📝MythOS describes itself as a networked knowledge platform where every idea, person, project and decision lives as a linked memo in a library you own. 📝Capacities' homepage says it "turns your ideas into connected objects, not files buried in folders." They split on structure: MythOS links memos by mention and files them by tag, while Capacities organizes ideas as objects of types the user creates, and its homepage says "Objects have structure. They have properties."
At a Glance
Structure and Linking
Capacities' homepage tells users to "Create the object types you need as you go." It adds "Link anything to anything" and says "Backlinks show you every connection at a glance." Its 📝daily note is framed simply: "Your daily note is your inbox." In MythOS the unit is the memo. Typing @ draws a mention to another memo, and typing # adds a tag that files it into a collection. Every mention becomes a 📝backlink, which is how the 📝Graph maps the library's 📝knowledge graph. Each day gets a 📝Daily Memo with a Tasks checklist and a Timeline.
Storage, Sync and Privacy
Capacities' pricing page lists "Synchronization across all devices," "Offline support" and "Full support for import and export" on Capacities Basic. Its homepage states "Data stored in certified EU data centers." Its documentation says "Capacities is not end-to-end encrypted, and that is a deliberate choice," and explains that "end-to-end encryption and cloud AI cannot both apply to the same note" (see 📝Sync / End-to-End Encryption). In MythOS, every memo carries its own visibility (public, unlisted, hidden or private), so private reflection and public writing live in the same library.
AI and Agent Access
MythOS exposes a library to any 📝MCP client through one endpoint, mythos.one/api/mcp. 📝Claude on the web, desktop, iOS and Android signs in over OAuth, and 📝Cursor connects by OAuth or an API key, which comes with Scholar and above. A connected client gets 60 tools for search, memo writes, templates, tasks and the daily journal, with four identity memos (Soul, Style, Human and Memory) loaded before it writes. Chat inside MythOS runs on six model providers, on a MythOS-funded balance or the user's own key; its Plans & Tiers memo says no plan includes AI credits. Capacities' developer page gives its MCP server as api.capacities.io/mcp and says "Any client that speaks MCP over HTTP can connect." Its pricing page lists "AI Chat Connectors for ChatGPT, Claude, and Cursor" and a Public API on Capacities Pro and Capacities Believer. The built-in AI assistant carries a light monthly budget on those plans and is not included on Capacities Basic.
Who Each Is For
Capacities' homepage says "We build for individuals who think for a living," naming "Writers, researchers, students, developers, and founders." MythOS's own overview says one library serves "private thinking, team collaboration, public writing, and the AI tools you work with." Its Plans & Tiers memo states that "writing is never the thing you pay for": its Free, Scribe, Scholar and Oracle plans sell reach, such as public publishing and agent access.
Related
- 📝MemPalace vs Obsidian vs MythOS as Claude Memory — the hub comparing MythOS with other memory systems
- 📝Capacities — reference memo on the object-based note-taking app
- 📝MythOS vs Tana — another tool that turns notes into typed objects, compared with MythOS
- 📝MythOS vs Logseq — MythOS compared with a block-based outliner