LibreAI / AI Agents / langmem
// agents · langchain-ai/langmem

langmem

LangMem: long-term memory primitives for LangGraph agents that learn and adapt from conversations.

★ 1.7k stars⑂ 194 forksMITupdated 2026-10
▦ visual — this project's README ships no embeddable screenshot,
so here's a placeholder. The guide below is complete regardless.
// project facts

Project facts

langmem is an open-source ai agents project by langchain-ai (langchain-ai/langmem on GitHub). It has 1,698 GitHub stars and 194 forks, is released under the MIT license, and was last updated on GitHub on 2 October 2026.

GitHub stars
1,698
Forks
194
License
MIT
Last updated on GitHub
2 October 2026
Category
AI Agents
Listing
Full install guide
Official site
Official site
// how it works

How it works

  1. Clarify your goal

    Decide your memory strategy: agents managing memory in the hot path during conversation, a background manager that consolidates knowledge, or both.

  2. Get the project

    Install LangMem from PyPI and configure an API key for your LLM provider.

  3. Install and configure

    Create a store (in-memory for development, database-backed for production) and give your agent the memory management and search tools with a namespace.

  4. Run your first task

    Chat with the agent normally; it records and retrieves memories itself, and you can verify recall by asking about earlier preferences.

// features

Why people love it

Core memory API

Storage-agnostic primitives for extracting, consolidating, and updating knowledge from conversations, usable with any storage system.

Hot-path memory tools

Ready-made manage and search memory tools let an agent record and look up information during active conversations, under your control of what gets stored.

Background memory manager

Automatically extracts, consolidates, and updates agent knowledge outside the conversation flow.

Native LangGraph integration

Works directly with LangGraph's Long-term Memory Store, which is available by default in LangGraph Platform deployments.

Prompt refinement

Beyond facts, LangMem can optimise agent behaviour through prompt updates informed by past interactions.

Production store options

Swap the development in-memory store for a persistent Postgres-backed store so memories survive restarts.

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// run it

Run it yourself

  1. Clone the project (optional)

    Most developers simply pip install the library.

    git clone https://github.com/langchain-ai/langmem.git
    cd langmem
  2. Install and configure a provider key

    Install LangMem and export the key for the LLM provider your agent will use.

    pip install -U langmem
    export ANTHROPIC_API_KEY=<your key>
  3. Create an agent with memory tools

    Wire the manage and search memory tools into a LangGraph agent with a store, following the README example. # see README for the full code snippet

    python -c "from langmem import create_manage_memory_tool, create_search_memory_tool; print('tools ready')"
// use cases

What you can build

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// faq

Questions, answered

Who maintains it?

It is maintained by LangChain (langchain-ai), the team behind LangGraph.

Is it free to use?

Yes, LangMem is MIT-licensed and free. You pay your LLM provider for the model calls the agent and memory manager make.

Does it need a paid API key?

Yes, you configure an API key for your chosen LLM provider (the README example uses Anthropic), and embeddings for the store use a configured embedding model.

How does it compare to a well-known alternative?

Vector databases store and retrieve text; LangMem adds the agent-facing layer: tools for in-conversation memory management, background consolidation, and prompt optimisation, integrated with LangGraph.

How do I get started?

Run pip install -U langmem, set your provider key, and follow the README's short example to build an agent with the two memory tools.

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// alternatives

Alternatives in AI Agents

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Get langmem

Free and open — grab the source, star the repo, and start creating.