🧠 The definitive curated map of memory for LLM agents — frameworks, research papers, benchmarks, taxonomy & deep dives.
1
0 commits
updated Jun 16, 2026
The definitive, curated map of memory for LLM agents — frameworks, research papers, benchmarks, taxonomy, and the deep dives that matter.
How do you make an agent that actually remembers? This is everything worth reading, running, and benchmarking.
Why memory? An LLM's context window is its short-term memory — fast, fully attended, and gone the moment the window clears or overflows. Everything an agent should remember across time — facts about a user, past conversations, learned skills, evolving state — has to live outside the window and be selectively retrieved back in. That problem — what to store, when to retrieve it, how to update it, and how to forget — is agentic memory. This list maps the entire space.
New to the space? This is the shortest path to competence:
⚠️ A note on benchmark scores throughout this list: memory benchmark numbers are heavily contested — they swing wildly with config, judge model, and harness. See the Zep ↔ Mem0 dispute before trusting any single SOTA claim. Treat vendor-reported scores as vendor-reported.
The accepted scaffolding comes from CoALA — Cognitive Architectures for Language Agents (Sumers, Yao, Narasimhan & Griffiths, 2023). It models any language agent as three parts: memory, an action space (internal reasoning + external tools), and a decision procedure. Its memory typology is lifted straight from human cognitive science (Tulving's episodic/semantic split) — which is why Letta, Mem0, LangMem, and Zep all map their features back to the same words.
mindmap
root((Agent Memory))
Short-term
Context window
Working scratchpad
Tool outputs
Long-term
Episodic
Past events
Task traces
Semantic
Facts about user
Domain knowledge
Procedural
System prompt rules
Reusable skills
Operations
Encode / Write
Retrieve
Update / Resolve conflict
Forget / Decay
Consolidate / Reflect
Architectures
Vector RAG
Knowledge graph
Hierarchical paging
Summarization buffer
| Short-term / working memory | Long-term memory | |
|---|---|---|
| Where | Inside the context window | Outside the window (vector / graph / SQL / files) |
| Lifetime | One reasoning episode; volatile | Persists across sessions; effectively unbounded |
| OS analogy (MemGPT) | RAM | Disk |
| Constraint | Finite token budget | Retrieval quality — agent only sees what gets pulled in |
The central engineering problem is context management: deciding which slice of a huge long-term store gets loaded into the small working set, and when. Letta and Anthropic both call this context engineering.
| Subtype | Human analog | In an agent | Stored as |
|---|---|---|---|
| Episodic | Memory of specific events | "What happened" — interactions, traces, outcomes | Event/episode summaries, past trajectories |
| Semantic | General world knowledge | "What is true" — user facts, preferences, entities | Vector-embedded facts, KG triples |
| Procedural | Skills / how-to | "How to act" — rules, workflows, skills | Editable system prompt, code, skill libraries |
A widely cited refinement (LangMem) is the distillation hierarchy: raw episodic experiences distill into semantic facts; repeated semantic patterns crystallize into procedural rules. Memory consolidates upward, specific → general, over time.
flowchart LR
I[Interaction] -->|encode / extract| W[Write to store]
W --> S[(Long-term store)]
S -->|retrieve: vector / graph / recency| C[Context window]
C --> R[Reflect / summarize]
R --> S
S -->|consolidate + dedup| S
S -->|forget / decay / supersede| S
C --> I
| Architecture | How it works | Strength | Weakness | Reference impl |
|---|---|---|---|---|
| Vector RAG | Embed memories, retrieve by similarity | Simple, ubiquitous | Weak at structured/temporal reasoning & conflicts | Pinecone, Chroma, pgvector |
| Knowledge / temporal graph | Entities + relations as a graph; bi-temporal validity windows | Best for temporal reasoning & conflict resolution | More infra, extraction cost | Graphiti / Zep |
| Hierarchical paging (LLM-as-OS) | Core (RAM) / recall (cache) / archival (cold) tiers; agent pages data in/out via tools | Illusion of unbounded context; agent self-manages | Latency of tool-call paging | Letta / MemGPT |
| Summarization buffer | Rolling summary of old turns + verbatim recent window | Cheap, easy | Lossy | LangChain buffer memory |
Production systems usually combine these — e.g. Redis for session state, a vector DB for semantic recall, Postgres for episodic/procedural, a graph for relations.
⭐ Star counts are rough order-of-magnitude as of June 2026 — they move fast.
| Project | Stars | What it does | Approach | Lang | License |
|---|---|---|---|---|---|
| Mem0 | ~59k | Universal memory layer for AI agents | Hybrid vector + graph + KV, auto extraction (user/session/agent scopes) | Python | Apache-2.0 |
| Letta (ex-MemGPT) | ~23k | Platform for stateful, self-improving agents | Hierarchical OS-style paging (core / recall / archival), self-managed via tools | Python | Apache-2.0 |
| Cognee | ~18k | AI memory platform, persistent long-term memory | Hybrid graph + vector KG (ECL pipeline) | Python | Apache-2.0 |
| Memori | ~15k | Agent-native memory infra | Structured entity/event/fact extraction, LLM-agnostic | Py/TS/Rust | Apache-2.0 |
| memU | ~14k | Memory harness for proactive agents | Multimodal → typed MemoryItems, ~10× token reduction | Python | Apache-2.0 |
| MemOS | ~10k | Self-evolving "memory OS" | Memory-OS abstraction, hybrid retrieval, cross-task skill reuse | TS/Python | Apache-2.0 |
| Second-Me | ~10k+ | "AI-native memory 2.0" — train your AI self | Persistent personal identity model | Py/TS | Apache-2.0 |
| Honcho | ~5k | Memory modeling people/groups over time | Reasoning-first peer representations, async background inference | Py/TS | AGPL-3.0 |
| OpenMemory | ~4k | Local persistent memory for LLM apps | Local cognitive memory engine, MCP server | TS | Apache-2.0 |
| MemMachine | ~3k | Universal memory layer | Scalable, interoperable storage + retrieval | Python | Apache-2.0 |
| Memobase | ~3k | User-profile long-term memory for chatbots | Structured profiles + time-aware event timelines, <100ms | Py/Go/TS | Apache-2.0 |
| ReMe (ex-MemoryScope) | ~3k | Memory kit for agents (Alibaba/AgentScope) | Extract / reuse / share memory across users & agents | Python | Apache-2.0 |
| Memary | ~3k | Memory layer for autonomous agents | Neo4j knowledge-graph + entity memory | Python | MIT |
| LangMem | ~2k | Memory primitives so agents learn/adapt | Extraction + prompt refinement; semantic/procedural; any store | Python | MIT |
| Redis Agent Memory Server | ~1k | Fast memory server on Redis | Short-term session + long-term vector, MCP server | Python | Apache-2.0 |
| A-MEM | ~1k | Agentic memory (NeurIPS 2025) | Zettelkasten-style dynamic organization + linking | Python | MIT |
| MemoryOS | research | Memory OS for personalized agents (EMNLP 2025 Oral) | Hierarchical Storage/Updating/Retrieval/Generation | Python | — |
| Motorhead | ~850 | Memory + IR server for LLMs | Session memory + incremental summarization | Rust | Apache-2.0 ⚠️ low activity |
| HybridAGI | small | Neuro-symbolic agent w/ graph memory | Graph + vector memory | Python | GPL-3.0 |
| memonto | small | Ontology-based memory management | Graph/ontology-driven | Python | — |
| Project | Stars | What it does | Approach | License |
|---|---|---|---|---|
| Graphiti | ~28k | Build temporal knowledge graphs for agents | Bi-temporal KG (fact-validity windows, provenance) — powers Zep | Apache-2.0 |
| Microsoft GraphRAG | ~20k+ | Graph-based RAG / community summarization | Graph extraction + community summaries | MIT |
| Zep | ~5k | Context-engineering platform on Graphiti | Temporal KG memory, sub-200ms context assembly | Apache-2.0 |
| txtai | ~13k | Embeddings DB for semantic search + LLM workflows | Vector + graph + SQL; RAG/memory backbone | Apache-2.0 |
Memory modules built into the major agent frameworks — use these if you're already on the framework.
| Framework | Memory module | Approach | License |
|---|---|---|---|
| LangChain / LangGraph | Buffer / summary / vector-store memory; LangGraph persistent store + checkpoints | Buffer/summary/vector + durable store | MIT |
| LlamaIndex | Chat memory buffers, vector memory, composable memory blocks | Vector + summary + composable | MIT |
| Haystack | Conversation + document memory via stores | Store-backed memory | Apache-2.0 |
| Semantic Kernel | Semantic memory plugins / connectors | Embedding/vector, pluggable connectors | MIT |
| CrewAI | Short/long-term + entity memory (Qdrant Edge) | Short + long + entity, hierarchical isolation | MIT |
| AutoGen / AG2 | Message history + teachable-agent memory | Conversation history + teachability | MIT |
| OpenAI Agents SDK | Sessions for conversation state | Session-based memory | MIT |
| Google ADK | Session state + MemoryService (pluggable backends) | Session state + memory service (e.g. Vertex RAG) | Apache-2.0 |
| PraisonAI | Graph + vector memory | Graph + vector | MIT |
Persistent memory for coding assistants (Claude Code, Copilot, Cursor) and agent-agnostic memory runtimes.
| Project | Stars | What it does | Lang |
|---|---|---|---|
| Supermemory | ~27k | Fast/scalable memory + context engine, runs locally | TS |
| EverOS | ~7k | Portable self-evolving memory across agents | Python |
| agentmemory | ~5k | Persistent memory for coding agents | TS/Python |
| ByteRover / Cipher | ~5k | Portable memory layer for coding agents (MCP) | TS |
| claude-mem | mid | Cross-session context for coding agents | TS |
| Engram | mid | Agent-agnostic persistent memory (Go, SQLite FTS5, MCP) | Go |
| BaseAI | mid | Serverless agent framework with vector memory primitive | TS |
| mem-agent | model | 4B model fine-tuned for memory ops over markdown files | weights |
The dimensions that actually differentiate memory systems. Use these as your evaluation columns.
| System | Persistence | Backend | Temporal reasoning | Conflict resolution | Self-editing | Write timing | Deploy |
|---|---|---|---|---|---|---|---|
| Mem0 | Cross-session | Vector + graph + KV | Timestamps | Dedup + merge | No | Hot-path | OSS + Cloud |
| Letta | Cross-session | Postgres + vector | Timestamps | Supersede (agent-managed) | ✅ Yes (tools) | Hot-path | OSS + Cloud |
| Zep / Graphiti | Cross-session | Bi-temporal graph | ✅ Bi-temporal | ✅ Supersede-with-history | No | Background | OSS + Cloud |
| Cognee | Cross-session | Graph + vector | Timestamps | Dedup | No | Pipeline | OSS |
| LangMem | Cross-session | Any (LangGraph store) | App-defined | App-defined | Partial | Hot + background | OSS + SDK |
| MemOS / MemoryOS | Cross-session | Hierarchical tiers | Timestamps | Segmented-page update | ✅ Yes | Hot + background | OSS |
| Memobase | Cross-session | Profile + timeline | ✅ Time-aware events | Profile merge | No | Background | OSS + Cloud |
Key dimensions not shown but worth checking per project: multi-user namespacing, forgetting/decay policy, retrieval method (vector vs hybrid vs graph), tokens-per-query cost, and which benchmarks each reports.
| Service | What it is |
|---|---|
| Mem0 Platform | Managed memory layer (also OSS); large token-cost reduction claims; broad integrations + OpenMemory MCP server |
| Zep Cloud | Managed temporal-KG memory for enterprise-scale agents |
| Letta Cloud | Managed MemGPT-style stateful agents (core/recall/archival) |
| LangMem SDK | Long-term memory over the LangGraph store (Postgres/MongoDB backends) |
| ChatGPT Memory | Consumer persistent memory — saved memories + chat history, background "dreaming" update |
| Anthropic Memory Tool | File-based memory tool on the Claude Developer Platform for cross-session state |
Grouped by category, newest-first within each group. arXiv IDs verified.
⚠️ Memory scores are config/judge/harness-dependent and frequently contested. Always note who reported a number.
| Benchmark | Year | Measures | Size | Links |
|---|---|---|---|---|
| LoCoMo | 2024 | Very long conversational memory: single/multi-hop QA, temporal reasoning, event summarization, multimodal gen | 10 convos, ~300 turns, ~1.5K QA | paper · site · data |
| LongMemEval | 2024 (ICLR 2025) | 5 abilities: extraction, multi-session, temporal, knowledge updates, abstention | 500 curated Qs, scalable history | paper · site · code |
| BEAM | 2025/26 | Memory at 1M–10M tokens, 10 categories; unsolvable by bigger context | 1M & 10M scale | explainer |
| MemoryAgentBench | 2025 (ICLR 2026) | Accurate Retrieval, Test-Time Learning, Long-Range Understanding, Conflict Resolution | inject-once/query-many | paper · code |
| ConvoMem | 2025 | Conversational memory + memory-vs-RAG crossover study | 75,336 QA pairs | paper |
| MemBench | 2025 (ACL Findings) | Factual vs reflective memory; participation vs observation | — | paper · code |
| DialSim | 2024 | Real-time multi-party dialogue (TV shows), time-constrained, temporal-KG QA | ~350K tokens, ~1K Qs/session | paper · site |
| PerLTQA | 2024 | Personalized long-term QA: semantic + episodic (Chinese) | 8,593 Qs, 30 characters | paper |
| MemGPT DMR | 2023 | Deep Memory Retrieval — cross-session consistency (built on MSC) | derived from MSC | paper |
| MSC (Multi-Session Chat) | 2021 | Long-term open-domain consistency, persona retention | 5 sessions/dialog | paper |
| MemoryBank / SiliconFriend | 2023 (AAAI) | AI-companion recall + personality adaptation; forgetting-curve | qual + simulated | paper · code |
These test long context-window retrieval, not persistent cross-session memory — a distinction worth keeping straight.
| Benchmark | Year | Measures | Links |
|---|---|---|---|
| Needle in a Haystack | 2023 | Single-fact retrieval at varying depth/length in-context | repo |
| RULER | 2024 (NVIDIA) | "Real" effective context size; 13 tasks, 4K–1M tokens | paper · code |
| BABILong | 2024 (NeurIPS) | Reasoning over facts scattered in very long docs, up to 11M tokens | paper |
| Long Range Arena (LRA) | 2020 (ICLR) | Efficient-Transformer quality on long sequences (architecture-era) | paper · code |
Contributions welcome! See CONTRIBUTING.md. Found a missing project, paper, or benchmark? Open a PR or issue. The bar: it must be a real, locatable resource specifically about agentic / LLM-agent memory, with a working link.
To the extent possible under law, the contributors have waived all copyright and related rights to this work (CC0-1.0).
🧠 The definitive curated map of memory for LLM agents — frameworks, research papers, benchmarks, taxonomy & deep dives.
1
0 commits
updated Jun 16, 2026
The definitive, curated map of memory for LLM agents — frameworks, research papers, benchmarks, taxonomy, and the deep dives that matter.
How do you make an agent that actually remembers? This is everything worth reading, running, and benchmarking.
Why memory? An LLM's context window is its short-term memory — fast, fully attended, and gone the moment the window clears or overflows. Everything an agent should remember across time — facts about a user, past conversations, learned skills, evolving state — has to live outside the window and be selectively retrieved back in. That problem — what to store, when to retrieve it, how to update it, and how to forget — is agentic memory. This list maps the entire space.
New to the space? This is the shortest path to competence:
⚠️ A note on benchmark scores throughout this list: memory benchmark numbers are heavily contested — they swing wildly with config, judge model, and harness. See the Zep ↔ Mem0 dispute before trusting any single SOTA claim. Treat vendor-reported scores as vendor-reported.
The accepted scaffolding comes from CoALA — Cognitive Architectures for Language Agents (Sumers, Yao, Narasimhan & Griffiths, 2023). It models any language agent as three parts: memory, an action space (internal reasoning + external tools), and a decision procedure. Its memory typology is lifted straight from human cognitive science (Tulving's episodic/semantic split) — which is why Letta, Mem0, LangMem, and Zep all map their features back to the same words.
mindmap
root((Agent Memory))
Short-term
Context window
Working scratchpad
Tool outputs
Long-term
Episodic
Past events
Task traces
Semantic
Facts about user
Domain knowledge
Procedural
System prompt rules
Reusable skills
Operations
Encode / Write
Retrieve
Update / Resolve conflict
Forget / Decay
Consolidate / Reflect
Architectures
Vector RAG
Knowledge graph
Hierarchical paging
Summarization buffer
| Short-term / working memory | Long-term memory | |
|---|---|---|
| Where | Inside the context window | Outside the window (vector / graph / SQL / files) |
| Lifetime | One reasoning episode; volatile | Persists across sessions; effectively unbounded |
| OS analogy (MemGPT) | RAM | Disk |
| Constraint | Finite token budget | Retrieval quality — agent only sees what gets pulled in |
The central engineering problem is context management: deciding which slice of a huge long-term store gets loaded into the small working set, and when. Letta and Anthropic both call this context engineering.
| Subtype | Human analog | In an agent | Stored as |
|---|---|---|---|
| Episodic | Memory of specific events | "What happened" — interactions, traces, outcomes | Event/episode summaries, past trajectories |
| Semantic | General world knowledge | "What is true" — user facts, preferences, entities | Vector-embedded facts, KG triples |
| Procedural | Skills / how-to | "How to act" — rules, workflows, skills | Editable system prompt, code, skill libraries |
A widely cited refinement (LangMem) is the distillation hierarchy: raw episodic experiences distill into semantic facts; repeated semantic patterns crystallize into procedural rules. Memory consolidates upward, specific → general, over time.
flowchart LR
I[Interaction] -->|encode / extract| W[Write to store]
W --> S[(Long-term store)]
S -->|retrieve: vector / graph / recency| C[Context window]
C --> R[Reflect / summarize]
R --> S
S -->|consolidate + dedup| S
S -->|forget / decay / supersede| S
C --> I
| Architecture | How it works | Strength | Weakness | Reference impl |
|---|---|---|---|---|
| Vector RAG | Embed memories, retrieve by similarity | Simple, ubiquitous | Weak at structured/temporal reasoning & conflicts | Pinecone, Chroma, pgvector |
| Knowledge / temporal graph | Entities + relations as a graph; bi-temporal validity windows | Best for temporal reasoning & conflict resolution | More infra, extraction cost | Graphiti / Zep |
| Hierarchical paging (LLM-as-OS) | Core (RAM) / recall (cache) / archival (cold) tiers; agent pages data in/out via tools | Illusion of unbounded context; agent self-manages | Latency of tool-call paging | Letta / MemGPT |
| Summarization buffer | Rolling summary of old turns + verbatim recent window | Cheap, easy | Lossy | LangChain buffer memory |
Production systems usually combine these — e.g. Redis for session state, a vector DB for semantic recall, Postgres for episodic/procedural, a graph for relations.
⭐ Star counts are rough order-of-magnitude as of June 2026 — they move fast.
| Project | Stars | What it does | Approach | Lang | License |
|---|---|---|---|---|---|
| Mem0 | ~59k | Universal memory layer for AI agents | Hybrid vector + graph + KV, auto extraction (user/session/agent scopes) | Python | Apache-2.0 |
| Letta (ex-MemGPT) | ~23k | Platform for stateful, self-improving agents | Hierarchical OS-style paging (core / recall / archival), self-managed via tools | Python | Apache-2.0 |
| Cognee | ~18k | AI memory platform, persistent long-term memory | Hybrid graph + vector KG (ECL pipeline) | Python | Apache-2.0 |
| Memori | ~15k | Agent-native memory infra | Structured entity/event/fact extraction, LLM-agnostic | Py/TS/Rust | Apache-2.0 |
| memU | ~14k | Memory harness for proactive agents | Multimodal → typed MemoryItems, ~10× token reduction | Python | Apache-2.0 |
| MemOS | ~10k | Self-evolving "memory OS" | Memory-OS abstraction, hybrid retrieval, cross-task skill reuse | TS/Python | Apache-2.0 |
| Second-Me | ~10k+ | "AI-native memory 2.0" — train your AI self | Persistent personal identity model | Py/TS | Apache-2.0 |
| Honcho | ~5k | Memory modeling people/groups over time | Reasoning-first peer representations, async background inference | Py/TS | AGPL-3.0 |
| OpenMemory | ~4k | Local persistent memory for LLM apps | Local cognitive memory engine, MCP server | TS | Apache-2.0 |
| MemMachine | ~3k | Universal memory layer | Scalable, interoperable storage + retrieval | Python | Apache-2.0 |
| Memobase | ~3k | User-profile long-term memory for chatbots | Structured profiles + time-aware event timelines, <100ms | Py/Go/TS | Apache-2.0 |
| ReMe (ex-MemoryScope) | ~3k | Memory kit for agents (Alibaba/AgentScope) | Extract / reuse / share memory across users & agents | Python | Apache-2.0 |
| Memary | ~3k | Memory layer for autonomous agents | Neo4j knowledge-graph + entity memory | Python | MIT |
| LangMem | ~2k | Memory primitives so agents learn/adapt | Extraction + prompt refinement; semantic/procedural; any store | Python | MIT |
| Redis Agent Memory Server | ~1k | Fast memory server on Redis | Short-term session + long-term vector, MCP server | Python | Apache-2.0 |
| A-MEM | ~1k | Agentic memory (NeurIPS 2025) | Zettelkasten-style dynamic organization + linking | Python | MIT |
| MemoryOS | research | Memory OS for personalized agents (EMNLP 2025 Oral) | Hierarchical Storage/Updating/Retrieval/Generation | Python | — |
| Motorhead | ~850 | Memory + IR server for LLMs | Session memory + incremental summarization | Rust | Apache-2.0 ⚠️ low activity |
| HybridAGI | small | Neuro-symbolic agent w/ graph memory | Graph + vector memory | Python | GPL-3.0 |
| memonto | small | Ontology-based memory management | Graph/ontology-driven | Python | — |
| Project | Stars | What it does | Approach | License |
|---|---|---|---|---|
| Graphiti | ~28k | Build temporal knowledge graphs for agents | Bi-temporal KG (fact-validity windows, provenance) — powers Zep | Apache-2.0 |
| Microsoft GraphRAG | ~20k+ | Graph-based RAG / community summarization | Graph extraction + community summaries | MIT |
| Zep | ~5k | Context-engineering platform on Graphiti | Temporal KG memory, sub-200ms context assembly | Apache-2.0 |
| txtai | ~13k | Embeddings DB for semantic search + LLM workflows | Vector + graph + SQL; RAG/memory backbone | Apache-2.0 |
Memory modules built into the major agent frameworks — use these if you're already on the framework.
| Framework | Memory module | Approach | License |
|---|---|---|---|
| LangChain / LangGraph | Buffer / summary / vector-store memory; LangGraph persistent store + checkpoints | Buffer/summary/vector + durable store | MIT |
| LlamaIndex | Chat memory buffers, vector memory, composable memory blocks | Vector + summary + composable | MIT |
| Haystack | Conversation + document memory via stores | Store-backed memory | Apache-2.0 |
| Semantic Kernel | Semantic memory plugins / connectors | Embedding/vector, pluggable connectors | MIT |
| CrewAI | Short/long-term + entity memory (Qdrant Edge) | Short + long + entity, hierarchical isolation | MIT |
| AutoGen / AG2 | Message history + teachable-agent memory | Conversation history + teachability | MIT |
| OpenAI Agents SDK | Sessions for conversation state | Session-based memory | MIT |
| Google ADK | Session state + MemoryService (pluggable backends) | Session state + memory service (e.g. Vertex RAG) | Apache-2.0 |
| PraisonAI | Graph + vector memory | Graph + vector | MIT |
Persistent memory for coding assistants (Claude Code, Copilot, Cursor) and agent-agnostic memory runtimes.
| Project | Stars | What it does | Lang |
|---|---|---|---|
| Supermemory | ~27k | Fast/scalable memory + context engine, runs locally | TS |
| EverOS | ~7k | Portable self-evolving memory across agents | Python |
| agentmemory | ~5k | Persistent memory for coding agents | TS/Python |
| ByteRover / Cipher | ~5k | Portable memory layer for coding agents (MCP) | TS |
| claude-mem | mid | Cross-session context for coding agents | TS |
| Engram | mid | Agent-agnostic persistent memory (Go, SQLite FTS5, MCP) | Go |
| BaseAI | mid | Serverless agent framework with vector memory primitive | TS |
| mem-agent | model | 4B model fine-tuned for memory ops over markdown files | weights |
The dimensions that actually differentiate memory systems. Use these as your evaluation columns.
| System | Persistence | Backend | Temporal reasoning | Conflict resolution | Self-editing | Write timing | Deploy |
|---|---|---|---|---|---|---|---|
| Mem0 | Cross-session | Vector + graph + KV | Timestamps | Dedup + merge | No | Hot-path | OSS + Cloud |
| Letta | Cross-session | Postgres + vector | Timestamps | Supersede (agent-managed) | ✅ Yes (tools) | Hot-path | OSS + Cloud |
| Zep / Graphiti | Cross-session | Bi-temporal graph | ✅ Bi-temporal | ✅ Supersede-with-history | No | Background | OSS + Cloud |
| Cognee | Cross-session | Graph + vector | Timestamps | Dedup | No | Pipeline | OSS |
| LangMem | Cross-session | Any (LangGraph store) | App-defined | App-defined | Partial | Hot + background | OSS + SDK |
| MemOS / MemoryOS | Cross-session | Hierarchical tiers | Timestamps | Segmented-page update | ✅ Yes | Hot + background | OSS |
| Memobase | Cross-session | Profile + timeline | ✅ Time-aware events | Profile merge | No | Background | OSS + Cloud |
Key dimensions not shown but worth checking per project: multi-user namespacing, forgetting/decay policy, retrieval method (vector vs hybrid vs graph), tokens-per-query cost, and which benchmarks each reports.
| Service | What it is |
|---|---|
| Mem0 Platform | Managed memory layer (also OSS); large token-cost reduction claims; broad integrations + OpenMemory MCP server |
| Zep Cloud | Managed temporal-KG memory for enterprise-scale agents |
| Letta Cloud | Managed MemGPT-style stateful agents (core/recall/archival) |
| LangMem SDK | Long-term memory over the LangGraph store (Postgres/MongoDB backends) |
| ChatGPT Memory | Consumer persistent memory — saved memories + chat history, background "dreaming" update |
| Anthropic Memory Tool | File-based memory tool on the Claude Developer Platform for cross-session state |
Grouped by category, newest-first within each group. arXiv IDs verified.
⚠️ Memory scores are config/judge/harness-dependent and frequently contested. Always note who reported a number.
| Benchmark | Year | Measures | Size | Links |
|---|---|---|---|---|
| LoCoMo | 2024 | Very long conversational memory: single/multi-hop QA, temporal reasoning, event summarization, multimodal gen | 10 convos, ~300 turns, ~1.5K QA | paper · site · data |
| LongMemEval | 2024 (ICLR 2025) | 5 abilities: extraction, multi-session, temporal, knowledge updates, abstention | 500 curated Qs, scalable history | paper · site · code |
| BEAM | 2025/26 | Memory at 1M–10M tokens, 10 categories; unsolvable by bigger context | 1M & 10M scale | explainer |
| MemoryAgentBench | 2025 (ICLR 2026) | Accurate Retrieval, Test-Time Learning, Long-Range Understanding, Conflict Resolution | inject-once/query-many | paper · code |
| ConvoMem | 2025 | Conversational memory + memory-vs-RAG crossover study | 75,336 QA pairs | paper |
| MemBench | 2025 (ACL Findings) | Factual vs reflective memory; participation vs observation | — | paper · code |
| DialSim | 2024 | Real-time multi-party dialogue (TV shows), time-constrained, temporal-KG QA | ~350K tokens, ~1K Qs/session | paper · site |
| PerLTQA | 2024 | Personalized long-term QA: semantic + episodic (Chinese) | 8,593 Qs, 30 characters | paper |
| MemGPT DMR | 2023 | Deep Memory Retrieval — cross-session consistency (built on MSC) | derived from MSC | paper |
| MSC (Multi-Session Chat) | 2021 | Long-term open-domain consistency, persona retention | 5 sessions/dialog | paper |
| MemoryBank / SiliconFriend | 2023 (AAAI) | AI-companion recall + personality adaptation; forgetting-curve | qual + simulated | paper · code |
These test long context-window retrieval, not persistent cross-session memory — a distinction worth keeping straight.
| Benchmark | Year | Measures | Links |
|---|---|---|---|
| Needle in a Haystack | 2023 | Single-fact retrieval at varying depth/length in-context | repo |
| RULER | 2024 (NVIDIA) | "Real" effective context size; 13 tasks, 4K–1M tokens | paper · code |
| BABILong | 2024 (NeurIPS) | Reasoning over facts scattered in very long docs, up to 11M tokens | paper |
| Long Range Arena (LRA) | 2020 (ICLR) | Efficient-Transformer quality on long sequences (architecture-era) | paper · code |
Contributions welcome! See CONTRIBUTING.md. Found a missing project, paper, or benchmark? Open a PR or issue. The bar: it must be a real, locatable resource specifically about agentic / LLM-agent memory, with a working link.
To the extent possible under law, the contributors have waived all copyright and related rights to this work (CC0-1.0).