📝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. 📝Heptabase's homepage calls it "An intelligent visual knowledge base for anyone who wants to understand and create knowledge, not just collect it." They split on the working surface: Heptabase breaks sources into cards on whiteboards, while MythOS links memos that can be published, shared and handed to AI agents over 📝MCP.
At a Glance
Sources and Structure
Heptabase's homepage tells users to "Break any source into cards, by hand or with AI, then read deeper through every citation," with supported sources including PDFs, web pages, YouTube videos, podcasts, Readwise and Zotero. It then says to "Use nested tags and properties to give your worldview a structure, then rework it as you learn." Its essentials include bi-directional links, daily journals, a web clipper, offline access and real-time collaboration. In MythOS the unit is the memo. Typing @ draws a mention to another memo, and every mention becomes a 📝backlink that the 📝Graph uses to map the library as a 📝knowledge graph. Each day gets a 📝Daily Memo, MythOS's form of the 📝daily note. Every memo carries its own visibility, public, unlisted, hidden or private, and Version History keeps 13 months of restorable edits.
AI and Agent Access
Heptabase's help center states that "Heptabase MCP (Model Context Protocol) lets AI assistants work with your Heptabase space." The server sits at api.heptabase.com/mcp with OAuth, and the article covers ChatGPT, 📝Claude Code, Cursor, Antigravity CLI and Grok. A connected assistant can "search by keyword or by meaning," "create and edit note cards and journals" and "create whiteboards, sections, connections, and mind maps." MCP requires a Pro, Premium or Premium+ subscription or an active free trial. The plugin page adds: "With the Heptabase plugin, your AI agent can manage your knowledge base and create explainer videos from any source." The pricing page lists "AI agent (Gemini models only)" on Pro and "AI agent (GPT, Claude, Gemini)" plus an AI tutor on Premium. MythOS exposes a library through one endpoint, mythos.one/api/mcp. 📝Claude on the web, desktop, iOS and Android signs in over OAuth, and 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 states that no plan includes AI credits.
Who Each Is For
Heptabase's pricing page describes Pro as "For anyone building a lifelong knowledge base" and Premium as "For learners and researchers who need extra AI credits at a lower cost." 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": the 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
- 📝Heptabase — reference memo on the visual knowledge base
- 📝MythOS vs Logseq — MythOS compared with an open-source outliner
- 📝Bidirectional Links / Backlinks — reference memo on the linking model behind mentions and bi-directional links