Monolithos
The Personal Agent OS that belongs to you
About Monolithos
Monolithos is a desktop and mobile app that connects your notes, files and AI work into one memory you own, as the starting point for what the company calls a Personal Agent OS. Instead of re-introducing yourself to an AI chat every session, you work from a local vault of Markdown and YAML files, and the AI answers from your own materials and preferences. The vault is plain text you can open in any editor, and Monolithos opens existing Obsidian vaults natively with no import or conversion.
The current release (v1.0.2) runs on macOS, Windows and iOS, with an interface in English, Simplified Chinese, Traditional Chinese, Japanese and Korean. Eight modules share the same vault, covering memory and recall, multi-step AI tasks, writing, meeting notes, slide decks, audio briefs and an image library. The site is explicit that the full agent experience (goals carried over time, work that continues while you are away) is still in development and that release notes define what is available today. Pricing is a 7-day trial followed by monthly or yearly plans, plus a limited lifetime seat.
You install the app on Mac, Windows or iPhone and point it at a vault, either a new one or an Obsidian vault you already have. Monolithos reads that Markdown and builds memory from it; a component the site calls the Watcher proposes memory changes and waits for your confirmation, and recall shows the sources an answer was based on.
From there you work through the modules. Chat and Deep Research sessions draw on your vault, Flow runs multi-step AI tasks that pause for your judgment at consequential steps, and outputs such as documents, decks and audio briefs are saved back into the vault. A folder you mark as the Private Domain is never sent into cloud AI context, and Projects bind a selected set of sources so long tasks cannot pull in unrelated material.
- •User-owned memory - Memory lives in Markdown and YAML on your device; traits can be traced, adjusted and removed, and files stay readable if you cancel.
- •Obsidian compatibility - Opens any Obsidian vault with the same Markdown, tags and links, so both apps can work on the same files.
- •Flow - Multi-step AI tasks for research, writing and finished work, with steps that need your judgment pausing for approval.
- •Minutes - Meeting capture with on-device transcription; summaries and live insights send transcript text (not audio) to cloud AI.
- •Prism and Audio - Prism turns Markdown into presentation decks and Audio turns your notes into a podcast-style brief.
- •Private Domain and Projects - Folder boundaries that cloud recall, chat and crystallization cannot cross, plus project scopes that snapshot their sources.
Monolithos is aimed at people who keep a long-term personal knowledge base, especially Obsidian users who want AI recall and writing over their existing vault without migrating it. Researchers and writers can use it to move from sources to notes, decks and audio while keeping provenance, and professionals handling sensitive material can keep a Private Domain out of cloud AI. It also suits anyone who wants their AI context to stay portable across model changes rather than locked inside one chat provider.
Pricing
$39 - $89/mo
- The Core$39/mo
- The Max$89/mo
- The Founder$999 once
From the vendor pricing page, 2026-10-15
