ChainMemory
Mem0
Agentmemory
Memori
Tempreon
cognee
TheSecondBrain.dev
Suprflo
KeepZen
Obsidian.md
Evernote
Notion
Bear
Apple Notes
Notepad++
Keep My Notes
ChainMemory gives your AI agents persistent memory that belongs to YOU โ not to a single vendor.
Save a memory in ChatGPT, recall it in Claude or Gemini. Available via Chrome extension, MCP server (npm), or REST API. Every memory gets a cryptographic fingerprint and project states are anchored with Merkle proofs, so anyone can independently verify integrity โ no trust required.
Memories consolidate into a structured Project Brain (decisions, milestones, risks) instead of a pile of raw notes. Multi-agent native: Claude, Cursor and GPT share one consolidated state. Free tier available.
KeepZen - note-taking app for people who spend more time writing than organizing. No blocks, no databases, no noise. Just you and your thoughts.
Come back to clean writing. KeepZen removes the noise and leaves just you and your thoughts โ no complex setup, no tracking, just your words in calm, clear order.
Your notes are encrypted in your browser with your passphrase. The key never leaves your device โ we never see it, and we never store it. When you use sync, only encrypted data is sent to our servers. We cannot read your notes.
Zero-knowledge by design.
Start keeping your thoughts safe. No account required to get started. Your data stays with you. Optional sync when you're ready.
ChainMemory KeepZenKeepZen's answer:
KeepZen is built for those who refuse to choose between convenience and privacy. While mainstream tools scan your notes for AI training and "privacy-first" alternatives often require complex manual setup to sync, KeepZen offers a "Third Way." You get absolute end-to-end encryption (E2EE) and seamless multi-device sync out of the box. Itโs the only tool that feels as simple as a notepad but is as secure as a digital vault.
KeepZen's answer:
KeepZen occupies the "Goldilocks zone" of note-taking. It is zero-config private: you get the absolute security of end-to-end encryption (E2EE) and the speed of local-first architecture without having to set up a server or manage complex plugins. Itโs a professional-grade vault that feels as simple as a piece of paper.
KeepZen's answer:
Our users are "Digital Minimalists"โwriters, researchers, and creators who find themselves overwhelmed by the "noise" of modern productivity tools. They are individuals who value their intellectual privacy and want a sanctuary where they can think without being tracked, scanned, or interrupted by AI assistants.
KeepZen's answer:
KeepZen was born from a moment of frustration. I opened a popular note-taking app to capture a fleeting, personal thought, only to be met by a loading spinner and a popup for a new AI feature. The realization was immediate: our digital "private" spaces had become crowded and loud. KeepZen was built to reclaim that silenceโcreating a tool that stays out of your way and keeps your data truly yours.
KeepZen's answer:
Mem0 - Your private, local memory layer for all AI tools
Obsidian.md - A second brain, for you, forever. Obsidian is a powerful knowledge base that works on top of a local folder of plain text Markdown files.
Agentmemory - Persistent memory for Claude Code, Codex & coding agents
Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Memori - Persistent memory from agent trace, not just conversation
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.