaults(token_limit=40000)
```

## Using Standalone

```
from llama_index.core.llms import ChatMessage


chat_history = [
    ChatMessage(role="user", content="Hello, how are you?"),
    ChatMessage(role="assistant", content="I'm doing well, thank you!"),
]


# put a list of messages
memory.put_messages(chat_history)


# put one message at a time
# memory.put_message(chat_history[0])
```

```
# Get the last X messages that fit into a token limit
history = memory.get()
```

```
# Get all messages
all_history = memory.get_all()
```

```
# clear the memory
memory.reset()
```

## Using with Agents

You can set the memory in any agent in the `.run()` method.

```
import os


os.environ["OPENAI_API_KEY"] = "sk-proj-..."
```

```
from llama_index.core.agent.workflow import ReActAgent, FunctionAgent
from llama_index.core.workflow import Context
from llama_index.llms.openai import OpenAI




memory = ChatMemoryBuffer.from_defaults(token_limit=40000)


agent = FunctionAgent(tools=[], llm=OpenAI(model="gpt-4o-mini"))


# context to hold the chat history/state
ctx = Context(agent)
```

```
resp = await agent.run("Hello, how are you?", ctx=ctx, memory=memory)
```

```
print(memory.get_all())
```

```
[ChatMessage(role=<MessageRole.USER: 'user'>, additional_kwargs={}, blocks=[TextBlock(block_type='text', text='Hello, how are you?')]), ChatMessage(role=<MessageRole.ASSISTANT: 'assistant'>, additional_kwargs={}, blocks=[TextBlock(block_type='text', text="Hello! I'm just a program, so I don't have feelings, but I'm here and ready to help you. How can I assist you today?")])]
```