SecondBrain · Guides · MCP memory server
What is an MCP memory server?
How an MCP memory server works, in plain English
Think of MCP as a universal plug for AI assistants. An MCP server offers a small set of tools, and any connected assistant can call them mid-conversation. A memory server typically offers tools like save, search and update. When you tell Claude "remember that my parking spot is 4B", Claude calls the save tool; when you later ask ChatGPT "where did I park?", ChatGPT calls the search tool against the same server and finds the answer.
Three properties make this powerful:
- It is assistant-agnostic. One memory serves Claude, ChatGPT, Gemini, Cursor and Claude Code at the same time, because they all speak the same protocol.
- It survives everything. New chat, new device, new assistant: the memory is external, so nothing resets it.
- You own the boundary. The server decides what is exposed. A good memory server isolates your account, encrypts data and lets you delete everything.
The main MCP memory options in 2026
| Option | Made for | How memories get in | Hosting | Open source |
|---|---|---|---|---|
| SecondBrain | Everyday users: one personal memory across assistants | Voice or text on iPhone, Android and web, plus assistants saving mid-chat | Managed, EU-hosted, sign in with Apple or Google | Plugin and connector public on GitHub |
| OpenMemory (Mem0) | Developers wanting a local-first memory layer | Assistants and apps via API and MCP | Self-hosted, local by default | Yes |
| Basic Memory | Markdown and Obsidian users | Assistants write local Markdown notes over MCP | Self-hosted, local files | Yes |
| Zep | Production AI agents in software products | Application events and conversations via API | Cloud or self-hosted | Core open source |
| Supermemory | Developers and coding agents | API, integrations and MCP | Cloud | Partly |
| Reference memory server | Trying MCP memory locally | Assistant tool calls into a local knowledge graph | Self-hosted, runs on your machine | Yes (Model Context Protocol project) |
Managed or self-hosted?
Pick managed if you are not going to run servers for fun. A managed memory like SecondBrain takes about two minutes to connect, works from your phone, keeps everything synced, and needs no API keys: you sign in with Apple or Google. The trade-off is that it is a hosted service with a Pro subscription for the shared memory layer.
Pick self-hosted if you are technical and want full control of storage. Basic Memory keeps everything in local Markdown you can open in Obsidian; OpenMemory gives developers a programmable local memory layer. The trade-offs are setup and maintenance, typing-first capture, and wiring each assistant yourself.
If your goal is specifically one memory shared between ChatGPT and Claude, the step-by-step setup is in how to share one memory between ChatGPT and Claude.
Questions people ask
Is MCP an open standard?
Yes. The Model Context Protocol was introduced by Anthropic in November 2024 as an open standard and has since been adopted well beyond Claude, including by OpenAI and Google. Any assistant that speaks MCP can connect to any MCP server, which is why one memory server can serve several different assistants.
Do MCP memory servers work with ChatGPT?
Yes. ChatGPT supports connecting to remote MCP servers through connectors, and desktop AI tools like Cursor and Claude Code support MCP natively. Managed services simplify the wiring: with SecondBrain you run npx secondbrain-connect once, sign in, and ChatGPT, Gemini and Cursor reach the same memory as Claude.
Can I self-host an MCP memory server?
Yes. Open-source options such as Basic Memory, OpenMemory by Mem0 and the reference memory server from the Model Context Protocol project can run on your own machine. You handle installation, storage and updates, and capture is typing-first. Managed options like SecondBrain trade self-hosting for a two-minute setup, phone capture and synced hosting.
What is the difference between MCP memory and ChatGPT's memory?
ChatGPT's built-in memory is owned by one vendor and works only inside ChatGPT. An MCP memory lives outside any single assistant: Claude, ChatGPT, Gemini and your coding tools can all read and write it. You keep one set of facts, and switching assistants no longer means losing what they know about you.
The managed one, with voice
SecondBrain is an MCP memory you can talk to. Free on iPhone, Android and the web.