RemnantChat

RemnantChat is a free (as in both price and freedom) communication tool. Designed to be the simplest way to connect with others privately and securely, it is:

• Fully open source (licensed under GPL v2)
• Peer-to-peer
  • Whenever possible, otherwise a TURN server is used to ensure reliable peer connection
• End-to-end encrypted (via WebRTC)
• Ephemeral
  • Message content is never persisted to disk on either the client or server
• Decentralized
  • There is no API server. All that's required for RemnantChat to function is availability of GitHub for static assets, and public WebTorrent and STUN/TURN relay servers for establishing peer-to-peer communication.
• Embeddable
• Self-hostable

RemnantChat uses the Create React App toolchain. The secure networking and streaming magic would not be possible without Trystero. File transfer functionality is powered by secure-file-transfer.

Status

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How to use it

Open https://RemnantChat.im/ and join a room to start chatting with anyone else who is in the room. By default, room names are random UUIDs that are generated client-side. To privately communicate with someone, it is recommended to join one of these randomly-generated rooms and share the URL (via the "🔗" button at the top of the page) to whomever you wish to communicate with via a secure medium of your choosing (such as Burner Note or Yopass). Your user name will be presented to you, and it would be good to share that with who you will be chatting with beforehand so they know they're talking to you.

Features

• Multiple peers per room (limited only by the number of peer connections your browser supports).
• Public and private rooms.
• Video and audio chatting.
• Screen sharing.
• File sharing:
  • Unlimited file size transfers.
  • Files are encrypted prior to sending and decrypted by the receiver (the key is the room name).
• Embedding into other web apps via iframe.
• Markdown support via react-markdown.
  • Includes support for syntax highlighting of code.
• Conversation backfilling from peers when a new participant joins.
• Multiline message support (hold shift and press enter).
• Dark and light themes.
• Automatic peer verification via client-side public-key cryptography.

Anti-features

• Messages are never persisted to disk. When you leave a peer room, messages are cleared from memory and cannot be retrieved.
• RemnantChat is an entirely client-side communication app. It uses public WebTorrent servers to establish peer connections and STUN/TURN relay servers when direct peer-to-peer connections cannot be established, but there is no RemnantChat API server.
• No analytics, tracking, or telemetry of any kind.
• This is a community-driven and unfunded project that makes no money. The users come first and there is no corporate influence or financial interest involved.

Why another chat app?

There is no shortage of user-friendly chat apps available, but they rely on a central service to facilitate communication. It is difficult to trust these central services, as commercial interests and government pressure can compel service operators to work against the best interest of the users. Even when user data is handled in good faith by service operators, the possibility remains that encrypted data held at rest may be decrypted against the user's will.

RemnantChat designs around these risks with a web meshe architecture. There is no central service operator that stores or potentially mishandles communication data. Some services are required to establish an initial connection between peers, but otherwise the app uses direct peer-to-peer communication for everything. Any services that are used by RemnantChat have no association with the project and are publicly available for all to use.

Use cases

RemnantChat offers a private and secure solution for:

• Organizing groups of people, such as unions or political movements
• Conveniently moving text or data from one device to another
• Video chatting with friends and family across operating systems (such as Android and iOS)
• IT troubleshooting via screen sharing
• Livestreaming
• Sharing sensitive information such as passwords
• Much more!

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Note from the developer

💻️ Project status

I consider RemnantChat feature-complete inasmuch it does all the things I personally need it to do. I don't have specific plans to add significant functionality in the future, but I may do so if it seems fun to me at the time. I am committed to fixing any significant bugs that are reported, so please open an issue if you discover one! Aside from that, RemnantChat is effectively in maintenance mode for the foreseeable future.

If you would like a feature to be implemented and are willing to pay a development cost to ensure it gets done, please file a GitHub issue describing the feature and indicate that you are willing to compensate for the work. If you are not willing to pay, please open a GitHub issue regardless. I may implement it if it seems fun to do so, but other members of the community may also step up to implement it via Pull Requests.

I will always make time support Pull Requests from others. If you're willing to put in the work to improve RemnantChat, I am willing to help shepherd that work along and get it shipped.

If you don't agree with the direction of the project, you are welcome to fork RemnantChat and take it in another one.

🏗️ Support and custom development

I'm willing to do paid installations and customizations of RemnantChat for your needs. If you'd like to contract me to make a version of RemnantChat that is custom built for you, please email me at jeremyckahn@gmail.com and let me know what you have in mind to get started.

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Veracity

The core of RemnantChat's security model is the fact that it is fully open source. You are free (and encouraged) to fully audit the project source code and infrastructure. Not only is the source code available under the terms of the GPL, but all build logs are publicly accessible as well.

If you would like to verify that the app hosted at https://RemnantChat.im/ is the one that is hosted on GitHub, you can use dig:

$ dig RemnantChat.im

; <<>> DiG 9.18.1-1ubuntu1.1-Ubuntu <<>> RemnantChat.im
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61332
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;RemnantChat.im.                        IN      A

;; ANSWER SECTION:
RemnantChat.im.         231     IN      CNAME   jeremyckahn.github.io.
jeremyckahn.github.io.  231     IN      A       185.199.111.153
jeremyckahn.github.io.  231     IN      A       185.199.110.153
jeremyckahn.github.io.  231     IN      A       185.199.109.153
jeremyckahn.github.io.  231     IN      A       185.199.108.153

To examine the static assets that are served to end users, you can audit the gh-pages branch.

Project roadmap

See the full ticket backlog here.

Environments

• Production environment: https://RemnantChat.im/
  • Mirror: https://RemnantChat.vercel.app/ (note that peers cannot connect across domains)
• Staging: https://RemnantChat-git-develop-jeremyckahn.vercel.app/

SDK

You can use the official RemnantChat SDK to embed the app as a Web Component called <chat-room />.

<script src="https://RemnantChat.im/sdk.js"></script>

<chat-room />

The <chat-room /> component supports the following optional attributes:

• room: The name of the RemnantChat room the user should join. The default value is the URL of the embedding page.
• user-name: The friendly name of the user (which they can change).
• user-id: The static ID of the user. The default value is a random UUID.
• root-url: The URL of the RemnantChat instance to use. The default value is https://RemnantChat.im/.
• color-mode: light or dark. The default value is dark.
• play-message-sound: Whether or not to play a sound when a user receives a message while the window is not in focus. The default value is false.

As well as the following standard <iframe /> attributes:

• height
• width
• style
• referrerpolicy
• sandbox

Available Scripts

In the project directory, you can run:

npm dev

Runs the entire stack (client + WebTorrent tracker) locally.

npm start

Runs the front end app in the development mode. Uses public WebTorrent trackers.
Open http://localhost:3000 to view it in your browser.

The page will reload when you make changes. You may also see any lint errors in the console.

npm test

Launches the test runner in the interactive watch mode. See the section about running tests for more information.

npm run build

Builds the app for production to the build folder. It correctly bundles React in production mode and optimizes the build for the best performance.

The build is minified and the filenames include the hashes.

Self-hosting

RemnantChat is designed to be forked and self-hosted. If you would like to change pairing or relay server configuration, or you simply prefer to control your own builds and versions, just fork this repo and follow the steps below.

Caveats

RemnantChat peer connections are bound to the instance's domain. So, a user of RemnantChat at https://RemnantChat.im/ would not be able to connect to a user of a RemnantChat instance on another domain (such as a personal GitHub Pages-hosted fork).

Necessary steps after forking

Assuming you are hosting RemnantChat on GitHub Pages:

1. Change the homepage property in package.json to whatever URL your RemnantChat instance will be hosted from. This will be something like https://github_user_or_org_name.github.io/RemnantChat/.
2. Define a DEPLOY_KEY GitHub Action secret (at https://github.com/github_user_or_org_name/RemnantChat/settings/secrets/actions). See the docs for peaceiris/actions-gh-pages for more information.

Deployment

On GitHub

When hosted on GitHub Pages and the configuration above has been done, the Production environment is updated when the remote main branch is updated (once GitHub Actions are enabled).

On non-GitHub hosts

Build the app with PUBLIC_URL="https://your-domain-here.com" npm run build, and then serve the build directory. Any static file serving solution should work provided it is using a secure context.

Runtime configuration

Explore the files in src/config to modify pairing and relay server configuration.

Troubleshooting

If you run into any issues with a custom RemnantChat installation, first ensure that you are using the latest version of the code. If you are hosting your installation with GitHub Pages, sync your main branch and not your gh-pages branch. Updating your main branch will trigger a proper rebuild of your gh-pages branch.

• https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

Peers won't connect

This could happen for a variety of reasons. The most likely of which is that one or more peers cannot connect directly and must use the configured STUN/TURN relay as a fallback. The standard relay is free and does not guarantee any level of service, so it may simply be unavailable for some time (or just not work at all for some users). There's not much to do other than wait until it becomes available again, or possibly try from another device or location.

Issues specific to browsers with ad blocking extensions

Some ad blockers (such as uBlock Origin) prevent connections to certain WebTorrent servers. This prevents RemnantChat peers from connecting. To work around this, you can either disable your ad blocker or self-host your own RemnantChat instance.

Issues specific to iOS Safari

RemnantChat works on iOS Safari, but browser-level bugs often prevent peers from rejoining the room when the browser is closed and later reopened (for instance, when switching applications). The suggested workaround for this issue is to refresh the page to rejoin the room.

Issues specific to Firefox

Per #36, check your about:config settings and ensure that media.peerconnection.enabled is enabled.

Security

RemnantChat undergoes weekly security audits to identify and address potential vulnerabilities. Reports from all audits can be found in Issues.

Contributors

⚠️ Disclaimer

By using RemnantChat, you agree to accept full responsibility for your actions related to its use. Additionally, you agree not to hold any contributors to the RemnantChat project responsible for any result of your use of it. The developers of RemnantChat do not endorse illegal activity.