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ReviewRamble

The best AI tools for agent memory in 2026

Memory layers let an agent remember users, decisions and project conventions between sessions instead of starting cold each time. They range from a knowledge graph that tracks when facts changed to a simple notebook for one coding agent.

By Sheela · Updated Oct 26, 2026 · How we review

How we chose: each pick is a product, model or project we have reviewed that does this job according to our review of it, ranked by our rating out of 5. We take no affiliate commission.

Also ranked: the best open-source RAG tools

  1. 1

    GitHub Repos: RAG & data

    Graphiti

    For agents whose facts change over time, Graphiti is the open-source memory layer to beat, provided you will run a graph database and pay for LLM extraction on every write.

    Best for: Teams building long-running agents that must remember changing facts about users, accounts or the world.

    Price: Free and open source under Apache 2.0. You supply the graph database and pay for LLM and embedding calls during ingestion.

    Read our Graphiti review
    4.3/5
  2. 2

    GitHub Repos: RAG & data

    Mem0

    Mem0 is still the quickest way to give an agent a memory, but the open-source SDK is increasingly the trial version of a platform that keeps graph memory and the best benchmark scores for itself.

    Best for: Developers adding cross-session user memory to chatbots and agents.

    Price: Open-source SDK free under Apache 2.0. Platform: Free (10,000 adds and 1,000 retrievals a month for the first 30 days with model calls included, then 50,000 adds and 10,000 retrievals with your own LLM key, usage-billed beyond that up to a cap you set); Custom plans by quote. The earlier $19 Starter and $249 Pro plans are no longer listed.

    Read our Mem0 review
    4.0/5
  3. 3

    GitHub Repos: RAG & data

    Cognee

    Cognee builds a shared knowledge graph from almost any source, but its defaults need an owner before they meet production.

    Best for: Teams building several agents that need a shared knowledge graph assembled from many sources.

    Price: Open source under Apache 2.0. Cognee Cloud: free up to 1M tokens and one workspace, then $1 per 1M tokens plus $5 per extra workspace a month; Enterprise is a quoted BYOC engagement.

    Read our Cognee review
    3.8/5
  4. 4

    GitHub Repos: Skills & plugins

    claude-mem

    Real cross-session memory for Claude Code, wrapped in an installer that steers you towards a hosted subscription and a compression bill you have to watch.

    Best for: Developers on long-running projects who want the agent to remember past sessions.

    Price: Open source (Apache-2.0). Compression runs on your Anthropic plan or your own key. Hosted CMEM plans: Pro $30/month, Heavy $70/month, Max $100/month with overages; TeamBrain pricing not announced.

    Read our claude-mem review
    3.7/5
  5. 5

    MCP Servers: Data & databases

    Qdrant MCP Server

    A tidy, local-first memory for agents that already sit next to Qdrant, deliberately too small to be a general interface to the database.

    Best for: Teams already running Qdrant who want a simple, self-hosted semantic memory or snippet store for their agents.

    Price: Free and open source (Apache 2.0). Qdrant is free to self-host; Qdrant Cloud has a free single-node tier (0.5 vCPU, 1 GB RAM, 4 GB disk), usage-based Standard and a Premium tier with a minimum spend.

    Read our Qdrant MCP Server review
    3.7/5
  6. 6

    MCP Servers: Developer

    Memory (reference server)

    A readable local file and a substring search make this a decent notebook for one agent, and a weak long-term memory once the graph grows.

    Best for: Hobbyists and developers learning how persistent memory over MCP works.

    Price: Free and open source.

    Read our Memory (reference server) review
    3.5/5
  7. 7

    MCP Servers: Developer

    MCP Memory Keeper

    A thoughtful answer to losing work at compaction, wrapped in 38 tools and a commit command most users should switch off.

    Best for: Claude Code users who run long sessions and are willing to tell the agent when to checkpoint and restore.

    Price: Free and MIT-licensed.

    Read our MCP Memory Keeper review
    3.4/5

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