Documentation
Everything Concord does, and how.
Peer-to-peer, end-to-end encrypted group chat. This manual covers installing it on every platform, guilds and direct messages, calls, devices and backups, what is private and from whom, and running the optional rendezvous.
Start here
Getting startedHow to install Concord on each platform, create your identity on first run, start or join a guild, and check that other people can reach you.Accounts and identityWhat "an account" means in Concord: a key pair you hold rather than a record on a server, the passphrase that protects it on each device, the recovery phrase that can rebuild it, and the profile other people see.Multiple devicesHow to use one account on several devices: linking a new device with a QR code, what it receives and what stays separate afterwards, and how to remove a device you no longer use or no longer have.Backups and recoveryWhat can be recovered if you lose a device or forget your passphrase, and how: the recovery phrase for your identity, linked devices and backup files for your history, and Markdown export for a readable copy.
Talking
Guilds and channelsHow to create a guild, invite people and join one, organize channels and categories, and use messages, threads, polls and events. It also covers leaving a guild, handing it over, and importing an older community's history.Roles and permissionsHow a guild decides who may do what: the owner, named roles, the seven permissions a role can grant, and the rank rules that stop anyone granting themselves more power than they have.Forum boardsA forum channel is a board of posts, each with its own title and thread of replies. This page covers writing posts, tags, answered and closed posts, and sorting, filtering and laying out a board.Direct messagesPrivate conversations outside any guild: one-to-one messages, group DMs, your own Notes, message requests from people you do not know, and how messages reach someone who is offline.Files and mediaHow images, videos, voice messages and other files are sent, encrypted and fetched, along with custom emoji, the guild GIF pack, doodles, memes, sounds, and what link previews reach out to.SearchHow to search your messages: what the search covers, the filters you can type, and the limits of a search that runs entirely on your own device.Voice and videoHow to talk, turn on a camera and share your screen in voice channels, direct-message calls and meetings, how to set up your microphone and push-to-talk, and how calls connect: directly between participants, or through a relay that hides your IP address.NotificationsHow Concord tells you something happened: notification levels for each guild and channel, mentions, alert words, sounds, desktop and Android notifications, the Android Stay connected service, and optional push wakes.
Safety
Moderation and safetyThe tools for keeping yourself and a guild safe: blocking, message requests, reporting, muting and removing members, deleting messages, invites, and how a guild governs itself without a server.Privacy and encryptionWhat Concord encrypts, who can see what, what a rendezvous node learns, and what stays unprotected, in plain language. The formal policy is PRIVACY.md; the engineering detail is DESIGN.md, especially §13 Threat model.
Making it yours
Settings and themesWhat is in Settings and where to find it, with a closer look at Appearance: themes, theme packs, effects, color, shape, font and density.Keyboard shortcutsEvery keyboard shortcut in the desktop app, the Markdown you can type in a message, and the slash commands. Press ? or Ctrl+/ in the app to see the same list.BotsHow to write a bot for Concord: run the headless concord --bot and drive it with newline-delimited JSON from any language.Running a rendezvousHow to decide whether your group needs a rendezvous node, and how to run one locally, with Docker, on a VPS or on fly.io.
Help
TroubleshootingWhat to do when peers cannot reach each other, messages do not arrive, a call has no sound, or the app will not open or unlock, and where to look for diagnostics.FAQShort answers to the questions people ask first about Concord: servers, data, recovery, offline delivery, bots and security.
Developers
ArchitectureHow Concord's code is layered, from the Svelte UI down through the Go core to the network, and how the same core is packaged as a desktop window, a browser-served binary, a phone app and a headless client.Protocol and data modelThe libp2p protocols Concord speaks, what travels on each, how peers catch up on history, and how a peer stores what it has seen. DESIGN.md has the reasoning; this page is the map.Building from sourceHow to build each Concord binary from a checkout: the browser-served build, the desktop window, the headless client, the rendezvous node, the Android and iOS apps, and the Windows cross-build.TestingThe checks a change has to pass, exactly as CI runs them, and the slower suites and harnesses for what the gate does not cover: the network integration tests, local multi-peer runs, and the browser end-to-end scripts.ContributingConcord is a peer-to-peer, end-to-end-encrypted chat app: a Go core (identity, MLS, libp2p, storage) with a Svelte UI that the same core serves either into a browser or into a native desktop window.ReleasingEverything a maintainer needs that a user does not: building each front end from source, running a handful of peers side by side, standing up your own rendezvous node, and cutting a signed release.Design in depthConcord is a peer-to-peer group chat, voice and video application: a Go core with a Svelte front end, shipped as one binary. There is no company, no account database, and no server that stores your messages. Every guild ("server") is a cryptographic group, every message is end-to-end encrypted, and the one piece of infrastructure it can use is untrusted by construction.Push wakesConcord delivers messages over live connections. When the app is open, or backgrounded with "Stay connected" on, nothing here is needed — the node holds its connections and gossip arrives instantly. When the app has been closed, or Android has reclaimed the process, a message deposited for you sits in a rendezvous mailbox until you next open Concord.