Keychat is a free, open source chat app for Windows built on the Nostr protocol, with Bitcoin Ecash support. It suits people who want private messaging without tying their identity to a central company, and people curious about combining chat with Bitcoin payments. The project is licensed under AGPL-3.0, and its code is public on GitHub.
The app draws on several open standards at once. It runs on Nostr for its network and identity layer, adds Bitcoin Ecash for payments, and uses the Signal Protocol and MLS Protocol for encrypted messaging. The last code update is dated July 23, 2026, and the current release is v1.41.1+6513, so the project is actively maintained. Installing it on Windows needs a little extra care, which we cover below.
What Is Keychat and Who Is It For?
Keychat is a messaging app designed around open protocols rather than a single company's servers. Its goal is to let people talk privately while keeping control of their identity and, optionally, their payments in one place.
The app fits several kinds of users. Privacy-minded people who already use Nostr will recognize the identity model right away. Bitcoin users who want to send small amounts inside a conversation may find the ecash side useful. Developers and open source enthusiasts can read the AGPL-3.0 licensed code on GitHub to see how it works.
If you are new to decentralized apps, expect a learning curve. The app asks you to think about keys and backups in a way that mainstream chat apps do not. Once that idea clicks, most of the rest feels familiar: you add contacts, start conversations, and send messages much as you would elsewhere.
How Nostr Identity Replaces a Traditional Account
On a typical chat service, a company stores your account and can reset your password through email. Nostr works differently. Your identity is a cryptographic key pair, and signing a message with your private key is what proves it came from you.
The public key is safe to share. It is the address other people use to find you and verify your messages. The private key must stay secret, and it is the only way to recover control of the identity. If you lose it, no support team can restore it, and if someone else gets it, they can act as you.
Nostr messages are passed through relays, which are independent servers that store and forward signed events. Because no single relay owns your identity, you can switch relays without losing your contacts. Understanding this model before you start will prevent most of the common problems new users run into.
What Does Ecash Mean in a Chat App?
Ecash is a payment method in which value is represented by digital tokens rather than by entries on a public ledger. Chaumian-style ecash, the family Bitcoin Ecash belongs to, aims to make payments more private because the parties do not need to publish every transfer to the world.
In a chat setting, ecash can make small payments feel like a natural part of the conversation. Someone can send a tip, split a bill, or settle a quick debt without leaving the app. Readers should understand that the security of ecash depends on how tokens are stored and redeemed, so it is wise to start with small amounts while you learn.
Bitcoin Ecash sits next to the Lightning Network and on-chain Bitcoin in the wider ecosystem. Each has trade-offs in speed, fees, and privacy. Comparing them before you choose a payment method is more useful than assuming one is always better.
Key features
Nostr-Based Identity
Bitcoin Ecash Support
Signal and MLS Encryption
Cross-Platform Availability
Supported coins
Keychat's documentation mentions Bitcoin (BTC), the Lightning Network and Nostr. The app's ecash features are built on Bitcoin Ecash, so it is best thought of as a chat app with a Bitcoin payment layer rather than a general wallet.
How to install Keychat on Windows
- 1
Download the Installer from an Official Source
Download only from the official website or from the Releases page of the project's GitHub repository at github.com/keychat-io/keychat-app. Avoid download links shared in chats, forums or search ads, since these are a common way for fake installers to spread.
- 2
Verify the File Before Running It
Compute the SHA-256 hash of the downloaded file. In PowerShell, run Get-FileHash followed by the file path. Compare the result with the checksum published on the release page, if one is listed. A mismatch means the file should not be run.
- 3
Handle Antivirus and Windows Warnings Carefully
The Windows build is not yet code-signed or notarized, so Windows SmartScreen or your antivirus may warn you or block the installer. Do not turn your protection off entirely. After verifying the hash, you can add an exclusion for that single file, then remove it once installation is complete.
-
Run the Installer and Generate Your Keys
Launch the installer and follow the prompts. On first start, create your Nostr keys inside the app. Back up the private key immediately in a password manager or offline notes, because it is the only way to restore your identity later.
How to use Keychat
Keychat is simple to start with once you understand the identity model. The steps below follow the basic flow.
- Open the app and generate your Nostr keys.
- Back up your private key somewhere offline before you add any contacts.
- Share your public key with a friend so they can find you and start a conversation.
- Add a contact by entering their public key, then send your first direct message.
- Try a group chat once your contacts are set up, to see how MLS-based group messaging behaves.
- If you want to use Bitcoin Ecash, start with a small amount and check how tokens are stored and redeemed before you rely on the feature.
- Keep the app updated by checking the official site for new releases.
Pros & cons
- Free and open source under the AGPL-3.0 license
- No registration required; you start by generating Nostr keys
- Listed for Windows, macOS, Linux, Android, iOS and web or extension
- Combines encrypted chat with Bitcoin Ecash and Lightning references
- Code was updated recently, with a July 2026 update in the repository
- The Windows build is not yet code-signed or notarized
- Antivirus tools may flag the installer and block it
- Losing your private key means losing control of your identity
- Concepts like relays and ecash take time to understand for beginners
Is Keychat safe?
Keychat handles private keys and possibly payments, so treat installation with care. Download only from the official website or the GitHub Releases page, and never from a mirror or a link shared in a chat. Verify the SHA-256 checksum of the installer before running it, because the Windows build is not yet code-signed or notarized. Expect antivirus warnings, and handle them with a single-file exclusion rather than by turning protection off. Never enter your private key or seed phrase on a third-party website, including anything that claims to be a support or recovery page. Because the code is open under AGPL-3.0, anyone can review it, which is a meaningful advantage over closed software. Check the latest version on the official website before installing.
- Official source only. Download from github.com/keychat-io/keychat-app. Ignore ads and lookalike domains.
- Check the SHA-256. Compare the installer hash with the value the developer publishes before running it.
- Never share your seed phrase. No developer, support agent or website — including CryptApps — will ever ask for it.
Alternatives
Keychat differs from most Nostr clients by combining chat with a Bitcoin Ecash payment layer. Vega is a cross-platform desktop client focused on Nostr itself, while Nostrid offers binaries for Android, Windows, macOS and Linux. Notedeck is a Rust-based desktop Nostr browser from Damus, which suits users who want to explore the network rather than chat. Baywallet combines a Lightning wallet with a Nostr client, and Bro App uses Nostr and Lightning to pay bills peer to peer. If your main goal is private conversations with an optional Bitcoin payment feature, Keychat is the closest fit. If you mostly want a general Nostr browser or a dedicated wallet, one of the other options may serve you better.
Specifications
- Price
- Free
- Type
- Open source
- License
- agpl-3.0
- Latest version
- v1.41.1+6513
- Last update
- 23 Jul 2026
- Windows support
- Yes (Windows build or installer)
- Source code
- github.com/keychat-io/keychat-app
Frequently asked questions
Yes, Keychat is free and distributed as open source under the AGPL-3.0 license. Its source code is public on GitHub, so anyone can read, build or modify it under the license terms. A free download still requires care, so verify the installer as described in the safety section before you run it.
No. Keychat does not require registration. You generate a pair of Nostr keys, and the public key serves as your ID for others to find you. Keep the private key safe, because it is the only way to prove control of that identity, and no one can reset it for you.
It can be, if you get the installer from the official source and verify it. The Windows build is not yet code-signed or notarized, so Windows security tools may show warnings. Check the SHA-256 hash before running the file, and never enter your private key on third-party websites.
Yes. Keychat is built on Bitcoin Ecash, and its documentation mentions Bitcoin (BTC) and the Lightning Network. Ecash works differently from on-chain Bitcoin, so read how its features work before you use them. This page does not offer financial advice.
Nostr is an open protocol for publishing and exchanging signed messages through independent servers called relays. Users are identified by cryptographic keys rather than by accounts on a single company's platform. Clients such as Keychat connect to relays to send and receive messages.
Antivirus tools often flag software that is unsigned or new to them. The Keychat Windows installer does not yet have a code signature or notarization, which can trigger warnings. Verify the checksum first, then consider a single-file exclusion instead of disabling protection altogether.
Verdict
Keychat is a good fit for people who want encrypted chat built on Nostr, with Bitcoin Ecash available as an optional feature. It suits privacy-minded users, Bitcoin enthusiasts who want to test ecash inside conversations, and anyone curious about open protocols. It is less suitable for users who want a one-click experience or who are not ready to manage private keys. Verify the installer carefully on Windows, back up your keys from the start, and review the latest release notes before you rely on it for anything important.