NOTE: To improve organization, Concord has been moved to the Concord Communication GitHub organization.
Open-source, independent, real-time messaging platform inspired by Discord. Here's what it can do:
- Host your own server, on your own hardware (no "cloud" servers). All the server's data is yours; do whatever you want with it, or nothing at all.
- Join someone else's server (with encryption between you and the server).
- Send and receive messages in real time, in different "channels" on a server.
- Send and receive private messages with other server members.
And here's what we have planned for the future:
- Threads: create a spin-off thread of messages from a single source message, to keep the main chat tidy.
- Voice communication, both in channels, and in private messages. The plan is to give all channels a configurable set of capabilities: by default all channels support text messages, but you can add voice chat support, streaming support, and more.
- Comprehensive server permissions system. We want to make it as easy as possible to configure the server's permissions to give admins fine-grained control over what users on their server can do. To this end, we plan on adding roles that can be assigned to particular users to grant them certain permissions.
- Emoji and formatted text support. React to a message with an emoji, and use markdown in your messages.
- File uploads: Allow users on your server to share files with each other as attachments to messages, with a high degree of configurability, so that you can decide how to deal with all the uploaded data.
- Plugins, bots, and automation! We want to make Concord as extensible as possible, so we plan to add first-class support for third-party plugins, and an API for developers to create bots that can participate in a server. We also want to provide admins with utilities for automating tasks without needing to know how to code (like auto-moderation, old data pruning, spam filters, etc.).
- Opt-in discovery services, so that users can find servers without needing an invitation.
Client application is currently work-in-progress.
To start up your own server, download the latest
concord-server.jar JAR file from the releases page and run it with Java (version 16 or higher). The first time you run the server with
java -jar concord-server.jar, it will generate a
server-config.json configuration file, and a
concord-server.db database file.
Configuring the Server
You probably want to customize your server a bit. To do so, first stop your server by typing
stop in the console where you started the server initially. Now you can edit
server-config.json and restart the server once you're done. A description of the attributes is given below:
nameThe name of the server.
descriptionA short description of what this server is for, or who it's run by.
portThe port on which the server accepts client connections.
acceptAllNewClientsWhether to automatically accept any new client that registers to this server. Set to false by default, meaning an administrator needs to approve any pending registration before it is complete.
chatHistoryMaxCountThe maximum amount of chat messages that a client can request from the server at any given time. Decrease this to improve performance.
chatHistoryDefaultCountThe default number of chat messages that are provided to clients when they join a channel, if they don't explicitly request a certain amount. Decrease this to improve performance.
maxMessageLengthThe maximum length of a message. Messages longer than this will be rejected.
channelsContains a list of all channels that the server uses. Each channel has an
description. It is advised that you do not add or remove channels manually! Instead, use the
remove-channelCLI commands that are available while the server is running.
discoveryServersA list of URLs to which this server should send its metadata for publishing. Keep this empty if you don't want your server to be publicly visible.
As mentioned briefly, the server supports a basic command-line-interface with some commands. You can show the commands that are available via the
Each server uses a single Nitrite database to hold messages and other information.