Memory MCP Server

Name: Enhanced Knowledge Graph Memory Server
Author: danielsimonjr

Version NPM License MCP TypeScript Coverage

An enhanced fork of the official Model Context Protocol memory server with advanced features for hierarchical nesting, intelligent compression, semantic search, graph algorithms, archiving, advanced search, and multi-format import/export.

Enterprise-grade knowledge graph with 106 tools, hierarchical organization, semantic search with embeddings, graph traversal algorithms, duplicate detection, smart archiving, sophisticated search capabilities, project scoping, temporal knowledge graph, semantic forget, and agent diary for long-term memory management.

Features

Core Memory Capabilities

Knowledge Graph Storage: Entity-Relation-Observation model for structured memory
Persistent Memory: Information persists across chat sessions with JSONL or SQLite storage
Dual Storage Backends: JSONL (human-readable) or SQLite with better-sqlite3 (3-10x faster, FTS5 search)
Full CRUD Operations: Create, read, update, delete entities and relations
Flexible Search: Text-based, fuzzy, boolean, semantic, and TF-IDF ranked search

Advanced Features

Category	Tools	Description
Hierarchical Nesting	9	Parent-child relationships for organizing tree structures
Graph Algorithms	4	Path finding, connected components, centrality metrics
Intelligent Search	3	Hybrid multi-layer search with query analysis and reflection
Semantic Search	3	Embedding-based similarity search with OpenAI or local models
Memory Compression	4	Intelligent duplicate detection and merging with similarity scoring
Advanced Search	7	TF-IDF ranking, boolean queries, fuzzy matching, auto-select
Observation Normalization	1	Coreference resolution and temporal anchoring
Tag Management	11	Tags, aliases, bulk operations, importance scores
Saved Searches	5	Store and execute frequent queries
Import/Export	2	7 export formats with brotli compression, 3 import formats
Graph Analytics	2	Statistics, validation, integrity checks
Ref Index	4	Cross-session symbolic reference registration and resolution
Artifacts	3	Named versioned content blobs attached to entities
Temporal Search	1	Time-window filtered search across the knowledge graph
Distillation	1	Configure automated observation distillation pipelines
Freshness	5	Staleness tracking, expiry detection, and freshness reporting
LLM Query	1	Natural-language question answering over the graph
Governance	4	Transactional audit trail, history, and rollback
Role Profiles	2	Per-agent role assignment and profile listing
Entropy	2	Entropy-based noise filtering and information density scoring
Consolidation	3	Background memory consolidation scheduling and control
Formatter	1	Salience-budget-aware context formatting
Collaborative	1	Multi-agent context synthesis
Failure Handling	2	Session failure distillation and graceful session end
Cognitive Load	2	Working-memory load analysis and adaptive reduction
Project Scoping	1	List and filter entities by project
Memory Versioning	2	Entity version chains and per-entity version history
Semantic Forget	1	Two-tier deletion: exact match → semantic similarity fallback
Profiles	2	User/agent profile get and update
Temporal KG	3	Temporal relation invalidation, time-travel queries, relation timeline
Ingestion	1	Format-agnostic conversation/document ingestion pipeline
Agent Diary	2	Per-agent persistent journal write and read

Comparison with Official Memory Server

Feature	Official	Enhanced (This Fork)
Entity/Relation/Observation Management	✅	✅
Basic Search	✅	✅
Hierarchical Nesting	❌	✅ Parent-child trees
Graph Algorithms	❌	✅ Path finding, centrality
Semantic Search	❌	✅ Embedding-based similarity
Memory Compression	❌	✅ Duplicate detection
Brotli Compression	❌	✅ Backups, exports, responses
Smart Archiving	❌	✅ Criteria-based
Advanced Search	❌	✅ TF-IDF + Boolean + Fuzzy
SQLite Backend	❌	✅ better-sqlite3 (3-10x faster)
Full-Text Search	❌	✅ FTS5 with BM25 ranking
Timestamps	❌	✅ createdAt + lastModified
Import/Export Formats	❌	✅ 7 export / 3 import
Input Validation	❌	✅ Zod schemas
Backup & Restore	❌	✅ Compressed snapshots
Intelligent Search	❌	✅ Hybrid + Query Analysis + Reflection
Observation Normalization	❌	✅ Coreference resolution + temporal anchoring
Total Tools	11	106
Code Structure	Monolithic	Modular (77 files)

Quick Start

1. Install from NPM

npm install -g @danielsimonjr/memory-mcp

Or use with npx (no installation required):

npx @danielsimonjr/memory-mcp

2. Configure Claude Desktop

Add to claude_desktop_config.json:

Using NPM Global Install:

{
  "mcpServers": {
    "memory": {
      "command": "mcp-server-memory"
    }
  }
}

Using NPX:

{
  "mcpServers": {
    "memory": {
      "command": "npx",
      "args": ["-y", "@danielsimonjr/memory-mcp"]
    }
  }
}

3. Restart Claude Desktop

Restart Claude Desktop to load the enhanced memory server.

4. Start Using

Tell Claude:

Please remember that I prefer TypeScript over JavaScript.
Tag this as "preferences" with importance 8.
Create a parent entity called "Development Preferences" and nest this under it.

Installation

Local Build

# Clone repository
git clone https://github.com/danielsimonjr/memory-mcp.git
cd memory-mcp

# Install and build
npm install
npm run build

# Run tests (2800+ tests)
npm test

# Type check
npm run typecheck

Claude Desktop Configuration

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (Mac) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "memory": {
      "command": "node",
      "args": ["<PATH_TO>/memory-mcp/dist/index.js"],
      "env": {
        "MEMORY_FILE_PATH": "<PATH_TO>/memory.jsonl"
      }
    }
  }
}

VS Code

Add to .vscode/mcp.json:

{
  "servers": {
    "memory": {
      "command": "node",
      "args": ["/path/to/memory-mcp/dist/index.js"]
    }
  }
}

Core Concepts

Entities

Primary nodes in the knowledge graph.

interface Entity {
  name: string;           // Unique identifier
  entityType: string;     // Classification
  observations: string[]; // Facts about the entity
  parentId?: string;      // Parent entity name for hierarchical nesting
  tags?: string[];        // Lowercase tags for categorization
  importance?: number;    // 0-10 scale for prioritization
  createdAt?: string;     // ISO 8601 timestamp
  lastModified?: string;  // ISO 8601 timestamp
}

Relations

Directed connections between entities.

interface Relation {
  from: string;           // Source entity name
  to: string;             // Target entity name
  relationType: string;   // Relationship type (active voice)
  createdAt?: string;     // ISO 8601 timestamp
  lastModified?: string;  // ISO 8601 timestamp
}

Observations

Discrete facts about entities. Each observation should be atomic and independently manageable.

API Reference

Complete Tool List (106 Tools)

Entity Operations (4 tools)

Tool	Description
`create_entities`	Create multiple new entities
`delete_entities`	Remove entities and their relations
`read_graph`	Read entire knowledge graph
`open_nodes`	Retrieve specific nodes by name

Relation Operations (2 tools)

Tool	Description
`create_relations`	Create relations between entities
`delete_relations`	Remove specific relations

Observation Management (3 tools)

Tool	Description
`add_observations`	Add observations to entities
`delete_observations`	Remove specific observations
`normalize_observations`	Normalize observations (resolve pronouns, anchor dates)

Search (7 tools)

Tool	Description
`search_nodes`	Search with filters (tags, importance)
`search_by_date_range`	Filter by date range
`search_nodes_ranked`	TF-IDF relevance ranking
`boolean_search`	Boolean queries (AND/OR/NOT)
`fuzzy_search`	Typo-tolerant search
`get_search_suggestions`	"Did you mean?" suggestions
`search_auto`	Auto-select best search method

Intelligent Search (3 tools)

Tool	Description
`hybrid_search`	Multi-layer search combining semantic, lexical, and symbolic signals
`analyze_query`	Extract entities, temporal references, and classify query complexity
`smart_search`	Reflection-based iterative search until results meet adequacy threshold

Semantic Search (3 tools)

Tool	Description
`semantic_search`	Search by semantic similarity using embeddings
`find_similar_entities`	Find entities similar to a reference entity
`index_embeddings`	Build or rebuild the semantic search index

Saved Searches (5 tools)

Tool	Description
`save_search`	Save search query for reuse
`execute_saved_search`	Execute a saved search
`list_saved_searches`	List all saved searches
`delete_saved_search`	Delete a saved search
`update_saved_search`	Update saved search parameters

Tag Management (6 tools)

Tool	Description
`add_tags`	Add tags to an entity
`remove_tags`	Remove tags from an entity
`set_importance`	Set entity importance (0-10)
`add_tags_to_multiple_entities`	Bulk tag operation
`replace_tag`	Replace tag globally
`merge_tags`	Merge two tags into one

Tag Aliases (5 tools)

Tool	Description
`add_tag_alias`	Create tag synonym
`list_tag_aliases`	List all aliases
`remove_tag_alias`	Remove an alias
`get_aliases_for_tag`	Get aliases for canonical tag
`resolve_tag`	Resolve alias to canonical form

Hierarchical Nesting (9 tools)

Tool	Description
`set_entity_parent`	Set/remove parent relationship
`get_children`	Get immediate children
`get_parent`	Get parent entity
`get_ancestors`	Get all ancestors (parent chain)
`get_descendants`	Get all descendants (recursive)
`get_subtree`	Get entity + descendants with relations
`get_root_entities`	Get entities with no parent
`get_entity_depth`	Get depth in hierarchy
`move_entity`	Move entity to new parent

Graph Algorithms (4 tools)

Tool	Description
`find_shortest_path`	Shortest path between entities (BFS)
`find_all_paths`	All paths with max depth limit
`get_connected_components`	Detect isolated subgraphs
`get_centrality`	Calculate centrality metrics (degree, betweenness, PageRank)

Graph Analytics (2 tools)

Tool	Description
`get_graph_stats`	Comprehensive graph statistics
`validate_graph`	Validate graph integrity

Compression & Archiving (4 tools)

Tool	Description
`find_duplicates`	Find similar entities by threshold
`merge_entities`	Merge multiple entities into one
`compress_graph`	Auto compression with dry-run
`archive_entities`	Archive by age, importance, or tags

Import & Export (2 tools)

Tool	Description
`export_graph`	Export in 7 formats (JSON, CSV, GraphML, GEXF, DOT, Markdown, Mermaid) with compression
`import_graph`	Import from JSON/CSV/GraphML with merge strategies

Ref Index (4 tools)

Tool	Description
`register_ref`	Register a symbolic reference pointing to an entity
`resolve_ref`	Resolve a symbolic reference to its target entity
`deregister_ref`	Remove a registered symbolic reference
`list_refs`	List all registered symbolic references

Artifacts (3 tools)

Tool	Description
`create_artifact`	Create a named versioned content blob attached to an entity
`get_artifact`	Retrieve an artifact by name and optional version
`list_artifacts`	List all artifacts, optionally filtered by entity

Temporal Search (1 tool)

Tool	Description
`search_by_time`	Search entities and observations within a time window

Distillation (1 tool)

Tool	Description
`configure_distillation`	Configure automated observation distillation pipelines

Freshness (5 tools)

Tool	Description
`check_freshness`	Check freshness status of a specific entity
`get_stale_entities`	List entities that have exceeded their staleness threshold
`get_expired_entities`	List entities past their explicit expiry date
`refresh_entity`	Reset the freshness timestamp on an entity
`freshness_report`	Generate a full freshness report across the graph

LLM Query (1 tool)

Tool	Description
`query_natural_language`	Answer natural-language questions over the knowledge graph

Governance (4 tools)

Tool	Description
`governance_transaction`	Execute a governed, audited graph transaction
`audit_query`	Query the audit log with filters
`audit_history`	Retrieve full audit history for an entity
`rollback_operation`	Roll back a previously recorded operation

Role Profiles (2 tools)

Tool	Description
`set_agent_role`	Assign a role profile to the current agent context
`list_role_profiles`	List all available agent role profiles

Entropy (2 tools)

Tool	Description
`enable_entropy_filter`	Enable entropy-based noise filtering for search results
`compute_entropy`	Compute information-density entropy score for an entity

Consolidation (3 tools)

Tool	Description
`start_consolidation`	Start the background memory consolidation service
`stop_consolidation`	Stop the background memory consolidation service
`run_consolidation_now`	Trigger an immediate consolidation pass

Formatter (1 tool)

Tool	Description
`format_with_salience_budget`	Format context output respecting a token salience budget

Collaborative (1 tool)

Tool	Description
`synthesize_collaborative_context`	Synthesize a unified context view from multiple agent memory spaces

Failure Handling (2 tools)

Tool	Description
`distill_failure`	Distill and store key observations from a failed session
`end_session`	Gracefully end a session and persist in-flight state

Cognitive Load (2 tools)

Tool	Description
`analyze_cognitive_load`	Analyze working-memory load in the current context
`adaptive_reduce_memories`	Adaptively reduce memory set to fit cognitive load target

Project Scoping (1 tool)

Tool	Description
`list_projects`	List all project IDs present in the graph and filter entities by project

Memory Versioning (2 tools)

Tool	Description
`get_entity_versions`	Retrieve all versions of a versioned entity by name
`get_version_chain`	Get the full version chain from root to latest for an entity

Semantic Forget (1 tool)

Tool	Description
`forget_memory`	Delete an entity by exact name, falling back to semantic similarity if no exact match found

Profiles (2 tools)

Tool	Description
`get_profile`	Retrieve a user or agent profile entity
`update_profile`	Update observations and metadata on a profile entity

Temporal KG (3 tools)

Tool	Description
`invalidate_relation`	Mark a relation as ended by setting its temporal validity end date
`query_as_of`	Retrieve all relations for an entity that were valid at a given point in time
`timeline`	Return a chronological list of relation events for an entity

Ingestion (1 tool)

Tool	Description
`ingest`	Ingest a conversation, document, or free-form text into the knowledge graph

Agent Diary (2 tools)

Tool	Description
`diary_write`	Append an entry to the agent's persistent diary
`diary_read`	Read diary entries for an agent, optionally filtered by date range

Configuration

Environment Variables

Variable	Description	Default
`MEMORY_FILE_PATH`	Path to storage file	`memory.jsonl` (current directory)
`MEMORY_STORAGE_TYPE`	Storage backend: `jsonl` or `sqlite`	`jsonl`
`MEMORY_EMBEDDING_PROVIDER`	Embedding provider: `openai`, `local`, or `none`	`none`
`MEMORY_OPENAI_API_KEY`	OpenAI API key (required if provider is `openai`)	-
`MEMORY_EMBEDDING_MODEL`	Embedding model to use	`text-embedding-3-small` (OpenAI) / `Xenova/all-MiniLM-L6-v2` (local)
`MEMORY_AUTO_INDEX_EMBEDDINGS`	Auto-index entities on creation	`false`

Storage Backends

Feature	JSONL (Default)	SQLite (better-sqlite3)
Format	Human-readable text	Native binary database
Transactions	Basic	Full ACID with WAL mode
Full-Text Search	Basic	FTS5 with BM25 ranking
Performance	Good	3-10x faster
Concurrency	Single-threaded	Thread-safe with async-mutex
Best For	Small graphs, debugging	Large graphs (10k+ entities)

Using SQLite:

{
  "mcpServers": {
    "memory": {
      "command": "node",
      "args": ["/path/to/memory-mcp/dist/index.js"],
      "env": {
        "MEMORY_STORAGE_TYPE": "sqlite",
        "MEMORY_FILE_PATH": "/path/to/data/memory.db"
      }
    }
  }
}

Storage Files

When you set MEMORY_FILE_PATH, the server automatically creates related files:

/your/data/directory/
├── memory.jsonl                    # Main knowledge graph
├── memory-saved-searches.jsonl     # Saved search queries
├── memory-tag-aliases.jsonl        # Tag synonym mappings
└── .backups/                       # Timestamped backups
    ├── backup_2026-01-08_10-30-00-123.jsonl
    └── backup_2026-01-08_10-30-00-123.jsonl.meta.json

Migration Tool

Convert between JSONL and SQLite formats:

cd tools/migrate-from-jsonl-to-sqlite
npm install && npm run build

# JSONL to SQLite
node dist/migrate-from-jsonl-to-sqlite.js --from memory.jsonl --to memory.db

# SQLite to JSONL
node dist/migrate-from-jsonl-to-sqlite.js --from memory.db --to memory.jsonl

Development

Prerequisites

Node.js 18+
npm 9+
TypeScript 5.6+

Build Commands

npm install           # Install dependencies
npm run build         # Build TypeScript
npm test              # Run tests (2800+ tests)
npm run typecheck     # Strict type checking
npm run watch         # Development watch mode
npm run clean         # Remove dist/ directory
npm run docs:deps     # Generate dependency graph

Architecture

┌─────────────────────────────────────────────────────┐
│  Layer 1: MCP Protocol Layer                        │
│  server/MCPServer.ts + toolDefinitions (106 tools)  │
│  + toolHandlers + responseCompressor                │
└──────────────────────┬──────────────────────────────┘
                       │
┌──────────────────────┴──────────────────────────────┐
│  Layer 2: Managers + Context (Lazy Initialization)  │
│  ManagerContext (aliased as KnowledgeGraphManager)  │
│  • EntityManager   (CRUD + hierarchy + archive)     │
│  • RelationManager (relation CRUD)                  │
│  • SearchManager   (search + compression + stats)   │
│  • IOManager       (import + export + backup)       │
│  • TagManager      (tag aliases)                    │
│  • GraphTraversal  (path finding, centrality)       │
│  • SemanticSearch  (embeddings, similarity)         │
└──────────────────────┬──────────────────────────────┘
                       │
┌──────────────────────┴──────────────────────────────┐
│  Layer 3: Storage Layer                             │
│  core/GraphStorage.ts (JSONL + in-memory cache)     │
│  core/SQLiteStorage.ts (better-sqlite3 + FTS5)      │
│  core/StorageFactory.ts (backend selection)         │
└─────────────────────────────────────────────────────┘

Project Structure

memory-mcp/
├── src/                            # Source (77 TypeScript files)
│   ├── index.ts                    # Entry point
│   ├── core/                       # Core managers (12 files)
│   │   ├── ManagerContext.ts           # Context holder (lazy init)
│   │   ├── EntityManager.ts            # Entity CRUD + hierarchy
│   │   ├── RelationManager.ts          # Relation CRUD
│   │   ├── GraphStorage.ts             # JSONL I/O + caching
│   │   ├── SQLiteStorage.ts            # SQLite with better-sqlite3
│   │   ├── TransactionManager.ts       # ACID transactions
│   │   ├── StorageFactory.ts           # Storage backend factory
│   │   ├── HierarchyManager.ts         # Tree operations
│   │   ├── ObservationManager.ts       # Observation CRUD
│   │   ├── GraphTraversal.ts           # Path finding, centrality
│   │   ├── GraphEventEmitter.ts        # Event system
│   │   └── index.ts
│   ├── server/                     # MCP protocol (4 files)
│   │   ├── MCPServer.ts                # Server setup
│   │   ├── toolDefinitions.ts          # 106 tool schemas
│   │   ├── toolHandlers.ts             # Handler registry
│   │   └── responseCompressor.ts       # Brotli compression
│   ├── search/                     # Search implementations (29 files)
│   │   ├── SearchManager.ts            # Search orchestrator
│   │   ├── BasicSearch.ts              # Text matching
│   │   ├── RankedSearch.ts             # TF-IDF scoring
│   │   ├── BooleanSearch.ts            # AND/OR/NOT logic
│   │   ├── FuzzySearch.ts              # Typo tolerance
│   │   ├── SemanticSearch.ts           # Embedding-based
│   │   ├── EmbeddingService.ts         # Provider abstraction
│   │   ├── VectorStore.ts              # Vector storage
│   │   └── ...                         # + 12 more
│   ├── features/                   # Advanced capabilities (9 files)
│   │   ├── IOManager.ts                # Import/export/backup
│   │   ├── TagManager.ts               # Tag aliases
│   │   ├── AnalyticsManager.ts         # Graph stats
│   │   ├── ArchiveManager.ts           # Entity archival
│   │   ├── CompressionManager.ts       # Duplicate detection
│   │   ├── StreamingExporter.ts        # Large graph exports
│   │   ├── ObservationNormalizer.ts    # Coreference resolution
│   │   ├── KeywordExtractor.ts         # Keyword extraction
│   │   └── index.ts
│   ├── types/                      # TypeScript definitions (2 files)
│   ├── utils/                      # Shared utilities (18 files)
│   └── workers/                    # Worker pool (2 files)
├── tests/                          # Test suite (97 files, 2800+ tests)
│   ├── unit/                       # Unit tests
│   ├── integration/                # Integration tests
│   ├── e2e/                        # End-to-end tests
│   └── performance/                # Benchmarks
├── dist/                           # Compiled output
├── docs/                           # Documentation
│   ├── architecture/               # Architecture docs
│   ├── guides/                     # User guides
│   └── reports/                    # Sprint reports
├── tools/                          # Standalone utilities
│   ├── chunking-for-files/         # File splitting
│   ├── compress-for-context/       # CTON compression
│   ├── create-dependency-graph/    # Dependency analyzer
│   └── migrate-from-jsonl-to-sqlite/
├── CHANGELOG.md                    # Version history
└── README.md                       # This file

Dependencies

Production:

@modelcontextprotocol/sdk: ^1.21.1
better-sqlite3: ^11.7.0
zod: ^4.1.13
async-mutex: ^0.5.0
@danielsimonjr/workerpool: ^10.0.1

Development:

typescript: ^5.6.2
vitest: ^4.0.13
@vitest/coverage-v8: ^4.0.13
@types/better-sqlite3: ^7.6.12

Documentation

Comprehensive documentation in docs/:

Architecture

API.md - Complete API documentation for all 106 tools
ARCHITECTURE.md - Technical architecture and system design
COMPONENTS.md - Component breakdown and responsibilities
OVERVIEW.md - High-level project overview
DEPENDENCY_GRAPH.md - Module dependencies

User Guides

HIERARCHY.md - Parent-child relationships (9 tools)
COMPRESSION.md - Duplicate detection and merging
ARCHIVING.md - Memory lifecycle and archiving
QUERY_LANGUAGE.md - Boolean search syntax

Development

WORKFLOW.md - Development procedures
MIGRATION.md - Version upgrade guide

Contributing

We welcome contributions!

See:

CONTRIBUTING.md - Contribution guidelines
CODE_OF_CONDUCT.md - Community standards

Ways to Help:

Report bugs
Request features
Submit pull requests
Improve documentation
Add tests

Changelog

All notable changes are documented in CHANGELOG.md.

Current version: v12.0.0 - View full changelog

Recent highlights:

v12.0.0 (106 tools): 12 new tools — Project Scoping, Memory Versioning, Semantic Forget, Profiles, Temporal KG, Ingestion, Agent Diary (memoryjs v1.8.0/v1.9.0)
v12.0.0 (94 tools): 32 new tools — Ref Index, Artifacts, Temporal Search, Distillation, Freshness, LLM Query, Governance, Role Profiles, Entropy, Consolidation, Formatter, Collaborative, Failure Handling, Cognitive Load
v11.1.1: npm tarball cleanup, excluded data files from published package
v11.1.0: MCP error framing, dynamic server version, handler smoke tests, response compressor tests

License

MIT License - see LICENSE

Acknowledgments

Original Project

Enhanced fork of Model Context Protocol memory server by Anthropic.

Developer

Daniel Simon Jr.

Major Enhancements

Hierarchical nesting with parent-child relationships
Graph algorithms: path finding, centrality, connected components
Semantic search with embedding-based similarity
Brotli compression for backups, exports, and responses
Memory compression with intelligent duplicate detection
Smart archiving with criteria-based filtering
Advanced search: TF-IDF, boolean, and fuzzy matching
Multi-format import/export with merge strategies
SQLite backend with better-sqlite3 (3-10x faster)
Transaction support with ACID guarantees
Comprehensive test suite (2800+ tests, 97 test files)

Repository: https://github.com/danielsimonjr/memory-mcp NPM: https://www.npmjs.com/package/@danielsimonjr/memory-mcp Issues: https://github.com/danielsimonjr/memory-mcp/issues