Memoria de búfer conversacional
Implemente una memoria conversacional básica para almacenar y recuperar interacciones anteriores dentro del contexto de un agente.
Memoria de búfer conversacional es una lección gratuita de AI Agents with LangChain & Autonomous Workflows en CoddyKit. Esta es la lección 2 de 4. Puedes leer la lección completa abajo gratuitamente — luego la practicas en el navegador con un editor de código integrado y un tutor de IA 24/7. Forma parte de la ruta de aprendizaje de AI Agents with LangChain & Autonomous Workflows, y tu progreso se sincroniza en la web y la app de CoddyKit. El curso de AI Agents with LangChain & Autonomous Workflows incluye 4 lecciones en total.
Partes de esta lección aún no han sido traducidas y se muestran en inglés.
Why Agents Need Memory
Imagine having a conversation where you instantly forget everything said just a moment ago. That's what happens to an AI agent without memory!
Agents often need to recall past interactions to maintain context. Without memory, each turn is a fresh start, leading to repetitive or nonsensical conversations.
What is Buffer Memory?
ConversationBufferMemory is LangChain's simplest memory type. It stores the raw, unsummarized conversation history directly.
Think of it like keeping a full transcript of everything said, in the exact order it was said. It's straightforward and easy to use for basic conversational recall.
Initializing Buffer Memory
To use ConversationBufferMemory, you simply import it and create an instance. It's often integrated into a Chain, but we can explore it standalone first.
Let's initialize a memory object and peek at its initial (empty) state:
from langchain.memory import ConversationBufferMemory
# Initialize the memory
memory = ConversationBufferMemory()
print("Memory initialized!")
# You can see its content (it will be empty at first)
print(memory.load_memory_variables({}))Saving Conversation Context
The save_context method is how you add new user inputs and AI outputs to the memory. It takes two dictionaries: one for inputs and one for outputs.
This method is crucial because it's how the memory 'learns' from the ongoing conversation and builds its history.
Code Demo: Saving Context
Let's add a simple interaction to our memory object and see how it stores the conversation turn.
Notice how the 'input' and 'output' are paired and stored as 'Human' and 'AI' messages.
from langchain.memory import ConversationBufferMemory
memory = ConversationBufferMemory()
# Simulate a user input and an AI response
memory.save_context(
{"input": "Hi there!"},
{"output": "Hello! How can I help you?"}
)
print("Memory after one turn:")
print(memory.load_memory_variables({}))Retrieving Stored History
To access the stored conversation history, you use the load_memory_variables method. It returns a dictionary containing the memory content.
By default, the conversation history is stored under the key 'history'. This key is what you'll typically pass into your LLM's prompt template.
Customizing the Memory Key
By default, ConversationBufferMemory stores history under the key 'history'. However, your prompt template might expect a different variable name, like 'chat_history'.
You can change this using the memory_key parameter during initialization:
from langchain.memory import ConversationBufferMemory
# Initialize with a custom memory_key
memory = ConversationBufferMemory(memory_key="my_chat_history")
memory.save_context(
{"input": "What's up?"},
{"output": "Not much, just coding!"}
)
print("Memory with custom key:")
print(memory.load_memory_variables({}))Integrating with an LLM Chain
Here's how you integrate ConversationBufferMemory into an LLMChain. The memory_key in the ConversationBufferMemory must match the variable name in your PromptTemplate (e.g., chat_history).
Remember to replace 'YOUR_API_KEY' with your actual OpenAI key if you want to run this example fully.
from langchain.memory import ConversationBufferMemory
from langchain.chains import LLMChain
from langchain_openai import OpenAI
from langchain.prompts import PromptTemplate
import os
# Set your OpenAI API key (replace with your actual key or env var)
# os.environ["OPENAI_API_KEY"] = "YOUR_API_KEY"
# Initialize LLM (using a dummy if API key not set)
llm = OpenAI(temperature=0) # You might need to set openai_api_key=os.environ.get("OPENAI_API_KEY")
# Initialize memory with a key matching the prompt template
memory = ConversationBufferMemory(memory_key="chat_history")
# Define a prompt template that expects 'chat_history'
template = """You are a friendly chatbot.
{chat_history}
Human: {human_input}
AI:"""
prompt = PromptTemplate(
input_variables=["chat_history", "human_input"],
template=template
)
# Create an LLMChain with the memory
conversation = LLMChain(
llm=llm,
prompt=prompt,
verbose=False,
memory=memory
)
# First turn
print("Human: What is your capital?")
response1 = conversation.predict(human_input="What is your capital?")
print(f"AI: {response1}")
# Second turn - the AI should remember the context
print("\nHuman: And what about its population?")
response2 = conversation.predict(human_input="And what about its population?")
print(f"AI: {response2}")When to Use Buffer Memory
ConversationBufferMemory is excellent for short, direct conversations where you need exact recall of recent turns.
- Pros: Simple to implement, stores full, unedited conversation details.
- Cons: Can quickly exceed the LLM's context window for longer chats, no summarization or filtering, leading to higher token usage and costs.
Quick Check
Let's test your understanding of ConversationBufferMemory.
Buffer Memory Summary
We've successfully explored ConversationBufferMemory, LangChain's simplest way to give agents a basic form of memory:
- It stores raw conversation history.
- You use
save_contextto add turns andload_memory_variablesto retrieve them. - It's ideal for short, direct conversations but can quickly hit LLM context limits with longer chats.
- Remember to set
memory_keyif your prompt expects a different variable name for history.
Next, we'll dive into more advanced memory solutions that handle longer conversations better!
Preguntas frecuentes
¿La lección «Memoria de búfer conversacional» es gratis?
Sí — el texto completo de «Memoria de búfer conversacional» es gratis para leer aquí en la web. Para practicarla de forma interactiva (editor de código integrado y tutor de IA 24/7) y desbloquear el resto del curso de AI Agents with LangChain & Autonomous Workflows, actualiza a CoddyKit PRO. El curso de AI Agents with LangChain & Autonomous Workflows incluye 4 lecciones en total.
¿Qué aprenderé en «Memoria de búfer conversacional»?
Implemente una memoria conversacional básica para almacenar y recuperar interacciones anteriores dentro del contexto de un agente. Practicas AI Agents with LangChain & Autonomous Workflows con código real que ejecutas directamente en el navegador, y un tutor de IA 24/7 responde tus preguntas mientras trabajas en la lección.
¿Necesito experiencia previa para empezar AI Agents with LangChain & Autonomous Workflows?
No se requiere experiencia previa. AI Agents with LangChain & Autonomous Workflows en CoddyKit está estructurado para principiantes hasta estudiantes avanzados, así que puedes empezar aquí o desde el inicio y avanzar a tu ritmo. Esta es la lección 2 de 4.
¿Cuánto tiempo toma la lección «Memoria de búfer conversacional»?
La mayoría de las lecciones de CoddyKit toman alrededor de 5–10 minutos. Cada una es compacta e interactiva, así que avanzas constantemente y retomas exactamente por donde dejaste en la web y la app.
¿Puedo escribir y ejecutar código en esta lección de AI Agents with LangChain & Autonomous Workflows?
Sí. Cada lección de AI Agents with LangChain & Autonomous Workflows incluye un editor de código integrado, así que escribes y ejecutas código real directamente en tu navegador y obtienes retroalimentación instantánea de IA — sin configuración local necesaria.
Todas las lecciones de este curso
- Conceptos de memoria de los agentes
- Memoria de búfer conversacional
- Soluciones avanzadas de memoria
- Estrategias de memoria de entidades y resúmenes