Memory Implementations

This document lists the memory classes exported by multimind.memory, what state each one is actually in, and how to use the ones that work. Every class below is importable from multimind.memory; the lightweight ones are imported eagerly and the rest resolve lazily on first access.

All memory classes derive from BaseMemory, whose contract is five async methods: add_message(message), get_messages(), clear(), save() and load(). A class that does not implement all five is abstract and raises TypeError: Can't instantiate abstract class ... when constructed. Those classes are listed separately below as scaffolds; their constructor signatures and helper methods exist, but you cannot use them without subclassing.

For the authoritative stable/beta/planned status, see feature-status.md.

Extras

Extra	Needed for
none (core install)	BufferMemory, BufferWindowMemory, SummaryMemory, SummaryBufferMemory, TokenAwareMemory, EntityMemory, TimeWeightedMemory, HierarchicalMemory, EpisodicMemory, SemanticMemory, ProceduralMemory, AssociativeMemory, EmotionalMemory, DeclarativeMemory, SpatialMemory, TemporalMemory, SensoryMemory, VersionedMemory, EventSourcedMemory, CognitiveScratchpadMemory, ActiveLearningMemory, ConsensusMemory, ReinforcementMemory, GenerativeMemory, ChatMemory, SimpleMemory, CombinedMemory, ReadOnlyMemory, SQLAlchemyMemory
pip install "multimind-sdk[memory]" (redis, numpy, networkx)	VectorStoreMemory, KnowledgeGraphMemory, HybridMemory, ContextualMemory, WorkingMemory, ForgettingCurveMemory, NoveltyMemory, DNCMemory, ImplicitMemory, PlanningMemory, RedisMemory, plus the scaffolds that need numpy
pip install "multimind-sdk[finetune]" (torch)	FastWeightMemory, AdapterMemory, FederatedMemory, BayesianMemory, AdvancedMemory

Implemented Memory Types

These classes implement the full BaseMemory contract and can be instantiated directly. Most of the LLM-backed ones take a BaseLLM instance (for example OpenAIModel) as their first argument and call it for summarization, routing or extraction.

Conversation buffers (no LLM required)

• BufferMemory(memory_key="chat_history", max_tokens=2000, max_messages=None, strategy="sliding", ...) - stores conversation history with sliding/FIFO/LRU pruning
• BufferWindowMemory(window_size=10, window_type="count", ...) - sliding window of recent messages
• SummaryBufferMemory(max_messages=None, max_tokens=None, summary_interval=10, ...) - buffer plus periodic summaries
• TokenAwareMemory - token-budgeted history
• TimeWeightedMemory(decay_rate=0.1, ...) - time-decayed relevance
• EntityMemory(entity_types=None, relationship_types=None, ...) - entity and relationship tracking
• ChatMemory, SimpleMemory, CombinedMemory, ReadOnlyMemory - small utility memories
• SQLAlchemyMemory, RedisMemory - persistence-backed buffers (RedisMemory needs the memory extra)

LLM-backed memories (llm is the first constructor argument)

• SummaryMemory(llm, ...) - summarized conversation history
• VectorStoreMemory(llm, vector_store_config=None, similarity_threshold=0.7, ...) - embedding-based similarity retrieval over a FAISS store by default
• KnowledgeGraphMemory(llm, ...) - graph of entities and relations (needs networkx)
• HybridMemory(llm, memory_types=None, routing_threshold=0.7, ...) - routes each message to the best of several child memories
• HierarchicalMemory(llm, ...), ContextualMemory(llm, ...), EpisodicMemory(llm, ...), SemanticMemory(llm, ...), ProceduralMemory(llm, ...), WorkingMemory(llm, ...), AssociativeMemory(llm, ...), EmotionalMemory(llm, ...), DeclarativeMemory(llm, ...), SpatialMemory(llm, ...), TemporalMemory(llm, ...), SensoryMemory(llm, ...), ForgettingCurveMemory(llm, ...), NoveltyMemory(llm, ...), VersionedMemory(llm, ...), EventSourcedMemory(llm, ...), CognitiveScratchpadMemory(llm, ...), ActiveLearningMemory(llm, ...), DNCMemory(llm, ...)

Other implemented memories

• ImplicitMemory(skill_decay=0.95, max_skills=1000, ...) - skill tracking with prerequisite graph
• ConsensusMemory(node_id, nodes=None, ...) - local in-process replication with majority-vote reads; networked RAFT (elections, RPCs) is not implemented and raises NotImplementedError
• ReinforcementMemory(total_budget=1000, ...) - tabular Q-learning for keep/evict/compress budgeting
• PlanningMemory(similarity_threshold=0.8, ...) - plan-step recording with success-weighted next-step suggestions
• GenerativeMemory - regeneration bookkeeping with a caller-supplied generator

Scaffolds (abstract, cannot be instantiated)

The following classes exist and expose their own methods (for example add_memory / get_memory on the quantum classes), but they do not implement add_message, get_messages, clear, save and/or load from BaseMemory. Constructing them raises TypeError. Treat them as starting points for a subclass, not as usable memories.

Class	Notes
TokenBufferMemory	token-count buffer; missing save/load
MetaMemory(base_memory, ...)	memory about memories
SketchMemory	count-min sketch / bloom-filter approximate storage
CausalMemory	causal relationship store
NeuroSymbolicMemory	neural + symbolic hybrid
AutobiographicalMemory	self-referential event memory
ProspectiveMemory	reminders / intentions
ExplicitMemory	fact store
AdaptiveMemory	self-tuning context size
HTMMemory(input_size=1024, num_columns=2048, ...)	hierarchical temporal memory
SpikingMemory	neuromorphic spiking network with STDP
BayesianMemory	nonparametric Bayesian clustering (needs torch)
QRAM, QAM, TopologicalMemory, QuantumClassicalHybridMemory	classical simulations of quantum memory designs, not quantum hardware
FastWeightMemory, AdapterMemory, FederatedMemory	torch-based (finetune extra); implement add_memory/get_memory only

Nothing in the package implements holographic, DNA or neuromorphic-quantum memory. There are no ShortTermMemory or LongTermMemory classes; use BufferMemory / BufferWindowMemory for short-term history and VectorStoreMemory or SQLAlchemyMemory for durable storage.

Usage Examples

import asyncio
from multimind import OpenAIModel
from multimind.memory import BufferMemory, VectorStoreMemory, HybridMemory, SummaryMemory

model = OpenAIModel(model_name="gpt-4o-mini")   # reads OPENAI_API_KEY

async def main():
    # Plain conversation buffer (no LLM calls)
    conv_memory = BufferMemory()
    await conv_memory.add_message({"role": "user", "content": "This is an example memory"})
    print(await conv_memory.get_messages())

    # Vector store memory (requires multimind-sdk[memory]; embeds via the model)
    vector_memory = VectorStoreMemory(llm=model)

    # Summary memory (calls the model to summarize older turns)
    summary_memory = SummaryMemory(llm=model)

    # Hybrid memory routes each message to the best child memory (uses the model)
    hybrid_memory = HybridMemory(
        llm=model,
        memory_types=[BufferMemory, VectorStoreMemory],
    )
    await hybrid_memory.add_message({"role": "user", "content": "Remember that I prefer Python."})
    print(await hybrid_memory.get_messages())

asyncio.run(main())

Agents use a separate, simpler multimind.agents.AgentMemory(max_history=100) for task/response history; see rag.md.

Best Practices

1. Memory Selection

   • Start with BufferMemory; add SummaryMemory or VectorStoreMemory only when history outgrows the context window
   • Check the extras table above before importing a memory type
   • Do not rely on the scaffold classes in production code

2. Memory Configuration

   • VectorStoreMemory defaults to a FAISS backend; the FAISS backend ignores filter_criteria, so get(memory_id) is not reliable once more than one vector is stored
   • Set storage_path when you need save()/load() persistence

3. Memory Management

   • Call clear() between unrelated conversations
   • LLM-backed memories make model calls on add_message; budget for that cost

Contributing

To contribute new memory implementations (or to finish one of the scaffolds):

1. Create or edit a file in the multimind/memory directory
2. Implement all five BaseMemory methods: add_message, get_messages, clear, save, load
3. Register the class in multimind/memory/__init__.py (_LAZY_ATTRS, with the extra it needs)
4. Update this document and feature-status.md
5. Add tests
6. Submit a pull request