Cairn
An offline-first knowledge and education server: Wikipedia, courses, maps, local AI and RAG, with the internet unplugged.
- Status:
- Active
- Stack
- 7
- Architecture notes
- 6
Overview
A self-contained knowledge and education server, built as a derivative of Crosstalk Solutions' Project NOMAD under Apache-2.0 and rebranded so none of the upstream marks are reused. A management UI called the Command Center installs, configures and updates a set of containerised tools — offline Wikipedia and reference libraries through Kiwix, Khan Academy courses through Kolibri, regional maps through ProtoMaps, a data workbench through CyberChef, local notes, and a local AI chat with document upload and semantic search over Ollama and Qdrant. An internet connection is needed only during install and when you choose to pull new content; after that there is zero telemetry and nothing leaves the box.
Architecture Breakdown
How it works
Core mechanics, failure recovery paths, and system design decisions.
- 01
Command Center over Docker
A management UI and API orchestrate every tool as its own container, handling install, configuration and updates so a deployment is one script rather than a dozen compose files. A Debian-based host is the only requirement; no desktop environment, everything is reached through the browser.
- 02
Offline by construction
Connectivity is tested against 1.1.1.1 first and falls back to endpoints the app already contacts, so a network that blocks Cloudflare is not misread as offline. The check endpoint is overridable by env var or from the UI, and the whole stack runs with the link down.
- 03
Local AI with retrieval
Chat runs against a local Ollama model or any OpenAI-compatible server such as LM Studio, with uploaded documents chunked into Qdrant for semantic search. The model can also be pointed at a separate GPU host without moving the rest of the stack.
- 04
Supply Depot
A one-click catalogue of extra apps — PDF tools, file browser, e-book library, password manager — plus a path to run your own custom containers alongside the managed ones.
- 05
Auto-updates with a dry run
Opt-in updates install only minor and patch versions of the Command Center, inside a configurable window, after a cool-off, and only when pre-flight disk and queue checks pass. An Ace command runs the entire decision pipeline — window wrap, cool-off, prerelease, disk — without ever triggering an update, and the deterministic scenario suite is safe to wire into CI.
- 06
Open by default
There is no authentication: Cairn is meant to be reached without hurdles on a trusted LAN, and access is controlled at the network layer. It is explicitly not built to face the internet.
Key Takeaways
Engineering Highlights
- Runs with the internet unplugged — install and content downloads are the only online steps
- Zero built-in telemetry; nothing is sent anywhere at runtime
- Connectivity check falls back past a blocked 1.1.1.1 instead of declaring the box offline
- Auto-update logic has a full dry-run mode and a deterministic scenario suite for CI
- Derivative of Project NOMAD (Apache-2.0), with upstream names, domains and services removed per §6
Honest aboutscope: no auth by design, and not intended to be exposed to the internet
Stack & Tools
- Docker
- Kiwix
- Ollama
- Qdrant
- Kolibri
- ProtoMaps
- Node.js