mnemo-mcp 2.0.0b2

Open-source MCP Server for persistent AI memory with embedded sync

Mnemo MCP Server

mcp-name: io.github.n24q02m/mnemo-mcp

Persistent memory MCP server with hybrid retrieval (FTS5 + sqlite-vec + RRF fusion + cross-encoder rerank + temporal decay) and embedded sync. Open, free, unlimited.

Sister projects from n24q02m (click to expand)

Project	Tagline	Tag
better-code-review-graph	Knowledge graph for token-efficient code reviews -- fixed search, configurabl...	MCP
better-email-mcp	IMAP/SMTP email server for AI agents -- 6 composite tools with multi-account ...	MCP
better-godot-mcp	Composite MCP server for Godot Engine -- 17 mega-tools for AI-assisted game d...	MCP
better-notion-mcp	Markdown-first Notion API server for AI agents -- 10 composite tools replacin...	MCP
better-telegram-mcp	MCP server for Telegram with dual-mode support: Bot API (httpx) for quick bot...	MCP
claude-plugins	Full documentation: mcp.n24q02m.com — unified docs for all 8 servers + the mc...	Marketplace
imagine-mcp	Production-grade MCP server for image and video understanding + generation ac...	MCP
jules-task-archiver	Chrome Extension for bulk operations on Jules tasks via batchexecute API -- a...	Tooling
mcp-core	Unified MCP Streamable HTTP 2025-11-25 transport, OAuth 2.1 Authorization Ser...	MCP
mnemo-mcp	Persistent AI memory with hybrid search and embedded sync. Open, free, unlimi...	MCP
qwen3-embed	Lightweight Qwen3 text embedding and reranking via ONNX Runtime and GGUF	Library
skret	Secrets without the server.	CLI
web-core	Shared web infrastructure package for search, scraping, HTTP security, and st...	Library
wet-mcp	Open-source MCP Server for web search, content extraction, library docs & mul...	MCP

Table of contents

• Features
• Status
• Documentation
• Tools
• Security
• Build from Source
• Trust Model
• License

Roadmap (current = Phase 1 / v1.x)

Phase	Version	Status	Highlights
Phase 1	v1.x	Shipped	Typed memory(action="capture") (6 context_types + dedup) -- RRF (k=60) hybrid fusion + cross-encoder rerank + temporal decay -- importance x recency archive policy + restore -- Alembic migrations -- multi-provider LLM dispatch -- plugin trinity (recall-context + memory-commit skills, SessionStart + opt-in PostToolUse hooks)
Phase 2	v1.x+1	Shipped	LLM-driven compression of older memories + Passport sync (encrypted import/export bundle for cross-machine bootstrap) -- AES-256-GCM + Argon2id, S3 / R2 / B2 / MinIO + GDrive backends, delta-sync with LWW per row
Phase 3	v2.0.0	Shipped (BREAKING)	Temporal knowledge graph -- bitemporal valid_from / valid_to columns -- entity resolution via embedding KNN -- entity_search / entity_graph / history actions -- KG-aware passport bundle sections -- KG_AUTO_ENABLED opt-in auto-extract on capture

Features

• Hybrid retrieval -- FTS5 + sqlite-vec, fused via Reciprocal Rank Fusion (k=60), then re-ranked by a cross-encoder chain (qwen3-reranker local -> Jina -> Cohere) with temporal decay and importance boost
• Typed capture -- memory(action="capture") with 6 context_types (conversation/fact/preference/skill/task/decision), embedding-based dedup, and a multi-provider LLM dispatcher (Gemini > OpenAI > Anthropic > xAI)
• Knowledge graph -- Automatic entity extraction and relation tracking; top results boosted by graph proximity
• Importance scoring + archive policy -- LLM-scored 0.0-1.0 importance; soft-archive when recency_factor * (1 - importance) > 1.0; restore action available
• Auto-archive trigger -- Background sweep every Nth capture (default 100) -- no cron required
• STM-to-LTM consolidation -- LLM summarization of related memories in a category
• Duplicate detection -- Warns before adding semantically similar memories
• Zero config -- Built-in local Qwen3 ONNX embedding + reranking, no API keys needed. Optional cloud providers (Jina AI, Gemini, OpenAI, Cohere)
• Multi-machine sync -- JSONL-based merge sync via Google Drive (bundled Desktop OAuth public client)
• Plugin trinity -- Ships /recall-context + /memory-commit skills and SessionStart + opt-in PostToolUse hooks (see docs/ARCHITECTURE.md)
• Proactive memory -- Tool descriptions and skills guide AI to save preferences, decisions, facts at the right moment
• Phase 2: LLM compression -- Per-turn compression via the multi-provider dispatcher targets ~3x token reduction at >=0.9 fact retention; graceful skip when no provider configured (see docs/compression.md)
• Phase 2: Encrypted passport sync -- AES-256-GCM bundles + Argon2id KDF, S3 (R2 / B2 / MinIO) and Google Drive backends, delta-sync with last-write-wins per row (see docs/passport.md). Bootstrap via the new passport-bootstrap skill.
• Phase 3: Temporal knowledge graph (v2.0) -- Bitemporal columns (valid_from / valid_to / superseded_by) on every memory + entity-resolution dedup (embedding KNN at default 0.85 cosine threshold) + audit trail (memory_audit table with prev/new state hashes) + new actions (entity_search / entity_graph / history) + opt-in KG_AUTO_ENABLED auto-extract on capture. BREAKING for clients that called memory.get expecting historical-inclusive results: pass as_of for time-travel; default now filters to current-state (valid_to IS NULL).

Comparison vs. peers

Feature	mnemo-mcp	Mem0	Letta	OpenMemory
Hybrid retrieval (FTS + vec)	yes (FTS5 + sqlite-vec + RRF)	yes	partial	yes
Cross-encoder rerank chain	yes (qwen3 local + Jina + Cohere)	partial (Cohere only)	no	no
Temporal decay scoring	yes (exp half-life)	no	no	no
Importance boost in rank	yes (LLM 0.0-1.0)	no	no	no
Soft-archive + restore policy	yes (importance x recency)	no	no	no
Self-hostable (single SQLite file)	yes (zero ext deps)	partial (cloud-first)	yes (Postgres)	yes (Postgres + Qdrant)
Multi-provider LLM dispatch	yes (Gemini/OpenAI/Anthropic/xAI auto-detect)	partial	yes	partial
Plugin trinity (skills + hooks)	yes (recall-context + memory-commit)	n/a	n/a	n/a
Multi-machine sync	yes (GDrive bundled OAuth)	yes (cloud)	n/a	n/a
E2E-encrypted passport sync (Phase 2)	yes (AES-256-GCM + Argon2id, S3 + GDrive)	no	no	no
LLM compression on capture (Phase 2)	yes (multi-provider, ~3x at >=0.90 retention)	no	no	no
Backend-pluggable sync architecture	yes (S3 / R2 / B2 / MinIO + GDrive)	no	no	no
Bitemporal valid_from / valid_to queries (Phase 3)	yes (as_of time-travel)	no	partial (events only)	no
Entity resolution via embedding KNN (Phase 3)	yes (cosine threshold tunable)	no	no	no
Audit trail with state hashes (Phase 3)	yes (memory_audit table)	no	no	no

Status

2026-05-02 -- Architecture stabilization update

Past months saw significant churn around credential handling and the daemon-bridge auto-spawn pattern. This caused multi-process races, browser tab spam, and inconsistent setup UX across plugins. As of v, the architecture is stable: 2 clean modes (stdio + HTTP), no daemon-bridge layer, no auto-spawn from stdio.

Apologies for the instability period. If you encountered issues with prior versions, please update to v+ and follow the current setup docs -- most prior workarounds are no longer needed.

Related plugins from the same author:

• wet-mcp -- Web search + content extraction
• imagine-mcp -- Image/video understanding + generation
• better-notion-mcp -- Notion API
• better-email-mcp -- Email management
• better-telegram-mcp -- Telegram
• better-godot-mcp -- Godot Engine
• better-code-review-graph -- Code review knowledge graph

All plugins share the same architecture -- install once, learn pattern transfers.

Documentation

Full docs at mcp.n24q02m.com/servers/mnemo-mcp/:

• Setup -- install methods for Claude Code, Codex, Gemini CLI, Cursor, Windsurf, mcp.json
• Modes overview -- stdio / local-relay / remote-relay / remote-oauth
• Multi-user setup -- per-JWT-sub credential model

Install with AI agent -- paste this to your AI coding agent:

Install MCP server mnemo-mcp following the steps at https://raw.githubusercontent.com/n24q02m/claude-plugins/main/plugins/mnemo-mcp/setup-with-agent.md

Tools

3 MCP tools, 13 memory actions:

Tool	Actions	Description
memory	add, capture, search, list, update, delete, export, import, stats, restore, archived, archive_now, consolidate	Core CRUD + typed capture (6 context_types) + hybrid search (RRF + rerank + temporal decay) + import/export + soft-archive + restore + on-demand archive sweep + LLM consolidation
config	status, sync, set, warmup, setup_sync, setup_status, setup_start, setup_skip, setup_reset, setup_complete, setup_relay	Server status, trigger sync, update settings, pre-download embedding model, authenticate sync provider, manage HTTP setup form lifecycle
help	topic="memory" or topic="config"	Full documentation for any tool

Plugin trinity (Claude Code marketplace install):

Component	Trigger	Purpose
mnemo:recall-context skill	session start, before significant decisions, "what do I know about X?"	Pulls cwd / topic-relevant memories with context_type filtering
mnemo:memory-commit skill	"remember this" / "save this" / "ghi nho" / "luu lai"	Typed manual capture with context_type decision tree
mnemo:knowledge-audit skill	periodic / "audit memory"	Find duplicates, contradictions, stale entries; consolidate
mnemo:session-handoff skill	end of session	Capture decisions / preferences / corrections / conventions / open questions
SessionStart hook	every session init	Non-blocking nudge to invoke recall-context
PostToolUse hook (opt-in)	CAPTURE_AUTO_ENABLED=true	Hint memory-commit after Write/Edit of CLAUDE.md / AGENTS.md / ARCHITECTURE.md / docs/*.md

MCP Resources

URI	Description
mnemo://stats	Database statistics and server status

MCP Prompts

Prompt	Parameters	Description
save_summary	summary	Generate prompt to save a conversation summary as memory
recall_context	topic	Generate prompt to recall relevant memories about a topic

Security

• Graceful fallbacks -- Cloud → Local embedding, no cross-mode fallback
• Sync token security -- OAuth tokens stored at ~/.mnemo-mcp/tokens/ with 600 permissions
• Input validation -- Sync provider, folder, remote validated against allowlists
• Error sanitization -- No credentials in error messages

Build from Source

git clone https://github.com/n24q02m/mnemo-mcp.git
cd mnemo-mcp
uv sync
uv run mnemo-mcp

Trust Model

This plugin implements TC-Local (machine-bound, single trust principal). See mcp-core/docs/TRUST-MODEL.md for full classification.

Mode	Storage	Encryption	Who can read your data?
stdio (default)	~/.mnemo-mcp/config.json	AES-GCM, machine-bound key	Only your OS user (file perm 0600)
HTTP self-host	Same as stdio	Same	Only you (admin = user)

License

MIT -- See LICENSE.