Exocortex

A personal knowledge OS that thinks while you sleep.

Exocortex is a self-hosted reasoning engine for your notes. It ingests what you read, hear, and decide; stores it as an append-only graph (Postgres + pgvector + Apache AGE); and asks an LLM to compile a plain-Markdown wiki from that graph every night. Obsidian, Notion, Telegram, and your shell are surfaces — the brain lives in Postgres.

What it does

• Ingests vault files, mail, RSS feeds, meeting transcripts, and anything you POST to /capture — turning each into typed thoughts and graph edges
• Synthesises the graph on a schedule (default daily) into a compiled Markdown wiki, perspective-typed by domain (client, project, person, news cluster, …)
• Answers questions via GraphRAG — hybrid retrieval over pgvector HNSW + Apache AGE traversal, with provenance-aware ranking and inline citations
• Surfaces contradictions (find_contradictions), open action items, and gaps in your knowledge through an MCP server and a capture API

It is not a notes app, not a search wrapper around your files, and not a chatbot. It is a system that processes your knowledge on its own clock against your data.

When Exocortex makes sense

You probably want Exocortex if:

• You already have a substantial body of personal notes (a few hundred files at minimum) and the volume has stopped being manageable by hand
• You want the system to surface things — contradictions, forgotten notes, knowledge gaps — without you having to ask
• You are comfortable running Postgres in Docker on a small VPS or a homelab, and reading enough YAML to configure a few plugins
• You want plain Markdown as the rendered output, on disk, so any editor (Obsidian, vim, VS Code) keeps working

You probably do not want Exocortex if:

• You are looking for a notes app with sync and a polished mobile UI — Obsidian or Notion are still better at that, and Exocortex treats both as surfaces, not replacements
• You have under a hundred notes and process them by hand without pain — the system's overhead is wasted on small corpora
• You are not comfortable self-hosting; there is no managed version and the license does not allow anyone to offer one

Architecture in one diagram

                      L1 — sources of truth
   ┌─────────────────────────────────────────────────────┐
   │   vault/*.md   ·   email   ·   RSS   ·   meetings   │
   └─────────────────────────────────────────────────────┘
                            │  Capture API (POST /capture)
                            ▼
                      L2 — the graph
   ┌─────────────────────────────────────────────────────┐
   │   thoughts (pgvector)   ─edges (AGE, 35 types)─→    │
   │              syntheses (LLM, on-demand)             │
   └─────────────────────────────────────────────────────┘
              │                              │
      write-time fork                  query-time fork
   (wiki compiler nightly)           (GraphRAG, MCP tools)
              │                              │
              ▼                              ▼
                      L3 — surfaces
   ┌─────────────────────────────────────────────────────┐
   │  Obsidian wiki   ·   Notion   ·   Telegram   ·  CLI │
   └─────────────────────────────────────────────────────┘

The graph (L2) is canonical. Surfaces (L3) are regenerated from it. Edits go to L1; nothing edits L2 directly. See EXOCORTEX.md for the long version.

Quick start (5 min)

Walk through examples/hello-world/ — a self-contained guide that takes you from docker compose up to your first synthesised page in under five minutes, with no plugins and a toy vault.

Examples

• examples/hello-world/ — minimal, no plugins, ~5 min
• examples/acme-corp/ — a fictional company plugin with a custom perspective, MCP tool, and domain compiler in ~150 lines

Documentation

Full docs site: https://exocortex-os.github.io/exocortex/ (also browsable as Markdown under docs/).

• EXOCORTEX.md — design document (motivation, architecture, plugin system, principles, roadmap)
• Writing a plugin — the five extension points end-to-end, walked through the acme-corp example
• Contributing — house rules, where to start, what we won't merge
• plugins/README.md — short version of the plugin contract (registry API, entry points)

License

Apache 2.0 with the Commons Clause — see LICENSE, NOTICE, ATTRIBUTION.md, and docs/legal/license.md for the plain-language version. Short form: use it, modify it, build on it; you cannot resell Exocortex itself or run it as a paid SaaS.