Legion
Peer-to-peer · Open source

Your devices, working together for you.

Legion is a network of your own devices that cooperate to do real work — while your data stays entirely under your control. No backend. No cloud. No company in the middle.

Start reading →See a day in the life

A day in the life of Legion

There is no “backend”. You are the cloud.

Just a collection of devices you own — or rent, on your terms — that form a group called a cohort and cooperate using peer-to-peer rules to process speech, run AI models, store data and display apps.

The old model

  • One server does everything
  • Data lives on company servers
  • If the server dies, you're stuck
  • You trust the company with your data
  • “Sorry, our service is discontinued”

The Legion model

  • Many small devices each do a little
  • Data stays on your devices
  • If one device dies, others pick up
  • You control who sees your data
  • Your network works forever

Choose your path

Read it your way.

These pages are a book with several entrances. Pick the one that fits how you like to learn — you can always jump between them.

AShow me the storyThe big picture, a full day-in-the-life example, and the core ideas.Start the story →BI need the detailsEvery part of the system — nodes, networking, identity, consensus.Explore the parts →CI want to buildDeploy the platform, write apps in TypeScript, and design for any screen.Start building →DUnder the hoodThe complete architecture map, layer by layer, with the code layout.Go deep →

Why it feels different

Your devices should work for you, not for a company.

Your data stays yours

No company server in the middle. Your data lives on devices you control — full stop.

No single point of failure

If one device dies, others pick up. Your network works as long as you have devices.

Four layers of privacy

Data flows outward from private to public — never inward without your explicit permission.

No passwords, ever

Your identity is 12 words you write on paper. No email, no sign-in, no company to trust.

Works offline

On one local network with no internet, discovery, consensus and AI all keep working.

One brain, many faces

Your assistant lives on the network, not a device. Switch phone to laptop mid-sentence.

The full guide

Eleven chapters, plain English.

From the first big idea to the deepest layer of the architecture — no jargon left unexplained.

01What is Legion?The big picture: peer-to-peer, your data, your control — and the four layers of privacy.02A day in the life of LegionA complete story: from your phone on day zero to a full personal network with remote access.03The big ideasFive principles that guide every design choice in Legion.04The building blocksNodes, capabilities, cohorts, modules and the plugin system — the pieces everything is made of.05How nodes talkDiscovery, seed nodes, gossip, bridges and the messaging that connects devices across the world.06Who is who?Identity without passwords: master seeds, DIDs, certificates, pairing and recovery.07How agreement happensConsensus, epochs, trust scores and Byzantine fault tolerance — agreement without a boss.08Running the platformDeployment: your own devices, rented slots, providers and every common setup.09Building appsWriting Legion apps in TypeScript: the API, distribution, permissions and handoff.10The screenThree rendering tiers, from microcontrollers to phones — one app, any device.11Under the hoodThe full architecture map: twelve layers, the code layout and a request's complete journey.

Your devices. Your rules.

Legion is being built as open source — every specification will be made public, and anyone can contribute. Start with the big picture, or dive straight into the architecture.

What is Legion? →Browse the glossary