cogmem-agent 0.2.0

Human-like cognitive memory for AI agents — emotion-gated recall with adaptive forgetting

Cognitive Memory

日本語

Human-like cognitive memory for AI agents — emotion-gated recall with adaptive forgetting.

Unlike traditional vector databases that treat all memories equally, Cognitive Memory models how humans actually remember: emotionally significant experiences persist longer, while routine information naturally fades. This makes AI agents feel more natural and context-aware.

Key Features

• Emotion-gated recall: Arousal scores modulate memory persistence
• Adaptive forgetting: High-arousal memories decay slower (configurable half-life)
• Adaptive search gate: Skips trivial queries (greetings, acknowledgments)
• FailOpen design: Falls back to keyword search when embeddings are unavailable
• Zero required dependencies: Core uses only Python stdlib (sqlite3, urllib)
• Pluggable embeddings: Ollama (built-in), OpenAI, or any custom provider

Why Cognitive Memory?

Traditional RAG and vector databases retrieve memories by semantic similarity alone. Every memory is treated equally — a casual greeting and a critical business decision have the same weight. This leads to noisy, context-poor recall that makes AI agents feel mechanical.

Cognitive Memory changes this by modeling three aspects of human cognition:

1. Emotion-Gated Recall

Each memory entry carries an arousal score (0.0–1.0) that reflects emotional intensity — surprise, insight, conflict, determination. High-arousal memories are weighted more heavily in search results.

Query	Traditional Vector DB	Cognitive Memory
"past pricing decisions"	Returns all mentions of "pricing" ranked by text similarity	Prioritizes the heated debate where pricing strategy was reversed (arousal: 0.9) over routine price update logs (arousal: 0.2)

What triggers high arousal? Conversations with emotional or cognitive significance:

Conversation	Arousal	Why it matters
"Wait, that assumption is wrong!"	0.9	Direction change — a premise collapsed
"I see, so that's how it works!"	0.8	Aha moment — cognitive breakthrough
"Let's stop this approach. Because..."	0.7	Rejection decision — a turning point
"This is the third time this topic came up"	0.7	Pattern recognition — metacognition
"Phase 1 complete"	0.6	Milestone — phase transition
"We need to investigate..."	0.4	Open question emerged

These are remembered. Meanwhile, greetings ("hello"), acknowledgments ("ok"), and navigation ("let's move on") score near 0 and are skipped entirely by the adaptive search gate.

2. Adaptive Forgetting

Memories decay over time — but not uniformly. The decay half-life adapts to arousal:

half_life = base_half_life * (1 + arousal)

• A routine status update (arousal: 0.2) has a half-life of 72 days and fades quickly
• A critical pivot decision (arousal: 0.9) has a half-life of 114 days and persists far longer

This means your agent naturally "forgets" noise while retaining the moments that matter — just like human memory.

3. Adaptive Search Gate

Not every user message needs memory retrieval. Greetings ("hello"), acknowledgments ("ok"), and trivial messages are automatically detected and skipped, saving unnecessary embedding API calls and reducing noise in results.

The Result

Aspect	Without Cognitive Memory	With Cognitive Memory
Recall quality	All memories ranked equally by text similarity	Important memories surface first, noise fades
Over time	Old memories never decay, search gets noisier	Natural forgetting keeps results relevant
Agent personality	Generic, robotic responses	Remembers what mattered, feels more human
Wasted searches	Every message triggers vector search	Trivial messages are skipped automatically

Install

pip install cogmem-agent

Embedding Setup (recommended)

Cognitive Memory uses Ollama for local embeddings. Without it, the library falls back to keyword search only.

# 1. Install Ollama (macOS)
brew install ollama

# 2. Start the server
ollama serve

# 3. Download the embedding model (~2.2 GB)
ollama pull zylonai/multilingual-e5-large

Other platforms: see ollama.com/download

You can also use OpenAI or any custom embedding provider — see Embedding Providers.

With vs Without Ollama

Cognitive Memory works in two modes depending on whether an embedding provider is available:

With Ollama, search upgrades from exact keyword matching to semantic understanding. All core Cognitive Memory features become available: related concept discovery, cross-lingual search, typo tolerance, emotion-based ranking, and adaptive forgetting. It runs entirely locally with no additional cost or privacy risk — just ~2.2 GB of disk space.

	Without Ollama (keyword mode)	With Ollama (semantic mode)
Search method	Exact keyword matching (grep)	Vector similarity + emotion scoring
"pricing strategy"	Matches only entries containing the exact words "pricing" and "strategy"	Also finds entries about "LTV:CAC optimization", "revenue model", "cost structure"
Cross-lingual	Japanese query only matches Japanese text	"価格戦略" finds both Japanese and English entries about pricing
Typos / synonyms	"competetor analysis" returns nothing	Understands intent, returns competitor-related entries
Scoring	Binary match (found or not)	(0.7 * cosine_sim + 0.3 * arousal) * time_decay — nuanced ranking
Adaptive forgetting	Not available (all matches are equal)	Old low-arousal entries naturally fade from results
Latency	< 1ms	~15ms (local, no network roundtrip)
Privacy	Local	Local — no data leaves your machine
Cost	Free	Free (Ollama is open-source)
Disk usage	0	~2.2 GB (model weight)

Recommendation: Install Ollama to unlock the full cognitive memory experience. The keyword fallback is designed as a safety net, not as the primary mode of operation.

Quick Start

CLI

cogmem init                        # Initialize project
cogmem index                       # Build/update index
cogmem search "past decisions"     # Search memories
cogmem status                      # Show statistics

Python API

from cognitive_memory import MemoryStore, CogMemConfig

config = CogMemConfig.from_toml("cogmem.toml")
with MemoryStore(config) as store:
    store.index_dir()
    result = store.search("past competition analysis")
    for r in result.results:
        print(f"{r.date} [{r.score:.2f}] {r.content[:80]}")

Convenience API

from cognitive_memory import search
result = search("past decisions")  # Auto-finds cogmem.toml

Scoring Formula

score = (0.7 * cosine_sim + 0.3 * arousal) * time_decay

Where time_decay uses an adaptive half-life:

half_life = base_half_life * (1 + arousal)

High-arousal memories (insights, conflicts, surprises) decay slower — just like human memory.

Configuration

cogmem.toml:

[cogmem]
logs_dir = "memory/logs"
db_path = "memory/vectors.db"

[cogmem.scoring]
sim_weight = 0.7
arousal_weight = 0.3
base_half_life = 60.0
decay_floor = 0.3

[cogmem.embedding]
provider = "ollama"
model = "zylonai/multilingual-e5-large"
url = "http://localhost:11434/api/embed"
timeout = 10

Custom Embedding Provider

class MyEmbedder:
    def embed(self, text: str) -> list[float] | None: ...
    def embed_batch(self, texts: list[str]) -> list[list[float]] | None: ...

store = MemoryStore(config, embedder=MyEmbedder())

Documentation

• Quick Start
• Log Format
• Embedding Providers

References

Papers

• NFD: Nurture-First Development — Architectural framework for AI agent personality development through experiential layers and crystallization
• A-MEM: Agentic Memory for LLM Agents — Atomic note-based memory structuring for autonomous agents

Projects

• memory-lancedb-pro — Adaptive gate and time decay pipeline design reference
• memU — Experiential layer implementation reference
• A-mem — Atomic notes implementation reference

License

MIT