Best AI Agent Memory Platforms in 2026
A model forgets everything when the conversation ends. A memory layer extracts what matters (preferences, facts, decisions) and gives it back to the agent next time, without stuffing the whole history into the prompt. Here are the leading options in 2026: two open-source libraries and two managed services.
AI Agent Memory Tools Compared
| Tool | Pricing | Free tier |
|---|---|---|
| Mem0 | Free · paid from $19/mo | |
| Zep | Free · paid from $125/mo | |
| Cognee | Free · paid from $1/mo | |
| Supermemory | Free · paid from $19/mo |
The Best AI Agent Memory Tools, Ranked
1. Mem0
Free tier· Free · paid from $19/moOpen-source (Apache-2.0) memory layer for AI agents: remembers users, sessions and agent state across conversations. Self-host or use the managed platform.
- Apache-2.0 with the largest community in the category
- Drops into an existing agent as a library
- Cheap managed tiers from $19/month
2. Zep
Free tier· Free · paid from $125/moManaged context-graph memory for agents, built on the open-source Graphiti engine: tracks how facts change over time. SOC 2 Type II on Enterprise.
- Temporal graph: knows when facts changed
- Retrieval does not consume credits
- Open-source engine (Graphiti) underneath
3. Cognee
Free tier· Free · paid from $1/moOpen-source (Apache-2.0) knowledge-graph memory for agents: turns documents, code and conversations into a graph you can query. Runs locally without an LLM key.
- Graph memory with evidence for every answer
- Runs locally without an LLM key
- Cheap usage-based cloud
4. Supermemory
Free tier· Free · paid from $19/moHosted memory and context API for AI apps: user profiles, memory and document search in one call, with connectors for Gmail, Drive, Notion and GitHub.
- Memory plus document RAG in one API
- Built-in connectors for Gmail, Drive, Notion, GitHub
- Low entry price ($19/month)
How to choose a ai agent memory tool
- Decide what you need to remember. Facts about a user need a memory API; facts that change over time, or knowledge spread across documents, need a graph.
- Choose Mem0 for the most widely used open-source memory layer, which drops into an existing agent as a library.
- Choose Cognee to build a knowledge graph from documents, code and conversations, with the evidence behind each answer. It runs locally without an LLM key.
- Choose Zep when it matters when a fact changed, not just what it is. Its graph engine, Graphiti, is open source.
- Choose Supermemory for one hosted API that combines user memory with document search and ready-made connectors.
- Treat every vendor benchmark as a claim: each of these reports leading scores on LoCoMo or LongMemEval under its own settings.
Frequently Asked Questions
What are the best ai agent memory tools for startups in 2026?⌄
The best ai agent memory tools for startups in 2026 include Mem0, Zep, Cognee, Supermemory. Compare them by pricing, free tiers, and features in the list above.
What is the best free ai agent memory tool?⌄
Free ai agent memory options include Mem0, Zep, Cognee, Supermemory — all offer a free tier suitable for bootstrapped startups and MVPs.
How do I choose a ai agent memory tool?⌄
Start with your budget and team size, prefer tools with a free tier to validate, and make sure your pick integrates with the rest of your stack. App Stack Builder can recommend a complete, budget-aware stack in about 60 seconds.
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