实体与摘要记忆策略
不再局限于原始缓冲区，而是跟踪命名实体并持续生成摘要，让代理在长对话中记住重要事实，同时避免令牌预算失控。
实体与摘要记忆策略 是 CoddyKit 上的免费 AI Agents with LangChain & Autonomous Workflows 课时。 这是第 4 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 AI Agents with LangChain & Autonomous Workflows 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 AI Agents with LangChain & Autonomous Workflows 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Why Buffers Are Not Enough
A plain buffer stores every message verbatim. In long chats this quickly exceeds the model context window and wastes tokens on irrelevant chatter.
Two smarter strategies fix this: summary memory compresses the past, and entity memory tracks specific facts about people and things.
What Is Summary Memory?
Summary memory uses an LLM to keep a running, condensed summary of the conversation. Instead of replaying 50 turns, the agent reads a few sentences capturing the gist.
- Keeps token usage roughly constant
- Preserves long-term context
- Loses fine-grained wording
ConversationSummaryMemory
LangChain's ConversationSummaryMemory calls the LLM after each turn to update the summary. You pass it the same model the agent uses.
from langchain.memory import ConversationSummaryMemory
from langchain_openai import ChatOpenAI
llm = ChatOpenAI(model='gpt-4o-mini')
memory = ConversationSummaryMemory(llm=llm)Saving and Reading the Summary
As turns happen you save context; reading the variables returns the compressed history rather than raw turns.
memory.save_context(
{'input': 'My name is Ana and I love hiking.'},
{'output': 'Nice to meet you, Ana!'}
)
print(memory.load_memory_variables({}))Summary Buffer: Best of Both
ConversationSummaryBufferMemory keeps recent turns verbatim AND summarizes older ones once a token limit is crossed. Recent context stays sharp while old context is compressed.
from langchain.memory import ConversationSummaryBufferMemory
memory = ConversationSummaryBufferMemory(
llm=llm,
max_token_limit=200
)What Is Entity Memory?
Entity memory extracts named things — people, projects, places — and stores a fact sheet for each. When an entity reappears, the agent recalls exactly what it knows.
This is ideal for personal assistants that must remember user preferences.
ConversationEntityMemory
The entity memory uses the LLM to detect entities and maintain a per-entity store.
from langchain.memory import ConversationEntityMemory
memory = ConversationEntityMemory(llm=llm)
memory.save_context(
{'input': 'Deepak is leading the Mars project.'},
{'output': 'Got it.'}
)Inspecting the Entity Store
Each entity accumulates facts. Asking about an entity loads only its relevant summary into the prompt.
vars = memory.load_memory_variables(
{'input': 'What is Deepak working on?'}
)
print(vars['entities'])Choosing a Strategy
Pick based on the use case:
- Buffer: short, exact conversations
- Summary: long chats where the gist matters
- Summary Buffer: long chats needing recent precision
- Entity: assistants tracking facts about specific subjects
Cost and Latency Trade-offs
Summary and entity memory make extra LLM calls on every turn to update their state. That adds cost and latency.
Use cheaper, faster models for the memory-update step than for the main agent reasoning when possible.
Combining Memories
For sophisticated agents you can combine memories with CombinedMemory, e.g. a summary for flow plus entity memory for facts. Just ensure their output keys do not collide.
from langchain.memory import CombinedMemory
memory = CombinedMemory(memories=[summary_mem, entity_mem])Quick Check
Test your understanding of advanced memory strategies.
Recap
You learned memory strategies beyond raw buffers:
- Summary memory compresses history with the LLM
- Summary buffer keeps recent turns exact and summarizes the rest
- Entity memory tracks facts about named subjects
- Each adds LLM calls — balance cost vs. recall
- Combine memories for richer agents
Choosing the right strategy keeps agents both knowledgeable and efficient.
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常见问题解答
「实体与摘要记忆策略」课时是免费的吗？
是的 — 「实体与摘要记忆策略」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 AI Agents with LangChain & Autonomous Workflows 课程的其余内容，请升级到 CoddyKit PRO。 AI Agents with LangChain & Autonomous Workflows 课程共包含 4 节课。
「实体与摘要记忆策略」这节课中我会学到什么？
不再局限于原始缓冲区，而是跟踪命名实体并持续生成摘要，让代理在长对话中记住重要事实，同时避免令牌预算失控。 你通过在浏览器中直接运行的动手代码来练习 AI Agents with LangChain & Autonomous Workflows，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 AI Agents with LangChain & Autonomous Workflows 需要有经验吗？
无需任何先前经验。CoddyKit 上的 AI Agents with LangChain & Autonomous Workflows 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 4 节课，共 4 节。
「实体与摘要记忆策略」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 AI Agents with LangChain & Autonomous Workflows 课中编写并运行代码吗？
能。每节 AI Agents with LangChain & Autonomous Workflows 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。