Khoj
A self-hosted second brain
What it is
An AI 'second brain' that indexes your personal corpus — PDFs, Markdown, org-mode, Notion, Word docs — for semantic search and chat. Custom agents with personas and tools, scheduled automations, and clients for browser, Obsidian, Emacs, desktop, and WhatsApp, with local LLMs for zero-cloud operation.
Why it's interesting
One of the few personal-AI-companion projects that is both genuinely open source and battle-tested at scale. The Emacs and org-mode roots give it unusual depth with plain-text knowledge bases, and the agents plus automations turn it from search into a proactive assistant.
Use cases
- Private chat over a lifetime of notes
- A personal research assistant with web plus document grounding
- A self-hosted alternative to ChatGPT-with-memory
Who it's for
PKM enthusiasts, privacy-focused individuals, self-hosters
Setup
Moderate. Docker Compose self-host (Postgres with pgvector), ~8GB RAM baseline, more for local inference; a hosted option exists
Limitations & cautions
The 2.x line is still beta, and the best experience assumes a text-centric knowledge base.
Editorial takeaway
The 'personal AI' most products only promise: your data, your machine, your rules — and it actually ships.