"What's the best memory system for 📝Claude?" is one of the most-asked questions in AI-builder communities — and the three most common answers are 📝MemPalace, 📝Obsidian, and 📝MythOS. Each solves a different slice of the problem.

MemPalace is an automated memory backend that stores conversations verbatim and makes them semantically searchable. Obsidian is a Markdown note-taking app that users have retrofitted as a memory system via 📝MCP plugins. MythOS is an AI-native knowledge platform designed from day one for human-AI collaboration, with an identity layer, permission model, and cross-client MCP distribution. Picking between them is not a matter of which is "better" in the abstract; it is a question of which gap in a given workflow most needs filling — capture, curation, or augmentation-by-design.

The Three Architectures

MemPalace is a capture-first system. It mines chat logs (Claude Code, Claude.ai, ChatGPT, Slack, plain text), stores everything verbatim in ChromaDB, and exposes a 19-tool MCP server for semantic retrieval. The philosophy is "never lose information" — no LLM extraction, no summarization, just a faithful record with tiered context loading that fits in about 170 tokens at wake-up. Best at retrieval over raw conversation history. Weakest at producing artifacts a human wants to read.
Obsidian is a curation-first system. The user writes notes in Markdown files, connects them with wikilinks, and exposes the vault to Claude through one of several community MCP servers. There is no automatic capture — every memory exists because a human chose to write it down. Best at hand-authored knowledge with a 1,800-plugin ecosystem. Weakest at scaling past a few hundred notes and at context efficiency; MCP servers typically dump full files into the prompt.
MythOS is an augmentation-first system. Memos are structured artifacts with an Objective / Subjective / Contexts template, a living identity layer (Soul, Style, Human, Memory) loaded automatically at every session, three-tier visibility with audience tags, and RAG-powered retrieval via chat_with_library. Best at making an AI identity-aware, permission-aware, and cross-client by default. Weakest at verbatim preservation of raw session transcripts — MythOS captures decisions and artifacts, not every word.

What Each Actually Solves

MemPalace solves "I want Claude to remember what we already said" — raw session continuity, verbatim recall, and temporal reasoning about when a fact was true.
Obsidian solves "I want Claude to read my written notes" — turning a personal knowledge vault into AI-accessible context.
MythOS solves "I want Claude to know who I am and work from my structured knowledge" — identity-aware augmentation, curated artifacts, and cross-device continuity.

When to Pick Each

Pick MemPalace if the bottleneck is losing conversation history between sessions and the goal is zero-friction automatic capture. The right answer when the thing you would most hate to lose is the transcript.
Pick Obsidian if you already have a Markdown note-taking habit and you want Claude to read those notes without changing your workflow. The right answer when what matters is what you already wrote.
Pick MythOS if you want an AI that knows your collaboration values, communication style, and current context without manual prompting — across Claude.ai, 📝Claude Code, 📝Cursor, and any MCP client. The right answer when what matters is that the AI is aligned with how you think.

Many builders run more than one. MemPalace + MythOS is a common pattern: verbatim capture at one layer, curated knowledge at another. Obsidian + MythOS is rarer but viable for users deeply invested in Markdown workflows.

Pairwise Comparisons

📝MemPalace vs Obsidian — side-by-side of the two non-MythOS options
📝MemPalace vs MythOS — verbatim backend vs. curated knowledge platform
📝Obsidian vs MythOS as Claude Memory — Markdown vault vs. AI-native knowledge

FAQ

Can I use more than one?

Yes. All three expose MCP servers, so Claude can call into MemPalace, Obsidian, and MythOS in the same conversation. They answer different questions and do not conflict — MemPalace gives you "what did we say?", Obsidian gives you "what did I write?", MythOS gives you "what do I know, and who am I?"

Which one is most beginner-friendly?

Obsidian — open a folder, start writing. MythOS is next: account signup, browser-based editor. MemPalace requires Python and ChromaDB comfort, plus MCP configuration.

Which one scales best past 1,000 memories?

MythOS and MemPalace both. MythOS uses 📝RAG with vector embeddings; MemPalace uses ChromaDB directly. Obsidian's MCP servers typically degrade past a few hundred notes because they dump files into context.

Which one is best for cross-device use?

MythOS — web, mobile apps, CLI, and any MCP-compatible client via OAuth or API key. MemPalace is local-first; Obsidian's MCP integration is desktop-only.

Which one is best for team or shared knowledge?

MythOS — three-tier visibility, communities, and a social layer. MemPalace is fundamentally single-user. Obsidian has external add-ons (Publish, Sync) but they were not built for AI collaboration.

📝MCP vs RAG — the retrieval-strategy lens underlying these architectures
📝Karpathy's Flag in the Ground — LLM Knowledge Bases — the "LLM Knowledge Base" pattern that frames this category
📝The Augmentation Stack — MythOS's framework for memory, mind, and mouth

I built MythOS because neither a verbatim backend nor a Markdown vault gave me what I actually needed: an AI that knows who I am, works from my structured knowledge, respects my permission model, and follows me across every client and device without re-explaining anything. MemPalace and Obsidian are excellent tools — I recommend them without hesitation for the problems they solve best. They were never going to be MythOS because they are solving different problems. The right question for a given builder is not "which is best?" but "which layer am I missing?" Capture, curation, or augmentation — the answer tells you which one to install first.