fragmented-memory 2.0.0

Fragmented memory system for Hermes Agent — automatically retrieve relevant memory fragments and inject them into conversation context

Fragmented Memory Plugin for Hermes Agent

The Fragmented Memory system automatically retrieves relevant memory fragments and injects them into the conversation context for each dialogue.

User: "How did we set up that React project structure last time?"
                      ↓
         Fragmented Memory System     ← Redis + RediSearch
                      ↓
    ┌─────────────────────────────────────┐
    │  [1] User prefers TypeScript + Vite    │
    │  [2] Previous projects used pinia state management │
    │  [3] Backend suggested using .NET 10 implementation       │
    └─────────────────────────────────────┘
                      ↓
         Model directly uses fragments to answer

Features

• Semantic Splitting — auto-split conversations into standalone fragments
• BM25 Full-Text Search — works out of the box with no external API
• Optional Vector Search — KNN via RediSearch (OpenAI / DashScope embedder)
• Time Decay — newer fragments rank higher (60-day half-life configurable)
• Sentiment Weighting — emotional fragments get priority
• User Feedback — mark fragments useful/useless to improve ranking
• Hot Topic Boost — frequently discussed topics rank higher
• Auto Sync — every turn is archived automatically, memory tool writes are synced
• Auto Maintenance — consolidation + selective forgetting to keep storage tidy

Requirements

• Python 3.10+
• Hermes Agent 0.12+ — provides MemoryProvider interface
• Redis 7+ — with RediSearch module (v2.6+)
• jieba — Chinese tokenization (auto-installed)
• Embedding API (optional) — OpenAI / DashScope / any compatible /v1/embeddings service

Installation

pip install fragmented-memory

Or install directly from GitHub:

pip install git+https://github.com/j-zly/fragmented-memory.git

Configuration

Configuration precedence (high to low): Environment variables > JSON config file > config.yaml inline > defaults

1. Create Redis Index (first-time usage)

The code will auto-create (ensure_index()), or execute manually:

redis-cli FT.CREATE idx:memories ON HASH PREFIX 1 "memory:frag:" SCHEMA \
    content TEXT WEIGHT 1 \
    tags TAG SEPARATOR "," \
    category TAG SEPARATOR "," \
    source TEXT WEIGHT 1 \
    created TEXT WEIGHT 0 \
    fragment_type TAG SEPARATOR "," \
    embed_bin VECTOR FLAT 6 TYPE FLOAT32 DIM 1536 DISTANCE_METRIC COSINE

Dimension (DIM) is dynamically adjusted based on the embedding model used, default 1536. For Docker: docker run -d --name redis-stack -p 6379:6379 redis/redis-stack:latest

2. Hermes Configuration

Enable in ~/.hermes/config.yaml:

memory:
  provider: fragmented

Detailed configuration is recommended in a JSON config file (not embedded in config.yaml):

~/.config/fragmented-memory/config.json:

{
  "redis_host": "127.0.0.1",
  "redis_port": 6379,
  "top_k": 5,
  "candidate_k": 10,
  "embedder": {
    "provider": "dashscope",
    "api_key": "sk-xxx",
    "model": "text-embedding-v2"
  }
}

If embedder is not configured, only BM25 full-text search mode will be used.

Also supports environment variable configuration (highest precedence):

export FRAGMENTED_REDIS_HOST=127.0.0.1
export FRAGMENTED_REDIS_PORT=6379
export FRAGMENTED_TOP_K=5
export FRAGMENTED_EMBEDDER=dashscope
export FRAGMENTED_EMBEDDER_MODEL=text-embedding-v2
export OPENAI_API_KEY=sk-xxx        # embedder API key

3. Restart Gateway

# For CLI mode, restart session is sufficient
# For Gateway mode, restart the process

Configuration Reference

Config Item	Environment Variable	Default Value	Description
redis_host	FRAGMENTED_REDIS_HOST	127.0.0.1	Redis address
redis_port	FRAGMENTED_REDIS_PORT	6379	Redis port
top_k	FRAGMENTED_TOP_K	5	Number of final fragments returned
candidate_k	FRAGMENTED_CANDIDATE_K	10	Candidate fragments count (for KNN)
tag_filter	FRAGMENTED_TAG_FILTER	""	Tag filtering (comma-separated)
bm25_limit	FRAGMENTED_BM25_LIMIT	10	BM25 search candidate count
decay_half_days	FRAGMENTED_DECAY_HALF_DAYS	60	Time decay half-life (days)
embed_cache_ttl	FRAGMENTED_EMBED_CACHE_TTL	3600	Embedding cache TTL (seconds)
sentiment_boost_positive	—	1.5	Positive fragment weight multiplier
sentiment_boost_negative	—	1.3	Negative fragment weight multiplier
feedback_positive_boost	—	1.3	Positive feedback bonus weight
feedback_negative_penalty	—	0.5	Negative feedback penalty coefficient
hot_topic_boost	—	1.2	Hot topic weighting multiplier
embedder.provider	FRAGMENTED_EMBEDDER	openai	openai / dashscope
embedder.api_key	OPENAI_API_KEY	—	Embedding API key
embedder.base_url	FRAGMENTED_EMBEDDER_URL	https://api.openai.com/v1	API endpoint
embedder.model	FRAGMENTED_EMBEDDER_MODEL	text-embedding-3-small	Embedding model name
consolidate_min_group	—	2	Minimum fragments to trigger consolidation
consolidate_max_age_hours	—	72	Minimum age (hours) before fragments can be consolidated
forget_max_age_days	—	30	Number of days before fragments might be forgotten
forget_dry_run	—	true	Safe mode for forgetting: only count, don't delete
hot_topic_decay_half_days	—	30	Hot topic time decay half-life (days)
emotion_intensity_factor	—	0.4	Emotion intensity → weight coefficient (0=disabled, 1=max)
attention_boost_max	—	1.5	Maximum attention weighting value
attention_base_increment	—	2.0	Base attention increment per mention
attention_emotion_factor	—	1.5	Emotion intensity amplification factor for attention

sentiment_*, feedback_*, hot_topic_* and other ranking weight parameters currently only support configuration through JSON config file, not environment variables. Set to 1.0 to disable the effect of that dimension.

Embedding Models and Dimensions

Model	Dimensions
OpenAI text-embedding-3-small	1536
OpenAI text-embedding-3-large	3072
OpenAI text-embedding-ada-002	1536
DashScope text-embedding-v2	1536
DashScope text-embedding-v3	1024

Dimensions are automatically detected, switching models doesn't require reconfiguration.

Synonym Table

Stored in Redis Hash fragmented:synonyms, expanded at search time to improve recall:

redis-cli HSET fragmented:synonyms setup '["install","configure","deploy","setup"]'
redis-cli HSET fragmented:synonyms fix '["fix","modify","correct","repair","solve"]'

Verification

Check logs after startup:

Memory provider 'fragmented' registered (0 tools)
fragmented: connected (session=xxx, top_k=5, tag_filter=(none))
fragmented: BM25-only mode (no embedder configured)

Architecture

┌────────────────────────────────────────────────────────┐
│                    User sends message                  │
└──────────────────┬─────────────────────────────────────┘
                   │
         ┌─────────▼─────────┐
         │   prefetch()       │  ← Automatically triggered
         │   ↓                │
         │  BM25 Full-Text Search │  ← Default, zero cost
         │  (KNN Vector search) │  ← Optional (needs embedder)
         │   ↓                │
         │  Six-dimensional Re-ranking │  ← Similarity × Time decay
         │                    │    × Emotion × Feedback × Hot Topic × Attention
         │   ↓                │
         │  Top N Injected into Context   │
         └─────────┬─────────┘
                   │
         ┌─────────▼─────────┐
         │   Model Response   │  ← Fragments can be used as reference
         └───────────────────┘
                   │
         ┌─────────▼─────────┐
         │   sync_turn()      │  ← Automatically archive at end of conversation
         │   Smart Sentence Splitting      │  ← Protect abbreviations/numbers/quotes
         │   Attention Tracking        │  ← Extract keywords and increase attention score
         │   ↓                │
         │   Stored in Redis        │  ← Available for next retrieval
         └───────────────────┘
                   │
         ┌─────────▼─────────┐
         │   [cron] Every 2h     │  ← Background maintenance
         │   ① Multi-level Consolidation       │  ← Same topic→LLM summarization→level+1
         │   ② Selective Forgetting     │  ← Cleanup low-value fragments
         └───────────────────┘

License

MIT