"Google Cloud Spanner" matching MCP servers:

The Universal Cross-Model Episodic Memory Standard. Local-first, project-scoped SQLite memory engine for Google Antigravity, Claude Code, Cursor, Windsurf, and Codex. Zero cloud lock-in.

MCP server that connects any AI to your Obsidian vault. Save articles from your phone, search across notes, build a compounding knowledge base. 15 tools, three transport modes (stdio, HTTP, cloud), zero-install Google Drive OAuth onboarding.

Privacy-first local document search using semantic search. Runs entirely on your machine with no cloud services, supporting PDF, DOCX, TXT, and Markdown files.

Captures ideas from conversations and organizes them into a persistent, hierarchical mindmap. Supports search, deduplication, export, import, and cloud sync.

Enables searching Google Scholar with Scholar operators, year ranges, cited-by and all-versions lookups, and retrieving citations in five styles with BibTeX and EndNote export links as structured JSON.

MCP server that gives Claude Code and other MCP clients persistent memory using plain Markdown notes stored on your disk and optionally synced to cloud storage (iCloud, OneDrive, Google Drive, Dropbox).

Persistent, local, cross-IDE memory for AI agents — markdown source of truth, LanceDB-powered semantic search, zero cloud dependency

Local-first MCP server for governed AI memory where agents propose memories and humans approve them, with optional cloud sync.

Enables natural language tracking and exploration of books, movies/TV, quotes, podcasts, and personalized recommendations, using Google Cloud Firestore as a private, intelligent entertainment memory and AI curator.

Provides AI agents and teams with self-hosted adaptive memory, combining hybrid search and a self-improving neural memory graph to enable precise recall and serendipitous discovery across MCP-compatible clients.

Persistent memory MCP server for Claude Code — self-hosted, n8n + PostgreSQL + pgvector. Team memory for AI agents with multi-user roles, multi-project namespacing, and hybrid vector + keyword search. No cloud required.

Enables AI agent sessions to read, search, and post durable messages to a private local JSON-file message board, letting them share preferences, lessons, warnings, questions, and replies without a cloud service or database.

Wctx is an MCP server that captures structured, evidence-backed context from completed coding agent sessions and serves it to future sessions, enabling cross-repository knowledge reuse without cloud dependencies or embeddings.

Privacy-first personal knowledge database for your AI that ingests data exports (Google Takeout first) and exposes them via MCP tools like search and list items. Runs locally with no cloud or telemetry.

Secure MCP server for querying Google NotebookLM notebooks. Enables AI assistants to list notebooks, read sources, and ask the NotebookLM AI questions about your sources.

Provides persistent memory, cryptographic audit trail, and HMAC-verified skill admission for Claude Code, running locally on PostgreSQL with zero cloud sync.

A cloud-based vector memory service that provides AI assistants with persistent storage, semantic search, and entity management via the Model Context Protocol. It features multi-tenant isolation and bidirectional synchronization with macOS and Google contacts and calendars.

Bridges TiMEM's cloud MCP server with DeepSeek Harness to provide long-term memory tools and automatic memory skills for AI models, enabling persistent context and learned behaviors across conversations.

A minimal, tag-free personal memory system that syncs across all Claude interfaces (mobile, web, desktop, Claude Code). Built on Cloudflare's edge stack for zero-maintenance serverless operation.

Local semantic search MCP server for markdown docs and Granola meeting transcripts that runs entirely on your machine with no API keys, no cloud, and no cost.