Memlord

Self-hosted MCP memory server for personal use and teams

Quickstart • How It Works • MCP Tools • Configuration • Requirements • License

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✨ Features

• 🔍 Hybrid search — BM25 (full-text) + vector KNN (pgvector) fused via Reciprocal Rank Fusion
• 📂 Multi-user — each user sees only their own memories; workspaces for shared team knowledge
• 🛠️ 10 MCP tools — store, retrieve, recall, list, search by tag, get, update, delete, move, list workspaces
• 🌐 Web UI — browse, search, edit and delete memories in the browser; export/import JSON
• 🔒 OAuth 2.1 — full in-process authorization server, always enabled
• 🐘 PostgreSQL — pgvector for embeddings, tsvector for full-text search
• 📊 Progressive disclosure — search returns compact snippets by default; call get_memory(id) only for what you need, reducing token usage
• 🔁 Deduplication — automatically detects near-identical memories before saving, preventing noise accumulation

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🆚 How Memlord compares

	Memlord	OpenMemory	mcp-memory-service	basic-memory
Search	BM25 + vector + RRF	Vector only (Qdrant)	BM25 + vector + RRF	BM25 + vector
Embeddings	Local ONNX, zero config	OpenAI default; Ollama optional	Local ONNX, zero config	Local FastEmbed
Storage	PostgreSQL + pgvector	PostgreSQL + Qdrant	SQLite-vec / Cloudflare Vectorize	SQLite + Markdown files
Multi-user	✅	❌ single-user in practice	⚠️ agent-ID scoping, no isolation	❌
Workspaces	✅ shared + personal, invite links	⚠️ "Apps" namespace	⚠️ tags + conversation_id	✅ per-project flag
Authentication	✅ OAuth 2.1	❌ none (self-hosted)	✅ OAuth 2.0 + PKCE	❌
Web UI	✅ browse, edit, export	✅ Next.js dashboard	✅ rich UI, graph viz, quality scores	❌ local; cloud only
MCP tools	10	5	15+	~20
Self-hosted	✅ single process	✅ Docker (3 containers)	✅	✅
Memory input	Manual (explicit store)	Auto-extracted by LLM	Manual	Manual (Markdown notes)
Memory types	fact / preference / instruction / feedback	auto-extracted facts	—	observations + wiki links
Time-aware search	✅ natural language dates	⚠️ REST only, not in MCP tools	—	✅ recent_activity
Token efficiency	✅ progressive disclosure	❌	—	✅ build_context traversal
Import / Export	✅ JSON	✅ ZIP (JSON + JSONL)	—	✅ Markdown (human-readable)
License	AGPL-3.0 / Commercial	Apache 2.0	Apache 2.0	AGPL-3.0

Where competitors have a real edge:

• OpenMemory — auto-extracts memories from raw conversation text; no need to decide what to store manually; good import/export
• mcp-memory-service — richer web UI (graph visualization, quality scoring, 8 tabs); more permissive license (Apache 2.0); multiple transport options (stdio, SSE, HTTP)
• basic-memory — memories are human-readable Markdown files you can edit, version-control, and read without any server; wiki-style entity links form a local knowledge graph; ~20 MCP tools

When to pick Memlord:

• You want zero-config local embeddings — ONNX model ships with the server, no Ollama or external API needed
• You run a multi-user team server with proper OAuth 2.1 auth and invite-based workspaces
• You want a production-grade database (PostgreSQL) that scales beyond a single machine's SQLite
• You manage memories explicitly — store exactly what matters, typed and tagged, not everything the LLM decides to extract
• You want a self-hosted Web UI with full CRUD and JSON export, without a cloud subscription

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🚀 Quickstart

# Install dependencies
uv sync --dev

# Download ONNX model (~23 MB)
uv run python scripts/download_model.py

# Run migrations
alembic upgrade head

# Start the server
memlord

Open http://localhost:8000 for the Web UI. The MCP endpoint is at /mcp.

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🐳 Docker

cp .env.example .env
docker compose up

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🔍 How It Works

Each search request runs BM25 and vector KNN in parallel, then merges results via Reciprocal Rank Fusion:

flowchart TD
    Q([query]) --> BM25["BM25\nsearch_vector @@ websearch_to_tsquery"]
    Q --> EMB["ONNX embed\nall-MiniLM-L6-v2 · 384d · local"]
    EMB --> KNN["KNN\nembedding <=> query_vector\ncosine distance"]
    BM25 --> RRF["RRF fusion\nscore = 1/(k+rank_bm25) + 1/(k+rank_vec)\nk=60"]
    KNN --> RRF
    RRF --> R([top-N results])

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⚙️ Configuration

All settings use the MEMLORD_ prefix. See .env.example for the full list.

Variable	Default	Description
MEMLORD_DB_URL	postgresql+asyncpg://postgres:postgres@localhost/memlord	PostgreSQL connection URL
MEMLORD_PORT	8000	Server port
MEMLORD_BASE_URL	http://localhost:8000	Public URL for OAuth
MEMLORD_OAUTH_JWT_SECRET	memlord-dev-secret-please-change	JWT signing secret

OAuth is always enabled. Set MEMLORD_BASE_URL to your public URL and change MEMLORD_OAUTH_JWT_SECRET before deploying.

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🛠️ MCP Tools

Tool	Description
store_memory	Save a memory (idempotent by content); raises on near-duplicates
retrieve_memory	Hybrid semantic + full-text search; returns snippets by default
recall_memory	Search by natural-language time expression; returns snippets by default
list_memories	Paginated list with type/tag filters
search_by_tag	AND/OR tag search
get_memory	Fetch a single memory by ID with full content
update_memory	Update content, type, tags, or metadata by ID
delete_memory	Delete by ID
move_memory	Move a memory to a different workspace
list_workspaces	List workspaces you are a member of (including personal)

Workspace management (create, invite, join, leave) is handled via the Web UI.

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💻 System Requirements

• Python 3.12
• PostgreSQL ≥ 15 with pgvector extension
• uv — Python package manager

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👨‍💻 Development

pyright src/           # type check
black .                # format
pytest                 # run tests
alembic-autogen-check  # verify migrations are up to date

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📄 License

Memlord is dual-licensed:

• AGPL-3.0 — free for open-source use. If you run a modified version as a network service, you must publish your source code.
• Commercial License — for proprietary or closed-source deployments. Contact [email protected] or [email protected] to purchase.