LlamaIndex Memory
Two-tier model: ChatMessage FIFO queue with overflow flushed into long-term Memory Block objects. Memory class replacing older ChatMemoryBuffer.
At a glance
- Type
- FIFO short-term + Memory Blocks
- Tier
- T2
- Section
- Framework-embedded memory
- Created
- 2022-11
- Latest release
- v0.14.21 2026-04-21
- License
- MIT
- GitHub
- 49.2k★ +1.2k/mo Python
- Pricing
- Free + paid
- Funding
- $28M total Series A · 2025-03
Taxonomy
- storage
- kv
- retrieval
- injection
- persistence
- cross-session
- update
- append-only
- unit
- episode
- governance
- inspectable
- conflict
- append-only
When to use
Optimised for: FIFO + Memory Blocks for chat agent context
Anti-fit: not for non-Python stacks
Pros & cons
Pros
Mature retrieval ecosystem behind it — memory benefits from years of LlamaIndex retrieval work.
Cons
Retrieval-tilted — memory feels like a RAG add-on rather than a first-class abstraction.
Claims & capabilities
May 2025 introduced flexible Memory API combining short-term FIFO chat history with pluggable Memory Blocks (StaticMemoryBlock, FactExtractionMemoryBlock, VectorMemoryBlock); 35% retrieval-accuracy improvement claim (overall framework, not memory-specific)
Technical surface
- API surface
- SDK: Python, TS
- Backend storage
- pluggable
- Deployment
- Both
- Embedding model
- multiple supported
- Multi-tenancy
- not applicable — library; namespace per index/session
- MCP
- via official adapter — llama-index-tools-mcp
- A2A
- supported — LlamaIndex A2A agent server
- OpenTelemetry
- via adapter — Arize Phoenix / OTel
Similar systems
Other framework-embedded memory in the catalog, ranked by inbound references.
- LangGraph Persistence T2
Distinct from LangMem. Built-in checkpointer saves graph state per super-step (short-term, thread-scoped). Store System adds long-term hierarchical key-value memory across threads with optional vector search + TTL. Postgres / Mongo / Redis stores for production.
- AutoGen Memory T2
ListMemory chronological context + teachable agents that vectorise corrections. Integrates with Mem0/Zep rather than building deep memory natively.
- CrewAI Memory T2
Memory subsystem inside the CrewAI orchestration framework; integrates with Mem0 for the long-term tier.
- AGiXT Adaptive Memory T2
Open-source AI automation platform. Routes between short-term and long-term memory adaptively across any LLM provider; plugin system for storage backends. Memory managed at the instruction-management layer — task context, instruction state, conversation history as unified agent state.
- Agno (Phidata) Memory T2
Agno (formerly Phidata). AgentStorage persists sessions to a DB; AgentMemory auto-classifies/store user preferences and conversation summaries. Single-line integrations with LanceDB, Pinecone, Weaviate, Qdrant.
- Botpress LLMz T1
Per-plan vector-DB storage quota + LLMz autonomous engine (in-session working memory) + Knowledge Base (semantic search over uploaded docs). Long-term user memory persists across sessions.
Related systems
References (1)
- LlamaIndex (framework) depends on at runtime — adjacent-infrastructure cell: requires LlamaIndex; BYO LLM + vector store